# Patent

## Title
Microorganisms and methods for enhancing the availability of reducing equivalents in the presence of methanol, and for producing 1,2-propanediol, n-propanol, 1,3-propanediol, or glycerol related thereto

## Abstract

Provided herein is a non-naturally occurring microbial organism having a methanol metabolic pathway that can enhance the availability of reducing equivalents in the presence of methanol. Such reducing equivalents can be used to increase the product yield of organic compounds produced by the microbial organism, such as 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. Also provided herein are methods for using such an organism to produce 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Ser. No. 61/766,635 filed Feb. 19, 2013, and U.S. Ser. No. 61/722,629 filed Nov. 5, 2012, each of which is incorporated herein by reference in its entirety.


1. SUMMARY
Provided herein are methods generally relating to metabolic and biosynthetic processes and microbial organisms capable of producing organic compounds. Specifically, provided herein is a non-naturally occurring microbial organism having a methanol metabolic pathway that can enhance the availability of reducing equivalents in the presence of methanol. Such reducing equivalents can be used to increase the product yield of organic compounds produced by the microbial organism, such as 1,2-propanediol, n-propanol, 1,3-propanediol and/or glycerol. Also provided herein are non-naturally occurring microbial organisms and methods thereof to produce optimal yields of 1,2-propanediol, n-propanol, 1,3-propanediol and/or glycerol.
In a first aspect, provided herein is a non-naturally occurring microbial organism having a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme expressed in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol. In certain embodiments, the methanol metabolic pathway comprises one or more enzymes selected from the group consisting of a methanol methyltransferase; a methylenetetrahydrofolate reductase; a methylenetetrahydrofolate dehydrogenase; a methenyltetrahydrofolate cyclohydrolase; a formyltetrahydrofolate deformylase; a formyltetrahydrofolate synthetase; a formate hydrogen lyase; a hydrogenase; a formate dehydrogenase; a methanol dehydrogenase; a formaldehyde activating enzyme; a formaldehyde dehydrogenase; a S-(hydroxymethyl)glutathione synthase; a glutathione-dependent formaldehyde dehydrogenase; and an S-formylglutathione hydrolase. Such organisms advantageously allow for the production of reducing equivalents, which can then be used by the organism for the production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol using any one of the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathways, respectively, provided herein.
In a second aspect, provided herein is a non-naturally occurring microbial organism having (1) a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme expressed in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol; and (2) a 1,2-propanediol pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a 1,2-propanediol pathway enzyme expressed in a sufficient amount to produce 1,2-propanediol. In certain embodiments, the 1,2-propanediol pathway enzyme is selected from the group consisting of a methylglyoxal synthase; a methylglyoxal reductase (acetol-forming); an acetol reductase; a methylglyoxal reductase (lactaldehyde-forming); and a lactaldehyde reductase.
In a third aspect, provided herein is a non-naturally occurring microbial organism having (1) a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme expressed in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol; and (2) a n-propanol pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a n-propanol pathway enzyme expressed in a sufficient amount to produce n-propanol. In certain embodiments, the n-propanol pathway enzyme is selected from the group consisting of a methylglyoxal synthase; a methylglyoxal reductase (acetol-forming); an acetol reductase; a methylglyoxal reductase (lactaldehyde-forming); a lactaldehyde reductase; a 1,2-propanediol dehydratase; and a propanal reductase.
In a fourth aspect, provided herein is a non-naturally occurring microbial organism having (1) a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme expressed in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol; and (2) a 1,3-propanediol pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a 1,3-propanediol pathway enzyme expressed in a sufficient amount to produce 1,3-propanediol. In certain embodiments, the 1,3-propanediol pathway enzyme is selected from the group consisting of a glyceraldehyde-3-phosphate reductase; a glycerol-3-phosphate phosphatase or a glycerol kinase; a glycerol dehydratase; a 3-hydroxypropanal reductase; a dihydroxyacetone phosphate phosphatase or a dihydroxyacetone kinase; a dihydroxyacetone reductase; and a dihydroxyacetone phosphate reductase.
In a fifth aspect, provided herein is a non-naturally occurring microbial organism having (1) a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme expressed in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol; and (2) a glycerol pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a glycerol pathway enzyme expressed in a sufficient amount to produce glycerol. In certain embodiments, the glycerol pathway enzyme is selected from the group consisting of a glyceraldehyde-3-phosphate reductase; a glycerol-3-phosphate phosphatase or a glycerol kinase; a dihydroxyacetone phosphate phosphatase or a dihydroxyacetone kinase; a dihydroxyacetone reductase; and a dihydroxyacetone phosphate reductase.
In other embodiments, the organism having a methanol metabolic pathway, either alone or in combination with a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway, as provided herein, further comprises a formaldehyde assimilation pathway that utilizes formaldehyde, e.g., obtained from the oxidation of methanol, in the formation of intermediates of certain central metabolic pathways that can be used, for example, in the formation of biomass. In some of embodiments, the formaldehyde assimilation pathway comprises a hexylose-6-phosphate synthase, 6-phospho-3-hexyloisomerase, dihydroxyacetone synthase or dihydroxyacetone kinase. In certain embodiments, provided herein is a non-naturally occurring microbial organism having a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol dehydrogenase expressed in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol and/or expressed in a sufficient amount to convert methanol to formaldehyde. In some embodiments, the microbial organism further comprises a formaldehyde assimilation pathway. In certain embodiments, the organism further comprises at least one exogenous nucleic acid encoding a formaldehyde assimilation pathway enzyme expressed in a sufficient amount to produce an intermediate of glycolysis. In certain embodiments, the formaldehyde assimilation pathway enzyme is selected from the group consisting of a hexylose-6-phosphate synthase, 6-phospho-3-hexyloisomerase, dihydroxyacetone synthase and dihydroxyacetone kinase.
In some embodiments, the organism further comprises one or more gene disruptions, occurring in one or more endogenous genes encoding protein(s) or enzyme(s) involved in native production of ethanol, glycerol, acetate, lactate, formate, CO2, and/or amino acids by said microbial organism, wherein said one or more gene disruptions confer increased production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol in said microbial organism. In some embodiments, one or more endogenous enzymes involved in native production of ethanol, glycerol, acetate, lactate, formate, CO2 and/or amino acids by the microbial organism, has attenuated enzyme activity or expression levels. In certain embodiments, the organism comprises from one to twenty-five gene disruptions. In other embodiments, the organism comprises from one to twenty gene disruptions. In some embodiments, the organism comprises from one to fifteen gene disruptions. In other embodiments, the organism comprises from one to ten gene disruptions. In some embodiments, the organism comprises from one to five gene disruptions. In certain embodiments, the organism comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25 gene disruptions or more.
In other aspects, provided herein are methods for producing 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, comprising culturing any one of the non-naturally occurring microbial organisms comprising a methanol metabolic pathway and a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway provided herein under conditions and for a sufficient period of time to produce 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. In certain embodiments, the organism is cultured in a substantially anaerobic culture medium. In one embodiment, provided herein is a method for producing 1,2-propanediol, comprising culturing any one of the non-naturally occurring microbial organisms comprising a methanol metabolic pathway and a 1,2-propanediol pathway provided herein under conditions and for a sufficient period of time to produce 1,2-propanediol. In another embodiment, provided herein is a method for producing n-propanol, comprising culturing any one of the non-naturally occurring microbial organisms comprising a n-propanol pathway provided herein under conditions and for a sufficient period of time to produce n-propanol. In another embodiment, provided herein is a method for producing 1,3-propanediol, comprising culturing any one of the non-naturally occurring microbial organisms comprising a methanol metabolic pathway and a 1,3-propanediol pathway provided herein under conditions and for a sufficient period of time to produce 1,3-propanediol. In yet another embodiment, provided herein is a method for producing glycerol, comprising culturing any one of the non-naturally occurring microbial organisms comprising a methanol metabolic pathway and a glycerol pathway provided herein under conditions and for a sufficient period of time to produce glycerol.



2. BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows exemplary metabolic pathways enabling the extraction of reducing equivalents from methanol. The enzymatic transformations shown are carried out by the following enzymes: 1A) a methanol methyltransferase, 1B) a methylenetetrahydrofolate reductase, 1C) a methylenetetrahydrofolate dehydrogenase, 1D) a methenyltetrahydrofolate cyclohydrolase, 1E) a formyltetrahydrofolate deformylase, 1F) a formyltetrahydrofolate synthetase, 1G) a formate hydrogen lyase, 1H) a hydrogenase, 1I) a formate dehydrogenase, 1J) a methanol dehydrogenase, 1K) a formaldehyde activating enzyme, 1L) a formaldehyde dehydrogenase, 1M) a S-(hydroxymethyl)glutathione synthase, 1N) a glutathione-dependent formaldehyde dehydrogenase, and 1O) a S-formylglutathione hydrolase. In certain embodiments, steps K and/or M are spontaneous.
FIG. 2 shows exemplary 1,2-propanediol and n-propanol pathways, which can be used to increase 1,2-propanediol or n-propanol, respectively, from carbohydrates when reducing equivalents produced by a methanol metabolic pathway provided herein are available. The enzymatic transformations shown are carried out by the following enzymes: 2A) a methylglyoxal synthase; 2B) a methylglyoxal reductase (acetol-forming); 2C) an acetol reductase; 2D) a methylglyoxal reductase (lactaldehyde-forming); 2E) a lactaldehyde reductase; 2F) a 1,2-propanediol dehydratase; and 2G) a propanal reductase. 1,2-propanediol production can be carried out by 2A, 2B and 2C; or 2A, 2D and 2E. n-Propanol production can be carried out by 2A, 2B, 2C, 2F and 2G; or 2A, 2D, 2E, 2F and 2G.
FIG. 3 shows exemplary 1,3-propanediol and glycerol pathways, which can be used to increase 1,3-propanediol or glycerol, respectively, from carbohydrates when reducing equivalents produced by a methanol metabolic pathway provided herein are available. The enzymatic transformations shown are carried out by the following enzymes: 3A) a glyceraldehyde-3-phosphate reductase; 3B) a glycerol-3-phosphate phosphatase or a glycerol kinase; 3C) a glycerol dehydratase; 3D) a 3-hydroxypropanal reductase; 3E) a dihydroxyacetone phosphate phosphatase or a dihydroxyacetone kinase: 3F) a dihydroxyacetone reductase; and 3G) a dihydroxyacetone phosphate reductase. 1,3-propanediol production can be carried out by 3A, 3B, 3C and 3D; 3G, 3B, 3C and 3D; or 3E, 3F, 3C and 3D. Glycerol production can be carried out by 3A and 3B; 3G and 3B; or 3E and 3F.
FIG. 4 shows an exemplary formaldehyde assimilation pathway. The enzymatic transformations are carried out by the following enzymes: 3A) a hexylose-6-phosphate synthase, and 3B) a 6-phospho-3-hexyloisomerase.
FIG. 5 shows an exemplary formaldehyde assimilation pathway. The enzymatic transformations are carried out by the following enzymes: 4A) a dihydroxyacetone synthase, and 4B) a dihydroxyacetone kinase.



3. DETAILED DESCRIPTION OF THE INVENTION
3.1 Definitions
As used herein, the term “non-naturally occurring” when used in reference to a microbial organism or microorganism of the invention is intended to mean that the microbial organism has at least one genetic alteration not normally found in a naturally occurring strain of the referenced species, including wild-type strains of the referenced species. Genetic alterations include, for example, modifications introducing expressible nucleic acids encoding metabolic polypeptides, other nucleic acid additions, nucleic acid deletions and/or other functional disruption of the microbial organism's genetic material. Such modifications include, for example, coding regions and functional fragments thereof, for heterologous, homologous or both heterologous and homologous polypeptides for the referenced species. Additional modifications include, for example, non-coding regulatory regions in which the modifications alter expression of a gene or operon. Exemplary metabolic polypeptides include enzymes or proteins within a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic pathway.
As used herein, “1,2-propanediol” (also known as propylene glycol; IUPAC name propane 1,2-diol) has the chemical formula HO—CH2—CHOH—CH3. The chemical structure of 1,2-propanediol is shown below:




As used herein, “n-propanol” (also known as propan-1-ol, 1-propyl alcohol, n-propyl alcohol, 1-propanol, or simply propanol; IUPAC name propan-1-ol) has the chemical formula CH3CH2CH2OH. The chemical structure of n-propanol is shown below:




As used herein, “1,3-propanediol” (IUPAC name propane-1,3-diol) has the formula CH2(CH2OH)2. The chemical structure of 1,3-propanediol is shown below:




As used herein, “glycerol” (also known as glycerine or glycerin; IUPAC name propane-1,2,3-triol) is a simple polyol compound. The chemical structure of glycerol is shown below:




A metabolic modification refers to a biochemical reaction that is altered from its naturally occurring state. Therefore, non-naturally occurring microorganisms can have genetic modifications to nucleic acids encoding metabolic polypeptides, or functional fragments thereof. Exemplary metabolic modifications are disclosed herein.
As used herein, the term “isolated” when used in reference to a microbial organism is intended to mean an organism that is substantially free of at least one component as the referenced microbial organism is found in nature. The term includes a microbial organism that is removed from some or all components as it is found in its natural environment. The term also includes a microbial organism that is removed from some or all components as the microbial organism is found in non-naturally occurring environments. Therefore, an isolated microbial organism is partly or completely separated from other substances as it is found in nature or as it is grown, stored or subsisted in non-naturally occurring environments. Specific examples of isolated microbial organisms include partially pure microbes, substantially pure microbes and microbes cultured in a medium that is non-naturally occurring.
As used herein, the terms “microbial,” “microbial organism” or “microorganism” are intended to mean any organism that exists as a microscopic cell that is included within the domains of archaea, bacteria or eukarya. Therefore, the term is intended to encompass prokaryotic or eukaryotic cells or organisms having a microscopic size and includes bacteria, archaea and eubacteria of all species as well as eukaryotic microorganisms such as yeast and fungi. The term also includes cell cultures of any species that can be cultured for the production of a biochemical.
As used herein, the term “CoA” or “coenzyme A” is intended to mean an organic cofactor or prosthetic group (nonprotein portion of an enzyme) whose presence is required for the activity of many enzymes (the apoenzyme) to form an active enzyme system. Coenzyme A functions in certain condensing enzymes, acts in acetyl or other acyl group transfer and in fatty acid synthesis and oxidation, pyruvate oxidation and in other acetylation.
As used herein, the term “substantially anaerobic” when used in reference to a culture or growth condition is intended to mean that the amount of oxygen is less than about 10% of saturation for dissolved oxygen in liquid media. The term also is intended to include sealed chambers of liquid or solid medium maintained with an atmosphere of less than about 1% oxygen.
As used herein, the term “gene disruption,” or grammatical equivalents thereof, is intended to mean a genetic alteration that renders the encoded gene product inactive or attenuated. The genetic alteration can be, for example, deletion of the entire gene, deletion of a regulatory sequence required for transcription or translation, deletion of a portion of the gene which results in a truncated gene product, or by any of various mutation strategies that inactivate or attenuate the encoded gene product. One particularly useful method of gene disruption is complete gene deletion because it reduces or eliminates the occurrence of genetic reversions in the non-naturally occurring microorganisms of the invention. The phenotypic effect of a gene disruption can be a null mutation, which can arise from many types of mutations including inactivating point mutations, entire gene deletions, and deletions of chromosomal segments or entire chromosomes. Specific antisense nucleic acid compounds and enzyme inhibitors, such as antibiotics, can also produce null mutant phenotype, therefore being equivalent to gene disruption.
As used herein, the term “growth-coupled” when used in reference to the production of a biochemical product is intended to mean that the biosynthesis of the referenced biochemical product is produced during the growth phase of a microorganism. In a particular embodiment, the growth-coupled production can be obligatory, meaning that the biosynthesis of the referenced biochemical is an obligatory product produced during the growth phase of a microorganism. The term “growth-coupled” when used in reference to the consumption of a biochemical is intended to mean that the referenced biochemical is consumed during the growth phase of a microorganism.
As used herein, the term “attenuate,” or grammatical equivalents thereof, is intended to mean to weaken, reduce or diminish the activity or amount of an enzyme or protein. Attenuation of the activity or amount of an enzyme or protein can mimic complete disruption if the attenuation causes the activity or amount to fall below a critical level required for a given pathway to function. However, the attenuation of the activity or amount of an enzyme or protein that mimics complete disruption for one pathway, can still be sufficient for a separate pathway to continue to function. For example, attenuation of an endogenous enzyme or protein can be sufficient to mimic the complete disruption of the same enzyme or protein for production of a fatty alcohol, fatty aldehyde or fatty acid product of the invention, but the remaining activity or amount of enzyme or protein can still be sufficient to maintain other pathways, such as a pathway that is critical for the host microbial organism to survive, reproduce or grow. Attenuation of an enzyme or protein can also be weakening, reducing or diminishing the activity or amount of the enzyme or protein in an amount that is sufficient to increase yield of a fatty alcohol, fatty aldehyde or fatty acid product of the invention, but does not necessarily mimic complete disruption of the enzyme or protein.
“Exogenous” as it is used herein is intended to mean that the referenced molecule or the referenced activity is introduced into the host microbial organism. The molecule can be introduced, for example, by introduction of an encoding nucleic acid into the host genetic material such as by integration into a host chromosome or as non-chromosomal genetic material such as a plasmid. Therefore, the term as it is used in reference to expression of an encoding nucleic acid refers to introduction of the encoding nucleic acid in an expressible form into the microbial organism. When used in reference to a biosynthetic activity, the term refers to an activity that is introduced into the host reference organism. The source can be, for example, a homologous or heterologous encoding nucleic acid that expresses the referenced activity following introduction into the host microbial organism. Therefore, the term “endogenous” refers to a referenced molecule or activity that is present in the host. Similarly, the term when used in reference to expression of an encoding nucleic acid refers to expression of an encoding nucleic acid contained within the microbial organism. The term “heterologous” refers to a molecule or activity derived from a source other than the referenced species whereas “homologous” refers to a molecule or activity derived from the host microbial organism. Accordingly, exogenous expression of an encoding nucleic acid of the invention can utilize either or both a heterologous or homologous encoding nucleic acid.
It is understood that when more than one exogenous nucleic acid is included in a microbial organism that the more than one exogenous nucleic acids refers to the referenced encoding nucleic acid or biosynthetic activity, as discussed above. It is further understood, as disclosed herein, that such more than one exogenous nucleic acids can be introduced into the host microbial organism on separate nucleic acid molecules, on polycistronic nucleic acid molecules, or a combination thereof, and still be considered as more than one exogenous nucleic acid. For example, as disclosed herein a microbial organism can be engineered to express two or more exogenous nucleic acids encoding a desired pathway enzyme or protein. In the case where two exogenous nucleic acids encoding a desired activity are introduced into a host microbial organism, it is understood that the two exogenous nucleic acids can be introduced as a single nucleic acid, for example, on a single plasmid, on separate plasmids, can be integrated into the host chromosome at a single site or multiple sites, and still be considered as two exogenous nucleic acids. Similarly, it is understood that more than two exogenous nucleic acids can be introduced into a host organism in any desired combination, for example, on a single plasmid, on separate plasmids, can be integrated into the host chromosome at a single site or multiple sites, and still be considered as two or more exogenous nucleic acids, for example three exogenous nucleic acids. Thus, the number of referenced exogenous nucleic acids or biosynthetic activities refers to the number of encoding nucleic acids or the number of biosynthetic activities, not the number of separate nucleic acids introduced into the host organism.
The non-naturally occurring microbial organisms of the invention can contain stable genetic alterations, which refers to microorganisms that can be cultured for greater than five generations without loss of the alteration. Generally, stable genetic alterations include modifications that persist greater than 10 generations, particularly stable modifications will persist more than about 25 generations, and more particularly, stable genetic modifications will be greater than 50 generations, including indefinitely.
Those skilled in the art will understand that the genetic alterations, including metabolic modifications exemplified herein, are described with reference to a suitable host organism such as E. coli and their corresponding metabolic reactions or a suitable source organism for desired genetic material such as genes for a desired metabolic pathway. However, given the complete genome sequencing of a wide variety of organisms and the high level of skill in the area of genomics, those skilled in the art will readily be able to apply the teachings and guidance provided herein to essentially all other organisms. For example, the E. coli metabolic alterations exemplified herein can readily be applied to other species by incorporating the same or analogous encoding nucleic acid from species other than the referenced species. Such genetic alterations include, for example, genetic alterations of species homologs, in general, and in particular, orthologs, paralogs or nonorthologous gene displacements.
An ortholog is a gene or genes that are related by vertical descent and are responsible for substantially the same or identical functions in different organisms. For example, mouse epoxide hydrolase and human epoxide hydrolase can be considered orthologs for the biological function of hydrolysis of epoxides. Genes are related by vertical descent when, for example, they share sequence similarity of sufficient amount to indicate they are homologous, or related by evolution from a common ancestor. Genes can also be considered orthologs if they share three-dimensional structure but not necessarily sequence similarity, of a sufficient amount to indicate that they have evolved from a common ancestor to the extent that the primary sequence similarity is not identifiable. Genes that are orthologous can encode proteins with sequence similarity of about 25% to 100% amino acid sequence identity. Genes encoding proteins sharing an amino acid similarity less that 25% can also be considered to have arisen by vertical descent if their three-dimensional structure also shows similarities. Members of the serine protease family of enzymes, including tissue plasminogen activator and elastase, are considered to have arisen by vertical descent from a common ancestor.
Orthologs include genes or their encoded gene products that through, for example, evolution, have diverged in structure or overall activity. For example, where one species encodes a gene product exhibiting two functions and where such functions have been separated into distinct genes in a second species, the three genes and their corresponding products are considered to be orthologs. For the production of a biochemical product, those skilled in the art will understand that the orthologous gene harboring the metabolic activity to be introduced or disrupted is to be chosen for construction of the non-naturally occurring microorganism. An example of orthologs exhibiting separable activities is where distinct activities have been separated into distinct gene products between two or more species or within a single species. A specific example is the separation of elastase proteolysis and plasminogen proteolysis, two types of serine protease activity, into distinct molecules as plasminogen activator and elastase. A second example is the separation of mycoplasma 5′-3′ exonuclease and Drosophila DNA polymerase III activity. The DNA polymerase from the first species can be considered an ortholog to either or both of the exonuclease or the polymerase from the second species and vice versa.
In contrast, paralogs are homologs related by, for example, duplication followed by evolutionary divergence and have similar or common, but not identical functions. Paralogs can originate or derive from, for example, the same species or from a different species. For example, microsomal epoxide hydrolase (epoxide hydrolase I) and soluble epoxide hydrolase (epoxide hydrolase II) can be considered paralogs because they represent two distinct enzymes, co-evolved from a common ancestor, that catalyze distinct reactions and have distinct functions in the same species. Paralogs are proteins from the same species with significant sequence similarity to each other suggesting that they are homologous, or related through co-evolution from a common ancestor. Groups of paralogous protein families include HipA homologs, luciferase genes, peptidases, and others.
A nonorthologous gene displacement is a nonorthologous gene from one species that can substitute for a referenced gene function in a different species. Substitution includes, for example, being able to perform substantially the same or a similar function in the species of origin compared to the referenced function in the different species. Although generally, a nonorthologous gene displacement will be identifiable as structurally related to a known gene encoding the referenced function, less structurally related but functionally similar genes and their corresponding gene products nevertheless will still fall within the meaning of the term as it is used herein. Functional similarity requires, for example, at least some structural similarity in the active site or binding region of a nonorthologous gene product compared to a gene encoding the function sought to be substituted. Therefore, a nonorthologous gene includes, for example, a paralog or an unrelated gene.
Therefore, in identifying and constructing the non-naturally occurring microbial organisms of the invention having 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic capability, those skilled in the art will understand with applying the teaching and guidance provided herein to a particular species that the identification of metabolic modifications can include identification and inclusion or inactivation of orthologs. To the extent that paralogs and/or nonorthologous gene displacements are present in the referenced microorganism that encode an enzyme catalyzing a similar or substantially similar metabolic reaction, those skilled in the art also can utilize these evolutionally related genes.
Orthologs, paralogs and nonorthologous gene displacements can be determined by methods well known to those skilled in the art. For example, inspection of nucleic acid or amino acid sequences for two polypeptides will reveal sequence identity and similarities between the compared sequences. Based on such similarities, one skilled in the art can determine if the similarity is sufficiently high to indicate the proteins are related through evolution from a common ancestor. Algorithms well known to those skilled in the art, such as Align, BLAST, Clustal W and others compare and determine a raw sequence similarity or identity, and also determine the presence or significance of gaps in the sequence which can be assigned a weight or score. Such algorithms also are known in the art and are similarly applicable for determining nucleotide sequence similarity or identity. Parameters for sufficient similarity to determine relatedness are computed based on well known methods for calculating statistical similarity, or the chance of finding a similar match in a random polypeptide, and the significance of the match determined. A computer comparison of two or more sequences can, if desired, also be optimized visually by those skilled in the art. Related gene products or proteins can be expected to have a high similarity, for example, 25% to 100% sequence identity. Proteins that are unrelated can have an identity which is essentially the same as would be expected to occur by chance, if a database of sufficient size is scanned (about 5%). Sequences between 5% and 24% may or may not represent sufficient homology to conclude that the compared sequences are related. Additional statistical analysis to determine the significance of such matches given the size of the data set can be carried out to determine the relevance of these sequences.
Exemplary parameters for determining relatedness of two or more sequences using the BLAST algorithm, for example, can be as set forth below. Briefly, amino acid sequence alignments can be performed using BLASTP version 2.0.8 (Jan. 5, 1999) and the following parameters: Matrix: 0 BLOSUM62; gap open: 11; gap extension: 1; x_dropoff: 50; expect: 10.0; wordsize: 3; filter: on. Nucleic acid sequence alignments can be performed using BLASTN version 2.0.6 (Sep. 16, 1998) and the following parameters: Match: 1; mismatch: −2; gap open: 5; gap extension: 2; x_dropoff: 50; expect: 10.0; wordsize: 11; filter: off. Those skilled in the art will know what modifications can be made to the above parameters to either increase or decrease the stringency of the comparison, for example, and determine the relatedness of two or more sequences.
3.2 Microbial Organisms that Utilize Reducing Equivalents Produced by the Metabolism of Methanol
Provided herein are methanol metabolic pathways engineered to improve the availability of reducing equivalents, which can be used for the production of product molecules. Exemplary product molecules include, without limitation, 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, although given the teachings and guidance provided herein, it will be recognized by one skilled in the art that any product molecule that utilizes reducing equivalents in its production can exhibit enhanced production through the biosynthetic pathways provided herein.
Methanol is a relatively inexpensive organic feedstock that can be derived from synthesis gas components, CO and H2, via catalysis. Methanol can be used as a source of reducing equivalents to increase the molar yield of product molecules from carbohydrates.
1,2-propanediol, n-propanol, 1,3-propanediol and/or glycerol are compounds of commercial significance. Industrial uses of 1,2-propanediol, n-propanol, 1,3-propanediol and/or glycerol include, for example, pharmaceutical formulations, humectants, solvents, sweeteners, preservative, food additives, monoglycerides, diglycerides, emulsifiers, antifreeze and de-icer agents, oil dispersants, solvents, resins, polyglycerol esters, moisturizer, oils, shortenings, margarines, and medical, personal care, cosmetic or pharmaceutical preparations.
There exists a need for the development of methods for effectively producing commercial quantities of compounds, such as 1,2-propanediol and glycerol, as well as n-propanol and 1,3-propanediol.
Accordingly, provided herein is bioderived 1,2-propanediol produced according to the methods described herein and biobased products comprising or obtained using the bioderived 1,2-propanediol. The biobased product can comprise at least 5%, at least 10%, at least 20%, at least 30%, at least 40% or at least 50% bioderived 1,2-propanediol. The biobased product can comprises a portion of said bioderived 1,2-propanediol as a repeating unit. The biobased product can be a molded product obtained by molding the biobased product.
Also provided herein is bioderived glycerol produced according to the methods described herein and biobased products comprising or obtained using the bioderived glycerol. The biobased product can comprise at least 5%, at least 10%, at least 20%, at least 30%, at least 40% or at least 50% bioderived glycerol. The biobased product can comprises a portion of said bioderived glycerol as a repeating unit. The biobased product can be a molded product obtained by molding the biobased product.
Also provided herein is bioderived n-propanol produced according to the methods described herein and biobased products comprising or obtained using the bioderived n-propanol. The biobased product can comprise at least 5%, at least 10%, at least 20%, at least 30%, at least 40% or at least 50% bioderived n-propanol. The biobased product can comprises a portion of said bioderived n-propanol as a repeating unit. The biobased product can be a molded product obtained by molding the biobased product.
Also provided herein is bioderived 1,3-propanediol produced according to the methods described herein and biobased products comprising or obtained using the bioderived 1,3-propanediol. The biobased product can comprise at least 5%, at least 10%, at least 20%, at least 30%, at least 40% or at least 50% bioderived 1,3-propanediol. The biobased product can comprises a portion of said bioderived 1,3-propanediol as a repeating unit. The biobased product can be a molded product obtained by molding the biobased product.
In numerous engineered pathways, realization of maximum product yields based on carbohydrate feedstock is hampered by insufficient reducing equivalents or by loss of reducing equivalents to byproducts. Methanol is a relatively inexpensive organic feedstock that can be used to generate reducing equivalents by employing one or more methanol metabolic enzymes as shown in FIG. 1. The reducing equivalents produced by the metabolism of methanol by one or more of the methanol metabolic pathways can then be used to power the glucose to 1,2-propanediol, n-propanol, 1,3-propanediol and glycerol production pathways, for example, as shown in FIGS. 2 and 3.
The product yields per C-mol of substrate of microbial cells synthesizing reduced fermentation products such as 1,2-propanediol, n-propanol, 1,3-propanediol and glycerol are limited by insufficient reducing equivalents in the carbohydrate feedstock. Reducing equivalents, or electrons, can be extracted from methanol using one or more of the enzymes described in FIG. 1. The reducing equivalents are then passed to acceptors such as oxidized ferredoxins, oxidized quinones, oxidized cytochromes, NAD(P)+, water, or hydrogen peroxide to form reduced ferredoxin, reduced quinones, reduced cytochromes, NAD(P)H, H2, or water, respectively. Reduced ferredoxin, reduced quinones and NAD(P)H are particularly useful as they can serve as redox carriers for various Wood-Ljungdahl pathway, reductive TCA cycle, or product pathway enzymes.
Specific examples of how additional redox availability from methanol can improve the yield of reduced products such as 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol are shown.
The maximum theoretical yield to produce n-propanol from glucose is 1.33 moles n-propanol per mole of glucose under aerobic conditions via the pathways shown in FIG. 2. The reducing equivalents generated from the methanol metabolic pathways provided herein will be utilized to power the glucose to n-propanol production pathways. Theoretically, all carbons in glucose will be conserved, thus resulting in a maximal theoretical yield to produce n-propanol from glucose at 2 moles n-propanol per mole of glucose under either aerobic or anaerobic conditions as shown in FIG. 2:

Carbohydrates: 1C6H12O6→1.33C3H8O+2CO2+0.67H2O

Carbohydrates+H2: 1C6H12O6+6H2→2C3H8O+4H2O

In a similar manner, the maximum theoretical yield of 1,2-propanediol can be improved from 1.5 mol/mol to 2 mol/mol glucose. An exemplary flux distribution with the improved yields is shown in FIG. 2.

Carbohydrates: 1C6H12O6→1.5C3H8O2+1.5CO2 

Carbohydrates+H2: 1C6H12O6+4H2→2C3H8O2+2H2O

Other exemplary products for which the yields on carbohydrates can be improved by providing additional reducing equivalents are 1,3-propanediol (1,3-PDO) and glycerol. 1,3-PDO is mainly used as a building block in the production of polymers. It can be formulated into a variety of industrial products including composites, adhesives, laminates, coatings, moldings, aliphatic polyesters, copolyesters. It is also a solvent and used as an antifreeze and wood paint. 1,3-PDO can be chemically synthesized via the hydration of acrolein or by the hydroformylation of ethylene oxide to afford 3-hydroxypropionaldehyde. The resulting aldehyde is hydrogenated to give 1,3-PDO. Additionally, 1,3-PDO can be produced biologically (Nakamura and Whited, Curr Op Biol, 14:454-9 (2003)); Mendes et al. Appl Microbiol Biotechnol [in press] (2011)). The production of 1,3-PDO through fermentation of sugars has a theoretical yield of 1.5 mol 1,3-PDO per mol of glucose.

2C6H12O6→3C3H8O2+3CO2 

When the combined feedstock strategy is applied to 1,3-PDO production, the reducing equivalents generated from the methanol metabolic pathways provided herein can increase the 1,3-PDO theoretical yield based on glucose to 2 mol 1,3-PDO per mol of glucose by the pathways shown in FIG. 3.

1C6H12O6+4H2→2C3H8O2+2H2O or

1C6H12O6+4CO+2H2O→2C3H8O2+4CO2o 

1C6H12O6+2CO+2H2→2C3H8O2+2CO2 

Similarly, the production of glycerol through fermentation can be improved by the combined feedstock strategy. The production of glycerol through fermentation has a theoretical yield of 1.71 mol glycerol per mol of glucose.

7C6H12O6+6H2O→12C3H8O3+6CO2 

When the combined feedstocks strategy is applied to glycerol production, the reducing equivalents generated from the methanol metabolic pathways provided herein can increase the glycerol theoretical yield from glucose to 2 mol glycerol per mol of glucose with the pathways detailed in FIG. 3.

1C6H12O6+2H2→2C3H8O3 or

1C6H12O6+2CO+2H2O→2C3H8O3+2CO2 or

1C6H12O6+1CO+1H2+1H2O→2C3H8O3+1CO2 

In a first aspect, provided herein is a non-naturally occurring microbial organism having a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme expressed in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol. In certain embodiments, the methanol metabolic pathway comprises one or more enzymes selected from the group consisting of a methanol methyltransferase; a methylenetetrahydrofolate reductase; a methylenetetrahydrofolate dehydrogenase; a methenyltetrahydrofolate cyclohydrolase; a formyltetrahydrofolate deformylase; a formyltetrahydrofolate synthetase; a formate hydrogen lyase; a hydrogenase; a formate dehydrogenase; a methanol dehydrogenase; a formaldehyde activating enzyme; a formaldehyde dehydrogenase; a S-(hydroxymethyl)glutathione synthase; a glutathione-dependent formaldehyde dehydrogenase; and an S-formylglutathione hydrolase. Such organisms advantageously allow for the production of reducing equivalents, which can then be used by the organism for the production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol using any one of the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathways provided herein.
In certain embodiments, the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, or 1O or any combination of 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, and 1O, thereof, wherein 1A is a methanol methyltransferase; 1B is a methylenetetrahydrofolate reductase; 1C is a methylenetetrahydrofolate dehydrogenase; 1D is a methenyltetrahydrofolate cyclohydrolase; 1E is a formyltetrahydrofolate deformylase; 1F is a formyltetrahydrofolate synthetase; 1G is a formate hydrogen lyase; 1H is a hydrogenase, 1I is a formate dehydrogenase; 1J is a methanol dehydrogenase; 1K is a formaldehyde activating enzyme; 1L is a formaldehyde dehydrogenase; 1M is a S-(hydroxymethyl)glutathione synthase; 1N is glutathione-dependent formaldehyde dehydrogenase; and 1O is S-formylglutathione hydrolase. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase.
In one embodiment, the methanol metabolic pathway comprises 1A. In another embodiment, the methanol metabolic pathway comprises 1B. In another embodiment, the methanol metabolic pathway comprises 1C. In yet another embodiment, the methanol metabolic pathway comprises 1D. In one embodiment, the methanol metabolic pathway comprises 1E. In another embodiment, the methanol metabolic pathway comprises 1F. In another embodiment, the methanol metabolic pathway comprises 1G. In yet another embodiment, the methanol metabolic pathway comprises 1H. In one embodiment, the methanol metabolic pathway comprises 1I. In another embodiment, the methanol metabolic pathway comprises 1J. In another embodiment, the methanol metabolic pathway comprises 1K. In yet another embodiment, the methanol metabolic pathway comprises 1L. In yet another embodiment, the methanol metabolic pathway comprises 1M. In another embodiment, the methanol metabolic pathway comprises 1N. In yet another embodiment, the methanol metabolic pathway comprises 1O. Any combination of two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen or fifteen methanol metabolic pathway enzymes 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, and 1O is also contemplated.
In some embodiments, the methanol metabolic pathway is a methanol metabolic pathway depicted in FIG. 1.
In one aspect, provided herein is a non-naturally occurring microbial organism having a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme expressed in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol, wherein said methanol metabolic pathway comprises: (i) 1A and 1B, (ii) 1J; or (iii) 1J and 1K. In one embodiment, the methanol metabolic pathway comprises 1A and 1B. In another embodiment, the methanol metabolic pathway comprises 1J. In one embodiment, the methanol metabolic pathway comprises 1J and 1K. In certain embodiments, the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, and 1E. In some embodiments. the methanol metabolic pathway comprises 1A, 1B, 1C, 1D and 1F. In some embodiments, the methanol metabolic pathway comprises 1J, 1C, 1D and 1E. In one embodiment, the methanol metabolic pathway comprises 1J, 1C, 1D and 1F. In another embodiment, the methanol metabolic pathway comprises 1J and 1L. In yet another embodiment, the methanol metabolic pathway comprises 1J, 1M, 1N and 1O. In certain embodiments, the methanol metabolic pathway comprises 1J, 1N and 1O. In some embodiments, the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E. In one embodiment, the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1F. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase.
In certain embodiments, the methanol metabolic pathway comprises 1I. In certain embodiments, the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1I. In some embodiments, the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1I. In some embodiments, the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1I. In one embodiment, the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1I. In another embodiment, the methanol metabolic pathway comprises 1J, 1L and 1I. In yet another embodiment, the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1I. In certain embodiments, the methanol metabolic pathway comprises 1J, 1N, 1O and 1I. In some embodiments, the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1I. In one embodiment, the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1I. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase.
In certain embodiments, the methanol metabolic pathway comprises 1G. In certain embodiments, the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1G. In some embodiments. the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1G. In some embodiments, the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1G. In one embodiment, the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1G. In another embodiment, the methanol metabolic pathway comprises 1J, 1L and 1G. In yet another embodiment, the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1G. In certain embodiments, the methanol metabolic pathway comprises 1J, 1N, 1O and 1G. In some embodiments, the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1G. In one embodiment, the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1G. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase.
In certain embodiments, the methanol metabolic pathway comprises 1G and 1H In certain embodiments, the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E, 1G and 1H. In some embodiments. the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F, 1G and 1H. In some embodiments, the methanol metabolic pathway comprises 1J, 1C, 1D, 1E, 1G and 1H. In one embodiment, the methanol metabolic pathway comprises 1J, 1C, 1D, 1F, 1G and 1H. In another embodiment, the methanol metabolic pathway comprises 1J, 1L, 1G and 1H. In yet another embodiment, the methanol metabolic pathway comprises 1J, 1M, 1N, 1O, 1G and 1H. In certain embodiments, the methanol metabolic pathway comprises 1J, 1N, 1O, 1G and 1H. In some embodiments, the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E, 1G and 1H. In one embodiment, the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F, 1G and 1H. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase.
In certain embodiments, the formation of 5-hydroxymethylglutathione from formaldehyde is spontaneous (see, e.g., FIG. 1, step M). In some embodiments, the formation of 5-hydroxymethylglutathione from formaldehyde is catalyzed by a S-(hydroxymethyl)glutathione synthase (see, e.g., FIG. 1, step M). In certain embodiments, the formation of methylene-THF from formaldehyde is spontaneous (see, e.g., FIG. 1, step K). In certain embodiments, the formation of methylene-THF from formaldehyde is catalyzed by a formaldehyde activating enzyme (see, e.g., FIG. 1, step K).
In certain embodiments, the organism comprises two, three, four, five, six or seven exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism comprises two exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism comprises three exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism comprises four exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism comprises five exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism comprises six exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism comprises seven exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme.
Any non-naturally occurring eukaryotic organism comprising a methanol metabolic pathway and engineered to comprise a methanol metabolic pathway enzyme, such as those provided herein, can be engineered to further comprise one or more 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzymes.
In one embodiment, the non-naturally occurring microbial organism further comprises a 1,2-propanediol pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a 1,2-propanediol pathway enzyme expressed in a sufficient amount to produce 1,2-propanediol. In certain embodiments, the 1,2-propanediol pathway enzyme is selected from the group consisting of a methylglyoxal synthase; a methylglyoxal reductase (acetol-forming); an acetol reductase; a methylglyoxal reductase (lactaldehyde-forming); and a lactaldehyde reductase.
In another embodiment, the non-naturally occurring microbial organism further comprises a n-propanol pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a n-propanol pathway enzyme expressed in a sufficient amount to produce n-propanol. In certain embodiments, the n-propanol pathway enzyme is selected from the group consisting of a methylglyoxal synthase; a methylglyoxal reductase (acetol-forming); an acetol reductase; a methylglyoxal reductase (lactaldehyde-forming); a lactaldehyde reductase; a 1,2-propanediol dehydratase; and a propanal reductase.
In one embodiment, the non-naturally occurring microbial organism further comprises a 1,3-propanediol pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a 1,3-propanediol pathway enzyme expressed in a sufficient amount to produce 1,3-propanediol. In certain embodiments, the 1,3-propanediol pathway enzyme is selected from the group consisting of a glyceraldehyde-3-phosphate reductase; a glycerol-3-phosphate phosphatase or a glycerol kinase; a glycerol dehydratase; a 3-hydroxypropanal reductase; a dihydroxyacetone phosphate phosphatase or a dihydroxyacetone kinase; a dihydroxyacetone reductase; and a dihydroxyacetone phosphate reductase.
In other embodiments, the non-naturally occurring microbial organism has a glycerol pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a glycerol pathway enzyme expressed in a sufficient amount to produce glycerol. In certain embodiments, the glycerol pathway enzyme is selected from the group consisting of a glyceraldehyde-3-phosphate reductase; a glycerol-3-phosphate phosphatase or a glycerol kinase; a dihydroxyacetone phosphate phosphatase or a dihydroxyacetone kinase; a dihydroxyacetone reductase; and a dihydroxyacetone phosphate reductase.
In some embodiments, the non-naturally occurring microbial organisms having a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway include a set of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzymes.
Enzymes, genes and methods for engineering pathways from glycerol to various products, such as 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, into a microorganism, are now known in the art (see, e.g., U.S. Publ. No. 2011/0201089, which is herein incorporated by reference in its entirety). A set of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzymes represents a group of enzymes that can convert glucose to 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, respectively, as shown in FIGS. 2 and 3. The additional reducing equivalents obtained from the methanol metabolic pathways, as disclosed herein, improve the yields of all these products when utilizing carbohydrate-based feedstock.
Exemplary enzymes for the conversion of glucose to 1,2-propanediol (e.g., via methylglyoxyl) include a methylglyoxal synthase (FIG. 2, step A); a methylglyoxal reductase (acetol-forming) (FIG. 2, step B); an acetol reductase (FIG. 2, step C); a methylglyoxal reductase (lactaldehyde-forming) (FIG. 2, step D); and a lactaldehyde reductase (FIG. 2, step E).
In one aspect, provided herein is a non-naturally occurring microbial organism, comprising (1) a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol; and (2) a 1,2-propanediol pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a 1,2-propanediol pathway enzyme expressed in a sufficient amount to produce 1,2-propanediol. In one embodiment, the at least one exogenous nucleic acid encoding the methanol metabolic pathway enzyme enhances the availability of reducing equivalents in the presence of methanol in a sufficient amount to increase the amount of 1,2-propanediol produced by the non-naturally microbial organism. In some embodiments, the methanol metabolic pathway comprises any of the various combinations of methanol metabolic pathway enzymes described above or elsewhere herein.
In certain embodiments, (1) the methanol metabolic pathway comprises: 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, or 1O or any combination of 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, or 1O, thereof, wherein 1A is a methanol methyltransferase; 1B is a methylenetetrahydrofolate reductase; 1C is a methylenetetrahydrofolate dehydrogenase; 1D is a methenyltetrahydrofolate cyclohydrolase; 1E is a formyltetrahydrofolate deformylase; 1F is a formyltetrahydrofolate synthetase; 1G is a formate hydrogen lyase; 1H is a hydrogenase, 1I is a formate dehydrogenase; 1J is a methanol dehydrogenase; 1K is spontaneous or formaldehyde activating enzyme; 1L is a formaldehyde dehydrogenase; 1M is spontaneous or a S-(hydroxymethyl)glutathione synthase; 1N is glutathione-dependent formaldehyde dehydrogenase and 1O is S-formylglutathione hydrolase; and (2) the 1,2-propanediol pathway comprises 2A, 2B, 2C, 2D or 2E, or any combination thereof, wherein 2A is a methylglyoxal synthase; 2B is a methylglyoxal reductase (acetol-forming); 2C is an acetol reductase; 2D is a methylglyoxal reductase (lactaldehyde-forming); and 2E is a lactaldehyde reductase. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase.
In one embodiment, the 1,2-propanediol pathway comprises 2A. In another embodiment, the 1,2-propanediol pathway comprises 2B. In an embodiment, the 1,2-propanediol pathway comprises 2C. In another embodiment, the 1,2-propanediol pathway comprises 2D. In another embodiment, the 1,2-propanediol pathway comprises 2E. Any combination of two, three, four or five 1,2-propanediol pathway enzymes 2A, 2B, 2C, 2D and 2E is also contemplated.
In some embodiments, the methanol metabolic pathway is a methanol metabolic pathway depicted in FIG. 1, and the 1,2-propanediol pathway is a 1,2-propanediol pathway depicted in FIG. 2.
Exemplary sets of 1,2-propanediol pathway enzymes to convert glucose to 1,2-propanediol (e.g., via dicydroxyacetone phosphate and methylglyoxal) according to FIG. 2 include (i) 2A, 2B and 2C; (ii) 2A, 2D and 2E; and (iii) 2A, 2D and 2E.
In one embodiment, (1) the methanol metabolic pathway comprises 1A and 1B; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In another embodiment, (1) the methanol metabolic pathway comprises 1J; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In one embodiment, (1) the methanol metabolic pathway comprises 1J and 1K; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, and 1E; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In some embodiments (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D and 1F; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1E; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1F; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In another embodiment, (1) the methanol metabolic pathway comprises 1J and 1L; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N and 1O; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N and 1O; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1F; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In certain embodiments, (1) the methanol metabolic pathway comprises 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In certain embodiments, (1) the methanol metabolic pathway comprises 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In certain embodiments, (1) the methanol metabolic pathway comprises 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2B and 2C. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous.
In one embodiment, (1) the methanol metabolic pathway comprises 1A and 1B; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In another embodiment, (1) the methanol metabolic pathway comprises 1J; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J and 1K; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, and 1E; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D and 1F; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1E; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1F; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In another embodiment, (1) the methanol metabolic pathway comprises 1J and 1L; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N and 1O; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N and 1O; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1F; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous.
In one embodiment, (1) the methanol metabolic pathway comprises 1A and 1B; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In another embodiment, (1) the methanol metabolic pathway comprises 1J; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J and 1K; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, and 1E; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D and 1F; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1E; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1F; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In another embodiment, (1) the methanol metabolic pathway comprises 1J and 1L; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N and 1O; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N and 1O; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1F; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1I; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol meta bolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1G; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) the 1,2-propanediol pathway comprises 2A, 2D and 2E. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous.
In one embodiment, the non-naturally occurring microbial organism comprises (1) a methanol metabolic pathway comprising 1A and 1B; 1J; 1J and 1K; 1A, 1B, 1C, 1D, and 1E; 1A, 1B, 1C, 1D and 1F; 1J, 1C, 1D and 1E; 1J, 1C, 1D and 1F; 1J and 1L; 1J, 1M, 1N and 1O; 1J, 1N and 1O; 1J, 1K, 1C, 1D and 1E; 1J, 1K, 1C, 1D and 1F; 1I; 1A, 1B, 1C, 1D, 1E and 1I; 1A, 1B, 1C, 1D, 1F and 1I; 1J, 1C, 1D, 1E and 1I; 1J, 1C, 1D, 1F and 1I; 1J, 1L and 1I; 1J, 1M, 1N, 1O and 1I; 1J, 1N, 1O and 1I; 1J, 1K, 1C, 1D, 1E and 1I; 1J, 1K, 1C, 1D, 1F and 1I; 1G; 1A, 1B, 1C, 1D, 1E and 1G; 1A, 1B, 1C, 1D, 1F and 1G; 1J, 1C, 1D, 1E and 1G; 1J, 1C, 1D, 1F and 1G; 1J, 1L and 1G; 1J, 1M, 1N, 1O and 1G; 1J, 1N, 1O and 1G; 1J, 1K, 1C, 1D, 1E and 1G; 1J, 1K, 1C, 1D, 1F and 1G; 1G and 1H; 1A, 1B, 1C, 1D, 1E, 1G and 1H; 1A, 1B, 1C, 1D, 1F, 1G and 1H; 1J, 1C, 1D, 1E, 1G and 1H; 1J, 1C, 1D, 1F, 1G and 1H; 1J, 1L, 1G and 1H; 1J, 1M, 1N, 1O, 1G and 1H; 1J, 1N, 1O, 1G and 1H; 1J, 1K, 1C, 1D, 1E, 1G and 1H; or 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) a 1,2-propanediol pathway. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase.
Any methanol metabolic pathway provided herein can be combined with any 1,2-propanediol pathway provided herein.
Exemplary enzymes for the conversion of glucose to n-propanol (e.g., via methylglyoxyl) include a methylglyoxal synthase (FIG. 2, step A); a methylglyoxal reductase (acetol-forming) (FIG. 2, step B); an acetol reductase (FIG. 2, step C); a methylglyoxal reductase (lactaldehyde-forming) (FIG. 2, step D); a lactaldehyde reductase (FIG. 2, step E); a 1,2-propanediol dehydratase (FIG. 2, step F); and a propanal reductase (FIG. 2, step G).
In another aspect, provided herein is a non-naturally occurring microbial organism, comprising (1) a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol; and (2) an n-propanol pathway, wherein said organism comprises at least one exogenous nucleic acid encoding an n-propanol pathway enzyme expressed in a sufficient amount to produce n-propanol. In one embodiment, the at least one exogenous nucleic acid encoding the methanol metabolic pathway enzyme enhances the availability of reducing equivalents in the presence of methanol in a sufficient amount to increase the amount of n-propanol produced by the non-naturally microbial organism. In some embodiments, the methanol metabolic pathway comprises any of the various combinations of methanol metabolic pathway enzymes described above or elsewhere herein.
In certain embodiments, (1) the methanol metabolic pathway comprises: 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, or 1O or any combination of 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, or 1O, thereof, wherein 1A is a methanol methyltransferase; 1B is a methylenetetrahydrofolate reductase; 1C is a methylenetetrahydrofolate dehydrogenase; 1D is a methenyltetrahydrofolate cyclohydrolase; 1E is a formyltetrahydrofolate deformylase; 1F is a formyltetrahydrofolate synthetase; 1G is a formate hydrogen lyase; 1H is a hydrogenase, 1I is a formate dehydrogenase; 1J is a methanol dehydrogenase; 1K is spontaneous or formaldehyde activating enzyme; 1L is a formaldehyde dehydrogenase; 1M is spontaneous or a S-(hydroxymethyl)glutathione synthase; 1N is glutathione-dependent formaldehyde dehydrogenase and 1O is S-formylglutathione hydrolase; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2D, 2E, 2F or 2G or any combination thereof, wherein 2A is a methylglyoxal synthase; 2B is a methylglyoxal reductase (acetol-forming); 2C is an acetol reductase; 2D is a methylglyoxal reductase (lactaldehyde-forming); 2E is a lactaldehyde reductase; 2F is a 1,2-propanediol dehydratase; and 2G is a propanal reductase. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase.
In one embodiment, the n-propanol pathway comprises 2A. In another embodiment, the n-propanol pathway comprises 2B. In an embodiment, the n-propanol pathway comprises 2C. In another embodiment, the n-propanol pathway comprises 2D. In one embodiment, the n-propanol pathway comprises 2E. In yet another embodiment, the n-propanol pathway comprises 2F. In one embodiment, the n-propanol pathway comprises 2G. Any combination of two, three, four, five, six or seven n-propanol pathway enzymes 2A, 2B, 2C, 2D, 2E, 2F and 2G is also contemplated.
In some embodiments, the methanol metabolic pathway is a methanol metabolic pathway depicted in FIG. 1, and the n-propanol pathway is an n-propanol pathway depicted in FIG. 2.
Exemplary sets of n-propanol pathway enzymes to convert to convert glucose to n-propanol (e.g., via dicydroxyacetone phosphate and methylglyoxal) according to FIG. 2 include (i) 2A, 2B, 2C, 2F and 2G; and (ii) 2A, 2D, 2E, 2F and 2G.
In one embodiment, (1) the methanol metabolic pathway comprises 1A and 1B; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In another embodiment, (1) the methanol metabolic pathway comprises 1J; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J and 1K; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, and 1E; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D and 1F; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1E; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1F; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In another embodiment, (1) the methanol metabolic pathway comprises 1J and 1L; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N and 1O; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N and 1O; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1F; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1I; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1I; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1I; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1I; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1I; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1I; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1I; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1I; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1I; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1I; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1G; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1G; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1G; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1G; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1G; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1G; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1G; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1G; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1G; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1G; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2B, 2C, 2F and 2G. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase.
In one embodiment, (1) the methanol metabolic pathway comprises 1A and 1B; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In another embodiment, (1) the methanol metabolic pathway comprises 1J; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J and 1K; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, and 1E; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D and 1F; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1E; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1F; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In another embodiment, (1) the methanol metabolic pathway comprises 1J and 1L; and (2) the n-propanol pathway comprises 2A, 2D, 2E; 2F and 2G. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N and 1O; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N and 1O; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1F; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1I; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1I; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1I; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1I; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1I; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1I; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1I; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1I; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1I; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1I; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1G; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1G; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1G; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1G; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1G; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1G; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1G; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1G; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1G; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1G; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) the n-propanol pathway comprises 2A, 2D, 2E, 2F and 2G. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase.
In one embodiment, the non-naturally occurring microbial organism comprises (1) a methanol metabolic pathway comprising 1A and 1B; 1J; 1J and 1K; 1A, 1B, 1C, 1D, and 1E; 1A, 1B, 1C, 1D and 1F; 1J, 1C, 1D and 1E; 1J, 1C, 1D and 1F; 1J and 1L; 1J, 1M, 1N and 1O; 1J, 1N and 1O; 1J, 1K, 1C, 1D and 1E; 1J, 1K, 1C, 1D and 1F; 1I; 1A, 1B, 1C, 1D, 1E and 1I; 1A, 1B, 1C, 1D, 1F and 1I; 1J, 1C, 1D, 1E and 1I; 1J, 1C, 1D, 1F and 1I; 1J, 1L and 1I; 1J, 1M, 1N, 1O and 1I; 1J, 1N, 1O and 1I; 1J, 1K, 1C, 1D, 1E and 1I; 1J, 1K, 1C, 1D, 1F and 1I; 1G; 1A, 1B, 1C, 1D, 1E and 1G; 1A, 1B, 1C, 1D, 1F and 1G; 1J, 1C, 1D, 1E and 1G; 1J, 1C, 1D, 1F and 1G; 1J, 1L and 1G; 1J, 1M, 1N, 1O and 1G; 1J, 1N, 1O and 1G; 1J, 1K, 1C, 1D, 1E and 1G; 1J, 1K, 1C, 1D, 1F and 1G; 1G and 1H; 1A, 1B, 1C, 1D, 1E, 1G and 1H; 1A, 1B, 1C, 1D, 1F, 1G and 1H; 1J, 1C, 1D, 1E, 1G and 1H; 1J, 1C, 1D, 1F, 1G and 1H; 1J, 1L, 1G and 1H; 1J, 1M, 1N, 1O, 1G and 1H; 1J, 1N, 1O, 1G and 1H; 1J, 1K, 1C, 1D, 1E, 1G and 1H; or 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) a n-propanol pathway. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase.
Any methanol metabolic pathway provided herein can be combined with any n-propanol pathway provided herein.
Exemplary enzymes for the conversion of glucose to 1,3-propanediol (e.g., via glyceraldehydes-3-phosphate or dihydroxyacetone phosphate) include a glyceraldehyde-3-phosphate reductase (FIG. 3, step A); a glycerol-3-phosphate phosphatase or a glycerol kinase (FIG. 3, step B); a glycerol dehydratase (FIG. 3, step C); a 3-hydroxypropanal reductase (FIG. 3, step D); a dihydroxyacetone phosphate phosphatase or a dihydroxyacetone kinase (FIG. 3, step E); a dihydroxyacetone reductase (FIG. 3, step F); and a dihydroxyacetone phosphate reductase (FIG. 3, step G).
In another aspect, provided herein is a non-naturally occurring microbial organism, comprising (1) a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol; and (2) an 1,3-propanediol pathway, wherein said organism comprises at least one exogenous nucleic acid encoding an 1,3-propanediol pathway enzyme expressed in a sufficient amount to produce 1,3-propanediol. In one embodiment, the at least one exogenous nucleic acid encoding the methanol metabolic pathway enzyme enhances the availability of reducing equivalents in the presence of methanol in a sufficient amount to increase the amount of 1,3-propanediol produced by the non-naturally microbial organism. In some embodiments, the methanol metabolic pathway comprises any of the various combinations of methanol metabolic pathway enzymes described above or elsewhere herein.
In certain embodiments, (1) the methanol metabolic pathway comprises: 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, or 1O or any combination of 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, or 1O, thereof, wherein 1A is a methanol methyltransferase; 1B is a methylenetetrahydrofolate reductase; 1C is a methylenetetrahydrofolate dehydrogenase; 1D is a methenyltetrahydrofolate cyclohydrolase; 1E is a formyltetrahydrofolate deformylase; 1F is a formyltetrahydrofolate synthetase; 1G is a formate hydrogen lyase; 1H is a hydrogenase, 1I is a formate dehydrogenase; 1J is a methanol dehydrogenase; 1K is spontaneous or formaldehyde activating enzyme; 1L is a formaldehyde dehydrogenase; 1M is spontaneous or a S-(hydroxymethyl)glutathione synthase; 1N is glutathione-dependent formaldehyde dehydrogenase and 1O is S-formylglutathione hydrolase; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C, 3D, 3E, 3F or 3G, or any combination thereof, wherein 3A is a glyceraldehyde-3-phosphate reductase; 3B is a glycerol-3-phosphate phosphatase or a glycerol kinase; 3C is a glycerol dehydratase; 3D is a 3-hydroxypropanal reductase; 3E is a dihydroxyacetone phosphate phosphatase or a dihydroxyacetone kinase; 3F is a dihydroxyacetone reductase; and 3G is a dihydroxyacetone phosphate reductase. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase. In some embodiments, 3B is a glycerol-3-phosphate phosphatase. In other embodiments, 3C is a glycerol kinase. In some embodiments, 3E is a dihydroxyacetone phosphate phosphatase. In other embodiments, 3E is a dihydroxyacetone kinase.
In one embodiment, the 1,3-propanediol pathway comprises 3A. In another embodiment, the 1,3-propanediol pathway comprises 3B. In an embodiment, the 1,3-propanediol pathway comprises 3C. In another embodiment, the 1,3-propanediol pathway comprises 3D. In one embodiment, the 1,3-propanediol pathway comprises 3E. In yet another embodiment, the 1,3-propanediol pathway comprises 3F. In another embodiment, the 1,3-propanediol pathway comprises 3G. Any combination of two, three, four, five, six or seven 1,3-propanediol pathway enzymes 3A, 3B, 3C, 3D, 3E, 3F and 3G is also contemplated.
In some embodiments, the methanol metabolic pathway is a methanol metabolic pathway depicted in FIG. 1, and the 1,3-propanediol pathway is an 1,3-propanediol pathway depicted in FIG. 3.
Exemplary sets of 1,3-propanediol pathway enzymes to convert glucose to 1,3-propanediol (e.g., via glyceraldehydes-3-phosphate or dihydroxyacetone phosphate) according to FIG. 3, include (i) 3A, 3B, 3C and 3D; (ii) 3G, 3B, 3C and 3D; (iii) 3E, 3F, 3C and 3D.
In one embodiment, (1) the methanol metabolic pathway comprises 1A and 1B; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J and 1K; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, and 1E; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D and 1F; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1E; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1F; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J and 1L; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N and 1O; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N and 1O; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1I; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1I; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1I; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1I; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1I; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1I; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1I; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1I; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1I; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1I; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1G; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1G; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1G; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1G; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1G; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1G; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1G; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1G; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1G; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1G; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3A, 3B, 3C and 3D. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase. In some embodiments, 3B is a glycerol-3-phosphate phosphatase. In other embodiments, 3C is a glycerol kinase. In some embodiments, 3E is a dihydroxyacetone phosphate phosphatase. In other embodiments, 3E is a dihydroxyacetone kinase.
In one embodiment, (1) the methanol metabolic pathway comprises 1A and 1B; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J and 1K; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, and 1E; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D and 1F; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1E; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1F; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J and 1L; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N and 1O; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N and 1O; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1F; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1I; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1I; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1I; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1I; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1I; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1I; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1I; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1I; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1I; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1I; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1G; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1G; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1G; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1G; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1G; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1G; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1G; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1G; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1G; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1G; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1I, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3G, 3B, 3C and 3D. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase. In some embodiments, 3B is a glycerol-3-phosphate phosphatase. In other embodiments, 3C is a glycerol kinase. In some embodiments, 3E is a dihydroxyacetone phosphate phosphatase. In other embodiments, 3E is a dihydroxyacetone kinase.
In one embodiment, (1) the methanol metabolic pathway comprises 1A and 1B; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J and 1K; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, and 1E; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D and 1F; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1E; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1F; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J and 1L; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N and 1O; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N and 1O; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1F; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1I; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1I; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1I; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1I; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1I; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1I; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1I; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1I; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1I; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1I; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1G; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1G; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1G; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1G; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1G; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1G; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1G; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1G; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1G; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1G; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) the 1,3-propanediol pathway comprises 3E, 3F, 3C and 3D. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase. In some embodiments, 3B is a glycerol-3-phosphate phosphatase. In other embodiments, 3C is a glycerol kinase. In some embodiments, 3E is a dihydroxyacetone phosphate phosphatase. In other embodiments, 3E is a dihydroxyacetone kinase.
In one embodiment, the non-naturally occurring microbial organism comprises (1) a methanol metabolic pathway comprising 1A and 1B; 1J; 1J and 1K; 1A, 1B, 1C, 1D, and 1E; 1A, 1B, 1C, 1D and 1F; 1J, 1C, 1D and 1E; 1J, 1C, 1D and 1F; 1J and 1L; 1J, 1M, 1N and 1O; 1J, 1N and 1O; 1J, 1K, 1C, 1D and 1E; 1J, 1K, 1C, 1D and 1F; 1I; 1A, 1B, 1C, 1D, 1E and 1I; 1A, 1B, 1C, 1D, 1F and 1I; 1J, 1C, 1D, 1E and 1I; 1J, 1C, 1D, 1F and 1I; 1J, 1L and 1I; 1J, 1M, 1N, 1O and 1I; 1J, 1N, 1O and 1I; 1J, 1K, 1C, 1D, 1E and 1I; 1J, 1K, 1C, 1D, 1F and 1I; 1G; 1A, 1B, 1C, 1D, 1E and 1G; 1A, 1B, 1C, 1D, 1F and 1G; 1J, 1C, 1D, 1E and 1G; 1J, 1C, 1D, 1F and 1G; 1J, 1L and 1G; 1J, 1M, 1N, 1O and 1G; 1J, 1N, 1O and 1G; 1J, 1K, 1C, 1D, 1E and 1G; 1J, 1K, 1C, 1D, 1F and 1G; 1G and 1H; 1A, 1B, 1C, 1D, 1E, 1G and 1H; 1A, 1B, 1C, 1D, 1F, 1G and 1H; 1J, 1C, 1D, 1E, 1G and 1H; 1J, 1C, 1D, 1F, 1G and 1H; 1J, 1L, 1G and 1H; 1J, 1M, 1N, 1O, 1G and 1H; 1J, 1N, 1O, 1G and 1H; 1J, 1K, 1C, 1D, 1E, 1G and 1H; or 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) a 1,3-propanediol pathway. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase.
Any methanol metabolic pathway provided herein can be combined with any 1,3-propanediol pathway provided herein.
Exemplary enzymes for the conversion of glucose to glycerol (e.g., via glyceraldehydes-3-phosphate or dihydroxyacetone phosphate) include a glyceraldehyde-3-phosphate reductase (FIG. 3, step A); a glycerol-3-phosphate phosphatase or a glycerol kinase (FIG. 3, step B); a dihydroxyacetone phosphate phosphatase or a dihydroxyacetone kinase (FIG. 3, step E); a dihydroxyacetone reductase (FIG. 3, step F); and a dihydroxyacetone phosphate reductase (FIG. 3, step G).
In another aspect, provided herein is a non-naturally occurring microbial organism, comprising (1) a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol; and (2) an glycerol pathway, wherein said organism comprises at least one exogenous nucleic acid encoding an glycerol pathway enzyme expressed in a sufficient amount to produce glycerol. In one embodiment, the at least one exogenous nucleic acid encoding the methanol metabolic pathway enzyme enhances the availability of reducing equivalents in the presence of methanol in a sufficient amount to increase the amount of glycerol produced by the non-naturally microbial organism. In some embodiments, the methanol metabolic pathway comprises any of the various combinations of methanol metabolic pathway enzymes described above or elsewhere herein.
In certain embodiments, (1) the methanol metabolic pathway comprises: 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, or 1O or any combination of 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, or 1O, thereof, wherein 1A is a methanol methyltransferase; 1B is a methylenetetrahydrofolate reductase; 1C is a methylenetetrahydrofolate dehydrogenase; 1D is a methenyltetrahydrofolate cyclohydrolase; 1E is a formyltetrahydrofolate deformylase; 1F is a formyltetrahydrofolate synthetase; 1G is a formate hydrogen lyase; 1H is a hydrogenase, 1I is a formate dehydrogenase; 1J is a methanol dehydrogenase; 1K is spontaneous or formaldehyde activating enzyme; 1L is a formaldehyde dehydrogenase; 1M is spontaneous or a S-(hydroxymethyl)glutathione synthase; 1N is glutathione-dependent formaldehyde dehydrogenase and 1O is S-formylglutathione hydrolase; and (2) the glycerol pathway comprises 3A, 3B, 3E, 3F or 3G, or any combination thereof, wherein 3A is a glyceraldehyde-3-phosphate reductase; 3B is a glycerol-3-phosphate phosphatase or a glycerol kinase; 3E is a dihydroxyacetone phosphate phosphatase or a dihydroxyacetone kinase; 3F is a dihydroxyacetone reductase; and 3G is a dihydroxyacetone phosphate reductase. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase. In some embodiments, 3B is a glycerol-3-phosphate phosphatase. In other embodiments, 3C is a glycerol kinase. In some embodiments, 3E is a dihydroxyacetone phosphate phosphatase. In other embodiments, 3E is a dihydroxyacetone kinase.
In one embodiment, the glycerol pathway comprises 3A. In another embodiment, the glycerol pathway comprises 3B. In one embodiment, the glycerol pathway comprises 3E. In another embodiment, the glycerol pathway comprises 3F. In another embodiment, the glycerol pathway comprises 3G. In one embodiment, the glycerol pathway comprises 3H. Any combination of two, three, four or five glycerol pathway enzymes 3A, 3B, 3E, 3F and 3G is also contemplated.
In some embodiments, the methanol metabolic pathway is a methanol metabolic pathway depicted in FIG. 1, and the glycerol pathway is an glycerol pathway depicted in FIG. 3.
Exemplary sets of glycerol pathway enzymes for the conversion of glucose to glycerol (e.g., via glyceraldehydes-3-phosphate or dihydroxyacetone phosphate) include (i) 3A and 3B; (ii) 3G and 3B; and (iii) 3E and 3F.
In one embodiment, (1) the methanol metabolic pathway comprises 1A and 1B; and (2) the glycerol pathway comprises 3A and 3B. In another embodiment, (1) the methanol metabolic pathway comprises 1J; and (2) the glycerol pathway comprises 3A and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J and 1K; and (2) the glycerol pathway comprises 3A and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, and 1E; and (2) the glycerol pathway comprises 3A and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D and 1F; and (2) the glycerol pathway comprises 3A and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1E; and (2) the glycerol pathway comprises 3A and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1F; and (2) the glycerol pathway comprises 3A and 3B. In another embodiment, (1) the methanol metabolic pathway comprises 1J and 1L; and (2) the glycerol pathway comprises 3A and 3B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N and 1O; and (2) the glycerol pathway comprises 3A and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N and 1O; and (2) the glycerol pathway comprises 3A and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E; and (2) the glycerol pathway comprises 3A and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1F; and (2) the glycerol pathway comprises 3A and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1I; and (2) the glycerol pathway comprises 3A and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1I; and (2) the glycerol pathway comprises 3A and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1I; and (2) the glycerol pathway comprises 3A and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1I; and (2) the glycerol pathway comprises 3A and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1I; and (2) the glycerol pathway comprises 3A and 3B. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1I; and (2) the glycerol pathway comprises 3A and 3B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1I; and (2) the glycerol pathway comprises 3A and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1I; and (2) the glycerol pathway comprises 3A and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1I; and (2) the glycerol pathway comprises 3A and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1I; and (2) the glycerol pathway comprises 3A and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1G; and (2) the glycerol pathway comprises 3A and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1G; and (2) the glycerol pathway comprises 3A and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1G; and (2) the glycerol pathway comprises 3A and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1G; and (2) the glycerol pathway comprises 3A and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1G; and (2) the glycerol pathway comprises 3A and 3B. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1G; and (2) the glycerol pathway comprises 3A and 3B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1G; and (2) the glycerol pathway comprises 3A and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1G; and (2) the glycerol pathway comprises 3A and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1G; and (2) the glycerol pathway comprises 3A and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1G; and (2) the glycerol pathway comprises 3A and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1G and 1H; and (2) the glycerol pathway comprises 3A and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E, 1G and 1H; and (2) the glycerol pathway comprises 3A and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F, 1G and 1H; and (2) the glycerol pathway comprises 3A and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E, 1G and 1H; and (2) the glycerol pathway comprises 3A and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F, 1G and 1H; and (2) the glycerol pathway comprises 3A and 3B. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L, 1G and 1H; and (2) the glycerol pathway comprises 3A and 3B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O, 1G and 1H; and (2) the glycerol pathway comprises 3A and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O, 1G and 1H; and (2) the glycerol pathway comprises 3A and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E, 1G and 1H; and (2) the glycerol pathway comprises 3A and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) the glycerol pathway comprises 3A and 3B. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase. In some embodiments, 3B is a glycerol-3-phosphate phosphatase. In other embodiments, 3C is a glycerol kinase. In some embodiments, 3E is a dihydroxyacetone phosphate phosphatase. In other embodiments, 3E is a dihydroxyacetone kinase.
In one embodiment, (1) the methanol metabolic pathway comprises 1A and 1B; and (2) the glycerol pathway comprises 3G and 3B. In another embodiment, (1) the methanol metabolic pathway comprises 1J; and (2) the glycerol pathway comprises 3G and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J and 1K; and (2) the glycerol pathway comprises 3G and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, and 1E; and (2) the glycerol pathway comprises 3G and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D and 1F; and (2) the glycerol pathway comprises 3G and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1E; and (2) the glycerol pathway comprises 3G and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1F; and (2) the glycerol pathway comprises 3G and 3B. In another embodiment, (1) the methanol metabolic pathway comprises 1J and 1L; and (2) the glycerol pathway comprises 3G and 3B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N and 1O; and (2) the glycerol pathway comprises 3G and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N and 1O; and (2) the glycerol pathway comprises 3G and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E; and (2) the glycerol pathway comprises 3G and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1F; and (2) the glycerol pathway comprises 3G and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1I; and (2) the glycerol pathway comprises 3G and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1I; and (2) the glycerol pathway comprises 3G and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1I; and (2) the glycerol pathway comprises 3G and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1I; and (2) the glycerol pathway comprises 3G and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1I; and (2) the glycerol pathway comprises 3G and 3B. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1I; and (2) the glycerol pathway comprises 3G and 3B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1I; and (2) the glycerol pathway comprises 3G and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1I; and (2) the glycerol pathway comprises 3G and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1I; and (2) the glycerol pathway comprises 3G and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1I; and (2) the glycerol pathway comprises 3G and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1G; and (2) the glycerol pathway comprises 3G and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1G; and (2) the glycerol pathway comprises 3G and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1G; and (2) the glycerol pathway comprises 3G and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1G; and (2) the glycerol pathway comprises 3G and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1G; and (2) the glycerol pathway comprises 3G and 3B. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1G; and (2) the glycerol pathway comprises 3G and 3B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1G; and (2) the glycerol pathway comprises 3G and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1G; and (2) the glycerol pathway comprises 3G and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1G; and (2) the glycerol pathway comprises 3G and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1G; and (2) the glycerol pathway comprises 3G and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1G and 1H; and (2) the glycerol pathway comprises 3G and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E, 1G and 1H; and (2) the glycerol pathway comprises 3G and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F, 1G and 1H; and (2) the glycerol pathway comprises 3G and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E, 1G and 1H; and (2) the glycerol pathway comprises 3G and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F, 1G and 1H; and (2) the glycerol pathway comprises 3G and 3B. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L, 1G and 1H; and (2) the glycerol pathway comprises 3G and 3B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O, 1G and 1H; and (2) the glycerol pathway comprises 3G and 3B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O, 1G and 1H; and (2) the glycerol pathway comprises 3G and 3B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E, 1G and 1H; and (2) the glycerol pathway comprises 3G and 3B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) the glycerol pathway comprises 3G and 3B. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase. In some embodiments, 3B is a glycerol-3-phosphate phosphatase. In other embodiments, 3C is a glycerol kinase. In some embodiments, 3E is a dihydroxyacetone phosphate phosphatase. In other embodiments, 3E is a dihydroxyacetone kinase.
In one embodiment, (1) the methanol metabolic pathway comprises 1A and 1B; and (2) the glycerol pathway comprises 3E and 3F. In another embodiment, (1) the methanol metabolic pathway comprises 1J; and (2) the glycerol pathway comprises 3E and 3F. In one embodiment, (1) the methanol metabolic pathway comprises 1J and 1K; and (2) the glycerol pathway comprises 3E and 3F. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, and 1E; and (2) the glycerol pathway comprises 3E and 3F. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D and 1F; and (2) the glycerol pathway comprises 3E and 3F. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1E; and (2) the glycerol pathway comprises 3E and 3F. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1F; and (2) the glycerol pathway comprises 3E and 3F. In another embodiment, (1) the methanol metabolic pathway comprises 1J and 1L; and (2) the glycerol pathway comprises 3E and 3F. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N and 1O; and (2) the glycerol pathway comprises 3E and 3F. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N and 1O; and (2) the glycerol pathway comprises 3E and 3F. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E; and (2) the glycerol pathway comprises 3E and 3F. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1F; and (2) the glycerol pathway comprises 3E and 3F. In certain embodiments, (1) the methanol metabolic pathway comprises 1I; and (2) the glycerol pathway comprises 3E and 3F. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1I; and (2) the glycerol pathway comprises 3E and 3F. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1I; and (2) the glycerol pathway comprises 3E and 3F. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1I; and (2) the glycerol pathway comprises 3E and 3F. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1I; and (2) the glycerol pathway comprises 3E and 3F. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1I; and (2) the glycerol pathway comprises 3E and 3F. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1I; and (2) the glycerol pathway comprises 3E and 3F. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1I; and (2) the glycerol pathway comprises 3E and 3F. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1I; and (2) the glycerol pathway comprises 3E and 3F. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1I; and (2) the glycerol pathway comprises 3E and 3F. In certain embodiments, (1) the methanol metabolic pathway comprises 1G; and (2) the glycerol pathway comprises 3E and 3F. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E and 1G; and (2) the glycerol pathway comprises 3E and 3F. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F and 1G; and (2) the glycerol pathway comprises 3E and 3F. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1G; and (2) the glycerol pathway comprises 3E and 3F. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1G; and (2) the glycerol pathway comprises 3E and 3F. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1G; and (2) the glycerol pathway comprises 3E and 3F. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1G; and (2) the glycerol pathway comprises 3E and 3F. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1G; and (2) the glycerol pathway comprises 3E and 3F. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1G; and (2) the glycerol pathway comprises 3E and 3F. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1G; and (2) the glycerol pathway comprises 3E and 3F. In certain embodiments, (1) the methanol metabolic pathway comprises 1G and 1H; and (2) the glycerol pathway comprises 3E and 3F. In certain embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1E, 1G and 1H; and (2) the glycerol pathway comprises 3E and 3F. In some embodiments, (1) the methanol metabolic pathway comprises 1A, 1B, 1C, 1D, 1F, 1G and 1H; and (2) the glycerol pathway comprises 3E and 3F. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E, 1G and 1H; and (2) the glycerol pathway comprises 3E and 3F. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F, 1G and 1H; and (2) the glycerol pathway comprises 3E and 3F. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L, 1O and 1H; and (2) the glycerol pathway comprises 3E and 3F. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O, 1G and 1H; and (2) the glycerol pathway comprises 3E and 3F. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O, 1G and 1H; and (2) the glycerol pathway comprises 3E and 3F. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E, 1G and 1H; and (2) the glycerol pathway comprises 3E and 3F. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F, 10 and 1H; and (2) the glycerol pathway comprises 3E and 3F. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase. In some embodiments, 3B is a glycerol-3-phosphate phosphatase. In other embodiments, 3C is a glycerol kinase. In some embodiments, 3E is a dihydroxyacetone phosphate phosphatase. In other embodiments, 3E is a dihydroxyacetone kinase.
In one embodiment, the non-naturally occurring microbial organism comprises (1) a methanol metabolic pathway comprising 1A and 1B; 1J; 1J and 1K; 1A, 1B, 1C, 1D, and 1E; 1A, 1B, 1C, 1D and 1F; 1J, 1C, 1D and 1E; 1J, 1C, 1D and 1F; 1J and 1L; 1J, 1M, 1N and 1O; 1J, 1N and 1O; 1J, 1K, 1C, 1D and 1E; 1J, 1K, 1C, 1D and 1F; 1I; 1A, 1B, 1C, 1D, 1E and 1I; 1A, 1B, 1C, 1D, 1F and 1I; 1J, 1C, 1D, 1E and 1I; 1J, 1C, 1D, 1F and 1I; 1J, 1L and 1I; 1J, 1M, 1N, 1O and 1I; 1J, 1N, 1O and 1I; 1J, 1K, 1C, 1D, 1E and 1I; 1J, 1K, 1C, 1D, 1F and 1I; 1G; 1A, 1B, 1C, 1D, 1E and 1G; 1A, 1B, 1C, 1D, 1F and 1G; 1J, 1C, 1D, 1E and 1G; 1J, 1C, 1D, 1F and 1G; 1J, 1L and 1O; 1J, 1M, 1N, 1O and 1G; 1J, 1N, 1O and 1G; 1J, 1K, 1C, 1D, 1E and 1G; 1J, 1K, 1C, 1D, 1F and 1G; 1G and 1H; 1A, 1B, 1C, 1D, 1E, 1G and 1H; 1A, 1B, 1C, 1D, 1F, 1G and 1H; 1J, 1C, 1D, 1E, 1G and 1H; 1J, 1C, 1D, 1F, 1G and 1H; 1J, 1L, 1G and 1H; 1J, 1M, 1N, 1O, 1G and 1H; 1J, 1N, 1O, 1G and 1H; 1J, 1K, 1C, 1D, 1E, 1G and 1H; or 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) a glycerol pathway. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase.
Any methanol metabolic pathway provided herein can be combined with any glycerol pathway provided herein.
Also provided herein are exemplary pathways, which utilize formaldehyde produced from the oxidation of methanol (e.g., as provided in FIG. 1, step J) in the formation of intermediates of certain central metabolic pathways that can be used for the formation of biomass. One exemplary formaldehyde assimilation pathway that can utilize formaldehyde produced from the oxidation of methanol (e.g., as provided in FIG. 1) is shown in FIG. 4, which involves condensation of formaldehyde and D-ribulose-5-phosphate to form hexylose-6-phosphate (h6p) by hexylose-6-phosphate synthase (FIG. 4, step A). The enzyme can use Mg2+ or Mn2+ for maximal activity, although other metal ions are useful, and even non-metal-ion-dependent mechanisms are contemplated. H6p is converted into fructose-6-phosphate by 6-phospho-3-hexyloisomerase (FIG. 4, step B). Another exemplary pathway that involves the detoxification and assimilation of formaldehyde produced from the oxidation of methanol (e.g., as provided in FIG. 1) is shown in FIG. 5 and proceeds through dihydroxyacetone. Dihydroxyacetone synthase is a special transketolase that first transfers a glycoaldehyde group from xylulose-5-phosphate to formaldehyde, resulting in the formulation of dihydroxyacetone (DHA) and glyceraldehyde-3-phosphate (G3P), which is an intermediate in glycolysis (FIG. 5, step A). The DHA obtained from DHA synthase is then further phosphorylated to form DHA phosphate by a DHA kinase (FIG. 5, step B). DHAP can be assimilated into glycolysis and several other pathways. Rather than converting formaldehyde to formate and on to CO2 off-gassed, the pathways provided in FIGS. 4 and 5 show that carbon is assimilated, going into the final product.
Thus, in one embodiment, an organism having a methanol metabolic pathway, either alone or in combination with a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway, as provided herein, further comprises a formaldehyde assimilation pathway that utilizes formaldehyde, e.g., obtained from the oxidation of methanol, in the formation of intermediates of certain central metabolic pathways that can be used, for example, in the formation of biomass. In some of embodiments, the formaldehyde assimilation pathway comprises 4A or 4B, wherein 4A is a hexylose-6-phosphate synthase and 4B is a 6-phospho-3-hexyloisomerase In other embodiments, the formaldehyde assimilation pathway comprises 5A or 5B, wherein 5A is a dihydroxyacetone synthase and 5B is a dihydroxyacetone kinase.
In certain embodiments, provided herein is a non-naturally occurring microbial organism having a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol dehydrogenase (1J) expressed in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol and/or expressed in a sufficient amount to convert methanol to formaldehyde. In some embodiments, the microbial organism further comprises a formaldehyde assimilation pathway. In certain embodiments, the organism further comprises at least one exogenous nucleic acid encoding a formaldehyde assimilation pathway enzyme expressed in a sufficient amount to produce an intermediate of glycolysis and/or a metabolic pathway that can be used, for example, in the formation of biomass. In certain embodiments, the formaldehyde assimilation pathway enzyme is selected from the group consisting of a hexylose-6-phosphate synthase (4A), 6-phospho-3-hexyloisomerase (4B), dihydroxyacetone synthase (5A) and dihydroxyacetone kinase (5B).
In one aspect, provided herein is a non-naturally occurring microbial organism, comprising (1) a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol and/or expressed in a sufficient amount to convert methanol to formaldehyde; and (2) a formaldehyde assimilation pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a formaldehyde assimilation pathway enzyme expressed in a sufficient amount to produce an intermediate of glycolysis and/or a metabolic pathway that can be used, for example, in the formation of biomass. In specific embodiments, the methanol metabolic pathway comprises a methanol dehydrogenase (1J). In certain embodiments, the formaldehyde assimilation pathway enzyme is 4A, and the intermediate is a hexylose-6-phosphate, a fructose-6-phosphate, or a combination thereof. In other embodiments, the formaldehyde assimilation pathway enzyme is 4B, and the intermediate is a hexylose-6-phosphate, a fructose-6-phosphate, or a combination thereof. In yet other embodiments, the formaldehyde assimilation pathway enzyme is 4A and 4B, and the intermediate is a hexylose-6-phosphate, a fructose-6-phosphate, or a combination thereof. In some embodiments, the formaldehyde assimilation pathway enzyme is 5A, and the intermediate is a dihydroxyacetone (DHA), a dihydroxyacetone phosphate, or a combination thereof. In other embodiments, the formaldehyde assimilation pathway enzyme is 5B, and the intermediate is a DHA, a dihydroxyacetone phosphate, or a combination thereof. In yet other embodiments, the formaldehyde assimilation pathway enzyme is 5A and 5B, and the intermediate is a DHA, a dihydroxyacetone phosphate, or a combination thereof. In one embodiment, the at least one exogenous nucleic acid encoding the methanol metabolic pathway enzyme, in the presence of methanol, sufficiently enhances the availability of reducing equivalents and sufficiently increases formaldehyde assimilation to increase the production of 1,2-propanediol, n-propanol, 1,3-propanediol, glycerol, or other products described herein by the non-naturally microbial organism. In some embodiments, the methanol metabolic pathway comprises any of the various combinations of methanol metabolic pathway enzymes described above or elsewhere herein.
In certain embodiments, (1) the methanol metabolic pathway comprises: 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, or 1O or any combination of 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, or 1O, thereof, wherein 1A is a methanol methyltransferase; 1B is a methylenetetrahydrofolate reductase; 1C is a methylenetetrahydrofolate dehydrogenase; 1D is a methenyltetrahydrofolate cyclohydrolase; 1E is a formyltetrahydrofolate deformylase; 1F is a formyltetrahydrofolate synthetase; 1G is a formate hydrogen lyase; 1H is a hydrogenase, 1I is a formate dehydrogenase; 1J is a methanol dehydrogenase; 1K is spontaneous or formaldehyde activating enzyme; 1L is a formaldehyde dehydrogenase; 1M is spontaneous or a S-(hydroxymethyl)glutathione synthase; 1N is glutathione-dependent formaldehyde dehydrogenase and 1O is S-formylglutathione hydrolase; and (2) the formaldehyde assimilation pathway comprises 4A, 4B or a combination thereof, wherein 4A is a hexylose-6-phosphate synthase, and 4B is a 6-phospho-3-hexyloisomerase. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase. In some embodiments, the intermediate is a hexylose-6-phosphate. In other embodiments, the intermediate is a fructose-6-phosphate. In yet other embodiments, the intermediate is a hexylose-6-phosphate and a fructose-6-phosphate.
In one embodiment, the formaldehyde assimilation pathway comprises 4A. In another embodiment, the formaldehyde assimilation pathway comprises 4B. In one embodiment, the formaldehyde assimilation pathway comprises 4A and 4B.
In some embodiments, the methanol metabolic pathway is a methanol metabolic pathway depicted in FIG. 1, and a formaldehyde assimilation pathway depicted in FIG. 4. An exemplary set of formaldehyde assimilation pathway enzymes to convert D-ribulose-5-phosphate and formaldehyde to fructose-6-phosphate (via hexylose-6-phosphate) according to FIG. 4 include 4A and 4B.
In a specific embodiment, (1) the methanol metabolic pathway comprises 1J; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In other embodiments, (1) the methanol metabolic pathway comprises 1J and 1K; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1E; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1F; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In another embodiment, (1) the methanol metabolic pathway comprises 1J and 1L; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N and 1O; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N and 1O; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1F; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1I; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1I; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1I; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1I; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1I; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1I; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1I; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1G; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1G; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1G; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1G; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1G; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1G; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1G; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E, 1G and 1H; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F, 1G and 1H; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L, 1G and 1H; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O, 1G and 1H; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O, 1G and 1H; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E, 1G and 1H; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) the formaldehyde assimilation pathway comprises 4A and 4B. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In some embodiments, the intermediate is a hexylose-6-phosphate. In other embodiments, the intermediate is a fructose-6-phosphate. In yet other embodiments, the intermediate is a hexylose-6-phosphate and a fructose-6-phosphate.
In certain embodiments, (1) the methanol metabolic pathway comprises: 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, or 1O or any combination of 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1N, or 1O, thereof, wherein 1A is a methanol methyltransferase; 1B is a methylenetetrahydrofolate reductase; 1C is a methylenetetrahydrofolate dehydrogenase; 1D is a methenyltetrahydrofolate cyclohydrolase; 1E is a formyltetrahydrofolate deformylase; 1F is a formyltetrahydrofolate synthetase; 1G is a formate hydrogen lyase; 1H is a hydrogenase, 1I is a formate dehydrogenase; 1J is a methanol dehydrogenase; 1K is spontaneous or formaldehyde activating enzyme; 1L is a formaldehyde dehydrogenase; 1M is spontaneous or a S-(hydroxymethyl)glutathione synthase; 1N is glutathione-dependent formaldehyde dehydrogenase and 1O is S-formylglutathione hydrolase; and (2) the formaldehyde assimilation pathway comprises 5A, 5B or a combination thereof, wherein 5A is a dihydroxyacetone synthase and 5B is a dihydroxyacetone kinase. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In other embodiments, 1M is a S-(hydroxymethyl)glutathione synthase. In some embodiments, the intermediate is a DHA. In other embodiments, the intermediate is a dihydroxyacetone phosphate. In yet other embodiments, the intermediate is a DHA and a dihydroxyacetone phosphate.
In one embodiment, the formaldehyde assimilation pathway comprises 5A. In another embodiment, the formaldehyde assimilation pathway comprises 5B. In one embodiment, the formaldehyde assimilation pathway comprises 5A and 5B.
In some embodiments, the methanol metabolic pathway is a methanol metabolic pathway depicted in FIG. 1, and a formaldehyde assimilation pathway depicted in FIG. 5. An exemplary set of formaldehyde assimilation pathway enzymes to convert xyulose-5-phosphate and formaldehyde to dihydroxyacetone-phosphate (via DHA) according to FIG. 5 include 5A and 5B.
In a specific embodiment, (1) the methanol metabolic pathway comprises 1J; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In other embodiments, (1) the methanol metabolic pathway comprises 1J and 1K; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1E; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D and 1F; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In another embodiment, (1) the methanol metabolic pathway comprises 1J and 1L; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N and 1O; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N and 1O; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1E; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D and 1F; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1I; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1I; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1I; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1I; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1I; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1I; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1I; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E and 1G; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F and 1G; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L and 1G; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O and 1G; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O and 1G; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E and 1G; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F and 1G; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1E, 1G and 1H; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1C, 1D, 1F, 1G and 1H; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In another embodiment, (1) the methanol metabolic pathway comprises 1J, 1L, 1G and 1H; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In yet another embodiment, (1) the methanol metabolic pathway comprises 1J, 1M, 1N, 1O, 1G and 1H; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In certain embodiments, (1) the methanol metabolic pathway comprises 1J, 1N, 1O, 1G and 1H; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In some embodiments, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1E, 1G and 1H; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In one embodiment, (1) the methanol metabolic pathway comprises 1J, 1K, 1C, 1D, 1F, 1G and 1H; and (2) the formaldehyde assimilation pathway comprises 5A and 5B. In some embodiments, 1K is spontaneous. In other embodiments, 1K is a formaldehyde activating enzyme. In some embodiments, 1M is spontaneous. In some embodiments, the intermediate is a DHA. In other embodiments, the intermediate is a dihydroxyacetone phosphate. In yet other embodiments, the intermediate is a DHA and a dihydroxyacetone phosphate.
Any methanol metabolic pathway provided herein can be combined with any formaldehyde assimilation pathway provided herein. In addition, any methanol metabolic pathway provided herein can be combined with any 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway and any formaldehyde pathway provided herein.
Also provided herein are methods of producing formaldehyde comprising culturing a non-naturally occurring microbial organism having a methanol metabolic pathway provided herein. In some embodiments, the methanol metabolic pathway comprises 1J. In certain embodiments, the organism is cultured in a substantially anaerobic culture medium. In specific embodiments, the formaldehyde is an intermediate that is consumed (assimilated) in the production of 1,2-propanediol, n-propanol, 1,3-propanediol, glycerol and other products described herein.
Also provided herein are methods of producing an intermediate of glycolysis and/or a metabolic pathway that can be used, for example, in the formation of biomass, comprising culturing a non-naturally occurring microbial organism having a methanol metabolic pathway and a formaldehyde assimilation pathway, as provided herein, under conditions and for a sufficient period of time to produce the intermediate. In some embodiments, the intermediate is a hexylose-6-phosphate. In other embodiments, the intermediate is a fructose-6-phosphate. In yet other embodiments, the intermediate is a hexylose-6-phosphate and a fructose-6-phosphate. In some embodiments, the intermediate is a DHA. In other embodiments, the intermediate is a dihydroxyacetone phosphate. In yet other embodiments, the intermediate is a DHA and a dihydroxyacetone phosphate. In some embodiments, the methanol metabolic pathway comprises 1J. In certain embodiments, the organism is cultured in a substantially anaerobic culture medium. Such biomass can also be used in methods of producing any of the products, such as the biobased products, provided elsewhere herein.
In certain embodiments, the organism comprises two, three, four, five, six or seven exogenous nucleic acids, each encoding a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzyme. In some embodiments, the organism comprises two exogenous nucleic acids, each encoding a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzyme. In some embodiments, the organism comprises three exogenous nucleic acids, each encoding a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzyme. In some embodiments, the organism comprises four exogenous nucleic acids, each encoding a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzyme. In other embodiments, the organism comprises five exogenous nucleic acids, each encoding a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzyme. In some embodiments, the organism comprises six exogenous nucleic acids, each encoding a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzyme. In other embodiments, the organism comprises seven exogenous nucleic acids, each encoding a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzyme. In certain embodiments, the organism comprises two, three, four, five, six or seven exogenous nucleic acids, each encoding a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzyme; and the organism further comprises two, three, four, five, six or seven exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism further comprises two exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism further comprises three exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism comprises further four exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism further comprises five exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism further comprises six exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism further comprises seven exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme.
In some embodiments, the organism comprises two or more exogenous nucleic acids, each encoding a formaldehyde assimilation pathway enzyme. In some embodiments, the organism comprises two exogenous nucleic acids, each encoding a formaldehyde assimilation pathway enzyme. In certain embodiments, the organism comprises two exogenous nucleic acids, each encoding a formaldehyde assimilation pathway enzyme; and the organism further comprises two, three, four, five, six or seven exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism further comprises two exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism further comprises three exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism comprises further four exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism further comprises five exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism further comprises six exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme. In certain embodiments, the organism further comprises seven exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme.
In some embodiments, the at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme is a heterologous nucleic acid. In other embodiments, the at least one exogenous nucleic acid encoding a formaldehyde assimilation pathway enzyme is a heterologous nucleic acid. In other embodiments, the at least one exogenous nucleic acid encoding a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzyme is a heterologous nucleic acid. In certain embodiments, the at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme is a heterologous nucleic acid, and the at least one exogenous nucleic acid encoding a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzyme is a heterologous nucleic acid. In other embodiments, the at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme is a heterologous nucleic acid, and the at least one exogenous nucleic acid encoding a formaldehyde assimilation pathway enzyme is a heterologous nucleic acid.
In certain embodiments, the organism is in a substantially anaerobic culture medium.
It is understood that any of the pathways disclosed herein, as described in the Examples and exemplified in the figures, including the pathways of FIGS. 1, 2, 3, 4 and 5, can be utilized to generate a non-naturally occurring microbial organism that produces any pathway intermediate or product, as desired. Non-limiting examples of such intermediate or products are 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. As disclosed herein, such a microbial organism that produces an intermediate can be used in combination with another microbial organism expressing downstream pathway enzymes to produce a desired product. However, it is understood that a non-naturally occurring eukaryotic organism that produces a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway intermediate can be utilized to produce the intermediate as a desired product.
In certain embodiments, a non-naturally occurring microbial organism comprising a methanol metabolic pathway and a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway provided herein, further comprises one or more gene disruptions. In certain embodiments, the one or more gene disruptions confer increased production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol in the organism. In other embodiments, anon-naturally occurring microbial organism comprising a methanol metabolic pathway and a formaldehyde assimilation pathway provided herein, further comprises one or more gene disruptions. In some embodiments, the gene disruption is in an endogenous gene encoding a protein and/or enzyme involved in native production of ethanol, glycerol, acetate, lactate, formate, CO2, amino acids, or any combination thereof, by said microbial organism. In one embodiment, the gene disruption is in an endogenous gene encoding a protein and/or enzyme involved in native production of ethanol. In another embodiment, the gene disruption is in an endogenous gene encoding a protein and/or enzyme involved in native production of glycerol. In other embodiments, the gene disruption is in an endogenous gene encoding a protein and/or enzyme involved in native production of acetate. In another embodiment, the gene disruption is in an endogenous gene encoding a protein and/or enzyme involved in native production of lactate. In one embodiment, the gene disruption is in an endogenous gene encoding a protein and/or enzyme involved in native production of formate. In another embodiment, the gene disruption is in an endogenous gene encoding a protein and/or enzyme involved in native production of CO2. In other embodiments, the gene disruption is in an endogenous gene encoding a protein and/or enzyme involved in native production of amino acids by said microbial organism. In some embodiments, the protein or enzyme is a pyruvate decarboxylase, an ethanol dehydrogenase, a glycerol dehydrogenase, a glycerol-3-phosphatase, a glycerol-3-phosphate dehydrogenase, a lactate dehydrogenase, an acetate kinase, a phosphotransacetylase, a pyruvate oxidase, a pyruvate:quinone oxidoreductase, a pyruvate formate lyase, an alcohol dehydrogenase, a lactate dehydrogenase, a pyruvate dehydrogenase, a pyruvate formate-lyase-2-ketobutyrate formate-lyase, a pyruvate transporter, a monocarboxylate transporter, a NADH dehydrogenase, a cytochrome oxidase, a pyruvate kinase, or any combination thereof. In certain embodiments, the organism comprises from one to twenty-five gene disruptions. In other embodiments, the organism comprises from one to twenty gene disruptions. In some embodiments, the organism comprises from one to fifteen gene disruptions. In other embodiments, the organism comprises from one to ten gene disruptions. In some embodiments, the organism comprises from one to five gene disruptions. In certain embodiments, the organism comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25 gene disruptions or more.
In other embodiments, a non-naturally occurring microbial organism comprising a methanol metabolic pathway and a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway provided herein, further comprises one or more endogenous proteins or enzymes involved in native production of ethanol, glycerol, acetate, lactate, formate, CO2 and/or amino acids by said microbial organism, wherein said one or more endogenous proteins or enzymes has attenuated protein or enzyme activity and/or expression levels. In some embodiments, a non-naturally occurring microbial organism comprising a methanol metabolic pathway and a formaldehyde assimilation pathway provided herein, further comprises one or more endogenous proteins or enzymes involved in native production of ethanol, glycerol, acetate, lactate, formate, CO2 and/or amino acids by said microbial organism, wherein said one or more endogenous proteins or enzymes has attenuated protein or enzyme activity and/or expression levels. In one embodiment the endogenous protein or enzyme is a pyruvate decarboxylase, an ethanol dehydrogenase, a glycerol dehydrogenase, a glycerol-3-phosphatase, a glycerol-3-phosphate dehydrogenase, a lactate dehydrogenase, an acetate kinase, a phosphotransacetylase, a pyruvate oxidase, a pyruvate:quinone oxidoreductase, a pyruvate formate lyase, an alcohol dehydrogenase, a lactate dehydrogenase, a pyruvate dehydrogenase, a pyruvate formate-lyase-2-ketobutyrate formate-lyase, a pyruvate transporter, a monocarboxylate transporter, a NADH dehydrogenase, a cytochrome oxidase, a pyruvate kinase, or any combination thereof.
Each of the non-naturally occurring alterations provided herein result in increased production and an enhanced level of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, for example, during the exponential growth phase of the microbial organism, compared to a strain that does not contain such metabolic alterations, under appropriate culture conditions. Appropriate conditions include, for example, those disclosed herein, including conditions such as particular carbon sources or reactant availabilities and/or adaptive evolution.
Given the teachings and guidance provided herein, those skilled in the art will understand that to introduce a metabolic alteration, such as attenuation of an enzyme, it can be necessary to disrupt the catalytic activity of the one or more enzymes involved in the reaction. Alternatively, a metabolic alteration can include disrupting expression of a regulatory protein or cofactor necessary for enzyme activity or maximal activity. Furthermore, genetic loss of a cofactor necessary for an enzymatic reaction can also have the same effect as a disruption of the gene encoding the enzyme. Disruption can occur by a variety of methods including, for example, deletion of an encoding gene or incorporation of a genetic alteration in one or more of the encoding gene sequences. The encoding genes targeted for disruption can be one, some, or all of the genes encoding enzymes involved in the catalytic activity. For example, where a single enzyme is involved in a targeted catalytic activity, disruption can occur by a genetic alteration that reduces or eliminates the catalytic activity of the encoded gene product. Similarly, where the single enzyme is multimeric, including heteromeric, disruption can occur by a genetic alteration that reduces or destroys the function of one or all subunits of the encoded gene products. Destruction of activity can be accomplished by loss of the binding activity of one or more subunits required to form an active complex, by destruction of the catalytic subunit of the multimeric complex or by both. Other functions of multimeric protein association and activity also can be targeted in order to disrupt a metabolic reaction of the invention. Such other functions are well known to those skilled in the art. Similarly, a target enzyme activity can be reduced or eliminated by disrupting expression of a protein or enzyme that modifies and/or activates the target enzyme, for example, a molecule required to convert an apoenzyme to a holoenzyme. Further, some or all of the functions of a single polypeptide or multimeric complex can be disrupted according to the invention in order to reduce or abolish the catalytic activity of one or more enzymes involved in a reaction or metabolic modification of the invention. Similarly, some or all of enzymes involved in a reaction or metabolic modification of the invention can be disrupted so long as the targeted reaction is reduced or eliminated.
Given the teachings and guidance provided herein, those skilled in the art also will understand that an enzymatic reaction can be disrupted by reducing or eliminating reactions encoded by a common gene and/or by one or more orthologs of that gene exhibiting similar or substantially the same activity. Reduction of both the common gene and all orthologs can lead to complete abolishment of any catalytic activity of a targeted reaction. However, disruption of either the common gene or one or more orthologs can lead to a reduction in the catalytic activity of the targeted reaction sufficient to promote coupling of growth to product biosynthesis. Exemplified herein are both the common genes encoding catalytic activities for a variety of metabolic modifications as well as their orthologs. Those skilled in the art will understand that disruption of some or all of the genes encoding a enzyme of a targeted metabolic reaction can be practiced in the methods of the invention and incorporated into the non-naturally occurring microbial organisms of the invention in order to achieve the increased production of fatty alcohol, fatty aldehyde or fatty acid or growth-coupled product production.
Given the teachings and guidance provided herein, those skilled in the art also will understand that enzymatic activity or expression can be attenuated using well known methods. Reduction of the activity or amount of an enzyme can mimic complete disruption if the reduction causes activity of the enzyme to fall below a critical level that is normally required for the pathway to function. Reduction of enzymatic activity by various techniques rather than disruption can be important for an organism's viability. Methods of reducing enzymatic activity that result in similar or identical effects of a gene disruption include, but are not limited to: reducing gene transcription or translation; destabilizing mRNA, protein or catalytic RNA; and mutating a gene that affects enzyme kinetics. Natural or imposed regulatory controls can also accomplish enzyme attenuation including: promoter replacement; loss or alteration of transcription factors; introduction of inhibitory RNAs or peptides such as siRNA, antisense RNA, RNA or peptide/small-molecule binding aptamers, ribozymes, aptazymes and riboswitches; and addition of drugs and other chemicals that reduce or disrupt enzymatic activity such as gene splicing.
One of ordinary skill in the art will also recognize that attenuation of an enzyme can be done at various levels. For example, at the gene level, mutations causing a partial or complete null phenotype or epistatic genetic effects that mask the activity of a gene product can be used to attenuate an enzyme. At the gene expression level, methods for attenuation include: coupling transcription to an endogenous or exogenous inducer such as IPTG, then adding low or 0 levels of inducer during the production phase; introducing or modifying positive or negative regulators; modify histone acetylation/deacetylation in region where gene is integrated; introducing a transposition to disrupt a promoter or a regulatory gene; flipping of a transposable element or promoter region; deleting one allele resulting in loss of heterozygosity in a diploid organism; introducing nucleic acids that increase RNA degradation; or in bacteria, for example, introduction of a tmRNA tag, which can lead to RNA degradation and ribosomal stalling. At the translational level, attenuation can include: introducing rare codons to limit translation; introducing RNA interference molecules that block translation; modifying regions outside the coding sequence, such as introducing secondary structure into UTR regions to block translation or reduce efficiency of translation; adding RNAase sites for rapid transcript degradation; introducing antisense RNA oligomers or antisense transcripts; introducing RNA or peptide aptamers, ribozymes, aptazymes, riboswitches; or introducing translational regulatory elements involving RNA structure that can prevent or reduce translation that can be controlled by the presence or absence of small molecules. At the level of enzyme localization and/or longevity, enzyme attenuation can include: adding a degradation tag for faster protein turnover; or adding a localization tag that results in the enzyme being localized to a compartment where it would not be able to react normally. At the level of post-translational regulation, enzyme attenuation can include: increasing intracellular concentration of known inhibitors; or modifying post-translational modified sites. At the level of enzyme activity, enzyme attenuation can include: adding endogenous or exogenous inhibitor, such as a target-specific drug, to reduce enzyme activity; limiting availability of essential cofactors, such as B12, for an enzyme that require it; chelating a metal ion that is required for activity; or introducing a dominant negative mutation.
In some embodiments, microaerobic designs can be used based on the growth-coupled formation of the desired product. To examine this, production cones can be constructed for each strategy by first maximizing and, subsequently minimizing the product yields at different rates of biomass formation feasible in the network. If the rightmost boundary of all possible phenotypes of the mutant network is a single point, it implies that there is a unique optimum yield of the product at the maximum biomass formation rate possible in the network. In other cases, the rightmost boundary of the feasible phenotypes is a vertical line, indicating that at the point of maximum biomass the network can make any amount of the product in the calculated range, including the lowest amount at the bottommost point of the vertical line. Such designs are given a low priority.
The 1,2-propanediol-, n-propanol-, 1,3-propanediol- or glycerol-production strategies provided herein can be disrupted to increase production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. Accordingly, also provided herein is a non-naturally occurring microbial organism having metabolic modifications coupling 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol production to growth of the organism, where the metabolic modifications includes disruption of one or more genes selected from the genes encoding proteins and/or enzymes provided herein.
Each of the strains can be supplemented with additional deletions if it is determined that the strain designs do not sufficiently increase the production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol and/or couple the formation of the product with biomass formation. Alternatively, some other enzymes not known to possess significant activity under the growth conditions can become active due to adaptive evolution or random mutagenesis. Such activities can also be knocked out. However, gene deletions provided herein allow the construction of strains exhibiting high-yield production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, including growth-coupled production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol.
In another aspect, provided herein is a method for producing 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, comprising culturing any one of the non-naturally occurring microbial organisms comprising a methanol metabolic pathway and a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway provided herein under conditions and for a sufficient period of time to produce 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. In certain embodiments, the organism is cultured in a substantially anaerobic culture medium.
In one embodiment, provided herein are methods for producing 1,2-propanediol, comprising culturing an organism provided herein (e.g., a non-naturally occurring microbial organisms comprising a methanol metabolic pathway and a 1,2-propanediol pathway) under conditions and for a sufficient period of time to produce 1,2-propanediol. In some embodiments, the method comprises culturing, for a sufficient period of time to produce 1,2-propanediol, a non-naturally occurring microbial organism, comprising (1) a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol; and (2) a 1,2-propanediol pathway, comprising at least one exogenous nucleic acid encoding a 1,2-propanediol pathway enzyme expressed in a sufficient amount to produce 1,2-propanediol.
In another embodiment, provided herein are methods for producing n-propanol, comprising culturing an organism provided herein (e.g., a non-naturally occurring microbial organisms comprising a methanol metabolic pathway and an n-propanol pathway) under conditions and for a sufficient period of time to produce n-propanol. In some embodiments, the method comprises culturing, for a sufficient period of time to produce n-propanol, a non-naturally occurring microbial organism, comprising (1) a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol; and (2) an n-propanol pathway, comprising at least one exogenous nucleic acid encoding an n-propanol pathway enzyme expressed in a sufficient amount to produce n-propanol.
In other embodiments, provided herein are methods for producing 1,3-propanediol, comprising culturing an organism provided herein (e.g., a non-naturally occurring microbial organisms comprising a methanol metabolic pathway and an 1,3-propanediol pathway) under conditions and for a sufficient period of time to produce 1,3-propanediol. In some embodiments, the method comprises culturing, for a sufficient period of time to produce 1,3-propanediol, a non-naturally occurring microbial organism, comprising (1) a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol; and (2) an 1,3-propanediol pathway, comprising at least one exogenous nucleic acid encoding an 1,3-propanediol pathway enzyme expressed in a sufficient amount to produce 1,3-propanediol.
In yet other embodiments, provided herein are methods for producing glycerol, comprising culturing an organism provided herein (e.g., a non-naturally occurring microbial organisms comprising a methanol metabolic pathway and an glycerol pathway) under conditions and for a sufficient period of time to produce glycerol. In some embodiments, the method comprises culturing, for a sufficient period of time to produce glycerol, a non-naturally occurring microbial organism, comprising (1) a methanol metabolic pathway, wherein said organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol; and (2) an glycerol pathway, comprising at least one exogenous nucleic acid encoding an glycerol pathway enzyme expressed in a sufficient amount to produce glycerol.
In certain embodiments of the methods provided herein, the organism further comprises at least one nucleic acid encoding a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzyme expressed in a sufficient amount to produce 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. In some embodiments, the nucleic acid is an exogenous nucleic acid, in other embodiments. the nucleic acid is an endogenous nucleic acid. In some embodiments, the organism further comprises one or more gene disruptions provided herein that confer increased production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol in the organism. In certain embodiments, the one or more gene disruptions occurs in an endogenous gene encoding a protein or enzyme involved in native production of ethanol, glycerol, acetate, lactate, formate, CO2 and/or amino acids by said microbial organism. In other embodiments, the organism further comprises one or more endogenous proteins or enzymes involved in native production of ethanol, glycerol, acetate, lactate, formate, CO2 and/or amino acids by said microbial organism, wherein said one or more endogenous proteins or enzymes has attenuated protein or enzyme activity and/or expression levels. In certain embodiments, the organism is a Crabtree positive, eukaryotic organism, and the organism is cultured in a culture medium comprising glucose. In certain embodiments, the organism comprises from one to twenty-five gene disruptions. In other embodiments, the organism comprises from one to twenty gene disruptions. In some embodiments, the organism comprises from one to fifteen gene disruptions. In other embodiments, the organism comprises from one to ten gene disruptions. In some embodiments, the organism comprises from one to five gene disruptions. In certain embodiments, the organism comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25 gene disruptions or more.
In an additional embodiment, the invention provides a non-naturally occurring microbial organism having a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway, formaldehyde assimilation pathway and/or methanol metabolic pathway, wherein the non-naturally occurring microbial organism comprises at least one exogenous nucleic acid encoding an enzyme or protein that converts a substrate to a product. By way of example, in FIG. 1, the substrate of 1J is methanol, and the product is formaldehyde; the substrate of 1L is formaldehyde, and the product is formate; and so forth. One skilled in the art will understand that these are merely exemplary and that any of the substrate-product pairs disclosed herein suitable to produce a desired product and for which an appropriate activity is available for the conversion of the substrate to the product can be readily determined by one skilled in the art based on the teachings herein. Thus, provided herein are non-naturally occurring microbial organisms containing at least one exogenous nucleic acid encoding an enzyme or protein, where the enzyme or protein converts the substrates and products of a methanol metabolic pathway, such as that shown in FIG. 1; a, 2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway, such as that shown in FIG. 2 or 3; and/or a formaldehyde assimilation pathway, such as that shown in FIG. 4 or 5.
While generally described herein as a microbial organism that contains a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway, formaldehyde assimilation pathway, and/or a methanol metabolic pathway, it is understood that provided herein are also non-naturally occurring microbial organism comprising at least one exogenous nucleic acid encoding a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway, formaldehyde assimilation pathway, and/or a methanol metabolic pathway enzyme expressed in a sufficient amount to produce an intermediate of a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, pathway, formaldehyde assimilation pathway, and/or a methanol metabolic pathway intermediate. For example, as disclosed herein, a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway is exemplified in FIGS. 2 and 3. Therefore, in addition to a microbial organism containing a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway that produces 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, also provided herein is a non-naturally occurring microbial organism comprising at least one exogenous nucleic acid encoding a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway enzyme, where the microbial organism produces a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway intermediate.
In some embodiments, the carbon feedstock and other cellular uptake sources such as phosphate, ammonia, sulfate, chloride and other halogens can be chosen to alter the isotopic distribution of the atoms present in 1,2-propanediol, n-propanol, 1,3-propanediol and/or glycerol or any 1,2-propanediol, n-propanol, 1,3-propanediol and/or glycerol pathway intermediate. The various carbon feedstock and other uptake sources enumerated above will be referred to herein, collectively, as “uptake sources.” Uptake sources can provide isotopic enrichment for any atom present in the product 1,2-propanediol, n-propanol, 1,3-propanediol or a glycerol and/or 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway intermediate, or for side products generated in reactions diverging away from a 1,2-propanediol, n-propanol, 1,3-propanediol and/or glycerol pathway. Isotopic enrichment can be achieved for any target atom including, for example, carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus, chloride or other halogens.
In some embodiments, the uptake sources can be selected to alter the carbon-12, carbon-13, and carbon-14 ratios. In some embodiments, the uptake sources can be selected to alter the oxygen-16, oxygen-17, and oxygen-18 ratios. In some embodiments, the uptake sources can be selected to alter the hydrogen, deuterium, and tritium ratios. In some embodiments, the uptake sources can selected to alter the nitrogen-14 and nitrogen-15 ratios. In some embodiments, the uptake sources can be selected to alter the sulfur-32, sulfur-33, sulfur-34, and sulfur-35 ratios. In some embodiments, the uptake sources can be selected to alter the phosphorus-31, phosphorus-32, and phosphorus-33 ratios. In some embodiments, the uptake sources can be selected to alter the chlorine-35, chlorine-36, and chlorine-37 ratios.
In some embodiments, the isotopic ratio of a target atom can be varied to a desired ratio by selecting one or more uptake sources. An uptake source can be derived from a natural source, as found in nature, or from a man-made source, and one skilled in the art can select a natural source, a man-made source, or a combination thereof, to achieve a desired isotopic ratio of a target atom. An example of a man-made uptake source includes, for example, an uptake source that is at least partially derived from a chemical synthetic reaction. Such isotopically enriched uptake sources can be purchased commercially or prepared in the laboratory and/or optionally mixed with a natural source of the uptake source to achieve a desired isotopic ratio. In some embodiments, a target isotopic ratio of an uptake source can be obtained by selecting a desired origin of the uptake source as found in nature For example, as discussed herein, a natural source can be a biobased derived from or synthesized by a biological organism or a source such as petroleum-based products or the atmosphere. In some such embodiments, a source of carbon, for example, can be selected from a fossil fuel-derived carbon source, which can be relatively depleted of carbon-14, or an environmental or atmospheric carbon source, such as CO2, which can possess a larger amount of carbon-14 than its petroleum-derived counterpart.
Isotopic enrichment is readily assessed by mass spectrometry using techniques known in the art such as Stable Isotope Ratio Mass Spectrometry (SIRMS) and Site-Specific Natural Isotopic Fractionation by Nuclear Magnetic Resonance (SNIF-NMR). Such mass spectral techniques can be integrated with separation techniques such as liquid chromatography (LC) and/or high performance liquid chromatography (HPLC).
The unstable carbon isotope carbon-14 or radiocarbon makes up for roughly 1 in 1012 carbon atoms in the earth's atmosphere and has a half-life of about 5700 years. The stock of carbon is replenished in the upper atmosphere by a nuclear reaction involving cosmic rays and ordinary nitrogen (14N). Fossil fuels contain no carbon-14, as it decayed long ago. Burning of fossil fuels lowers the atmospheric carbon-14 fraction, the so-called “Suess effect”.
Methods of determining the isotopic ratios of atoms in a compound are well known to those skilled in the art. Isotopic enrichment is readily assessed by mass spectrometry using techniques known in the art such as accelerated mass spectrometry (AMS), Stable Isotope Ratio Mass Spectrometry (SIRMS) and Site-Specific Natural Isotopic Fractionation by Nuclear Magnetic Resonance (SNIF-NMR). Such mass spectral techniques can be integrated with separation techniques such as liquid chromatography (LC), high performance liquid chromatography (HPLC) and/or gas chromatography, and the like.
In the case of carbon, ASTM D6866 was developed in the United States as a standardized analytical method for determining the biobased content of solid, liquid, and gaseous samples using radiocarbon dating by the American Society for Testing and Materials (ASTM) International. The standard is based on the use of radiocarbon dating for the determination of a product's biobased content. ASTM D6866 was first published in 2004, and the current active version of the standard is ASTM D6866-11 (effective Apr. 1, 2011). Radiocarbon dating techniques are well known to those skilled in the art, including those described herein.
The biobased content of a compound is estimated by the ratio of carbon-14 (14C) to carbon-12 (12C). Specifically, the Fraction Modern (Fm) is computed from the expression: Fm=(S−B)/(M−B), where B, S and M represent the 14C/12C ratios of the blank, the sample and the modern reference, respectively. Fraction Modern is a measurement of the deviation of the 14C/12C ratio of a sample from “Modern.” Modern is defined as 95% of the radiocarbon concentration (in AD 1950) of National Bureau of Standards (NBS) Oxalic Acid I (i.e., standard reference materials (SRM) 4990b) normalized to δ13CVPDB=−19 per mil (Olsson, The use of Oxalic acid as a Standard. in, Radiocarbon Variations and Absolute Chronology, Nobel Symposium. 12th Proc., John Wiley & Sons, New York (1970)). Mass spectrometry results, for example, measured by ASM, are calculated using the internationally agreed upon definition of 0.95 times the specific activity of NBS Oxalic Acid I (SRM 4990b) normalized to δ13CVPDB=−19 per mil. This is equivalent to an absolute (AD 1950) 14C/12C ratio of 1.176±0.010×10−12 (Karlen et al., Arkiv Geofysik, 4:465-471 (1968)). The standard calculations take into account the differential uptake of one isotope with respect to another, for example, the preferential uptake in biological systems of C12 over C13 over C14, and these corrections are reflected as a Fm corrected for δ13.
An oxalic acid standard (SRM 4990b or HOx 1) was made from a crop of 1955 sugar beet. Although there were 1000 lbs made, this oxalic acid standard is no longer commercially available. The Oxalic Acid II standard (HOx 2; N.I.S.T designation SRM 4990 C) was made from a crop of 1977 French beet molasses. In the early 1980's, a group of 12 laboratories measured the ratios of the two standards. The ratio of the activity of Oxalic acid II to 1 is 1.2933±0.001 (the weighted mean). The isotopic ratio of HOx II is −17.8 per mille. ASTM D6866-11 suggests use of the available Oxalic Acid II standard SRM 4990 C (Hox2) for the modern standard (see discussion of original vs. currently available oxalic acid standards in Mann, Radiocarbon, 25(2):519-527 (1983)). A Fm=0% represents the entire lack of carbon-14 atoms in a material, thus indicating a fossil (for example, petroleum based) carbon source. A Fm=100%, after correction for the post-1950 injection of carbon-14 into the atmosphere from nuclear bomb testing, indicates an entirely modern carbon source. As described herein, such a “modern” source includes biobased sources.
As described in ASTM D6866, the percent modern carbon (pMC) can be greater than 100% because of the continuing but diminishing effects of the 1950s nuclear testing programs, which resulted in a considerable enrichment of carbon-14 in the atmosphere as described in ASTM D6866-11. Because all sample carbon-14 activities are referenced to a “pre-bomb” standard, and because nearly all new biobased products are produced in a post-bomb environment, all pMC values (after correction for isotopic fraction) must be multiplied by 0.95 (as of 2010) to better reflect the true biobased content of the sample. A biobased content that is greater than 103% suggests that either an analytical error has occurred, or that the source of biobased carbon is more than several years old.
ASTM D6866 quantities the biobased content relative to the material's total organic content and does not consider the inorganic carbon and other non-carbon containing substances present. For example, a product that is 50% starch-based material and 50% water would be considered to have a Biobased Content=100% (50% organic content that is 100% biobased) based on ASTM D6866. In another example, a product that is 50% starch-based material, 25% petroleum-based, and 25% water would have a Biobased Content=66.7% (75% organic content but only 50% of the product is biobased). In another example, a product that is 50% organic carbon and is a petroleum-based product would be considered to have a Biobased Content=0% (50% organic carbon but from fossil sources). Thus, based on the well known methods and known standards for determining the biobased content of a compound or material, one skilled in the art can readily determine the biobased content and/or prepared downstream products that utilize of the invention having a desired biobased content.
Applications of carbon-14 dating techniques to quantify bio-based content of materials are known in the art (Currie et al., Nuclear Instruments and Methods in Physics Research B, 172:281-287 (2000)). For example, carbon-14 dating has been used to quantify bio-based content in terephthalate-containing materials (Colonna et al., Green Chemistry, 13:2543-2548 (2011)). Notably, polypropylene terephthalate (PPT) polymers derived from renewable 1,3-propanediol and petroleum-derived terephthalic acid resulted in Fm values near 30% (i.e., since 3/11 of the polymeric carbon derives from renewable 1,3-propanediol and 8/11 from the fossil end member terephthalic acid) (Currie et al., supra, 2000). In contrast, polybutylene terephthalate polymer derived from both renewable BDO and renewable terephthalic acid resulted in bio-based content exceeding 90% (Colonna et al., supra, 2011).
Accordingly, in some embodiments, the present invention provides 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway intermediate thereof, that has a carbon-12, carbon-13, and carbon-14 ratio that reflects an atmospheric carbon, also referred to as environmental carbon, uptake source. For example, in some aspects, the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol intermediate thereof can have an Fm value of at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98% or as much as 100%. In some such embodiments, the uptake source is CO2. In some embodiments, the present invention provides 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol intermediate thereof, that has a carbon-12, carbon-13, and carbon-14 ratio that reflects petroleum-based carbon uptake source. In this aspect, the a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol intermediate can have an Fm value of less than 95%, less than 90%, less than 85%, less than 80%, less than 75%, less than 70%, less than 65%, less than 60%, less than 55%, less than 50%, less than 45%, less than 40%, less than 35%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%, less than 5%, less than 2% or less than 1%. In some embodiments, the present invention provides a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol intermediate thereof, that has a carbon-12, carbon-13, and carbon-14 ratio that is obtained by a combination of an atmospheric carbon uptake source with a petroleum-based uptake source. Using such a combination of uptake sources is one way by which the carbon-12, carbon-13, and carbon-14 ratio can be varied, and the respective ratios would reflect the proportions of the uptake sources.
Further, the present invention relates to biologically produced 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol intermediate thereof, as disclosed herein, and to the products derived therefrom, wherein the a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or an intermediate thereof, has a carbon-12, carbon-13, and carbon-14 isotope ratio of about the same value as the CO2 that occurs in the environment. For example, in some aspects the invention provides bioderived 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or an intermediate thereof, having a carbon-12 versus carbon-13 versus carbon-14 isotope ratio of about the same value as the CO2 that occurs in the environment, or any of the other ratios disclosed herein. It is understood, as disclosed herein, that a product can have a carbon-12 versus carbon-13 versus carbon-14 isotope ratio of about the same value as the CO2 that occurs in the environment, or any of the ratios disclosed herein, wherein the product is generated from bioderived 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or an intermediate thereof, as disclosed herein, wherein the bioderived product is chemically modified to generate a final product. Methods of chemically modifying a bioderived product of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or an intermediate thereof, to generate a desired product are well known to those skilled in the art, as described herein. The invention further provides pharmaceutical formulations, humectants, solvents, sweeteners, preservative, food additives, monoglycerides, diglycerides, emulsifiers, antifreeze and de-icer agents, oil dispersants, solvents, resins, polyglycerol esters, moisturizer, oils, shortenings, margarines, and medical, personal care, cosmetic or pharmaceutical preparations, and the like, having a carbon-12 versus carbon-13 versus carbon-14 isotope ratio of about the same value as the CO2 that occurs in the environment, wherein the pharmaceutical formulations, humectants, solvents, sweeteners, preservative, food additives, monoglycerides, diglycerides, emulsifiers, antifreeze and de-icer agents, oil dispersants, solvents, resins, polyglycerol esters, moisturizer, oils, shortenings, margarines, and medical, personal care, cosmetic or pharmaceutical preparations, and the like, are generated directly from or in combination with bioderived 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol or a bioderived intermediate thereof, as disclosed herein.
1,2-propanediol, n-propanol, 1,3-propanediol and glycerol, as well as intermediates thereof, are chemicals used in commercial and industrial applications. Non-limiting examples of such applications include production of pharmaceutical formulations, humectants, solvents, sweeteners, preservative, food additives, monoglycerides, diglycerides, emulsifiers, antifreeze and de-icer agents, oil dispersants, solvents, resins, polyglycerol esters, moisturizer, oils, shortenings, margarines, and medical, personal care, cosmetic or pharmaceutical preparations, and the like. Moreover, 1,2-propanediol, n-propanol, 1,3-propanediol and glycerol are also used as a raw material in the production of a wide range of products including pharmaceutical formulations, humectants, solvents, sweeteners, preservative, food additives, monoglycerides, diglycerides, emulsifiers, antifreeze and de-icer agents, oil dispersants, solvents, resins, polyglycerol esters, moisturizer, oils, shortenings, margarines, and medical, personal care, cosmetic or pharmaceutical preparations, and the like. Accordingly, in some embodiments, the invention provides biobased pharmaceutical formulations, humectants, solvents, sweeteners, preservative, food additives, monoglycerides, diglycerides, emulsifiers, antifreeze and de-icer agents, oil dispersants, solvents, resins, polyglycerol esters, moisturizer, oils, shortenings, margarines, and medical, personal care, cosmetic or pharmaceutical preparations, and the like, comprising one or more of bioderived 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or a bioderived intermediate thereof, produced by a non-naturally occurring microorganism of the invention or produced using a method disclosed herein.
As used herein, the term “bioderived” means derived from or synthesized by a biological organism and can be considered a renewable resource since it can be generated by a biological organism. Such a biological organism, in particular the microbial organisms of the invention disclosed herein, can utilize feedstock or biomass, such as, sugars or carbohydrates obtained from an agricultural, plant, bacterial, or animal source. Alternatively, the biological organism can utilize atmospheric carbon. As used herein, the term “biobased” means a product as described above that is composed, in whole or in part, of a bioderived compound of the invention. A biobased or bioderived product is in contrast to a petroleum derived product, wherein such a product is derived from or synthesized from petroleum or a petrochemical feedstock.
In some embodiments, the invention provides pharmaceutical formulations, humectants, solvents, sweeteners, preservative, food additives, monoglycerides, diglycerides, emulsifiers, antifreeze and de-icer agents, oil dispersants, solvents, resins, polyglycerol esters, moisturizer, oils, shortenings, margarines, and medical, personal care, cosmetic or pharmaceutical preparations, and the like, comprising bioderived 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or a bioderived intermediate thereof, wherein the bioderived 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or bioderived intermediate thereof, includes all or part of the a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or an intermediate thereof, used in the production of pharmaceutical formulations, humectants, solvents, sweeteners, preservative, food additives, monoglycerides, diglycerides, emulsifiers, antifreeze and de-icer agents, oil dispersants, solvents, resins, polyglycerol esters, moisturizer, oils, shortenings, margarines, and medical, personal care, cosmetic or pharmaceutical preparations, and the like. Thus, in some aspects, the invention provides a biobased pharmaceutical formulations, humectants, solvents, sweeteners, preservative, food additives, monoglycerides, diglycerides, emulsifiers, antifreeze and de-icer agents, oil dispersants, solvents, resins, polyglycerol esters, moisturizer, oils, shortenings, margarines, and medical, personal care, cosmetic or pharmaceutical preparations, and the like, comprising at least 2%, at least 3%, at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or 100% bioderived 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or a bioderived 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol intermediate, as disclosed herein. Additionally, in some aspects, the invention provides biobased pharmaceutical formulations, humectants, solvents, sweeteners, preservative, food additives, monoglycerides, diglycerides, emulsifiers, antifreeze and de-icer agents, oil dispersants, solvents, resins, polyglycerol esters, moisturizer, oils, shortenings, margarines, and medical, personal care, cosmetic or pharmaceutical preparations, and the like, wherein the a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol intermediate, used in its production is a combination of bioderived and petroleum derived 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol intermediate thereof. For example, biobased pharmaceutical formulations, humectants, solvents, sweeteners, preservative, food additives, monoglycerides, diglycerides, emulsifiers, antifreeze and de-icer agents, oil dispersants, solvents, resins, polyglycerol esters, moisturizer, oils, shortenings, margarines, and medical, personal care, cosmetic or pharmaceutical preparations, and the like, can be produced using 50% bioderived 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol and 50% petroleum derived 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol or other desired ratios such as 60%/40%, 70%/30%, 80%/20%, 90%/10%, 95%/5%, 100%/0%, 40%/60%, 30%/70%, 20%/80%, 10%/90% of bioderived/petroleum derived precursors, so long as at least a portion of the product comprises a bioderived product produced by the microbial organisms disclosed herein. It is understood that methods for producing pharmaceutical formulations, humectants, solvents, sweeteners, preservative, food additives, monoglycerides, diglycerides, emulsifiers, antifreeze and de-icer agents, oil dispersants, solvents, resins, polyglycerol esters, moisturizer, oils, shortenings, margarines, and medical, personal care, cosmetic or pharmaceutical preparations, and the like, using the bioderived 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, or a bioderived 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol intermediate thereof, of the invention are well known in the art.
In one embodiment, the product is a pharmaceutical formulation. In one embodiment, the product is a humectant. In one embodiment, the product is a solvent, sweetener. In one embodiment, the product is a preservative. In one embodiment, the product is a food additive. In one embodiment, the product is a monoglyceride. In one embodiment, the product is a diglyceride. In one embodiment, the product is a emulsifier. In one embodiment, the product is a antifreeze agent. In one embodiment, the product is a de-icer agent. In one embodiment, the product is a oil dispersant. In one embodiment, the product is a solvent. In one embodiment, the product is a resin. In one embodiment, the product is a polyglycerol ester. In one embodiment, the product is a moisturizer. In one embodiment, the product is a oil. In one embodiment, the product is a shortening. In one embodiment, the product is a margarine. In one embodiment, the product is a medical preparation. In one embodiment, the product is a personal care preparation. In one embodiment, the product is a cosmetic preparation. In one embodiment, the product is a pharmaceutical preparation.
In some embodiments, provided herein is a culture medium comprising bioderived 1,2-propanediol. In some embodiments, the bioderived 1,2-propanediol is produced by culturing a non-naturally occurring microbial organism having a methanol metabolic pathway and 1,2-propanediol pathway, as provided herein. In certain embodiments, the bioderived 1,2-propanediol has a carbon-12, carbon-13 and carbon-14 isotope ratio that reflects an atmospheric carbon dioxide uptake source. In one embodiment, the culture medium is separated from a non-naturally occurring microbial organism having a methanol metabolic pathway and 1,2-propanediol pathway.
In other embodiments, provided herein is a bioderived 1,2-propanediol. In some embodiments, the bioderived 1,2-propanediol is produced by culturing a non-naturally occurring microbial organism having a methanol metabolic pathway and 1,2-propanediol pathway, as provided herein. In certain embodiments, the bioderived 1,2-propanediol has a carbon-12, carbon-13 and carbon-14 isotope ratio that reflects an atmospheric carbon dioxide uptake source. In some embodiments, the bioderived 1,2-propanediol has an Fm value of at least 80%, at least 85%, at least 90%, at least 95% or at least 98%. In certain embodiments, the bioderived 1,2-propanediol is a component of culture medium.
In certain embodiments, provided herein is a composition comprising a bioderived 1,2-propanediol provided herein, for example, a bioderived 1,2-propanediol produced by culturing a non-naturally occurring microbial organism having a methanol metabolic pathway and 1,2-propanediol pathway, as provided herein. In some embodiments, the composition further comprises a compound other than said bioderived 1,2-propanediol. In certain embodiments, the compound other than said bioderived 1,2-propanediol is a trace amount of a cellular portion of a non-naturally occurring microbial organism having a methanol metabolic pathway and a 1,2-propanediol pathway, as provided herein.
In some embodiments, provided herein is a biobased product comprising a bioderived 1,2-propanediol provided herein. In certain embodiments, the biobased product is a pharmaceutical formulation, humectant, solvent, sweetener, preservative, food additive, monoglyceride, diglyceride, emulsifier, antifreeze agent, de-icer agent, oil dispersant, solvent, resin, polyglycerol ester, moisturizer, oil, shortening, margarine, medical preparation, personal care preparation, cosmetic preparation or pharmaceutical preparation. In certain embodiments, the biobased product comprises at least 5% bioderived 1,2-propanediol. In certain embodiments, the biobased product comprises at least 10% bioderived 1,2-propanediol. In some embodiments, the biobased product comprises at least 20% bioderived 1,2-propanediol. In other embodiments, the biobased product comprises at least 30% bioderived 1,2-propanediol. In some embodiments, the biobased product comprises at least 40% bioderived 1,2-propanediol. In other embodiments, the biobased product comprises at least 50% bioderived 1,2-propanediol. In one embodiment, the biobased product comprises a portion of said bioderived 1,2-propanediol as a repeating unit. In another embodiment, provided herein is a molded product obtained by molding the biobased product provided herein. In other embodiments, provided herein is a process for producing a biobased product provided herein, comprising chemically reacting said bioderived 1,2-propanediol with itself or another compound in a reaction that produces said biobased product. In certain embodiments, provided herein is a polymer comprising or obtained by converting the bioderived 1,2-propanediol. In other embodiments, provided herein is a method for producing a polymer, comprising chemically of enzymatically converting the bioderived 1,2-propanediol to the polymer. In yet other embodiments, provided herein is a composition comprising the bioderived 1,2-propanediol, or a cell lysate or culture supernatant thereof.
In some embodiments, provided herein is a culture medium comprising bioderived n-propanol. In some embodiments, the bioderived n-propanol is produced by culturing a non-naturally occurring microbial organism having a methanol metabolic pathway and n-propanol pathway, as provided herein. In certain embodiments, the bioderived n-propanol has a carbon-12, carbon-13 and carbon-14 isotope ratio that reflects an atmospheric carbon dioxide uptake source. In one embodiment, the culture medium is separated from a non-naturally occurring microbial organism having a methanol metabolic pathway and n-propanol pathway.
In other embodiments, provided herein is a bioderived n-propanol. In some embodiments, the bioderived n-propanol is produced by culturing a non-naturally occurring microbial organism having a methanol metabolic pathway and n-propanol pathway, as provided herein. In certain embodiments, the bioderived n-propanol has a carbon-12, carbon-13 and carbon-14 isotope ratio that reflects an atmospheric carbon dioxide uptake source. In some embodiments, the bioderived n-propanol has an Fm value of at least 80%, at least 85%, at least 90%, at least 95% or at least 98%. In certain embodiments, the bioderived n-propanol is a component of culture medium.
In certain embodiments, provided herein is a composition comprising a bioderived n-propanol provided herein, for example, a bioderived n-propanol produced by culturing a non-naturally occurring microbial organism having a methanol metabolic pathway and n-propanol pathway, as provided herein. In some embodiments, the composition further comprises a compound other than said bioderived n-propanol. In certain embodiments, the compound other than said bioderived n-propanol is a trace amount of a cellular portion of a non-naturally occurring microbial organism having a methanol metabolic pathway and a n-propanol pathway, as provided herein.
In some embodiments, provided herein is a biobased product comprising a bioderived n-propanol provided herein. In certain embodiments, the biobased product is a pharmaceutical formulation, humectant, solvent, sweetener, preservative, food additive, monoglyceride, diglyceride, emulsifier, antifreeze agent, de-icer agent, oil dispersant, solvent, resin, polyglycerol ester, moisturizer, oil, shortening, margarine, medical preparation, personal care preparation, cosmetic preparation or pharmaceutical preparation. In certain embodiments, the biobased product comprises at least 5% bioderived n-propanol. In certain embodiments, the biobased product comprises at least 10% bioderived n-propanol. In some embodiments, the biobased product comprises at least 20% bioderived n-propanol. In other embodiments, the biobased product comprises at least 30% bioderived n-propanol. In some embodiments, the biobased product comprises at least 40% bioderived n-propanol. In other embodiments, the biobased product comprises at least 50% bioderived n-propanol. In one embodiment, the biobased product comprises a portion of said bioderived n-propanol as a repeating unit. In another embodiment, provided herein is a molded product obtained by molding the biobased product provided herein. In other embodiments, provided herein is a process for producing a biobased product provided herein, comprising chemically reacting said bioderived n-propanol with itself or another compound in a reaction that produces said biobased product. In certain embodiments, provided herein is a polymer comprising or obtained by converting the bioderived n-propanol. In other embodiments, provided herein is a method for producing a polymer, comprising chemically of enzymatically converting the bioderived n-propanol to the polymer. In yet other embodiments, provided herein is a composition comprising the bioderived n-propanol, or a cell lysate or culture supernatant thereof.
In some embodiments, provided herein is a culture medium comprising bioderived 1,3-propanediol. In some embodiments, the bioderived 1,3-propanediol is produced by culturing a non-naturally occurring microbial organism having a methanol metabolic pathway and 1,3-propanediol pathway, as provided herein. In certain embodiments, the bioderived 1,3-propanediol has a carbon-12, carbon-13 and carbon-14 isotope ratio that reflects an atmospheric carbon dioxide uptake source. In one embodiment, the culture medium is separated from a non-naturally occurring microbial organism having a methanol metabolic pathway and 1,3-propanediol pathway.
In other embodiments, provided herein is a bioderived 1,3-propanediol. In some embodiments, the bioderived 1,3-propanediol is produced by culturing a non-naturally occurring microbial organism having a methanol metabolic pathway and 1,3-propanediol pathway, as provided herein. In certain embodiments, the bioderived 1,3-propanediol has a carbon-12, carbon-13 and carbon-14 isotope ratio that reflects an atmospheric carbon dioxide uptake source. In some embodiments, the bioderived 1,3-propanediol has an Fm value of at least 80%, at least 85%, at least 90%, at least 95% or at least 98%. In certain embodiments, the bioderived 1,3-propanediol is a component of culture medium.
In certain embodiments, provided herein is a composition comprising a bioderived 1,3-propanediol, provided herein, for example, a bioderived 1,3-propanediol produced by culturing a non-naturally occurring microbial organism having a methanol metabolic pathway and 1,3-propanediol pathway, as provided herein. In some embodiments, the composition further comprises a compound other than said bioderived 1,3-propanediol. In certain embodiments, the compound other than said bioderived 1,3-propanediol is a trace amount of a cellular portion of a non-naturally occurring microbial organism having a methanol metabolic pathway and a 1,3-propanediol pathway, as provided herein.
In some embodiments, provided herein is a biobased product comprising a bioderived 1,3-propanediol provided herein. In certain embodiments, the biobased product is a pharmaceutical formulation, humectant, solvent, sweetener, preservative, food additive, monoglyceride, diglyceride, emulsifier, antifreeze agent, de-icer agent, oil dispersant, solvent, resin, polyglycerol ester, moisturizer, oil, shortening, margarine, medical preparation, personal care preparation, cosmetic preparation or pharmaceutical preparation. In certain embodiments, the biobased product comprises at least 5% bioderived 1,3-propanediol. In certain embodiments, the biobased product comprises at least 10% bioderived 1,3-propanediol. In some embodiments, the biobased product comprises at least 20% bioderived 1,3-propanediol. In other embodiments, the biobased product comprises at least 30% bioderived 1,3-propanediol. In some embodiments, the biobased product comprises at least 40% bioderived 1,3-propanediol. In other embodiments, the biobased product comprises at least 50% bioderived 1,3-propanediol. In one embodiment, the biobased product comprises a portion of said bioderived 1,3-propanediol as a repeating unit. In another embodiment, provided herein is a molded product obtained by molding the biobased product provided herein. In other embodiments, provided herein is a process for producing a biobased product provided herein, comprising chemically reacting said bioderived 1,3-propanediol with itself or another compound in a reaction that produces said biobased product. In certain embodiments, provided herein is a polymer comprising or obtained by converting the bioderived 1,3-propanediol. In other embodiments, provided herein is a method for producing a polymer, comprising chemically of enzymatically converting the bioderived 1,3-propanediol to the polymer. In yet other embodiments, provided herein is a composition comprising the bioderived 1,3-propanediol, or a cell lysate or culture supernatant thereof.
In some embodiments, provided herein is a culture medium comprising bioderived glycerol. In some embodiments, the bioderived glycerol is produced by culturing a non-naturally occurring microbial organism having a methanol metabolic pathway and glycerol pathway, as provided herein. In certain embodiments, the bioderived glycerol has a carbon-12, carbon-13 and carbon-14 isotope ratio that reflects an atmospheric carbon dioxide uptake source. In one embodiment, the culture medium is separated from a non-naturally occurring microbial organism having a methanol metabolic pathway and glycerol pathway.
In other embodiments, provided herein is a bioderived glycerol. In some embodiments, the bioderived glycerol is produced by culturing a non-naturally occurring microbial organism having a methanol metabolic pathway and glycerol pathway, as provided herein. In certain embodiments, the bioderived glycerol has a carbon-12, carbon-13 and carbon-14 isotope ratio that reflects an atmospheric carbon dioxide uptake source. In some embodiments, the bioderived glycerol has an Fm value of at least 80%, at least 85%, at least 90%, at least 95% or at least 98%. In certain embodiments, the bioderived glycerol is a component of culture medium.
In certain embodiments, provided herein is a composition comprising a bioderived glycerol provided herein, for example, a bioderived glycerol produced by culturing a non-naturally occurring microbial organism having a methanol metabolic pathway and glycerol pathway, as provided herein. In some embodiments, the composition further comprises a compound other than said bioderived glycerol. In certain embodiments, the compound other than said bioderived glycerol is a trace amount of a cellular portion of a non-naturally occurring microbial organism having a methanol metabolic pathway and a glycerol pathway, as provided herein.
In some embodiments, provided herein is a biobased product comprising a bioderived glycerol provided herein. In certain embodiments. the biobased product is a pharmaceutical formulation, humectant, solvent, sweetener, preservative, food additive, monoglyceride, diglyceride, emulsifier, antifreeze agent, de-icer agent, oil dispersant, solvent, resin, polyglycerol ester, moisturizer, oil, shortening, margarine, medical preparation, personal care preparation, cosmetic preparation or pharmaceutical preparation. In certain embodiments, the biobased product comprises at least 5% bioderived glycerol. In certain embodiments, the biobased product comprises at least 10% bioderived glycerol. In some embodiments, the biobased product comprises at least 20% bioderived glycerol. In other embodiments, the biobased product comprises at least 30% bioderived glycerol. In some embodiments, the biobased product comprises at least 40% bioderived glycerol. In other embodiments, the biobased product comprises at least 50% bioderived glycerol. In one embodiment, the biobased product comprises a portion of said bioderived glycerol as a repeating unit. In another embodiment, provided herein is a molded product obtained by molding the biobased product provided herein. In other embodiments, provided herein is a process for producing a biobased product provided herein, comprising chemically reacting said bioderived glycerol with itself or another compound in a reaction that produces said biobased product. In certain embodiments, provided herein is a polymer comprising or obtained by converting the bioderived glycerol. In other embodiments, provided herein is a method for producing a polymer, comprising chemically of enzymatically converting the bioderived glycerol to the polymer. In yet other embodiments, provided herein is a composition comprising the bioderived glycerol, or a cell lysate or culture supernatant thereof.
The invention is described herein with general reference to the metabolic reaction, reactant or product thereof, or with specific reference to one or more nucleic acids or genes encoding an enzyme associated with or catalyzing the referenced metabolic reaction, reactant or product. Unless otherwise expressly stated herein, those skilled in the art will understand that reference to a reaction also constitutes reference to the reactants and products of the reaction. Similarly, unless otherwise expressly stated herein, reference to a reactant or product also references the reaction and that reference to any of these metabolic constitutes also references the gene or genes encoding the enzymes that catalyze the referenced reaction, reactant or product. Likewise, given the well known fields of metabolic biochemistry, enzymology and genomics, reference herein to a gene or encoding nucleic acid also constitutes a reference to the corresponding encoded enzyme and the reaction it catalyzes, or a protein associated with the reaction, as well as the reactants and products of the reaction.
Microbial organisms generally lack the capacity to synthesize 1,2-propanediol, n-propanol, 1,3-propanediol and/or glycerol, and therefore any of the compounds disclosed herein to be within the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol family of compounds, or otherwise known by those in the art to be within the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol family of compounds. Moreover, organisms having all of the requisite metabolic enzymatic capabilities are not known to produce 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol from the enzymes described and biochemical pathways exemplified herein. In contrast, the non-naturally occurring microbial organisms of the invention can generate 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol as a product, as well as intermediates thereof. The biosynthesis of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, as well as intermediates thereof, is particularly useful in chemical synthesis of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol family of compounds, it also allows for the further biosynthesis of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol family compounds and avoids altogether chemical synthesis procedures.
The non-naturally occurring microbial organisms of the invention that can produce 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol are produced by ensuring that a host microbial organism includes functional capabilities for the complete biochemical synthesis of at least one 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic pathway of the invention. Ensuring at least one requisite 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic pathway confers 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthesis capability onto the host microbial organism.
The organisms and methods are described herein with general reference to the metabolic reaction, reactant or product thereof, or with specific reference to one or more nucleic acids or genes encoding an enzyme associated with or catalyzing, or a protein associated with, the referenced metabolic reaction, reactant or product. Unless otherwise expressly stated herein, those skilled in the art will understand that reference to a reaction also constitutes reference to the reactants and products of the reaction. Similarly, unless otherwise expressly stated herein, reference to a reactant or product also references the reaction, and reference to any of these metabolic constituents also references the gene or genes encoding the enzymes that catalyze or proteins involved in the referenced reaction, reactant or product. Likewise, given the well known fields of metabolic biochemistry, enzymology and genomics, reference herein to a gene or encoding nucleic acid also constitutes a reference to the corresponding encoded enzyme and the reaction it catalyzes or a protein associated with the reaction as well as the reactants and products of the reaction.
The non-naturally occurring microbial organisms described herein can be produced by introducing expressible nucleic acids encoding one or more of the enzymes or proteins participating in one or more methanol metabolic, formaldehyde assimilation, and/or 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic pathways. Depending on the host microbial organism chosen for biosynthesis, nucleic acids for some or all of a particular methanol metabolic, formaldehyde assimilation, and/or 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic pathway can be expressed. For example, if a chosen host is deficient in one or more enzymes or proteins for a desired metabolic, assimilation, or biosynthetic pathway, then expressible nucleic acids for the deficient enzyme(s) or protein(s) are introduced into the host for subsequent exogenous expression. Alternatively, if the chosen host exhibits endogenous expression of some pathway genes, but is deficient in others, then an encoding nucleic acid is needed for the deficient enzyme(s) or protein(s) to achieve 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthesis and/or methanol metabolism. Thus, a non-naturally occurring microbial organism described herein can be produced by introducing exogenous enzyme or protein activities to obtain a desired metabolic pathway and/or a desired biosynthetic pathway can be obtained by introducing one or more exogenous enzyme or protein activities that, together with one or more endogenous enzymes or proteins, produces a desired product such as 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol.
Host microbial organisms can be selected from, and the non-naturally occurring microbial organisms generated in, for example, bacteria, yeast, fungus or any of a variety of other microorganisms applicable to fermentation processes. Exemplary bacteria include species selected from Escherichia coli, Klebsiella oxytoca, Anaerobiospirillum succiniciproducens, Actinobacillus succinogenes, Mannheimia succiniciproducens, Rhizobium etli, Bacillus subtilis, Corynebacterium glutamicum, Gluconobacter oxydans, Zymomonas mobilis, Lactococcus lactis, Lactobacillus plantarum, Streptomyces coelicolor, Clostridium acetobutylicum, Pseudomonas fluorescens, and Pseudomonas putida. Exemplary yeasts or fungi include species selected from Saccharomyces cerevisiae, Schizosaccharomyces pombe, Kluyveromyces lactis, Kluyveromyces marxianus, Aspergillus terreus, Aspergillus niger, Pichia pastoris, Rhizopus arrhizus, Rhizobus oryzae, and the like. E. coli is a particularly useful host organism since it is a well characterized microbial organism suitable for genetic engineering. Other particularly useful host organisms include yeast such as Saccharomyces cerevisiae. It is understood that any suitable microbial host organism can be used to introduce metabolic and/or genetic modifications to produce a desired product.
Depending on the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic, methanol metabolic and/or formaldehyde assimilation pathway constituents of a selected host microbial organism, the non-naturally occurring microbial organisms provided herein will include at least one exogenously expressed 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, formaldehyde assimilation and/or methanol metabolic pathway-encoding nucleic acid and up to all encoding nucleic acids for one or more 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic pathways, formaldehyde assimilation pathways and/or methanol metabolic pathways. For example, 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthesis can be established in a host deficient in a pathway enzyme or protein through exogenous expression of the corresponding encoding nucleic acid. In a host deficient in all enzymes or proteins of a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway, exogenous expression of all enzyme or proteins in the pathway can be included, although it is understood that all enzymes or proteins of a pathway can be expressed even if the host contains at least one of the pathway enzymes or proteins. For example, exogenous expression of all enzymes or proteins in a pathway for production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol can be included. The same holds true for the methanol metabolic pathways and formaldehyde assimilation pathways provided herein.
Given the teachings and guidance provided herein, those skilled in the art will understand that the number of encoding nucleic acids to introduce in an expressible form will, at least, parallel the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway, formaldehyde assimilation pathway, and methanol metabolic pathway deficiencies of the selected host microbial organism. Therefore, a non-naturally occurring microbial organism of the invention can have one, two, three, four, five, six, seven, eight, nine, or up to all nucleic acids encoding the enzymes or proteins constituting a methanol metabolic pathway, formaldehyde assimilation pathway, and/or 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic pathway disclosed herein. In some embodiments, the non-naturally occurring microbial organisms also can include other genetic modifications that facilitate or optimize 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthesis, formaldehyde assimilation, and/or methanol metabolism or that confer other useful functions onto the host microbial organism. One such other functionality can include, for example, augmentation of the synthesis of one or more of the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway precursors.
Generally, a host microbial organism is selected such that it produces the precursor of a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway, either as a naturally produced molecule or as an engineered product that either provides de novo production of a desired precursor or increased production of a precursor naturally produced by the host microbial organism. A host organism can be engineered to increase production of a precursor, as disclosed herein. In addition, a microbial organism that has been engineered to produce a desired precursor can be used as a host organism and further engineered to express enzymes or proteins of a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway.
In some embodiments, a non-naturally occurring microbial organism provided herein is generated from a host that contains the enzymatic capability to synthesize 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, assimilate formaldehyde and/or metabolize methanol. In this specific embodiment it can be useful to increase the synthesis or accumulation of a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway product, formaldehyde assimilation pathway product and/or methanol metabolic pathway product (e.g., reducing equivalents and/or formaldehyde) to, for example, drive 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway reactions toward 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol production. Increased synthesis or accumulation can be accomplished by, for example, overexpression of nucleic acids encoding one or more of the above-described 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, formaldehyde assimilation and/or methanol metabolic pathway enzymes or proteins. Over expression the enzyme(s) and/or protein(s) of the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway, formaldehyde assimilation, and/or methanol metabolic pathway can occur, for example, through exogenous expression of the endogenous gene(s), or through exogenous expression of the heterologous gene(s). Therefore, naturally occurring organisms can be readily generated to be non-naturally occurring microbial organisms, for example, producing 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol through overexpression of one, two, three, four, five, six, seven, eight, up to all nucleic acids encoding 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic pathway, and/or methanol metabolic pathway enzymes or proteins. Naturally occurring organisms can also be readily generated to be non-naturally occurring microbial organisms, for example, assimilating formaldehyde, through overexpression of one, two, three, four, five, six, seven, eight, up to all nucleic acids encoding formaldehyde assimilation pathway, and/or methanol metabolic pathway enzymes or proteins. In addition, a non-naturally occurring organism can be generated by mutagenesis of an endogenous gene that results in an increase in activity of an enzyme in the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, formaldehyde assimilation and/or methanol metabolic pathway biosynthetic pathway.
In particularly useful embodiments, exogenous expression of the encoding nucleic acids is employed. Exogenous expression confers the ability to custom tailor the expression and/or regulatory elements to the host and application to achieve a desired expression level that is controlled by the user. However, endogenous expression also can be utilized in other embodiments such as by removing a negative regulatory effector or induction of the gene's promoter when linked to an inducible promoter or other regulatory element. Thus, an endogenous gene having a naturally occurring inducible promoter can be up-regulated by providing the appropriate inducing agent, or the regulatory region of an endogenous gene can be engineered to incorporate an inducible regulatory element, thereby allowing the regulation of increased expression of an endogenous gene at a desired time. Similarly, an inducible promoter can be included as a regulatory element for an exogenous gene introduced into a non-naturally occurring microbial organism.
It is understood that, in methods provided herein, any of the one or more exogenous nucleic acids can be introduced into a microbial organism to produce a non-naturally occurring microbial organism provided herein. The nucleic acids can be introduced so as to confer, for example, a 3-hydroxyisobutyrate or MAA biosynthetic, formaldehyde assimilation and/or methanol metabolic pathway onto the microbial organism. Alternatively, encoding nucleic acids can be introduced to produce an intermediate microbial organism having the biosynthetic capability to catalyze some of the required reactions to confer 3-hydroxyisobutyrate or MAA biosynthetic, formaldehyde assimilation and/or methanol metabolic capability. For example, a non-naturally occurring microbial organism having a 3-hydroxyisobutyrate or MAA biosynthetic pathway, formaldehyde assimilation pathway and/or methanol metabolic pathway can comprise at least two exogenous nucleic acids encoding desired enzymes or proteins. Thus, it is understood that any combination of two or more enzymes or proteins of a biosynthetic pathway, formaldehyde assimilation pathway and/or metabolic pathway can be included in a non-naturally occurring microbial organism provided herein. Similarly, it is understood that any combination of three or more enzymes or proteins of a biosynthetic pathway, formaldehyde assimilation pathway and/or metabolic pathway can be included in a non-naturally occurring microbial organism of the invention, as desired, so long as the combination of enzymes and/or proteins of the desired biosynthetic pathway, formaldehyde assimilation pathway and/or metabolic pathway results in production of the corresponding desired product. Similarly, any combination of four or more enzymes or proteins of a biosynthetic pathway, formaldehyde assimilation pathway and/or methanol metabolic pathway as disclosed herein can be included in a non-naturally occurring microbial organism provided herein, as desired, so long as the combination of enzymes and/or proteins of the desired biosynthetic, assimilation and/or metabolic pathway results in production of the corresponding desired product.
In addition to the metabolism of methanol, assimilation of formaldehyde, and biosynthesis of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, as described herein, the non-naturally occurring microbial organisms and methods provided also can be utilized in various combinations with each other and with other microbial organisms and methods well known in the art to achieve product biosynthesis by other routes. For example, one alternative produce 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, other than use of the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol producers is through addition of another microbial organism capable of converting a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway intermediate to 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. One such procedure includes, for example, the fermentation of a microbial organism that produces a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway intermediate. The 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway intermediate can then be used as a substrate for a second microbial organism that converts the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway intermediate to 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. The 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway intermediate can be added directly to another culture of the second organism or the original culture of the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway intermediate producers can be depleted of these microbial organisms by, for example, cell separation, and then subsequent addition of the second organism to the fermentation broth can be utilized to produce the final product without intermediate purification steps.
In other embodiments, the non-naturally occurring microbial organisms and methods of the invention can be assembled in a wide variety of subpathways to achieve biosynthesis of for example, 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. In these embodiments, biosynthetic pathways for a desired product can be segregated into different microbial organisms, and the different microbial organisms can be co-cultured to produce the final product. In such a biosynthetic scheme, the product of one microbial organism is the substrate for a second microbial organism until the final product is synthesized. For example, the biosynthesis of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol can be accomplished by constructing a microbial organism that contains biosynthetic pathways for conversion of one pathway intermediate to another pathway intermediate or the product. Alternatively, 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol also can be biosynthetically produced from microbial organisms through co-culture or co-fermentation using two organisms in the same vessel, where the first microbial organism produces a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol intermediate and the second microbial organism converts the intermediate to 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol.
Given the teachings and guidance provided herein, those skilled in the art will understand that a wide variety of combinations and permutations exist for the non-naturally occurring microbial organisms and methods together with other microbial organisms, with the co-culture of other non-naturally occurring microbial organisms having subpathways and with combinations of other chemical and/or biochemical procedures well known in the art to produce 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol and/or metabolize methanol.
Sources of encoding nucleic acids for a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, formaldehyde assimilation, or methanol metabolic pathway enzyme or protein can include, for example, any species where the encoded gene product is capable of catalyzing the referenced reaction. Such species include both prokaryotic and eukaryotic organisms including, but not limited to, bacteria, including archaea and eubacteria, and eukaryotes, including yeast, plant, insect, animal, and mammal, including human. Exemplary species for such sources include, for example, Escherichia coli, Saccharomyces cerevisiae, Saccharomyces kluyveri, Candida boidinii, Clostridium kluyveri, Clostridium acetobutylicum, Clostridium beijerinckii, Clostridium saccharoperbutylacetonicum, Clostridium perfringens, Clostridium difficile, Clostridium botulinum, Clostridium tyrobutyricum, Clostridium tetanomorphum, Clostridium tetani, Clostridium propionicum, Clostridium aminobutyricum, Clostridium subterminale, Clostridium sticklandii, Ralstonia eutropha, Mycobacterium Bovis, Mycobacterium tuberculosis, Porphyromonas gingivalis, Arabidopsis thaliana, Thermus thermophilus, Pseudomonas species, including Pseudomonas aeruginosa, Pseudomonas putida, Pseudomonas stutzeri, Pseudomonas fluorescens, Homo sapiens, Oryctolagus cuniculus, Rhodobacter spaeroides, Thermoanaerobacter brockii, Metallosphaera sedula, Leuconostoc mesenteroides, Chloroflexus aurantiacus, Roseiflexus castenholzii, Erythrobacter, Simmondsia chinensis, Acinetobacter species, including Acinetobacter calcoaceticus and Acinetobacter baylyi, Porphyromonas gingivalis, Sulfolobus tokodaii, Sulfolobus solfataricus, Sulfolobus acidocaldarius, Bacillus subtilis, Bacillus cereus, Bacillus megaterium, Bacillus brevis, Bacillus pumilus, Rattus norvegicus, Klebsiella pneumonia, Klebsiella oxytoca, Euglena gracilis, Treponema denticola, Moorella thermoacetica, Thermotoga maritima, Halobacterium salinarum, Geobacillus stearothermophilus, Aeropyrum pernix, Sus scrofa, Caenorhabditis elegans, Corynebacterium glutamicum, Acidaminococcus fermentans, Lactococcus lactis, Lactobacillus plantarum, Streptococcus thermophilus, Enterobacter aerogenes, Candida, Aspergillus terreus, Pedicoccus pentosaceus, Zymomonas mobilus, Acetobacter pasteurians, Kluyveromyces lactis, Eubacterium barkeri, Bacteroides capillosus, Anaerotruncus colihominis, Natranaerobius thermophilusm, Campylobacter jejuni, Haemophilus influenzae, Serratia marcescens, Citrobacter amalonaticus, Myxococcus xanthus, Fusobacterium nuleatum, Penicillium chrysogenum, marine gamma proteobacierium, butyrate producingbacterium, Nocardia iowensis, Nocardia jarcinica, Streptomyces griseus, Schizosaccharomyces pombe, Geobacillus thermoglucosidasius, Salmonella typhimurium, Vibrio cholera, Heliobacter pylori, Nicotiana tabacum, Oryza sativa, Haloferax mediterranei, Agrobacterium tumefaciens, Achromobacter denitrificans, Fusobacterium nucleatum, Streptomyces clavuligenus, Acinetobacter baumanii, Mus musculus, Lachancea kluyveri, Trichomonas vaginalis, Trypanosoma brucei, Pseudomonas stutzeri, Bradyrhizobium japonicum, Mesorhizobium loti, Bos taurus, Nicotiana glutinosa, Vibrio vulnificus, Selenomonas ruminantium, Vibrio parahaemolyticus, Archaeoglobus fulgidus, Haloarcula marismortui, Pyrobaculum aerophilum, Mycobacterium smegmatis MC2 155, Mycobacterium avium subsp. paratuberculosis K-10, Mycobacterium marinum M, Tsukamurella paurometabola DSM 20162, Cyanobium PCC7001, Dictyostelium discoideum AX-1, as well as other exemplary species disclosed herein or available as source organisms for corresponding genes. However, with the complete genome sequence available for now more than 550 species (with more than half of these available on public databases such as the NCBI), including 395 microorganism genomes and a variety of yeast, fungi, plant, and mammalian genomes, the identification of genes encoding the requisite 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic activity for one or more genes in related or distant species, including for example, homologues, orthologs, paralogs and nonorthologous gene displacements of known genes, and the interchange of genetic alterations between organisms is routine and well known in the art. Accordingly, the metabolic alterations allowing biosynthesis of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, metabolism of methanol and/or assimilation of formaldehyde described herein with reference to a particular organism such as E. coli can be readily applied to other microorganisms, including prokaryotic and eukaryotic organisms alike. Given the teachings and guidance provided herein, those skilled in the art will know that a metabolic alteration exemplified in one organism can be applied equally to other organisms.
In some instances, such as when an alternative 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic, formaldehyde assimilation and/or methanol metabolic pathway exists in an unrelated species, 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthesis, formaldehyde assimilation and/or methanol metabolism can be conferred onto the host species by, for example, exogenous expression of a paralog or paralogs from the unrelated species that catalyzes a similar, yet non-identical metabolic reaction to replace the referenced reaction. Because certain differences among metabolic networks exist between different organisms, those skilled in the art will understand that the actual gene usage between different organisms may differ. However, given the teachings and guidance provided herein, those skilled in the art also will understand that the teachings and methods provided herein can be applied to all microbial organisms using the cognate metabolic alterations to those exemplified herein to construct a microbial organism in a species of interest that will synthesize 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, assimilate formaldehyde, and/or metabolize methanol.
Methods for constructing and testing the expression levels of a non-naturally occurring 1,2-propanediol-, n-propanol-, 1,3-propanediol- or glycerol-producing host can be performed, for example, by recombinant and detection methods well known in the art. Such methods can be found described in, for example, Sambrook et al., Molecular Cloning: A Laboratory Manual, Third Ed., Cold Spring Harbor Laboratory, New York (2001); and Ausubel et al., Current Protocols in Molecular Biology, John Wiley and Sons, Baltimore, Md. (1999).
Exogenous nucleic acid sequences involved in a pathway for metabolism of methanol, assimilation of formaldehyde and/or production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol can be introduced stably or transiently into a host cell using techniques well known in the art including, but not limited to, conjugation, electroporation, chemical transformation, transduction, transfection, and ultrasound transformation. For exogenous expression in E. coli or other prokaryotic cells, some nucleic acid sequences in the genes or cDNAs of eukaryotic nucleic acids can encode targeting signals such as an N-terminal mitochondrial or other targeting signal, which can be removed before transformation into prokaryotic host cells, if desired. For example, removal of a mitochondrial leader sequence led to increased expression in E. coli (Hoffmeister et al., J. Biol. Chem. 280:4329-4338 (2005)). For exogenous expression in yeast or other eukaryotic cells, genes can be expressed in the cytosol without the addition of leader sequence, or can be targeted to mitochondrion or other organelles, or targeted for secretion, by the addition of a suitable targeting sequence such as a mitochondrial targeting or secretion signal suitable for the host cells. Thus, it is understood that appropriate modifications to a nucleic acid sequence to remove or include a targeting sequence can be incorporated into an exogenous nucleic acid sequence to impart desirable properties. Furthermore, genes can be subjected to codon optimization with techniques well known in the art to achieve optimized expression of the proteins.
An expression vector or vectors can be constructed to include one or more 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic, formaldehyde assimilation and/or methanol metabolic pathway encoding nucleic acids as exemplified herein operably linked to expression control sequences functional in the host organism. Expression vectors applicable for use in the microbial host organisms provided include, for example, plasmids, phage vectors, viral vectors, episomes and artificial chromosomes, including vectors and selection sequences or markers operable for stable integration into a host chromosome. Additionally, the expression vectors can include one or more selectable marker genes and appropriate expression control sequences. Selectable marker genes also can be included that, for example, provide resistance to antibiotics or toxins, complement auxotrophic deficiencies, or supply critical nutrients not in the culture media. Expression control sequences can include constitutive and inducible promoters, transcription enhancers, transcription terminators, and the like which are well known in the art. When two or more exogenous encoding nucleic acids are to be co-expressed, both nucleic acids can be inserted, for example, into a single expression vector or in separate expression vectors. For single vector expression, the encoding nucleic acids can be operationally linked to one common expression control sequence or linked to different expression control sequences, such as one inducible promoter and one constitutive promoter. The transformation of exogenous nucleic acid sequences involved in a metabolic or synthetic pathway can be confirmed using methods well known in the art. Such methods include, for example, nucleic acid analysis such as Northern blots or polymerase chain reaction (PCR) amplification of mRNA, or immunoblotting for expression of gene products, or other suitable analytical methods to test the expression of an introduced nucleic acid sequence or its corresponding gene product. It is understood by those skilled in the art that the exogenous nucleic acid is expressed in a sufficient amount to produce the desired product, and it is further understood that expression levels can be optimized to obtain sufficient expression using methods well known in the art and as disclosed herein.
Suitable purification and/or assays to test, e.g., for the production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol can be performed using well known methods. Suitable replicates such as triplicate cultures can be grown for each engineered strain to be tested. For example, product and byproduct formation in the engineered production host can be monitored. The final product and intermediates, and other organic compounds, can be analyzed by methods such as HPLC (High Performance Liquid Chromatography), GC-MS (Gas Chromatography-Mass Spectroscopy) and LC-MS (Liquid Chromatography-Mass Spectroscopy) or other suitable analytical methods using routine procedures well known in the art. The release of product in the fermentation broth can also be tested with the culture supernatant. Byproducts and residual glucose can be quantified by HPLC using, for example, a refractive index detector for glucose and alcohols, and a UV detector for organic acids (Lin et al., Biotechnol. Bioeng. 90:775-779 (2005)), or other suitable assay and detection methods well known in the art. The individual enzyme or protein activities from the exogenous DNA sequences can also be assayed using methods well known in the art.
The 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol can be separated from other components in the culture using a variety of methods well known in the art. Such separation methods include, for example, extraction procedures as well as methods that include continuous liquid-liquid extraction, pervaporation, membrane filtration, membrane separation, reverse osmosis, electrodialysis, distillation, crystallization, centrifugation, extractive filtration, ion exchange chromatography, size exclusion chromatography, adsorption chromatography, and ultrafiltration. All of the above methods are well known in the art.
Any of the non-naturally occurring microbial organisms described herein can be cultured to produce and/or secrete the biosynthetic products, or intermediates thereof. For example, the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol producers can be cultured for the biosynthetic production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. Accordingly, in some embodiments, the invention provides culture medium having a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, formaldehyde assimilation and/or methanol metabolic pathway intermediate described herein. In some aspects, the culture medium can also be separated from the non-naturally occurring microbial organisms provided herein that produced the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, formaldehyde assimilation and/or methanol metabolic pathway intermediate. Methods for separating a microbial organism from culture medium are well known in the art. Exemplary methods include filtration, flocculation, precipitation, centrifugation, sedimentation, and the like.
In certain embodiments, for example, for the production of the production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, the recombinant strains are cultured in a medium with carbon source and other essential nutrients. It is sometimes desirable and can be highly desirable to maintain anaerobic conditions in the fermenter to reduce the cost of the overall process. Such conditions can be obtained, for example, by first sparging the medium with nitrogen and then sealing the flasks with a septum and crimp-cap. For strains where growth is not observed anaerobically, microaerobic or substantially anaerobic conditions can be applied by perforating the septum with a small hole for limited aeration. Exemplary anaerobic conditions have been described previously and are well-known in the art. Exemplary aerobic and anaerobic conditions are described, for example, in U.S. Publ. No. 2009/0047719. Fermentations can be performed in a batch, fed-batch or continuous manner, as disclosed herein. Fermentations can also be conducted in two phases, if desired. The first phase can be aerobic to allow for high growth and therefore high productivity, followed by an anaerobic phase of high 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol yields.
If desired, the pH of the medium can be maintained at a desired pH, in particular neutral pH, such as a pH of around 7 by addition of a base, such as NaOH or other bases, or acid, as needed to maintain the culture medium at a desirable pH. The growth rate can be determined by measuring optical density using a spectrophotometer (600 nm), and the glucose uptake rate by monitoring carbon source depletion over time.
The growth medium, can include, for example, any carbohydrate source which can supply a source of carbon to the non-naturally occurring microorganism. Such sources include, for example, sugars such as glucose, xylose, arabinose, galactose, mannose, fructose, sucrose and starch; or glycerol, alone as the sole source of carbon or in combination with other carbon sources described herein or known in the art. In one embodiment, the carbon source is a sugar. In one embodiment, the carbon source is a sugar-containing biomass. In some embodiments, the sugar is glucose. In one embodiment, the sugar is xylose. In another embodiment, the sugar is arabinose. In one embodiment, the sugar is galactose. In another embodiment, the sugar is fructose. In other embodiments, the sugar is sucrose. In one embodiment, the sugar is starch. In certain embodiments, the carbon source is glycerol. In some embodiments, the carbon source is crude glycerol. In one embodiment, the carbon source is crude glycerol without treatment. In other embodiments, the carbon source is glycerol and glucose. In another embodiment, the carbon source is methanol and glycerol. In one embodiment, the carbon source is carbon dioxide. In one embodiment, the carbon source is formate. In one embodiment, the carbon source is methane. In one embodiment, the carbon source is methanol. In one embodiment, the carbon source is chemoelectro-generated carbon (see, e.g., Liao et al. (2012) Science 335:1596). In one embodiment, the chemoelectro-generated carbon is methanol. In one embodiment, the chemoelectro-generated carbon is formate. In one embodiment, the chemoelectro-generated carbon is formate and methanol. In one embodiment, the carbon source is a sugar and methanol. In another embodiment, the carbon source is a sugar and glycerol. In other embodiments, the carbon source is a sugar and crude glycerol. In yet other embodiments, the carbon source is a sugar and crude glycerol without treatment. In one embodiment, the carbon source is a sugar-containing biomass and methanol. In another embodiment, the carbon source is a sugar-containing biomass and glycerol. In other embodiments, the carbon source is a sugar-containing biomass and crude glycerol. In yet other embodiments, the carbon source is a sugar-containing biomass and crude glycerol without treatment. Other sources of carbohydrate include, for example, renewable feedstocks and biomass. Exemplary types of biomasses that can be used as feedstocks in the methods of the invention include cellulosic biomass, hemicellulosic biomass and lignin feedstocks or portions of feedstocks. Such biomass feedstocks contain, for example, carbohydrate substrates useful as carbon sources such as glucose, xylose, arabinose, galactose, mannose, fructose and starch. Given the teachings and guidance provided herein, those skilled in the art will understand that renewable feedstocks and biomass other than those exemplified above also can be used for culturing the microbial organisms provided herein for the production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, and other pathway intermediates.
In one embodiment, the carbon source is glycerol. In certain embodiments, the glycerol carbon source is crude glycerol or crude glycerol without further treatment. In a further embodiment, the carbon source comprises glycerol or crude glycerol, and also sugar or a sugar-containing biomass, such as glucose. In a specific embodiment, the concentration of glycerol in the fermentation broth is maintained by feeding crude glycerol, or a mixture of crude glycerol and sugar (e.g., glucose). In certain embodiments, sugar is provided for sufficient strain growth. In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of from 200:1 to 1:200. In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of from 100:1 to 1:100. In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of from 100:1 to 5:1. In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of from 50:1 to 5:1. In certain embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 100:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 90:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 80:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 70:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 60:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 50:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 40:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 30:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 20:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 10:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 5:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 2:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 1:1. In certain embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 1:100. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 1:90. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 1:80. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 1:70. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 1:60. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 1:50. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 1:40. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 1:30. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 1:20. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 1:10. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 1:5. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of glycerol to sugar of 1:2. In certain embodiments of the ratios provided above, the sugar is a sugar-containing biomass. In certain other embodiments of the ratios provided above, the glycerol is a crude glycerol or a crude glycerol without further treatment. In other embodiments of the ratios provided above, the sugar is a sugar-containing biomass, and the glycerol is a crude glycerol or a crude glycerol without further treatment.
Crude glycerol can be a by-product produced in the production of biodiesel, and can be used for fermentation without any further treatment. Biodiesel production methods include (1) a chemical method wherein the glycerol-group of vegetable oils or animal oils is substituted by low-carbon alcohols such as methanol or ethanol to produce a corresponding fatty acid methyl esters or fatty acid ethyl esters by transesterification in the presence of acidic or basic catalysts; (2) a biological method where biological enzymes or cells are used to catalyze transesterification reaction and the corresponding fatty acid methyl esters or fatty acid ethyl esters are produced; and (3) a supercritical method, wherein transesterification reaction is carried out in a supercritical solvent system without any catalysts. The chemical composition of crude glycerol can vary with the process used to produce biodiesel, the transesterification efficiency, recovery efficiency of the biodiesel, other impurities in the feedstock, and whether methanol and catalysts were recovered. For example, the chemical compositions of eleven crude glycerol collected from seven Australian biodiesel producers reported that glycerol content ranged between 38% and 96%, with some samples including more than 14% methanol and 29% ash. In certain embodiments, the crude glycerol comprises from 5% to 99% glycerol. In some embodiments, the crude glycerol comprises from 10% to 90% glycerol. In some embodiments, the crude glycerol comprises from 10% to 80% glycerol. In some embodiments, the crude glycerol comprises from 10% to 70% glycerol. In some embodiments, the crude glycerol comprises from 10% to 60% glycerol. In some embodiments, the crude glycerol comprises from 10% to 50% glycerol. In some embodiments, the crude glycerol comprises from 10% to 40% glycerol. In some embodiments, the crude glycerol comprises from 10% to 30% glycerol. In some embodiments, the crude glycerol comprises from 10% to 20% glycerol. In some embodiments, the crude glycerol comprises from 80% to 90% glycerol. In some embodiments, the crude glycerol comprises from 70% to 90% glycerol. In some embodiments, the crude glycerol comprises from 60% to 90% glycerol. In some embodiments, the crude glycerol comprises from 50% to 90% glycerol. In some embodiments, the crude glycerol comprises from 40% to 90% glycerol. In some embodiments, the crude glycerol comprises from 30% to 90% glycerol. In some embodiments, the crude glycerol comprises from 20% to 90% glycerol. In some embodiments, the crude glycerol comprises from 20% to 40% glycerol. In some embodiments, the crude glycerol comprises from 40% to 60% glycerol. In some embodiments, the crude glycerol comprises from 60% to 80% glycerol. In some embodiments, the crude glycerol comprises from 50% to 70% glycerol. In one embodiment, the glycerol comprises 5% glycerol. In one embodiment, the glycerol comprises 10% glycerol. In one embodiment, the glycerol comprises 15% glycerol. In one embodiment, the glycerol comprises 20% glycerol. In one embodiment, the glycerol comprises 25% glycerol. In one embodiment, the glycerol comprises 30% glycerol. In one embodiment, the glycerol comprises 35% glycerol. In one embodiment, the glycerol comprises 40% glycerol. In one embodiment, the glycerol comprises 45% glycerol. In one embodiment, the glycerol comprises 50% glycerol. In one embodiment, the glycerol comprises 55% glycerol. In one embodiment, the glycerol comprises 60% glycerol. In one embodiment, the glycerol comprises 65% glycerol. In one embodiment, the glycerol comprises 70% glycerol. In one embodiment, the glycerol comprises 75% glycerol. In one embodiment, the glycerol comprises 80% glycerol. In one embodiment, the glycerol comprises 85% glycerol. In one embodiment, the glycerol comprises 90% glycerol. In one embodiment, the glycerol comprises 95% glycerol. In one embodiment, the glycerol comprises 99% glycerol.
In one embodiment, the carbon source is methanol or formate. In certain embodiments, methanol is used as a carbon source in the formaldehyde assimilation pathways provided herein. In one embodiment, the carbon source is methanol or formate. In other embodiments, formate is used as a carbon source in the formaldehyde assimilation pathways provided herein. In specific embodiments, methanol is used as a carbon source in the methanol metabolic pathways provided herein, either alone or in combination with the product pathways provided herein.
In one embodiment, the carbon source comprises methanol, and sugar (e.g., glucose) or a sugar-containing biomass. In another embodiment, the carbon source comprises formate, and sugar (e.g., glucose) or a sugar-containing biomass. In one embodiment, the carbon source comprises methanol, formate, and sugar (e.g., glucose) or a sugar-containing biomass. In specific embodiments, the methanol or formate, or both, in the fermentation feed is provided as a mixture with sugar (e.g., glucose) or sugar-comprising biomass. In certain embodiments, sugar is provided for sufficient strain growth.
In certain embodiments, the carbon source comprises methanol and a sugar (e.g., glucose). In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of from 200:1 to 1:200. In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of from 100:1 to 1:100. In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of from 100:1 to 5:1. In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of from 50:1 to 5:1. In certain embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 100:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 90:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 80:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 70:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 60:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 50:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 40:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 30:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 20:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 10:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 5:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 2:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 1:1. In certain embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 1:100. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 1:90. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 1:80. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 1:70. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 1:60. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 1:50. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 1:40. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 1:30. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 1:20. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 1:10. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 1:5. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol to sugar of 1:2. In certain embodiments of the ratios provided above, the sugar is a sugar-containing biomass.
In certain embodiments, the carbon source comprises formate and a sugar (e.g., glucose). In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of from 200:1 to 1:200. In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of from 100:1 to 1:100. In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of from 100:1 to 5:1. In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of from 50:1 to 5:1. In certain embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 100:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 90:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 80:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 70:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 60:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 50:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 40:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 30:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 20:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 10:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 5:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 2:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 1:1. In certain embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 1:100. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 1:90. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 1:80. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 1:70. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 1:60. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 1:50. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 1:40. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 1:30. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 1:20. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 1:10. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 1:5. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of formate to sugar of 1:2. In certain embodiments of the ratios provided above, the sugar is a sugar-containing biomass.
In certain embodiments, the carbon source comprises a mixture of methanol and formate, and a sugar (e.g., glucose). In certain embodiments, sugar is provided for sufficient strain growth. In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of from 200:1 to 1:200. In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of from 100:1 to 1:100. In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of from 100:1 to 5:1. In some embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of from 50:1 to 5:1. In certain embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 100:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 90:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 80:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 70:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 60:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 50:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 40:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 30:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 20:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 10:1. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 5:1. In one embodiment. the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 2:1. In one embodiment, the sugar (e.g. glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 1:1. In certain embodiments, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 1:100. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 1:90. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 1:80. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 1:70. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 1:60. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 1:50. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 1:40. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 1:30. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 1:20. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 1:10. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 1:5. In one embodiment, the sugar (e.g., glucose) is provided at a molar concentration ratio of methanol and formate to sugar of 1:2. In certain embodiments of the ratios provided above, the sugar is a sugar-containing biomass.
Given the teachings and guidance provided herein, those skilled in the art will understand that a non-naturally occurring microbial organism can be produced that secretes the biosynthesized compounds when grown on a carbon source such as a carbohydrate. Such compounds include, for example, 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol and any of the intermediate metabolites in the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway. All that is required is to engineer in one or more of the required enzyme or protein activities to achieve biosynthesis of the desired compound or intermediate including, for example, inclusion of some or all of the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic pathways. Accordingly, provided herein is a non-naturally occurring microbial organism that produces and/or secretes 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol when grown on a carbohydrate or other carbon source and produces and/or secretes any of the intermediate metabolites shown in the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway when grown on a carbohydrate or other carbon source. The 1,2-propanediol-, n-propanol-, 1,3-propanediol- or glycerol-producing microbial organisms provided herein can initiate synthesis from an intermediate. The same holds true for intermediates in the formaldehyde assimilation and methanol metabolic, pathways.
The non-naturally occurring microbial organisms provided herein are constructed using methods well known in the art as exemplified herein to exogenously express at least one nucleic acid encoding a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol biosynthetic pathway and/or methanol metabolic pathway enzyme or protein in sufficient amounts to produce 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. It is understood that the microbial organisms are cultured under conditions sufficient to produce 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. Following the teachings and guidance provided herein, the non-naturally occurring microbial organisms can achieve biosynthesis of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, resulting in intracellular concentrations between about 0.1-500 mM or more. Generally, the intracellular concentration of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol is between about 3-150 mM, particularly between about 5-125 mM and more particularly between about 8-100 mM, including about 10 mM, 20 mM, 50 mM, 80 mM, or more. Intracellular concentrations between and above each of these exemplary ranges also can be achieved from the non-naturally occurring microbial organisms provided herein.
In some embodiments, culture conditions include anaerobic or substantially anaerobic growth or maintenance conditions. Exemplary anaerobic conditions have been described previously and are well known in the art. Exemplary anaerobic conditions for fermentation processes are described herein and are described, for example, in U.S. Publ. No. 2009/0047719. Any of these conditions can be employed with the non-naturally occurring microbial organisms as well as other anaerobic conditions well known in the art. Under such anaerobic or substantially anaerobic conditions, the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol producers can synthesize 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol at intracellular concentrations of 5-100 mM or more as well as all other concentrations exemplified herein. It is understood that, even though the above description refers to intracellular concentrations, 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol can produce 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol intracellularly and/or secrete the product into the culture medium.
Exemplary fermentation processes include, but are not limited to, fed-batch fermentation and batch separation; fed-batch fermentation and continuous separation; and continuous fermentation and continuous separation. In an exemplary batch fermentation protocol, the production organism is grown in a suitably sized bioreactor sparged with an appropriate gas. Under anaerobic conditions, the culture is sparged with an inert gas or combination of gases, for example, nitrogen, N2/CO2 mixture, argon, helium, and the like. As the cells grow and utilize the carbon source, additional carbon source(s) and/or other nutrients are fed into the bioreactor at a rate approximately balancing consumption of the carbon source and/or nutrients. The temperature of the bioreactor is maintained at a desired temperature, generally in the range of 22-37 degrees C., but the temperature can be maintained at a higher or lower temperature depending on the growth characteristics of the production organism and/or desired conditions for the fermentation process. Growth continues for a desired period of time to achieve desired characteristics of the culture in the fermenter, for example, cell density, product concentration, and the like. In a batch fermentation process, the time period for the fermentation is generally in the range of several hours to several days, for example, 8 to 24 hours, or 1, 2, 3, 4 or 5 days, or up to a week, depending on the desired culture conditions. The pH can be controlled or not, as desired, in which case a culture in which pH is not controlled will typically decrease to pH 3-6 by the end of the run. Upon completion of the cultivation period, the fermenter contents can be passed through a cell separation unit, for example, a centrifuge, filtration unit, and the like, to remove cells and cell debris. In the case where the desired product is expressed intracellularly, the cells can be lysed or disrupted enzymatically or chemically prior to or after separation of cells from the fermentation broth, as desired, in order to release additional product. The fermentation broth can be transferred to a product separations unit. Isolation of product occurs by standard separations procedures employed in the art to separate a desired product from dilute aqueous solutions. Such methods include, but are not limited to, liquid-liquid extraction using a water immiscible organic solvent (e.g., toluene or other suitable solvents, including but not limited to diethyl ether, ethyl acetate, tetrahydrofuran (THF), methylene chloride, chloroform, benzene, pentane, hexane, heptane, petroleum ether, methyl tertiary butyl ether (MTBE), dioxane, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and the like) to provide an organic solution of the product, if appropriate, standard distillation methods, and the like, depending on the chemical characteristics of the product of the fermentation process.
In an exemplary fully continuous fermentation protocol, the production organism is generally first grown up in batch mode in order to achieve a desired cell density. When the carbon source and/or other nutrients are exhausted, feed medium of the same composition is supplied continuously at a desired rate, and fermentation liquid is withdrawn at the same rate. Under such conditions, the product concentration in the bioreactor generally remains constant, as well as the cell density. The temperature of the fermenter is maintained at a desired temperature, as discussed above. During the continuous fermentation phase, it is generally desirable to maintain a suitable pH range for optimized production. The pH can be monitored and maintained using routine methods, including the addition of suitable acids or bases to maintain a desired pH range. The bioreactor is operated continuously for extended periods of time, generally at least one week to several weeks and up to one month, or longer, as appropriate and desired. The fermentation liquid and/or culture is monitored periodically, including sampling up to every day, as desired, to assure consistency of product concentration and/or cell density. In continuous mode, fermenter contents are constantly removed as new feed medium is supplied. The exit stream, containing cells, medium, and product, are generally subjected to a continuous product separations procedure, with or without removing cells and cell debris, as desired. Continuous separations methods employed in the art can be used to separate the product from dilute aqueous solutions, including but not limited to continuous liquid-liquid extraction using a water immiscible organic solvent (e.g., toluene or other suitable solvents, including but not limited to diethyl ether, ethyl acetate, tetrahydrofuran (THF), methylene chloride, chloroform, benzene, pentane, hexane, heptane, petroleum ether, methyl tertiary butyl ether (MTBE), dioxane, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and the like), standard continuous distillation methods, and the like, or other methods well known in the art.
In addition to the culturing and fermentation conditions disclosed herein, growth condition for achieving biosynthesis of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol can include the addition of an osmoprotectant to the culturing conditions. In certain embodiments, the non-naturally occurring microbial organisms provided herein can be sustained, cultured or fermented as described herein in the presence of an osmoprotectant. Briefly, an osmoprotectant refers to a compound that acts as an osmolyte and helps a microbial organism as described herein survive osmotic stress. Osmoprotectants include, but are not limited to, betaines, amino acids, and the sugar trehalose. Non-limiting examples of such are glycine betaine, praline betaine, dimethylthetin, dimethylslfonioproprionate, 3-dimethylsulfonio-2-methylproprionate, pipecolic acid, dimethylsulfonioacetate, choline, L-carnitine and ectoine. In one aspect, the osmoprotectant is glycine betaine. It is understood to one of ordinary skill in the art that the amount and type of osmoprotectant suitable for protecting a microbial organism described herein from osmotic stress will depend on the microbial organism used. The amount of osmoprotectant in the culturing conditions can be, for example, no more than about 0.1 mM, no more than about 0.5 mM, no more than about 1.0 mM, no more than about 1.5 mM, no more than about 2.0 mM, no more than about 2.5 mM, no more than about 3.0 mM, no more than about 5.0 mM, no more than about 7.0 mM, no more than about 10 mM, no more than about 50 mM, no more than about 100 mM or no more than about 500 mM.
The culture conditions can include, for example, liquid culture procedures as well as fermentation and other large scale culture procedures. As described herein, particularly useful yields of the biosynthetic products of the invention can be obtained under anaerobic or substantially anaerobic culture conditions.
As described herein, one exemplary growth condition for achieving biosynthesis of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, as well as other pathway intermediates, includes anaerobic culture or fermentation conditions. In certain embodiments, the non-naturally occurring microbial organisms provided can be sustained, cultured or fermented under anaerobic or substantially anaerobic conditions. Briefly, anaerobic conditions refer to an environment devoid of oxygen. Substantially anaerobic conditions include, for example, a culture, batch fermentation or continuous fermentation such that the dissolved oxygen concentration in the medium remains between 0 and 10% of saturation. Substantially anaerobic conditions also includes growing or resting cells in liquid medium or on solid agar inside a sealed chamber maintained with an atmosphere of less than 1% oxygen. The percent of oxygen can be maintained by, for example, sparging the culture with an N2/CO2 mixture or other suitable non-oxygen gas or gases.
The culture conditions described herein can be scaled up and grown continuously for manufacturing of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. Exemplary growth procedures include, for example, fed-batch fermentation and batch separation; fed-batch fermentation and continuous separation, or continuous fermentation and continuous separation. All of these processes are well known in the art. Fermentation procedures are particularly useful for the biosynthetic production of commercial quantities of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. Generally, and as with non-continuous culture procedures, the continuous and/or near-continuous production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol will include culturing a non-naturally occurring 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol producing organism of the invention in sufficient nutrients and medium to sustain and/or nearly sustain growth in an exponential phase. Continuous culture under such conditions can be included, for example, growth for 1 day, 2, 3, 4, 5, 6 or 7 days or more. Additionally, continuous culture can include longer time periods of 1 week, 2, 3, 4 or 5 or more weeks and up to several months. Alternatively, organisms provided can be cultured for hours, if suitable for a particular application. It is to be understood that the continuous and/or near-continuous culture conditions also can include all time intervals in between these exemplary periods. It is further understood that the time of culturing the microbial organism of the invention is for a sufficient period of time to produce a sufficient amount of product for a desired purpose.
Fermentation procedures are well known in the art. Briefly, fermentation for the biosynthetic production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol can be utilized in, for example, fed-batch fermentation and batch separation; fed-batch fermentation and continuous separation, or continuous fermentation and continuous separation. Examples of batch and continuous fermentation procedures are well known in the art.
In addition to the above fermentation procedures using the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol producers for continuous production of substantial quantities of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol, the 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol producers also can be, for example, simultaneously subjected to chemical synthesis procedures to convert the product to other compounds or the product can be separated from the fermentation culture and sequentially subjected to chemical conversion to convert the product to other compounds, if desired.
To generate better producers, metabolic modeling can be utilized to optimize growth conditions. Modeling can also be used to design gene knockouts that additionally optimize utilization of the pathway (see, for example, U.S. Publ. Nos. 2002/0012939, 2003/0224363, 2004/0029149, 2004/0072723, 2003/0059792, 2002/0168654 and 2004/0009466, and U.S. Pat. No. 7,127,379). Modeling analysis allows reliable predictions of the effects on cell growth of shifting the metabolism towards more efficient production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol.
One computational method for identifying and designing metabolic alterations favoring biosynthesis of a desired product is the OptKnock computational framework (Burgard et al., Biotechnol. Bioeng. 84:647-657 (2003)). OptKnock is a metabolic modeling and simulation program that suggests gene deletion or disruption strategies that result in genetically stable microorganisms which overproduce the target product. Specifically, the framework examines the complete metabolic and/or biochemical network of a microorganism in order to suggest genetic manipulations that force the desired biochemical to become an obligatory byproduct of cell growth. By coupling biochemical production with cell growth through strategically placed gene deletions or other functional gene disruption, the growth selection pressures imposed on the engineered strains after long periods of time in a bioreactor lead to improvements in performance as a result of the compulsory growth-coupled biochemical production. Lastly, when gene deletions are constructed there is a negligible possibility of the designed strains reverting to their wild-type states because the genes selected by OptKnock are to be completely removed from the genome. Therefore, this computational methodology can be used to either identify alternative pathways that lead to biosynthesis of a desired product or used in connection with the non-naturally occurring microbial organisms for further optimization of biosynthesis of a desired product.
Briefly, OptKnock is a term used herein to refer to a computational method and system for modeling cellular metabolism. The OptKnock program relates to a framework of models and methods that incorporate particular constraints into flux balance analysis (FBA) models. These constraints include, for example, qualitative kinetic information, qualitative regulatory information, and/or DNA microarray experimental data. OptKnock also computes solutions to various metabolic problems by, for example, tightening the flux boundaries derived through flux balance models and subsequently probing the performance limits of metabolic networks in the presence of gene additions or deletions. OptKnock computational framework allows the construction of model formulations that allow an effective query of the performance limits of metabolic networks and provides methods for solving the resulting mixed-integer linear programming problems. The metabolic modeling and simulation methods referred to herein as OptKnock are described in, for example, U.S. Publ. No. 2002/0168654, International Patent Application No. PCT/US02/00660, and U.S. Publ. No. 2009/0047719.
Another computational method for identifying and designing metabolic alterations favoring biosynthetic production of a product is a metabolic modeling and simulation system termed SimPheny®. This computational method and system is described in, for example, U.S. Publ. No. 2003/0233218, and International Patent Application No. PCT/US03/18838. SimPheny® is a computational system that can be used to produce a network model in silico and to simulate the flux of mass, energy or charge through the chemical reactions of a biological system to define a solution space that contains any and all possible functionalities of the chemical reactions in the system, thereby determining a range of allowed activities for the biological system. This approach is referred to as constraints-based modeling because the solution space is defined by constraints such as the known stoichiometry of the included reactions as well as reaction thermodynamic and capacity constraints associated with maximum fluxes through reactions. The space defined by these constraints can be interrogated to determine the phenotypic capabilities and behavior of the biological system or of its biochemical components.
These computational approaches are consistent with biological realities because biological systems are flexible and can reach the same result in many different ways. Biological systems are designed through evolutionary mechanisms that have been restricted by fundamental constraints that all living systems must face. Therefore, constraints-based modeling strategy embraces these general realities. Further, the ability to continuously impose further restrictions on a network model via the tightening of constraints results in a reduction in the size of the solution space, thereby enhancing the precision with which physiological performance or phenotype can be predicted.
Given the teachings and guidance provided herein, those skilled in the art will be able to apply various computational frameworks for metabolic modeling and simulation to design and implement biosynthesis of a desired compound in host microbial organisms. Such metabolic modeling and simulation methods include, for example, the computational systems exemplified above as SimPheny® and OptKnock. For illustration of the invention, some methods are described herein with reference to the OptKnock computation framework for modeling and simulation. Those skilled in the art will know how to apply the identification, design and implementation of the metabolic alterations using OptKnock to any of such other metabolic modeling and simulation computational frameworks and methods well known in the art.
The methods described above will provide one set of metabolic reactions to disrupt. Elimination of each reaction within the set or metabolic modification can result in a desired product as an obligatory product during the growth phase of the organism. Because the reactions are known, a solution to the bilevel OptKnock problem also will provide the associated gene or genes encoding one or more enzymes that catalyze each reaction within the set of reactions. Identification of a set of reactions and their corresponding genes encoding the enzymes participating in each reaction is generally an automated process, accomplished through correlation of the reactions with a reaction database having a relationship between enzymes and encoding genes.
Once identified, the set of reactions that are to be disrupted in order to achieve production of a desired product are implemented in the target cell or organism by functional disruption of at least one gene encoding each metabolic reaction within the set. One particularly useful means to achieve functional disruption of the reaction set is by deletion of each encoding gene. However, in some instances, it can be beneficial to disrupt the reaction by other genetic aberrations including, for example, mutation, deletion of regulatory regions such as promoters or cis binding sites for regulatory factors, or by truncation of the coding sequence at any of a number of locations. These latter aberrations, resulting in less than total deletion of the gene set can be useful, for example, when rapid assessments of the coupling of a product are desired or when genetic reversion is less likely to occur.
To identify additional productive solutions to the above described bilevel OptKnock problem which lead to further sets of reactions to disrupt or metabolic modifications that can result in the biosynthesis, including growth-coupled biosynthesis of a desired product, an optimization method, termed integer cuts, can be implemented. This method proceeds by iteratively solving the OptKnock problem exemplified above with the incorporation of an additional constraint referred to as an integer cut at each iteration. Integer cut constraints effectively prevent the solution procedure from choosing the exact same set of reactions identified in any previous iteration that obligatorily couples product biosynthesis to growth. For example, if a previously identified growth-coupled metabolic modification specifies reactions 1, 2, and 3 for disruption, then the following constraint prevents the same reactions from being simultaneously considered in subsequent solutions. The integer cut method is well known in the art and can be found described in, for example, Burgard et al., Biotechnol. Prog. 17:791-797 (2001). As with all methods described herein with reference to their use in combination with the OptKnock computational framework for metabolic modeling and simulation, the integer cut method of reducing redundancy in iterative computational analysis also can be applied with other computational frameworks well known in the art including, for example, SimPheny®.
The methods exemplified herein allow the construction of cells and organisms that biosynthetically produce a desired product, including the obligatory coupling of production of a target biochemical product to growth of the cell or organism engineered to harbor the identified genetic alterations. Therefore, the computational methods described herein allow the identification and implementation of metabolic modifications that are identified by an in silico method selected from OptKnock or SimPheny®. The set of metabolic modifications can include, for example, addition of one or more biosynthetic pathway enzymes and/or functional disruption of one or more metabolic reactions including, for example, disruption by gene deletion.
As discussed above, the OptKnock methodology was developed on the premise that mutant microbial networks can be evolved towards their computationally predicted maximum-growth phenotypes when subjected to long periods of growth selection. In other words, the approach leverages an organism's ability to self-optimize under selective pressures. The OptKnock framework allows for the exhaustive enumeration of gene deletion combinations that force a coupling between biochemical production and cell growth based on network stoichiometry. The identification of optimal gene/reaction knockouts requires the solution of a bilevel optimization problem that chooses the set of active reactions such that an optimal growth solution for the resulting network overproduces the biochemical of interest (Burgard et al., Biotechnol. Bioeng. 84:647-657 (2003)).
An in silico stoichiometric model of E. coli metabolism can be employed to identify essential genes for metabolic pathways as exemplified previously and described in, for example, U.S. Publ. Nos. 2002/0012939, 2003/0224363, 2004/0029149, 2004/0072723, 2003/0059792, 2002/0168654 and 2004/0009466, and in U.S. Pat. No. 7,127,379. As disclosed herein, the OptKnock mathematical framework can be applied to pinpoint gene deletions leading to the growth-coupled production of a desired product. Further, the solution of the bilevel OptKnock problem provides only one set of deletions. To enumerate all meaningful solutions, that is, all sets of knockouts leading to growth-coupled production formation, an optimization technique, termed integer cuts, can be implemented. This entails iteratively solving the OptKnock problem with the incorporation of an additional constraint referred to as an integer cut at each iteration, as discussed above.
As disclosed herein, a nucleic acid encoding a desired activity of a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway, formaldehyde assimilation pathway, and/or methanol metabolic pathway can be introduced into a host organism. In some cases, it can be desirable to modify an activity of a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway, formaldehyde assimilation, or methanol metabolic pathway enzyme or protein to increase production of 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol; formaldehyde, and/or reducing equivalents. For example, known mutations that increase the activity of a protein or enzyme can be introduced into an encoding nucleic acid molecule. Additionally, optimization methods can be applied to increase the activity of an enzyme or protein and/or decrease an inhibitory activity, for example, decrease the activity of a negative regulator.
One such optimization method is directed evolution. Directed evolution is a powerful approach that involves the introduction of mutations targeted to a specific gene in order to improve and/or alter the properties of an enzyme. Improved and/or altered enzymes can be identified through the development and implementation of sensitive high-throughput screening assays that allow the automated screening of many enzyme variants (for example, >104). Iterative rounds of mutagenesis and screening typically are performed to afford an enzyme with optimized properties. Computational algorithms that can help to identify areas of the gene for mutagenesis also have been developed and can significantly reduce the number of enzyme variants that need to be generated and screened. Numerous directed evolution technologies have been developed (for reviews, see Hibbert et al., Biomol. Eng. 22:11-19 (2005); Huisman and Lalonde, In Biocatalysis in the pharmaceutical and biotechnology industries pgs. 717-742 (2007), Patel (ed.), CRC Press; Otten and Quax. Biomol. Eng. 22:1-9 (2005); and Sen et al., Appl Biochem. Biotechnol 143:212-223 (2007)) to be effective at creating diverse variant libraries, and these methods have been successfully applied to the improvement of a wide range of properties across many enzyme classes. Enzyme characteristics that have been improved and/or altered by directed evolution technologies include, for example: selectivity/specificity, for conversion of non-natural substrates; temperature stability, for robust high temperature processing; pH stability, for bioprocessing under lower or higher pH conditions; substrate or product tolerance, so that high product titers can be achieved; binding (Km), including broadening substrate binding to include non-natural substrates; inhibition (Ki), to remove inhibition by products, substrates, or key intermediates; activity (kcat), to increases enzymatic reaction rates to achieve desired flux; expression levels, to increase protein yields and overall pathway flux; oxygen stability, for operation of air sensitive enzymes under aerobic conditions; and anaerobic activity, for operation of an aerobic enzyme in the absence of oxygen.
A number of exemplary methods have been developed for the mutagenesis and diversification of genes to target desired properties of specific enzymes. Such methods are well known to those skilled in the art. Any of these can be used to alter and/or optimize the activity of a 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol pathway and/or a methanol metabolic pathway enzyme or protein. Such methods include, but are not limited to EpPCR, which introduces random point mutations by reducing the fidelity of DNA polymerase in PCR reactions (Pritchard et al., J. Theor. Biol. 234:497-509 (2005)); Error-prone Rolling Circle Amplification (epRCA), which is similar to epPCR except a whole circular plasmid is used as the template and random 6-mers with exonuclease resistant thiophosphate linkages on the last 2 nucleotides are used to amplify the plasmid followed by transformation into cells in which the plasmid is re-circularized at tandem repeats (Fujii et al., Nucleic Acids Res. 32:e145 (2004); and Fujii et al., Nat. Protocols 1:2493-2497 (2006)); DNA or Family Shuffling, which typically involves digestion of two or more variant genes with nucleases such as Dnase I or EndoV to generate a pool of random fragments that are reassembled by cycles of annealing and extension in the presence of DNA polymerase to create a library of chimeric genes (Stemmer, Proc. Natl. Acad. Sci. U.S.A. 91:10747-10751 (1994); and Stemmer, Nature 370:389-391 (1994)); Staggered Extension (StEP), which entails template priming followed by repeated cycles of 2 step PCR with denaturation and very short duration of annealing/extension (as short as 5 sec) (Zhao et al., Nat. Biotechnol. 16:258-261 (1998)); Random Priming Recombination (RPR), in which random sequence primers are used to generate many short DNA fragments complementary to different segments of the template (Shao et al., Nucleic Acids Res. 26:681-683 (1998)).
Additional methods include Heteroduplex Recombination, in which linearized plasmid DNA is used to form heteroduplexes that are repaired by mismatch repair (Volkov et al, Nucleic Acids Res. 27:e18 (1999); and Volkov et al., Methods Enzymol. 328:456-463 (2000)); Random Chimeragenesis on Transient Templates (RACHITT), which employs Dnase I fragmentation and size fractionation of single stranded DNA (ssDNA) (Coco et al., Nat. Biotechnol. 19:354-359 (2001)); Recombined Extension on Truncated templates (RETT), which entails template switching of unidirectionally growing strands from primers in the presence of unidirectional ssDNA fragments used as a pool of templates (Lee et al., J. Molec. Catalysis 26:119-129 (2003)); Degenerate Oligonucleotide Gene Shuffling (DOGS), in which degenerate primers are used to control recombination between molecules; (Bergquist and Gibbs, Methods Mol. Biol. 352:191-204 (2007); Bergquist et al., Biomol. Eng. 22:63-72 (2005); Gibbs et al., Gene 271:13-20 (2001)); Incremental Truncation for the Creation of Hybrid Enzymes (ITCHY), which creates a combinatorial library with 1 base pair deletions of a gene or gene fragment of interest (Ostermeier et al., Proc. Natl. Acad. Sci. U.S.A. 96:3562-3567 (1999); and Ostermeier et al., Nat. Biotechnol. 17:1205-1209 (1999)); Thio-Incremental Truncation for the Creation of Hybrid Enzymes (THIO-ITCHY), which is similar to ITCHY except that phosphothioate dNTPs are used to generate truncations (Lutz et al., Nucleic Acids Res. 29:E16 (2001)); SCRATCHY, which combines two methods for recombining genes, ITCHY and DNA shuffling (Lutz et al., Proc. Natl. Acad. Sci. U.S.A. 98:11248-11253 (2001)); Random Drift Mutagenesis (RNDM), in which mutations made via epPCR are followed by screening/selection for those retaining usable activity (Bergquist et al., Biomol. Eng. 22:63-72 (2005)); Sequence Saturation Mutagenesis (SeSaM), a random mutagenesis method that generates a pool of random length fragments using random incorporation of a phosphothioate nucleotide and cleavage, which is used as a template to extend in the presence of “universal” bases such as inosine, and replication of an inosine-containing complement gives random base incorporation and, consequently, mutagenesis (Wong et al., Biotechnol. J. 3:74-82 (2008); Wong et al., Nucleic Acids Res. 32:e26 (2004); and Wong et al., Anal. Biochem. 341:187-189 (2005)); Synthetic Shuffling, which uses overlapping oligonucleotides designed to encode “all genetic diversity in targets” and allows a very high diversity for the shuffled progeny (Ness et al., Nat. Biotechnol. 20:1251-1255 (2002)); Nucleotide Exchange and Excision Technology NexT, which exploits a combination of dUTP incorporation followed by treatment with uracil DNA glycosylase and then piperidine to perform endpoint DNA fragmentation (Muller et al., Nucleic Acids Res. 33:e117 (2005)).
Further methods include Sequence Homology-Independent Protein Recombination (SHIPREC), in which a linker is used to facilitate fusion between two distantly related or unrelated genes, and a range of chimeras is generated between the two genes, resulting in libraries of single-crossover hybrids (Sieber et al., Nat. Biotechnol. 19:456-460 (2001)); Gene Site Saturation MutagenesisTM (GSSMTTM), in which the starting materials include a supercoiled double stranded DNA (dsDNA) plasmid containing an insert and two primers which are degenerate at the desired site of mutations (Kretz et al., Methods Enzymol. 388:3-11 (2004)); Combinatorial Cassette Mutagenesis (CCM), which involves the use of short oligonucleotide cassettes to replace limited regions with a large number of possible amino acid sequence alterations (Reidhaar-Olson et al. Methods Enzymol. 208:564-586 (1991); and Reidhaar-Olson et al. Science 241:53-57 (1988)); Combinatorial Multiple Cassette Mutagenesis (CMCM), which is essentially similar to CCM and uses epPCR at high mutation rate to identify hot spots and hot regions and then extension by CMCM to cover a defined region of protein sequence space (Reetz et al., Angew. Chem. Int. Ed Engl. 40:3589-3591 (2001)); the Mutator Strains technique, in which conditional is mutator plasmids, utilizing the mutD5 gene, which encodes a mutant subunit of DNA polymerase III, to allow increases of 20 to 4000-X in random and natural mutation frequency during selection and block accumulation of deleterious mutations when selection is not required (Selifonova et al., Appl. Environ. Microbiol. 67:3645-3649 (2001)); Low et al., J. Mol. Biol. 260:359-3680 (1996)).
Additional exemplary methods include Look-Through Mutagenesis (LTM), which is a multidimensional mutagenesis method that assesses and optimizes combinatorial mutations of selected amino acids (Rajpal et al., Proc. Natl. Acad. Sci. U.S.A. 102:8466-8471 (2005)); Gene Reassembly, which is a DNA shuffling method that can be applied to multiple genes at one time or to create a large library of chimeras (multiple mutations) of a single gene (Tunable GeneReassemblyTM (TGRTM) Technology supplied by Verenium Corporation), in Silico Protein Design Automation (PDA), which is an optimization algorithm that anchors the structurally defined protein backbone possessing a particular fold, and searches sequence space for amino acid substitutions that can stabilize the fold and overall protein energetics, and generally works most effectively on proteins with known three-dimensional structures (Hayes et al., Proc. Natl. Acad. Sci. U.S.A. 99:15926-15931 (2002)); and Iterative Saturation Mutagenesis (ISM), which involves using knowledge of structure/function to choose a likely site for enzyme improvement, performing saturation mutagenesis at chosen site using a mutagenesis method such as Stratagene QuikChange (Stratagene; San Diego Calif.), screening/selecting for desired properties, and, using improved clone(s), starting over at another site and continue repeating until a desired activity is achieved (Reetz et al., Nat. Protocols 2:891-903 (2007); and Reetz et al., Angew. Chem. Int. Ed Engl. 45:7745-7751 (2006)).
Any of the aforementioned methods for mutagenesis can be used alone or in any combination. Additionally, any one or combination of the directed evolution methods can be used in conjunction with adaptive evolution techniques, as described herein.
Throughout this application various publications have been referenced. The disclosures of these publications in their entireties, including GenBank and GI number publications, are hereby incorporated by reference in this application in order to more fully describe the state of the art to which this invention pertains. Although the invention has been described with reference to the examples provided above, it should be understood that various modifications can be made without departing from the spirit of the invention.
It is understood that modifications which do not substantially affect the activity of the various embodiments of this invention are also included within the definition of the invention provided herein. Accordingly, the following examples are intended to illustrate but not limit the present invention.
4. EXAMPLES
4.1 Example I—Production of Reducing Equivalents Via a Methanol Metabolic Pathway
Exemplary methanol metabolic pathways are provided in FIG. 1.
FIG. 1, Step A—Methanol Methyltransferase
A complex of 3-methyltransferase proteins, denoted MtaA, MtaB, and MtaC, perform the desired methanol methyltransferase activity (Sauer et al., Eur. J. Biochem. 243:670-677 (1997); Naidu and Ragsdale, J. Bacteriol. 183:3276-3281 (2001); Tallant and Krzycki, J. Biol. Chem. 276:4485-4493 (2001); Tallant and Krzycki, J. Bacteriol. 179:6902-6911 (1997); Tallant and Krzycki, J. Bacteriol. 178:1295-1301 (1996); Ragsdale, S. W., Crit. Rev. Biochem. Mol. Biol. 39:165-195 (2004)).
MtaB is a zinc protein that can catalyze the transfer of a methyl group from methanol to MtaC, a corrinoid protein. Exemplary genes encoding MtaB and MtaC can be found in methanogenic archaea such as Methanosarcina barkeri (Maeder et al., J. Bacteriol. 188:7922-7931 (2006) and Methanosarcina acetivorans (Galagan et al., Genome Res. 12:532-542 (2002), as well as the acetogen, Moorella thermoacetica (Das et al., Proteins 67:167-176 (2007). In general, the MtaB and MtaC genes are adjacent to one another on the chromosome as their activities are tightly interdependent. The protein sequences of various MtaB and MtaC encoding genes in M. barkeri, M. acetivorans, and M. thermoaceticum can be identified by their following GenBank accession numbers.













Protein
GenBank ID
GI number
Organism







MtaB1
YP_304299
73668284
Methanosarcina barkeri


MtaC1
YP_304298
73668283
Methanosarcina barkeri


MtaB2
YP_307082
73671067
Methanosarcina barkeri


MtaC2
YP_307081
73671066
Methanosarcina barkeri


MtaB3
YP_304612
73668597
Methanosarcina barkeri


MtaC3
YP_304611
73668596
Methanosarcina barkeri


MtaB1
NP_615421
20089346
Methanosarcina acetivorans


MtaB1
NP_615422
20089347
Methanosarcina acetivorans


MtaB2
NP_619254
20093179
Methanosarcina acetivorans


MtaC2
NP_619253
20093178
Methanosarcina acetivorans


MtaB3
NP_616549
20090474
Methanosarcina acetivorans


MtaC3
NP_616550
20090475
Methanosarcina acetivorans


MtaB
YP_430066
83590057
Moorella thermoacetica


MtaC
YP_430065
83590056
Moorella thermoacetica


MtaA
YP_430064
83590056
Moorella thermoacetica









The MtaB1 and MtaC1 genes, YP_304299 and YP_304298, from M. barkeri were cloned into E. coli and sequenced (Sauer et al., Eur. J. Biochem. 243:670-677 (1997)). The crystal structure of this methanol-cobalamin methyltransferase complex is also available (Hagemeier et al., Proc. Natl. Acad. Sci. U.S.A. 103:18917-18922 (2006)). The MtaB genes, YP_307082 and YP_304612, in M. barkeri were identified by sequence homology to YP_304299. In general, homology searches are an effective means of identifying methanol methyltransferases because MtaB encoding genes show little or no similarity to methyltransferases that act on alternative substrates such as trimethylamine, dimethylamine, monomethylamine, or dimethylsulfide. The MtaC genes, YP_307081 and YP_304611 were identified based on their proximity to the MtaB genes and also their homology to YP_304298. The three sets of MtaB and MtaC genes from M. acetivorans have been genetically, physiologically, and biochemically characterized (Pritchett and Metcalf, Mol. Microhiol. 56:1183-1194 (2005)). Mutant strains lacking two of the sets were able to grow on methanol, whereas a strain lacking all three sets of MtaB and MtaC genes sets could not grow on methanol. This suggests that each set of genes plays a role in methanol utilization. The M. thermoacetica MtaB gene was identified based on homology to the methanogenic MtaB genes and also by its adjacent chromosomal proximity to the methanol-induced corrinoid protein, MtaC, which has been crystallized (Zhou et al., Acta Crystallogr. Sect. F. Struct. Biol. Cyrst. Commun. 61:537-540 (2005) and further characterized by Northern hybridization and Western Blotting ((Das et al., Proteins 67:167-176 (2007)).
MtaA is zinc protein that catalyzes the transfer of the methyl group from MtaC to either Coenzyme M in methanogens or methyltetrahydrofolate in acetogens. MtaA can also utilize methylcobalamin as the methyl donor. Exemplary genes encoding MtaA can be found in methanogenic archaea such as Methanosarcina barkeri (Maeder et al., J. Bacteriol. 188:7922-7931 (2006) and Methanosarcina acetivorans (Galagan et al., Genome Res. 12:532-542 (2002), as well as the acetogen, Moorella thermoacetica ((Das et al., Proteins 67:167-176 (2007)). In general, MtaA proteins that catalyze the transfer of the methyl group from CH3-MtaC are difficult to identify bioinformatically as they share similarity to other corrinoid protein methyltransferases and are not oriented adjacent to the MtaB and MtaC genes on the chromosomes. Nevertheless, a number of MtaA encoding genes have been characterized. The protein sequences of these genes in M. barkeri and M. acetivorans can be identified by the following GenBank accession numbers.













Protein
GenBank ID
GI number
Organism







MtaA
YP_304602
73668587
Methanosarcina barkeri


MtaA1
NP_619241
20093166
Methanosarcina acetivorans


MtaA2
NP_616548
20090473
Methanosarcina acetivorans









The MtaA gene, YP_304602, from M. barkeri was cloned, sequenced, and functionally overexpressed in E. coli (Harms and Thauer, Eur. J. Biochem. 235:653-659 (1996)). In M. acetivorans, MtaA1 is required for growth on methanol, whereas MtaA2 is dispensable even though methane production from methanol is reduced in MtaA2 mutants (Bose et al., J. Bacteriol. 190:4017-4026 (2008)). There are multiple additional MtaA homologs in M. barkeri and M. acetivorans that are as yet uncharacterized, but may also catalyze corrinoid protein methyltransferase activity.
Putative MtaA encoding genes in M. thermoacetica were identified by their sequence similarity to the characterized methanogenic MtaA genes. Specifically, three M. thermoacetica genes show high homology (>30% sequence identity) to YP_304602 from M. barkeri. Unlike methanogenic MtaA proteins that naturally catalyze the transfer of the methyl group from CH3-MtaC to Coenzyme M, an M. thermoacetica MtaA is likely to transfer the methyl group to methyltetrahydrofolate given the similar roles of methyltetrahydrofolate and Coenzyme M in methanogens and acetogens, respectively. The protein sequences of putative MtaA encoding genes from M. thermoacetica can be identified by the following Gen Bank accession numbers.













Protein
GenBank ID
GI number
Organism







MtaA
YP_430937
83590928
Moorella thermoacetica


MtaA
YP_431175
83591166
Moorella thermoacetica


MtaA
YP_430935
83590926
Moorella thermoacetica


MtaA
YP_430064
83590056
Moorella thermoacetica









FIG. 1, Step B—Methylenetetrahydrofolate Reductase

The conversion of methyl-THF to methylenetetrahydrofolate is catalyzed by methylenetetrahydrofolate reductase. In M. thermoacetica, this enzyme is oxygen-sensitive and contains an iron-sulfur cluster (Clark and Ljungdahl, J. Biol. Chem. 259:10845-10849 (1984). This enzyme is encoded by metF in E. coli (Sheppard et al., J. Bacteriol. 181:718-725 (1999) and CHY_1233 in C. hydrogenoformans (Wu et al., PLoS Genet. 1:e65 (2005). The M. thermoacetica genes, and its C. hydrogenoformans counterpart, are located near the CODH/ACS gene cluster, separated by putative hydrogenase and heterodisulfide reductase genes. Some additional gene candidates found bioinformatically are listed below. In Acetobacterium woodii metF is coupled to the Rnf complex through RnfC2 (Poehlein et al, PLoS One. 7:e33439). Homologs of RnfC are found in other organisms by blast search. The Rnf complex is known to be a reversible complex (Fuchs (2011) Annu. Rev. Microbiol. 65:631-658).













Protein
GenBank ID
GI number
Organism


















Moth_1191
YP_430048.1
83590039
Moorella thermoacetica


Moth_1192
YP_430049.1
83590040
Moorella thermoacetica


metF
NP_418376.1
16131779
Escherichia coli


CHY_1233
YP_360071.1
78044792
Carboxydothermus





hydrogenoformans


CLJU_c37610
YP_003781889.1
300856905
Clostridium ljungdahlii DSM





13528


DesfrDRAFT_3717
ZP_07335241.1
303248996
Desulfovibrio fructosovorans JJ


CcarbDRAFT_2950
ZP_05392950.1
255526026
Clostridium carboxidivorans





P7


Ccel74_010100023124
ZP_07633513.1
307691067
Clostridium cellulovorans





743B


Cphy_3110
YP_001560205.1
160881237
Clostridium





phytofermentans ISDg









FIG. 1, Steps C and D—Methylenetetrahydrofolate Dehydrogenase, Methenyltetrahydrofolate Cyclohydrolase

In M. thermoacetica, E. coli, and C. hydrogenoformans, methenyltetrahydrofolate cyclohydrolase and methylenetetrahydrofolate dehydrogenase are carried out by the bi-functional gene products of Moth_1516, folD, and CHY_1878, respectively (Pierce et al., Environ. Microbiol. 10:2550-2573 (2008); Wu et al., PLoS Genet. 1:e65 (2005); D'Ari and Rabinowitz, J. Biol. Chem. 266:23953-23958 (1991)). A homolog exists in C. carboxidivorans P7. Several other organisms also encode for this bifunctional protein as tabulated below.













Protein
GenBank ID
GI number
Organism


















Moth_1516
YP_430368.1
83590359
Moorella thermoacetica


folD
NP_415062.1
16128513
Escherichia coli


CHY_1878
YP_360698.1
78044829
Carboxydothermus





hydrogenoformans


CcarbDRAFT_2948
ZP_05392948.1
255526024
Clostridium carboxidivorans P7


folD
ADK16789.1
300437022
Clostridium ljungdahlii DSM





13528


folD-2
NP_951919.1
39995968
Geobacter sulfurreducens PCA


folD
YP_725874.1
113867385
Ralstonia eutropha H16


folD
NP_348702.1
15895353
Clostridium





acetobutylicum ATCC 824


folD
YP_696506.1
110800457
Clostridium perfringens


MGA3_09460
EIJ83438.1
387591119
Bacillus methanolicus MGA3


PB1_14689
ZP_10132349.1
387929672
Bacillus methanolicus PB1









FIG. 1, Step E—Formyltetrahydrofolate Deformylase

This enzyme catalyzes the hydrolysis of 10-formyltetrahydrofolate (formyl-THF) to THF and formate. In E. coli, this enzyme is encoded by purU and has been overproduced, purified, and characterized (Nagy, et al., J. Bacteriol. 3:1292-1298 (1995)). Homologs exist in Corynebacterium sp. U-96 (Suzuki, et al., Biosci. Biotechnol. Biochem. 69(5):952-956 (2005)), Corynebacterium glutamicum ATCC 14067, Salmonella enterica, and several additional organisms.













Protein
GenBank ID
GI number
Organism


















purU
AAC74314.1
1787483
Escherichia coli K-12 MG1655


purU
BAD97821.1
63002616
Corynebacterium sp. U-96


purU
EHE84645.1
354511740
Corynebacterium glutamicum





ATCC 14067


purU
NP_460715.1
16765100
Salmonella enterica subsp.





enterica serovar Typhimurium





str. LT2









FIG. 1, Step F—Formyltetrahydrofolate Synthetase

Formyltetrahydrofolate synthetase ligates formate to tetrahydrofolate at the expense of one ATP. This reaction is catalyzed by the gene product of Moth_0109 in M. thermoacetica (O'brien et al., Experientia Suppl. 26:249-262 (1976); Lovell et al., Arch. Microbiol. 149:280-285 (1988); Lovell et al., Biochemistry 29:5687-5694 (1990)), FHS in Clostridium acidurici (Whitehead and Rabinowitz, J. Bacteriol. 167:203-209 (1986); Whitehead and Rabinowitz, J. Bacteriol. 170:3255-3261 (1988), and CHY_2385 in C. hydrogenoformans (Wu et al., PLoS Genet. 1:e65 (2005). Homologs exist in C. carboxidivorans P7. This enzyme is found in several other organisms as listed below.













Protein
GenBank ID
GI number
Organism


















Moth_0109
YP_428991.1
83588982
Moorella thermoacetica


CHY_2385
YP_361182.1
78045024
Carboxydothermus





hydrogenoformans


FHS
P13419.1
120562
Clostridium acidurici


CcarbDRAFT_1913
ZP_05391913.1
255524966
Clostridium carboxidivorans P7


CcarbDRAFT_2946
ZP_05392946.1
255526022
Clostridium carboxidivorans P7


Dhaf_0555
ACL18622.1
219536883
Desulfitobacterium hafniense


Fhs
YP_001393842.1
153953077
Clostridium kluyveri DSM 555


Fhs
YP_003781893.1
300856909
Clostridium ljungdahlii DSM





13528


MGA3_08300
EIJ83208.1
387590889
Bacillus methanolicus MGA3


PB1_13509
ZP_10132113.1
387929436
Bacillus methanolicus PB1









FIG. 1, Step G—Formate Hydrogen Lyase

A formate hydrogen lyase enzyme can be employed to convert formate to carbon dioxide and hydrogen. An exemplary formate hydrogen lyase enzyme can be found in Escherichia coli. The E. coli formate hydrogen lyase consists of hydrogenase 3 and formate dehydrogenase-H (Maeda et al., Appl Microbiol Biotechnol 77:879-890 (2007)). It is activated by the gene product of fhlA. (Maeda et al., Appl Microbiol Biotechnol 77:879-890 (2007)). The addition of the trace elements, selenium, nickel and molybdenum, to a fermentation broth has been shown to enhance formate hydrogen lyase activity (Soini et al., Microb. Cell Fact. 7:26 (2008)). Various hydrogenase 3, formate dehydrogenase and transcriptional activator genes are shown below.













Protein
GenBank ID
GI number
Organism







hycA
NP_417205
16130632
Escherichia coli K-12 MG1655


hycB
NP_417204
16130631
Escherichia coli K-12 MG1655


hycC
NP_417203
16130630
Escherichia coli K-12 MG1655


hycD
NP_417202
16130629
Escherichia coli K-12 MG1655


hycE
NP_417201
16130628
Escherichia coli K-12 MG1655


hycF
NP_417200
16130627
Escherichia coli K-12 MG1655


hycG
NP_417199
16130626
Escherichia coli K-12 MG1655


hycH
NP_417198
16130625
Escherichia coli K-12 MG1655


hycI
NP_417197
16130624
Escherichia coli K-12 MG1655


fdhF
NP_418503
16131905
Escherichia coli K-12 MG1655


fhlA
NP_417211
16130638
Escherichia coli K-12 MG1655









A formate hydrogen lyase enzyme also exists in the hyperthermophilic archaeon, Thermococcus litoralis (Takacs et al., BMC. Microbiol 8:88 (2008)).
















Protein
GenBank ID
GI number
Organism





















mhyC
ABW05543
157954626
Thermococcus litoralis



mhyD
ABW05544
157954627
Thermococcus litoralis



mhyE
ABW05545
157954628
Thermococcus litoralis



myhF
ABW05546
157954629
Thermococcus litoralis



myhG
ABW05547
157954630
Thermococcus litoralis



myhH
ABW05548
157954631
Thermococcus litoralis



fdhA
AAB94932
2746736
Thermococcus litoralis



fdhB
AAB94931
157954625
Thermococcus litoralis










Additional formate hydrogen lyase systems have been found in Salmonella typhimurium, Klebsiella pneumoniae, Rhodospirillum rubrum, Methanobacterium formicicum (Vardar-Schara et al., Microbial Biotechnology 1:107-125 (2008)).
FIG. 1, Step H—Hydrogenase
Hydrogenase enzymes can convert hydrogen gas to protons and transfer electrons to acceptors such as ferredoxins, NAD+, or NADP+. Ralstonia eutropha H16 uses hydrogen as an energy source with oxygen as a terminal electron acceptor. Its membrane-bound uptake [NiFe]-hydrogenase is an “O2-tolerant” hydrogenase (Cracknell, et al. Proc Nat Acad Sci, 106(49) 20681-20686 (2009)) that is periplasmically-oriented and connected to the respiratory chain via a b-type cytochrome (Schink and Schlegel, Biochim. Biophys. Acta, 567, 315-324 (1979); Bernhard et al., Eur. J. Biochem. 248, 179-186 (1997)). R. eutropha also contains an O2-tolerant soluble hydrogenase encoded by the Hox operon which is cytoplasmic and directly reduces NAD+ at the expense of hydrogen (Schneider and Schlegel, Biochim. Biophys. Acta 452, 66-80 (1976); Burgdorf, J. Bact. 187(9) 3122-3132 (2005)). Soluble hydrogenase enzymes are additionally present in several other organisms including Geobacter sulfurreducens (Coppi, Microbiology 151, 1239-1254 (2005)), Synechocystis str. PCC 6803 (Germer, J. Biol. Chem., 284(52), 36462-36472 (2009)), and Thiocapsa roseopersicina (Rakhely, Appl. Environ. Microbiol. 70(2) 722-728 (2004)). The Synechocystis enzyme is capable of generating NADPH from hydrogen. Overexpression of both the Hox operon from Synechocystis str. PCC 6803 and the accessory genes encoded by the Hyp operon from Nostoc sp. PCC 7120 led to increased hydrogenase activity compared to expression of the Hox genes alone (Germer, J. Biol. Chem. 284(52), 36462-36472 (2009)).













Protein
GenBank ID
GI Number
Organism







HoxF
NP_942727.1
38637753
Ralstonia eutropha H16


HoxU
NP_942728.1
38637754
Ralstonia eutropha H16


HoxY
NP_942729.1
38637755
Ralstonia eutropha H16


HoxH
NP_942730.1
38637756
Ralstonia eutropha H16


HoxW
NP_942731.1
38637757
Ralstonia eutropha H16


HoxI
NP_942732.1
38637758
Ralstonia eutropha H16


HoxE
NP_953767.1
39997816
Geobacter sulfurreducens


HoxF
NP_953766.1
39997815
Geobacter sulfurreducens


HoxU
NP_953765.1
39997814
Geobacter sulfurreducens


HoxY
NP_953764.1
39997813
Geobacter sulfurreducens


HoxH
NP_953763.1
39997812
Geobacter sulfurreducens


GSU2717
NP_953762.1
39997811
Geobacter sulfurreducens


HoxE
NP_441418.1
16330690
Synechocystis str. PCC 6803


HoxF
NP_441417.1
16330689
Synechocystis str. PCC 6803


Unknown
NP_441416.1
16330688
Synechocystis str. PCC 6803


function


HoxU
NP_441415.1
16330687
Synechocystis str. PCC 6803


HoxY
NP_441414.1
16330686
Synechocystis str. PCC 6803


Unknown
NP_441413.1
16330685
Synechocystis str. PCC 6803


function


Unknown
NP_441412.1
16330684
Synechocystis str. PCC 6803


function


HoxH
NP_441411.1
16330683
Synechocystis str. PCC 6803


HypF
NP_484737.1
17228189
Nostoc sp. PCC 7120


HypC
NP_484738.1
17228190
Nostoc sp. PCC 7120


HypD
NP_484739.1
17228191
Nostoc sp. PCC 7120


Unknown
NP_484740.1
17228192
Nostoc sp. PCC 7120


function


HypE
NP_484741.1
17228193
Nostoc sp. PCC 7120


HypA
NP_484742.1
17228194
Nostoc sp. PCC 7120


HypB
NP_484743.1
17228195
Nostoc sp. PCC 7120


Hox1E
AAP50519.1
37787351
Thiocapsa roseopersicina


Hox1F
AAP50520.1
37787352
Thiocapsa roseopersicina


Hox1U
AAP50521.1
37787353
Thiocapsa roseopersicina


Hox1Y
AAP50522.1
37787354
Thiocapsa roseopersicina


Hox1H
AAP50523.1
37787355
Thiocapsa roseopersicina









The genomes of E. coli and other enteric bacteria encode up to four hydrogenase enzymes (Sawers, G., Antonie Van Leeuwenhoek 66:57-88 (1994); Sawers et al., J Bacteriol. 164:1324-1331 (1985); Sawers and Boxer, Eur. J Biochem. 156:265-275 (1986); Sawers et al., J Bacteriol. 168:398-404 (1986)). Given the multiplicity of enzyme activities E. coli or another host organism can provide sufficient hydrogenase activity to split incoming molecular hydrogen and reduce the corresponding acceptor. Endogenous hydrogen-lyase enzymes of E. coli include hydrogenase 3, a membrane-bound enzyme complex using ferredoxin as an acceptor, and hydrogenase 4 that also uses a ferredoxin acceptor. Hydrogenase 3 and 4 are encoded by the hyc and hyf gene clusters, respectively. Hydrogenase activity in E. coli is also dependent upon the expression of the hyp genes whose corresponding proteins are involved in the assembly of the hydrogenase complexes (Jacobi et al., Arch. Microbiol 158:444-451 (1992); Rangarajan et al., J Bacteriol. 190:1447-1458 (2008)). The M. thermoacetica and Clostridium ljungdahli hydrogenases are suitable for a host that lacks sufficient endogenous hydrogenase activity. M. thermoacetica and C. ljungdahli can grow with CO2 as the exclusive carbon source indicating that reducing equivalents are extracted from H2 to enable acetyl-CoA synthesis via the Wood-Ljungdahl pathway (Drake, H. L., J Bacteriol. 150:702-709 (1982); Drake and Daniel, Res Microbiol 155:869-883 (2004); Kellum and Drake, J Bacteriol. 160:466-469 (1984)). M. thermoacetica has homologs to several hyp, hyc, and hyf genes from E. coli. These protein sequences encoded for by these genes are identified by the following GenBank accession numbers. In addition, several gene clusters encoding hydrogenase functionality are present in M. thermoacetica and C. ljungdahli (see for example US 2012/0003652).
















Protein
GenBank ID
GI Number
Organism





















HypA
NP_417206
16130633
Escherichia coli



HypB
NP_417207
16130634
Escherichia coli



HypC
NP_417208
16130635
Escherichia coli



HypD
NP_417209
16130636
Escherichia coli



HypE
NP_417210
226524740
Escherichia coli



HypF
NP_417192
16130619
Escherichia coli



HycA
NP_417205
16130632
Escherichia coli



HycB
NP_417204
16130631
Escherichia coli



HycC
NP_417203
16130630
Escherichia coli



HycD
NP_417202
16130629
Escherichia coli



HycE
NP_417201
16130628
Escherichia coli



HycF
NP_417200
16130627
Escherichia coli



HycG
NP_417199
16130626
Escherichia coli



HycH
NP_417198
16130625
Escherichia coli



HycI
NP_417197
16130624
Escherichia coli



HyfA
NP_416976
90111444
Escherichia coli



HyfB
NP_416977
16130407
Escherichia coli



HyfC
NP_416978
90111445
Escherichia coli



HyfD
NP_416979
16130409
Escherichia coli



HyfE
NP_416980
16130410
Escherichia coli



HyfF
NP_416981
16130411
Escherichia coli



HyfG
NP_416982
16130412
Escherichia coli



HyfH
NP_416983
16130413
Escherichia coli



HyfI
NP_416984
16130414
Escherichia coli



HyfJ
NP_416985
90111446
Escherichia coli



HyfR
NP_416986
90111447
Escherichia coli










Proteins in M. thermoacetica whose genes are homologous to the E. coli hydrogenase genes are shown below.













Protein
GenBank ID
GI Number
Organism







Moth_2175
YP_431007
83590998
Moorella thermoacetica


Moth_2176
YP_431008
83590999
Moorella thermoacetica


Moth_2177
YP_431009
83591000
Moorella thermoacetica


Moth_2178
YP_431010
83591001
Moorella thermoacetica


Moth_2179
YP_431011
83591002
Moorella thermoacetica


Moth_2180
YP_431012
83591003
Moorella thermoacetica


Moth_2181
YP_431013
83591004
Moorella thermoacetica


Moth_2182
YP_431014
83591005
Moorella thermoacetica


Moth_2183
YP_431015
83591006
Moorella thermoacetica


Moth_2184
YP_431016
83591007
Moorella thermoacetica


Moth_2185
YP_431017
83591008
Moorella thermoacetica


Moth_2186
YP_431018
83591009
Moorella thermoacetica


Moth_2187
YP_431019
83591010
Moorella thermoacetica


Moth_2188
YP_431020
83591011
Moorella thermoacetica


Moth_2189
YP_431021
83591012
Moorella thermoacetica


Moth_2190
YP_431022
83591013
Moorella thermoacetica


Moth_2191
YP_431023
83591014
Moorella thermoacetica


Moth_2192
YP_431024
83591015
Moorella thermoacetica


Moth_0439
YP_429313
83589304
Moorella thermoacetica


Moth_0440
YP_429314
83589305
Moorella thermoacetica


Moth_0441
YP_429315
83589306
Moorella thermoacetica


Moth_0442
YP_429316
83589307
Moorella thermoacetica


Moth_0809
YP_429670
83589661
Moorella thermoacetica


Moth_0810
YP_429671
83589662
Moorella thermoacetica


Moth_0811
YP_429672
83589663
Moorella thermoacetica


Moth_0812
YP_429673
83589664
Moorella thermoacetica


Moth_0814
YP_429674
83589665
Moorella thermoacetica


Moth_0815
YP_429675
83589666
Moorella thermoacetica


Moth_0816
YP_429676
83589667
Moorella thermoacetica


Moth_1193
YP_430050
83590041
Moorella thermoacetica


Moth_1194
YP_430051
83590042
Moorella thermoacetica


Moth_1195
YP_430052
83590043
Moorella thermoacetica


Moth_1196
YP_430053
83590044
Moorella thermoacetica


Moth_1717
YP_430562
83590553
Moorella thermoacetica


Moth_1718
YP_430563
83590554
Moorella thermoacetica


Moth_1719
YP_430564
83590555
Moorella thermoacetica


Moth_1883
YP_430726
83590717
Moorella thermoacetica


Moth_1884
YP_430727
83590718
Moorella thermoacetica


Moth_1885
YP_430728
83590719
Moorella thermoacetica


Moth_1886
YP_430729
83590720
Moorella thermoacetica


Moth_1887
YP_430730
83590721
Moorella thermoacetica


Moth_1888
YP_430731
83590722
Moorella thermoacetica


Moth_1452
YP_430305
83590296
Moorella thermoacetica


Moth_1453
YP_430306
83590297
Moorella thermoacetica


Moth_1454
YP_430307
83590298
Moorella thermoacetica









Genes encoding hydrogenase enzymes from C. ljungdahli are shown below.













Protein
GenBank ID
GI Number
Organism







CLJU_c20290
ADK15091.1
300435324
Clostridium ljungdahli


CLJU_c07030
ADK13773.1
300434006
Clostridium ljungdahli


CLJU_c07040
ADK13774.1
300434007
Clostridium ljungdahli


CLJU_c07050
ADK13775.1
300434008
Clostridium jungdahli


CLJU_c07060
ADK13776.1
300434009
Clostridium ljungdahli


CLJU_c07070
ADK13777.1
300434010
Clostridium ljungdahli


CLJU_c07080
ADK13778.1
300434011
Clostridium ljungdahli


CLJU_c14730
ADK14541.1
300434774
Clostridium ljungdahli


CLJU_c14720
ADK14540.1
300434773
Clostridium ljungdahli


CLJU_c14710
ADK14539.1
300434772
Clostridium ljungdahli


CLJU_c14700
ADK14538.1
300434771
Clostridium ljungdahli


CLJU_c28670
ADK15915.1
300436148
Clostridium ljungdahli


CLJU_c28660
ADK15914.1
300436147
Clostridium ljungdahli


CLJU_c28650
ADK15913.1
300436146
Clostridium ljungdahli


CLJU_c28640
ADK15912.1
300436145
Clostridium ljungdahli









In some cases, hydrogenase encoding genes are located adjacent to a CODH. In Rhodospirillum rubrum, the encoded CODH/hydrogenase proteins form a membrane-bound enzyme complex that has been indicated to be a site where energy, in the form of a proton gradient, is generated from the conversion of CO and H2O to CO2 and H2 (Fox et al., J Bacteriol. 178:6200-6208 (1996)). The CODH-I of C. hydrogenoformans and its adjacent genes have been proposed to catalyze a similar functional role based on their similarity to the R. rubrum CODH/hydrogenase gene cluster (Wu et al., PLoS Genet. 1:e65 (2005)). The C. hydrogenoformans CODH-I was also shown to exhibit intense CO oxidation and CO2 reduction activities when linked to an electrode (Parkin et al., J Am. Chem. Soc. 129:10328-10329 (2007)).













Protein
GenBank ID
GI Number
Organism


















CooL
AAC45118
1515468
Rhodospirillum rubrum


CooX
AAC45119
1515469
Rhodospirillum rubrum


CooU
AAC45120
1515470
Rhodospirillum rubrum


CooH
AAC45121
1498746
Rhodospirillum rubrum


CooF
AAC45122
1498747
Rhodospirillum rubrum


CODH (CooS)
AAC45123
1498748
Rhodospirillum rubrum


CooC
AAC45124
1498749
Rhodospirillum rubrum


CooT
AAC45125
1498750
Rhodospirillum rubrum


CooJ
AAC45126
1498751
Rhodospirillum rubrum


CODH-I (CooS-I)
YP_360644
78043418
Carboxydothermus hydrogenoformans


CooF
YP_360645
78044791
Carboxydothermus hydrogenoformans


HypA
YP_360646
78044340
Carboxydothermus hydrogenoformans


CooH
YP_360647
78043871
Carboxydothermus hydrogenoformans


CooU
YP_360648
78044023
Carboxydothermus hydrogenoformans


CooX
YP_360649
78043124
Carboxydothermus hydrogenoformans


CooL
YP_360650
78043938
Carboxydothermus hydrogenoformans


CooK
YP_360651
78044700
Carboxydothermus hydrogenoformans


CooM
YP_360652
78043942
Carboxydothermus hydrogenoformans


CooC
YP_360654.1
78043296
Carboxydothermus hydrogenoformans


CooA-1
YP_360655.1
78044021
Carboxydothermus hydrogenoformans









Some hydrogenase and CODH enzymes transfer electrons to ferredoxins. Ferredoxins are small acidic proteins containing one or more iron-sulfur clusters that function as intracellular electron carriers with a low reduction potential. Reduced ferredoxins donate electrons to Fe-dependent enzymes such as ferredoxin-NADP+ oxidoreductase, pyruvate:ferredoxin oxidoreductase (PFOR) and 2-oxoglutarate:ferredoxin oxidoreductase (OFOR). The H. thermophilus gene fdx1 encodes a [4Fe-4S]-type ferredoxin that is required for the reversible carboxylation of 2-oxoglutarate and pyruvate by OFOR and PFOR, respectively (Yamamoto et al., Extremophiles 14:79-85 (2010)). The ferredoxin associated with the Sulfolobus solfataricus 2-oxoacid:ferredoxin reductase is a monomeric dicluster [3Fe-4S][4Fe-4S] type ferredoxin (Park et al. 2006). While the gene associated with this protein has not been fully sequenced, the N-terminal domain shares 93% homology with the zfx ferredoxin from S. acidocaldarius. The E. coli genome encodes a soluble ferredoxin of unknown physiological function, fdx. Some evidence indicates that this protein can function in iron-sulfur cluster assembly (Takahashi and Nakamura, 1999). Additional ferredoxin proteins have been characterized in Helicobacter pylori (Mukhopadhyay et al. 2003) and Campylobacter jejuni (van Vliet et al. 2001). A 2Fe-2S ferredoxin from Clostridium pasteurianum has been cloned and expressed in E. coli (Fujinaga and Meyer, Biochemical and Biophysical Research Communications, 192(3): (1993)). Acetogenic bacteria such as Moorella thermoacetica, Clostridium carboxidivorans P7. Clostridium ljungdahli and Rhodospirillum rubrum are predicted to encode several ferredoxins, listed below.













Protein
GenBank ID
GI Number
Organism


















fdx1
BAE02673.1
68163284
Hydrogenobacter thermophilus


M11214.1
AAA83524.1
144806
Clostridium pasteurianum


Zfx
AAY79867.1
68566938
Sulfolobus acidocalarius


Fdx
AAC75578.1
1788874
Escherichia coli


hp_0277
AAD07340.1
2313367
Helicobacter pylori


fdxA
CAL34484.1
112359698
Campylobacter jejuni


Moth_0061
ABC18400.1
83571848
Moorella thermoacetica


Moth_1200
ABC19514.1
83572962
Moorella thermoacetica


Moth_1888
ABC20188.1
83573636
Moorella thermoacetica


Moth_2112
ABC20404.1
83573852
Moorella thermoacetica


Moth_1037
ABC19351.1
83572799
Moorella thermoacetica


CcarbDRAFT_4383
ZP_05394383.1
255527515
Clostridium carboxidivorans P7


CcarbDRAFT_2958
ZP_05392958.1
255526034
Clostridium carboxidivorans P7


CcarbDRAFT_2281
ZP_05392281.1
255525342
Clostridium carboxidivorans P7


CcarbDRAFT_5296
ZP_05395295.1
255528511
Clostridium carboxidivorans P7


CcarbDRAFT_1615
ZP_05391615.1
255524662
Clostridium carboxidivorans P7


CcarbDRAFT_1304
ZP_05391304.1
255524347
Clostridium carboxidivorans P7


cooF
AAG29808.1
11095245
Carboxydothermus hydrogenoformans


fdxN
CAA35699.1
46143
Rhodobacter capsulatus


Rru_A2264
ABC23064.1
83576513
Rhodospirillum rubrum


Rru_A1916
ABC22716.1
83576165
Rhodospirillum rubrum


Rru_A2026
ABC22826.1
83576275
Rhodospirillum rubrum


cooF
AAC45122.1
1498747
Rhodospirillum rubrum


fdxN
AAA26460.1
152605
Rhodospirillum rubrum


Alvin_2884
ADC63789.1
288897953
Allochromatium vinosum DSM 180


Fdx
YP_002801146.1
226946073
Azotobacter vinelandii DJ


CKL_3790
YP_001397146.1
153956381
Clostridium kluyveri DSM 555


fer1
NP_949965.1
39937689
Rhodopseudomonas palustris CGA009


Fdx
CAA12251.1
3724172
Thauera aromatica


CHY_2405
YP_361202.1
78044690
Carboxydothermus hydrogenoformans


Fer
YP_359966.1
78045103
Carboxydothermus hydrogenoformans


Fer
AAC83945.1
1146198
Bacillus subtilis


fdx1
NP_249053.1
15595559
Pseudomonas aeruginosa PA01


yfhL
AP_003148.1
89109368
Escherichia coli K-12


CLJU_c00930
ADK13195.1
300433428
Clostridium ljungdahli


CLJU_c00010
ADK13115.1
300433348
Clostridium ljungdahli


CLJU_c01820
ADK13272.1
300433505
Clostridium ljungdahli


CLJU_c17980
ADK14861.1
300435094
Clostridium ljungdahli


CLJU_c17970
ADK14860.1
300435093
Clostridium ljungdahli


CLJU_c22510
ADK15311.1
300435544
Clostridium ljungdahli


CLJU_c26680
ADK15726.1
300435959
Clostridium ljungdahli


CLJU_c29400
ADK15988.1
300436221
Clostridium ljungdahli









Ferredoxin oxidoreductase enzymes transfer electrons from ferredoxins or flavodoxins to NAD(P)H. Two enzymes catalyzing the reversible transfer of electrons from reduced ferredoxins to NAD(P)+ are ferredoxin:NAD+ oxidoreductase (EC 1.18.1.3) and ferredoxin:NADP+ oxidoreductase (FNR, EC 1.18.11). Ferredoxin:NADP+ oxidoreductase (FNR, EC 1.18.1.2) has a noncovalently bound FAD cofactor that facilitates the reversible transfer of electrons from NADPH to low-potential acceptors such as ferredoxins or flavodoxins (Blaschkowski et al., Eur. J. Biochem. 123:563-569 (1982); Fujii et al., 1977). The Helicobacter pylori FNR, encoded by HP1164 (fqrB), is coupled to the activity of pyruvate:ferredoxin oxidoreductase (PFOR) resulting in the pyruvate-dependent production of NADPH (St et al. 2007). An analogous enzyme is found in Campylobacter jejuni (St Maurice et al., J. Bacteriol. 189:4764-4773 (2007)). A ferredoxin:NADP+ oxidoreductase enzyme is encoded in the E. coli genome by fpr (Bianchi et al. 1993). Ferredoxin:NAD+ oxidoreductase utilizes reduced ferredoxin to generate NADH from NAD+. In several organising, including E. coli, this enzyme is a component of multifunctional dioxygenase enzyme complexes. The ferredoxin:NAD+ oxidoreductase of E. coli, encoded by hcaD, is a component of the 3-phenylproppionate dioxygenase system involved in involved in aromatic acid utilization (Diaz et al. 1998). NADH:ferredoxin reductase activity was detected in cell extracts of Hydrogenobacter thermophilus, although a gene with this activity has not yet been indicated (Yoon et al. 2006). Additional ferredoxin:NAD(P)+ oxidoreductases have been annotated in Clostridium carboxydivorans P7. The NADH-dependent reduced ferredoxin: NADP oxidoreductase of C. kluyveri, encoded by nfnAB, catalyzes the concomitant reduction of ferredoxin and NAD+ with two equivalents of NADPH (Wang et al, J Bacteriol 192: 5115-5123 (2010)). Finally, the energy-conserving membrane-associated Rnf-type proteins (Seedorf et al, PNAS 105:2128-2133 (2008); and Herrmann, J. Bacteriol 190:784-791 (2008)) provide a means to generate NADH or NADPH from reduced ferredoxin.













Protein
GenBank ID
GI Number
Organism


















fqrB
NP_207955.1
15645778
Helicobacter pylori


fqrB
YP_001482096.1
157414840
Campylobacter jejuni


RPA3954
CAE29395.1
39650872
Rhodopseudomonas palustris


Fpr
BAH29712.1
225320633
Hydrogenobacter thermophilus


yumC
NP_391091.2
255767736
Bacillus subtilis


Fpr
P28861.4
399486
Escherichia coli


hcaD
AAC75595.1
1788892
Escherichia coli


LOC100282643
NP_001149023.1
226497434
Zea mays


NfnA
YP_001393861.1
153953096
Clostridium kluyveri


NfnB
YP_001393862.1
153953097
Clostridium kluyveri


CcarbDRAFT_2639
ZP_05392639.1
255525707
Clostridium carboxidivorans P7


CcarbDRAFT_2638
ZP_05392638.1
255525706
Clostridium carboxidivorans P7


CcarbDRAFT_2636
ZP_05392636.1
255525704
Clostridium carboxidivorans P7


CcarbDRAFT_5060
ZP_05395060.1
255528241
Clostridium carboxidivorans P7


CcarbDRAFT_2450
ZP_05392450.1
255525514
Clostridium carboxidivorans P7


CcarbDRAFT_1084
ZP_05391084.1
255524124
Clostridium carboxidivorans P7


RnfC
EDK33306.1
146346770
Clostridium kluyveri


RnfD
EDK33307.1
146346771
Clostridium kluyveri


RnfG
EDK33308.1
146346772
Clostridium kluyveri


RnfE
EDK33309.1
146346773
Clostridium kluyveri


RnfA
EDK33310.1
146346774
Clostridium kluyveri


RnfB
EDK33311.1
146346775
Clostridium kluyveri


CLJU_c11410 (RnfB)
ADK14209.1
300434442
Clostridium ljungdahlii


CLJU_c11400 (RnfA)
ADK14208.1
300434441
Clostridium ljungdahlii


CLJU_c11390 (RnfE)
ADK14207.1
300434440
Clostridium ljungdahlii


CLJU_c11380 (RnfG)
ADK14206.1
300434439
Clostridium ljungdahlii


CLJU_c11370 (RnfD)
ADK14205.1
300434438
Clostridium ljungdahlii


CLJU_c11360 (RnfC)
ADK14204.1
300434437
Clostridium ljungdahlii


MOTH_1518 (NfnA)
YP_430370.1
83590361
Moorella thermoacetica


MOTH_1517(NfnB)
YP_430369.1
83590360
Moorella thermoacetica


CHY_1992 (NfnA)
YP_360811.1
78045020
Carboxydothermus





hydrogenoformans


CHY_1993 (NfnB)
YP_360812.1
78044266
Carboxydothermus





hydrogenoformans


CLJU_c37220 (NfnAB)
YP_003781850.1
300856866
Clostridium ljungdahlii









FIG. 1, Step I—Formate Dehydrogenase

Formate dehydrogenase (FDH) catalyzes the reversible transfer of electrons from formate to an acceptor. Enzymes with FDH activity utilize various electron carriers such as, for example, NADH (EC 1.2.1.2), NADPH (EC 1.2.1.43), quinols (EC 1.1.5.6), cytochromes (EC 1.2.2.3) and hydrogenases (EC 1.1.99.33). FDH enzymes have been characterized from Moorella thermoacetica (Andreesen and Ljungdahl, J Bacteriol 116:867-873 (1973); Li et al., J Bacteriol 92:405-412 (1966); Yamamoto et al., J Biol Chem. 258:1826-1832 (1983). The loci, Moth_2312 is responsible for encoding the alpha subunit of formate dehydrogenase while the beta subunit is encoded by Moth_2314 (Pierce et al., Environ Microbiol (2008)). Another set of genes encoding formate dehydrogenase activity with a propensity for CO2 reduction is encoded by Sfum_2703 through Sfum 2706 in Syntrophobacter fumaroxidans (de Bok et al., Eur J Biochem. 270:2476-2485 (2003)); Reda et al., PNAS 105:10654-10658 (2008)). A similar set of genes presumed to carry out the same function are encoded by CHY_0731, CHY_0732, and CHY_0733 in C. hydrogenoformans (Wu et al., PLoS Genet. 1:e65 (2005)). Formate dehydrogenases are also found many additional organisms including C. carboxidivorans P7, Bacillus methanolicus, Burkholderia stabilis, Moorella thermoacetica ATCC 39073, Candida boidinii, Candida methylica, and Saccharomyces cerevisiae S288c. The soluble formate dehydrogenase from Ralstonia eutropha reduces NAD+ (fdsG, -B, -A, -C, -D) (Oh and Bowien, 1998)













Protein
GenBank ID
GI Number
Organism


















Moth_2312
YP_431142
148283121
Moorella thermoacetica


Moth_2314
YP_431144
83591135
Moorella thermoacetica


Sfum_2703
YP_846816.1
116750129
Syntrophobacter fumaroxidans


Sfum_2704
YP_846817.1
116750130
Syntrophobacter fumaroxidans


Sfum_2705
YP_846818.1
116750131
Syntrophobacter fumaroxidans


Sfum_2706
YP_846819.1
116750132
Syntrophobacter fumaroxidans


CHY_0731
YP_359585.1
78044572
Carboxydothermus hydrogenoformans


CHY_0732
YP_359586.1
78044500
Carboxydothermus hydrogenoformans


CHY_0733
YP_359587.1
78044647
Carboxydothermus hydrogenoformans


CcarbDRAFT_0901
ZP_05390901.1
255523938
Clostridium carboxidivorans P7


CcarbDRAFT_4380
ZP_05394380.1
255527512
Clostridium carboxidivorans P7


fdhA, MGA3_06625
EIJ82879.1
387590560
Bacillus methanolicus MGA3


fdhA, PB1_11719
ZP_10131761.1
387929084
Bacillus methanolicus PB1


fdhD, MGA3_06630
EIJ82880.1
387590561
Bacillus methanolicus MGA3


fdhD, PB1_11724
ZP_10131762.1
387929085
Bacillus methanolicus PB1


fdh
ACF35003.
194220249
Burkholderia stabilis


FDH1
AAC49766.1
2276465
Candida boidinii


Fdh
CAA57036.1
1181204
Candida methylica


FDH2
P0CF35.1
294956522
Saccharomyces cerevisiae S288c


FDH1
NP_015033.1
6324964
Saccharomyces cerevisiae S288c









FIG. 1, Step J—Methanol Dehydrogenase

NAD+ dependent methanol dehydrogenase enzymes (EC 1.1.1.244) catalyze the conversion of methanol and NAD+ to formaldehyde and NADH. An enzyme with this activity was first characterized in Bacillus methanolicus (Heggeset, et al., Applied and Environmental Microbiology, 78(15):5170-5181 (2012)). This enzyme is zinc and magnesium dependent, and activity of the enzyme is enhanced by the activating enzyme encoded by act (Kloosterman et al, J Biol Chem 277:34785-92 (2002)). Additional NAD(P)+ dependent enzymes can be identified by sequence homology. Methanol dehydrogenase enzymes utilizing different electron acceptors are also known in the art. Examples include cytochrome dependent enzymes such as mxaIF of the methylotroph Methylobacterium extorquens (Nunn et al, Nucl Acid Res 16:7722 (1988)). Methanol dehydrogenase enzymes of methanotrophs such as Methylococcus capsulatis function in a complex with methane monooxygenase (MMO) (Myronova et al, Biochem 45:11905-14 (2006)). Methanol can also be oxidized to formaldehyde by alcohol oxidase enzymes such as methanol oxidase (EC 1.1.3.13) of Candida boidinii (Sakai et al, Gene 114: 67-73 (1992)).













Protein
GenBank ID
GI Number
Organism


















mdh, MGA3_17392
EIJ77596.1
387585261
Bacillus methanolicus MGA3


mdh2, MGA3_07340
EIJ83020.1
387590701
Bacillus methanolicus MGA3


mdh3, MGA3_10725
EIJ80770.1
387588449
Bacillus methanolicus MGA3


act, MGA3_09170
EIJ83380.1
387591061
Bacillus methanolicus MGA3


mdh, PB1_17533
ZP_10132907.1
387930234
Bacillus methanolicus PB1


mdh1, PB1_14569
ZP_10132325.1
387929648
Bacillus methanolicus PB1


mdh2, PB1_12584
ZP_10131932.1
387929255
Bacillus methanolicus PB1


act, PB1_14394
ZP_10132290.1
387929613
Bacillus methanolicus PB1


BFZC1_05383
ZP_07048751.1
299535429
Lysinibacillus fusiformis


BFZC1_20163
ZP_07051637.1
299538354
Lysinibacillus fusiformis


Bsph_4187
YP_001699778.1
169829620
Lysinibacillus sphaericus


Bsph_1706
YP_001697432.1
169827274
Lysinibacillus sphaericus


MCA0299
YP_112833.1
53802410
Methylococcus capsulatis


MCA0782
YP_113284.1
53804880
Methylococcus capsulatis


mxaI
YP_002965443.1
240140963
Methylobacterium extorquens


mxaF
YP_002965446.1
240140966
Methylobacterium extorquens


AOD1
AAA34321.1
170820
Candida boidinii









FIG. 1, Step K—Spontaneous or Formaldehyde Activating Enzyme

The conversion of formaldehyde and THF to methylenetetrahydrofolate can occur spontaneously. It is also possible that the rate of this reaction can be enhanced by a formaldehyde activating enzyme. A formaldehyde activating enzyme (Fae) has been identified in Methylobacterium extorquens AM1 which catalyzes the condensation of formaldehyde and tetrahydromethanopterin to methylene tetrahydromethanopterin (Vorholt, et al., J. Bacteriol., 182(23), 6645-6650 (2000)). It is possible that a similar enzyme exists or can be engineered to catalyze the condensation of formaldehyde and tetrahydrofolate to methylenetetrahydrofolate. Homologs exist in several organisms including Xanthobacter autotrophicus Py2 and Hyphomicrobium denitrificans ATCC 51888.













Protein
GenBank ID
GI Number
Organism


















MexAM1_META1p1766
Q9FA38.3
17366061
Methylobacterium extorquens





AM1


Xaut_0032
YP_001414948.1
154243990
Xanthobacter autotrophicus Py2


Hden_1474
YP_003755607.1
300022996
Hyphomicrobium denitrificans





ATCC 51888









FIG. 1, Step L—Formaldehyde Dehydrogenase

Oxidation of formaldehyde to formate is catalyzed by formaldehyde dehydrogenase. An NAD+ dependent formaldehyde dehydrogenase enzyme is encoded by fdhA of Pseudomonas putida (Ito et al, J Bacteriol 176: 2483-2491 (1994)). Additional formaldehyde dehydrogenase enzymes include the NAD+ and glutathione independent formaldehyde dehydrogenase from Hyphomicrobium zavarzinii (Jerome et al, Appl Microbiol Biotechnol 77:779-88 (2007)), the glutathione dependent formaldehyde dehydrogenase of Pichia pastoris (Sunga et al, Gene 330:39-47 (2004)) and the NAD(P)+ dependent formaldehyde dehydrogenase of Methylobacter marinus (Speer et al, FEMS Microbiol Lett, 121(3):349-55 (1994)).













Protein
GenBank ID
GI Number
Organism


















fdhA
P46154.3
1169603
Pseudomonas putida


faoA
CAC85637.1
19912992
Hyphomicrobium zavarzinii


Fld1
CCA39112.1
328352714
Pichia pastoris


Fdh
P47734.2
221222447
Methylobacter marinus









In addition to the formaldehyde dehydrogenase enzymes listed above, alternate enzymes and pathways for converting formaldehyde to formate are known in the art. For example, many organisms employ glutathione-dependent formaldehyde oxidation pathways, in which formaldehyde is converted to formate in three steps via the intermediates S-hydroxymethylglutathione and S-formylglutathione (Vorholt et al, J Bacteriol 182:6645-50 (2000)). The enzymes of this pathway are S-(hydroxymethyl)glutathione synthase (EC 4.4.1.22), glutathione-dependent formaldehyde dehydrogenase (EC 1.1.1.284) and S-formylglutathione hydrolase (EC 3.1.2.12).
FIG. 1, Step M—Spontaneous or S-(Hydroxymethyl)Glutathione Synthase
While conversion of formaldehyde to S-hydroxymethylglutathione can occur spontaneously in the presence of glutathione, it has been shown by Goenrich et al (Goenrich, et al., J Biol Chem 277(5); 3069-72 (2002)) that au enzyme from Paracoccus denitrificans can accelerate this spontaneous condensation reaction. The enzyme catalyzing the conversion of formaldehyde and glutathione was purified and named glutathione-dependent formaldehyde-activating enzyme (Gfa). The gene encoding it, which was named gfa, is located directly upstream of the gene for glutathione-dependent formaldehyde dehydrogenase, which catalyzes the subsequent oxidation of S-hydroxymethylglutathione. Putative proteins with sequence identity to Gfa from P. denitrificans are present also in Rhodobacter sphaeroides, Sinorhizobium meliloti, and Mesorhizobium loti.













Protein
GenBank ID
GI Number
Organism


















Gfa
Q51669.3
38257308
Paracoccus denitrificans


Gfa
ABP71667.1
145557054
Rhodobacter sphaeroides ATCC





17025


Gfa
Q92WX6.1
38257348
Sinorhizobium meliloti 1021


Gfa
Q98LU4.2
38257349
Mesorhizobium loti MAFF303099









FIG. 1, Step N—Glutathione-Dependent Formaldehyde Dehydrogenase

Glutathione-dependent formaldehyde dehydrogenase (GS-FDH) belongs to the family of class III alcohol dehydrogenases. Glutathione and formaldehyde combine non-enzymatically to form hydroxymethylglutathione, the true substrate of the GS-FDH catalyzed reaction. The product, S-formylglutathione, is further metabolized to formic acid.













Protein
GenBank ID
GI Number
Organism


















frmA
YP_488650.1
388476464
Escherichia coli K-12 MG1655


SFA1
NP_010113.1
6320033
Saccharomyces cerevisiae





S288c


flhA
AAC44551.1
1002865
Paracoccus denitrificans


adhI
AAB09774.1
986949
Rhodobacter sphaeroides









FIG. 1, Step O—S-Formylglutathione Hydrolase

S-formylglutathione hydrolase is a glutathione thiol esterase found in bacteria, plants and animals. It catalyzes conversion of S-formylglutathione to formate and glutathione. The fghA gene of P. denitrificans is located in the same operon with gfa and flhA, two genes involved in the oxidation of formaldehyde to formate in this organism. In E. coli, FrmB is encoded in an operon with FrmR and FrmA, which are proteins involved in the oxidation of formaldehyde. YeiG of E. coli is a promiscuous serine hydrolase; its highest specific activity is with the substrate S-formylglutathione.













Protein
GenBank ID
GI Number
Organism


















frmB
NP_414889.1
16128340
Escherichia coli K-12 MG1655


yeiG
AAC75215.1
1788477
Escherichia coli K-12 MG1655


fghA
AAC44554.1
1002868
Paracoccus denitrificans









4.2 Example II—Enhanced Yield of 1,2-Propanediol and/or n-Propanol, 1,3-Propanediol and/or Glycerol from Carbohydrates Using Methanol
Exemplary methanol metabolic pathways for enhancing the availability of reducing equivalents are provided in FIG. 1.
1,2-propanediol and/or n-propanol can be achieved in a recombinant organism by the pathway shown in FIG. 2. Exemplary enzymes for the conversion of glucose to 1,2-propanediol and/or n-propanol by this route include 2A) a methylglyoxal synthase; 2B) a methylglyoxal reductase (acetol-forming); 2C) an acetol reductase; 2D) a methylglyoxal reductase (lactaldehyde-forming); 2E) a lactaldehyde reductase; 2F) a 1,2-propanediol dehydratase; and 2G) a propanal reductase. 1,2-propanediol production can be carried out by 2A, 2B and 2C; or 2A, 2D and 2E. n-propanol production can be carried out by 2A, 2B, 2C, 2F and 2G; or 2A, 2D, 2E, 2F and 2G.
FIG. 2 depicts two pathways for converting dihydroxyacetone phosphate to 1,2-propanediol or n-propanol. Both pathways require the initial formation of methylglyoxal from dihydroxyacetone phosphate by methylglyoxal synthase. Methylglyoxal can be subsequently reduced to form acetol or lactaldehyde by methylglyoxal reductase (acetol-forming) or methylglyoxal reductase (lactaldehyde-forming). Further reduction of acetol or lactaldehyde yields 1,2-propanediol. An enzyme with 1,2-propanediol dehydratase activity is required to dehydrate 1,2-propanediol to propanal. Propanal is further reduced to propanol by an aldehyde reductase or alcohol dehydrogenase.
Enzyme candidates for converting dihydroxyacetone phosphate to 1,2-propanediol and propanol are described in further detail below.
FIG. 2, Step A—Methylglyoxal Synthase
Methylglyoxal is formed from dihydroxyacetone phosphate by methylglyoxal synthase (MGS, EC 4.2.3.3). This activity is encoded by mgs in E. coli (Altaras and Cameron., Appl Env Microbiol., 65:1180-1185 (1999)). The introduction of exogenous MGS in yeast has been shown to result in the production of low levels of 1,2-propanediol (Hoffman. M. L., 1999, Metabolic engineering of 1,2-propanediol production in Saccharomyces cerevisiae. Ph.D. Dissertation, University of Wisconsin-Madison). Subsequent introduction of a glycerol dehydrogenase doubled the amount of propanediol formed. MGS enzymes from Thermus sp. GH5 and Clostridium acetobutylicum were cloned, expressed and characterized in E. coli (Pazhang et al, Appl Biochem Biotechnol 162:1519-28 (2010); Huang et al, Appl Env Microbiol 65:3244-7 (1999)).













Protein
GenBank ID
GI Number
Organism


















Mgs
AAC74049.2
87081809
Escherichia coli


EU744585.1:1 . . . 399
ACE81430.1
190663729
Thermus sp. GH5


mgsA
NP_348231.1
15894882
Clostridium





acetobutylicum









FIG. 2, Step B—Methylglyoxal Reductase (Acetol-Forming)

Methylglyoxal reductase can alternately be reduced to form acetol by an enzyme that converts aldehydes to alcohols. The aldehyde dehydrogenase enzyme of Leishmania donovani exhibits methylglyoxal reductase (acetol forming) activity (Rath et al, Gene 429:1-9 (2009)). Exemplary genes include alrA encoding a medium-chain alcohol dehydrogenase for C2-C14 (Tani et al., Appl. Environ. Microbiol. 66:5231-5235 (2000)), ADH2 from Saccharomyces cerevisiae (Atsumi et al., Nature 451:86-89 (2008)), yqhD from E. coli which has preference for molecules longer than C(3) (Sulzenbacher et al., 342:489-502 (2004)), and bdh I and bdh II from C. acetobutylicum which converts butyryaldehyde into butanol (Walter et al., 174:7149-7158 (1992)). YqhD catalyzes the reduction of a wide range of aldehydes using NADPH as the cofactor (Perez et al., J Biol. Chem. 283:7346-7353 (2008)). Another aldehyde reductase of E. coli with a broad substrate range is encoded by fucO. The adhA gene product from Zymomonas mobilisE has been demonstrated to have activity on a number of aldehydes including formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, and acrolein (Kinoshita et al., Appl Microbiol Biotechnol 22:249-254 (1985)). Additional aldehyde reductase candidates are encoded by bdh in C. saccharoperbutylacetonicum and Cbei_1722, Cbei_2181 and Cbei_2421 in C. beijerinckii.













Protein
GenBank ID
GI Number
Organism


















alr
ABP24363.1
145025448
Leishmania donovani


alrA
BAB12273.1
9967138
Acinetobacter sp. strain M-1


ADH2
NP_014032.1
6323961
Saccharomyces cerevisiae


yqhD
NP_417484.1
16130909
Escherichia coli


fucO
NP_417279.1
16130706
Escherichia coli


bdh I
NP_349892.1
15896543
Clostridium acetobutylicum


bdh II
NP_349891.1
15896542
Clostridium acetobutylicum


adhA
YP_162971.1
56552132
Zymomonas mobilis


bdh
BAF45463.1
124221917
Clostridium saccharoperbutylacetonicum


Cbei_1722
YP_001308850
150016596
Clostridium beijerinckii


Cbei_2181
YP_001309304
150017050
Clostridium beijerinckii


Cbei_2421
YP_001309535
150017281
Clostridium beijerinckii









Enzymes exhibiting 4-hydroxybutyrate dehydrogenase activity (EC 1.1.1.61) also fall into this category. Such enzymes have been characterized in Ralstonia eutropha (Bravo et al., J Forens Sci, 49:379-387 (2004)), Clostridium kluyveri (Wolff et al., Protein Expr. Purif: 6:206-212 (1995)) and Arabidopsis thaliana (Breitkreuz et al., J Biol Chem, 278:41552-41556 (2003)). The A. thaliana enzyme was cloned and characterized in yeast (Breitkreuz et al., J. Biol. Chem. 278:41552-41556 (2003)). Yet another gene is the alcohol dehydrogenase adhI from Geobacillus thermoglucosidasius (Jeon et al., J Biotechnol 135:127-133 (2008)).













Protein
GenBank ID
GI Number
Organism


















4hbd
YP_726053.1
113867564
Ralstonia eutropha H16


4hbd
L21902.1
146348486
Clostridium kluyveri DSM 555


4hbd
Q94B07
75249805
Arabidopsis thaliana


adhI
AAR91477.1
40795502
Geobacillus





thermoglucosidasius









Another exemplary enzyme is methylmalonate semialdehyde reductase, also known as 3-hydroxyisobutyrate dehydrogenase (EC 1.1.1.31). This enzyme participates in valine, leucine and isoleucine degradation and has been identified in bacteria, eukaryotes, and mammals. The enzyme encoded by P84067 from Thermus thermophilus HB8 has been structurally characterized (Lokanath et al., J Mol Biol, 352:905-17 (2005)). The reversibility of the human 3-hydroxyisobutyrate dehydrogenase was demonstrated using isotopically-labeled substrate (Manning et al., Biochem J, 231:481-4 (1985)). Additional genes encoding this enzyme include 3hidh in Homo sapiens (Hawes et al., Methods Enzymol, 324:218-228 (2000)) and Oryctolagus cuniculus (Hawes et al., supra; Chowdhury et al., Biosci. Biotechnol Biochem. 60:2043-2047 (1996)), mmsB in Pseudomonas aeruginosa and Pseudomonas putida, and dhat in Pseudomonas putida (Aberhart et al., J Chem. Soc. [Perkin 1] 6:1404-1406 (1979); Chowdhury et al., Biosci. Biotechnol Biochem. 60:2043-2047 (1996); Chowdhury et al., Biosci. Biotechnol Biochem. 67:438-441 (2003)). Several 3-hydroxyisobutyrate dehydrogenase enzymes have been characterized in the reductive direction, including mmsB from Pseudomonas aeruginosa (Gokarn et al., U.S. Pat. No. 739,676, (2008)) and mmsB from Pseudomonas putida.













Protein
GenBank ID
GI Number
Organism


















P84067
P84067
75345323
Thermus thermophilus


3hidh
P31937.2
12643395
Homo sapiens


3hidh
P32185.1
416872
Oryctolagus cuniculus


mmsB
NP_746775.1
26991350
Pseudomonas putida


mmsB
P28811.1
127211
Pseudomonas aeruginosa


dhat
Q59477.1
2842618
Pseudomonas putida









FIG. 2, Step C—Acetol Reductase

The ketone of acetol is further reduced to an alcohol, forming 1,2-propanediol, by an enzyme with acetol reductase activity. The aldehyde reductase alr of Leishmania donovani has been shown to catalyze this reaction (Rath et al, Gene 429:1-9 (2009)). Glycerol dehydrogenase enzymes, including gldA of E. coli and dhaD of Klebsiella pneumonia, also convert acetol to 1,2-PDO (Lee and Whitesides, J Org Chem, 51:25-36 (1986); Altaras and Cameron, Biotechnol Prog 16:940-46 (2000)) The enzyme candidates described previously for catalyzing the reduction of methylglyoxal to acetol or lactaldehyde are also suitable acetol reductase enzyme candidates.















Protein
GenBank ID
GI Number
Organism




















alr
ABP24363.1
145025448
Leishmania






donovani



gldA
AAC76927.2
87082352
Escherichia coli



dhaD
ABO15720.1
126513217
Klebsiella






pneumoniae









FIG. 2, Step D—Methylglyoxal Reductase (Lactaldehyde-Forming);

The conversion of methylglyoxal to lactaldehyde is catalyzed by an enzyme with methylglyoxal reductase (lactaldehyde-forming) activity. A number of alcohol dehydrogenase enzymes are suitable for catalyzing this reaction, including alcohol dehydrogenase (EC 1.1.1.1; 1.1.1.2), aldehyde reductase (EC 1.1.1.21), methylglyoxal reductase (EC 1.1.1.78; 1.1.1.283), glycerol dehydrogenase (EC 1.1.1.6), and others. Exemplary genes with methylglyoxal reductase (lactaldehyde-forming) activity include the glycerol dehydrogenase genes gldA of E. coli and dhaD of Klebsiella pneumoniae (Altaras and Cameron., Appl Env Microbiol., 65:1180-1185 (1999)). These genes were successfully employed in 1,2-PDO production pathways. Another enzyme with this activity is encoded by GRE2 of Saccharomyces cerevisiae (Chen et al, Yeast, 20:545-54 (2003)). Additional candidates include malate dehydrogenase (mdh) and lactate dehydrogenase (ldhA) of E. coli. The lactate dehydrogenase from Ralstonia eutropha has been shown to demonstrate high activities on 2-ketoacids of various chain lengths including lactate, 2-oxobutyrate, 2-oxopentanoate and 2-oxoglutarate (Steinbuchel et al., Eur. J. Biochem. 130:329-334 (1983)). Conversion of alpha-ketoadipate into alpha-hydroxyadipate can be catalyzed by 2-ketoadipate reductase, an enzyme reported to be found in rat and in human placenta (Suda et al., Arch. Biochem. Biophys. 176:610-620 (1976); Suda et al., Biochem. Biophys. Res. Commun. 77:586-591 (1977)). An additional oxidoreductase is the mitochondrial 3-hydroxybutyrate dehydrogenase (bdh) from the human heart which has been cloned and characterized (Marks et al., J. Biol. Chem. 267:15459-15463 (1992)). Alcohol dehydrogenase enzymes of C. beijerinckii (Ismaiel et al., J. Bacteriol. 175:5097-5105 (1993)) and T. brockii (Lamed et al., Biochem. J. 195:183-190 (1981); Peretz et al., Biochemistry. 28:6549-6555 (1989)) convert acetone to isopropanol. Methyl ethyl ketone reductase catalyzes the reduction of MEK to 2-butanol. Exemplary MEK reductase enzymes can be found in Rhodococcus ruber (Kosjek et al., Biotechnol Bioeng. 86:55-62 (2004)) and Pyrococcus furiosus (van der et al., Eur. J. Biochem. 268:3062-3068 (2001)).













Protein
GenBank ID
GI Number
Organism


















gldA
AAC76927.2
87082352
Escherichia coli


dhaD
ABO15720.1
126513217
Klebsiella pneumoniae


GRE2
Q12068.1
57013849
Saccharomyces cerevisiae


Mdh
AAC76268.1
1789632
Escherichia coli


ldhA
NP_415898.1
16129341
Escherichia coli


Ldh
YP_725182.1
113866693
Ralstonia eutropha


Bdh
AAA58352.1
177198
Homo sapiens


Adh
AAA23199.2
60592974
Clostridium beijerinckii NRRL





B593


Adh
P14941.1
113443
Thermoanaerobacter brockii





HTD4


Sadh
CAD36475
21615553
Rhodococcus ruber


adhA
AAC25556
3288810
Pyrococcus furiosus









FIG. 2, Step E—Lactaldehyde Reductase

Aldehyde reductase enzymes are required to convert lactaldehyde to 1,2-PDO. The aldehyde reductase encoded by fucO of E. coli converts S-lactaldehyde to 1,2-PDO (Altaras and Cameron., Appl Env Microbiol., 65:1180-1185 (1999)). Gene candidates in Saccharomyces cerevisiae include the aldehyde reductases GRE3, ALD2-6 and HFD1, glyoxylate reductases GOR1 and YPL113C and glycerol dehydrogenase GCY1 (WO 2011/022651A1). The enzyme candidates described previously for catalyzing the reduction of methylglyoxal to acetol or lactaldehyde are also suitable lactaldehyde reductase enzyme candidates.













Protein
GenBank ID
GI Number
Organism


















fucO
NP_417279.1
16130706
Escherichia coli


GRE3
P38715.1
731691
Saccharomyces cerevisiae


ALD2
CAA89806.1
825575
Saccharomyces cerevisiae


ALD3
NP_013892.1
6323821
Saccharomyces cerevisiae


ALD4
NP_015019.1
6324950
Saccharomyces cerevisiae


ALD5
NP_010996.2
330443526
Saccharomyces cerevisiae


ALD6
ABX39192.1
160415767
Saccharomyces cerevisiae


HFD1
Q04458.1
2494079
Saccharomyces cerevisiae


GOR1
NP_014125.1
6324055
Saccharomyces cerevisiae


YPL113C
AAB68248.1
1163100
Saccharomyces cerevisiae


GCY1
CAA99318.1
1420317
Saccharomyces cerevisiae









FIG. 2, Step F—1,2-Propanediol Dehydratase;

Dehydration of 1,2-propanediol to propanal is catalyzed by a diol dehydratase enzyme with 1,2-propanediol dehydratase activity. Exemplary diol dehydratase enzymes include propanediol dehydratase (EC 4.2.1.28), glycerol dehydratase (EC 4.2.1.30) and dihydroxy-acid dehydratase (EC 4.2.1.9). Enzymes may require adenosylcobalamin (B12) as a cofactor or be B12-independent. B12-dependent diol dehydratases contain alpha, beta and gamma subunits, which are all required for enzyme function.
Diol dehydratase or propanediol dehydratase enzymes (EC 4.2.1.28) capable of converting the secondary diol 2,3-butanediol to 2-butanone would be excellent candidates for this transformation. Exemplary 1,2-propanediol dehydratase enzyme candidates are found in Klebsiella pneumoniae (Toraya et al., Biochem. Biophys. Res. Commun. 69:475-480 (1976); Tobimatsu et al., Biosci. Biotechnol Biochem. 62:1774-1777 (1998)), Salmonella typhimurium (Bobik et al., J. Bacteriol. 179:6633-6639 (1997)), Klebsiella oxytoca (Tobimatsu et al., J Biol. Chem. 270:7142-7148 (1995)) and Lactobacillus collinoides (Sauvageot et al., FEMS Microbiol Lett. 209:69-74 (2002)). Methods for isolating diol dehydratase gene candidates in other organisms are well known in the art (e.g. U.S. Pat. No. 5,686,276).













Protein
GenBank ID
GI Number
Organism


















pddC
AAC98386.1
4063704
Klebsiella pneumoniae


pddB
AAC98385.1
4063703
Klebsiella pneumoniae


pddA
AAC98384.1
4063702
Klebsiella pneumoniae


pduC
AAB84102.1
2587029
Salmonella typhimurium


pduD
AAB84103.1
2587030
Salmonella typhimurium


pduE
AAB84104.1
2587031
Salmonella typhimurium


pddA
BAA08099.1
868006
Klebsiella oxytoca


pddB
BAA08100.1
868007
Klebsiella oxytoca


pddC
BAA08101.1
868008
Klebsiella oxytoca


pduC
CAC82541.1
18857678
Lactobacillus collinoides


pduD
CAC82542.1
18857679
Lactobacillus collinoides


pduE
CAD01091.1
18857680
Lactobacillus collinoides









Enzymes in the glycerol dehydratase family (EC 4.2.1.30) can also be used to dehydrate 1,2-propanediol. Exemplary gene candidates encoded by gldABC and dhaB123 in Klebsiella pneumoniae (World Patent WO 2008/137403) and (Toraya et al., Biochem. Biophys. Res. Commun. 69:475-480 (1976)), dhaBCE in Clostridium pasteuranum (Macis et al., FEMS Microbiol Lett. 164:21-28 (1998)) and dhaBCE in Citrobacter freundii (Seyfried et al., J Bacteriol. 178:5793-5796 (1996)). Variants of the B12-dependent diol dehydratase from K. pneumoniae with 80- to 336-fold enhanced activity were recently engineered by introducing mutations in two residues of the beta subunit (Qi et al., J. Biotechnol. 144:43-50 (2009)). Diol dehydratase enzymes with reduced inactivation kinetics were developed by DuPont using error-prone PCR (WO 2004/056963).













Protein
GenBank ID
GI Number
Organism


















gldA
AAB96343.1
1778022
Klebsiella pneumonia


gldB
AAB96344.1
1778023
Klebsiella pneumonia


gldC
AAB96345.1
1778024
Klebsiella pneumoniae


dhaB1
ABR78884.1
150956854
Klebsiella pneumoniae


dhaB2
ABR78883.1
150956853
Klebsiella pneumoniae


dhaB3
ABR78882.1
150956852
Klebsiella pneumoniae


dhaB
AAC27922.1
3360389
Clostridium pasteuranum


dhaC
AAC27923.1
3360390
Clostridium pasteuranum


dhaE
AAC27924.1
3360391
Clostridium pasteuranum


dhaB
P45514.1
1169287
Citrobacter freundii


dhaC
AAB48851.1
1229154
Citrobacter freundii


dhaE
AAB48852.1
1229155
Citrobacter freundii









If a B12-dependent diol dehydratase is utilized, heterologous expression of the corresponding reactivating factor is recommended. B12-dependent diol dehydratases are subject to mechanism-based suicide activation by substrates and some downstream products. Inactivation, caused by a tight association with inactive cobalamin, can be partially overcome by diol dehydratase reactivating factors in an ATP-dependent process. Regeneration of the B12 cofactor requires an additional ATP. Diol dehydratase regenerating factors are two-subunit proteins. Exemplary candidates are found in Klebsiella oxytoca (Mori et al., J Biol. Chem. 272:32034-32041 (1997)), Salmonella typhimurium (Bobik et al., J Bacteriol. 179:6633-6639 (1997); Chen et al., J Bacteriol. 176:5474-5482 (1994)), Lactobacillus collinoides (Sauvageot et al., FEMS Microbiol Lett. 209:69-74 (2002)), Klebsiella pneumonia (World Patent WO 2008/137403).













Protein
GenBank ID
GI Number
Organism


















ddrA
AAC15871
3115376
Klebsiella oxytoca


ddrB
AAC15872
3115377
Klebsiella oxytoca


pduG
AAB84105
16420573
Salmonella typhimurium


pduH
AAD39008
16420574
Salmonella typhimurium


pduG
YP_002236779
206579698
Klebsiella pneumonia


pduH
YP_002236778
206579863
Klebsiella pneumonia


pduG
CAD01092
29335724
Lactobacillus collinoides


pduH
AJ297723
29335725
Lactobacillus collinoides









B12-independent diol dehydratase enzymes utilize S-adenosylmethionine (SAM) as a cofactor and function under strictly anaerobic conditions. The glycerol dehydrogenase and corresponding activating factor of Clostridium butyricum, encoded by dhaB1 and dhaB2, have been well-characterized (O'Brien et al., Biochemistry 43:4635-4645 (2004); Raynaud et al., Proc. Natl. Acad. Sci U.S.A 100:5010-5015 (2003)). This enzyme was recently employed in a 1,3-propanediol overproducing strain of E. coli and was able to achieve very high titers of product (Tang et al., Appl. Environ. Microbiol. 75:1628-1634 (2009)). An additional B12-independent diol dehydratase enzyme and activating factor from Roseburia inulinivorans was shown to catalyze the conversion of 2,3-butanediol to 2-butanone (US 2009/09155870).













Protein
GenBank ID
GI Number
Organism







dhaB1
AAM54728.1
27461255
Clostridium butyricum


dhaB2
AAM54729.1
27461256
Clostridium butyricum


rdhtA
ABC25539.1
83596382
Roseburia inulinivorans


rdhtB
ABC25540.1
83596383
Roseburia inulinivorans









Dihydroxy-acid dehydratase (DHAD, EC 4.2.1.9) is a B12-independent enzyme participating in branched-chain amino acid biosynthesis. In its native role, it converts 2,3-dihydroxy-3-methylvalerate to 2-keto-3-methyl-valerate, a precursor of isoleucine. In valine biosynthesis the enzyme catalyzes the dehydration of 2,3-dihydroxy-isovalerate to 2-oxoisovalerate. The DHAD from Sulfolobus solfataricus has a broad substrate range and activity of a recombinant enzyme expressed in E. coli was demonstrated on a variety of aldonic acids (KIM et al., J. Biochem. 139:591-596 (2006)). The S. solfataricus enzyme is tolerant of oxygen unlike many diol dehydratase enzymes. Substrate (1) has not been tested to date. The E. coli enzyme, encoded by ilvD, is sensitive to oxygen, which inactivates its iron-sulfur cluster (Flint et al., J. Biol. Chem. 268:14732-14742 (1993)). Similar enzymes have been characterized in Neurospora crassa (Altmiller et al., Arch. Biochem. Biophys. 138:160-170 (1970)) and Salmonella typhimurium (Armstrong et al., Biochim. Biophys. Acta 498:282-293 (1977)).













Protein
GenBank ID
GI Number
Organism







ilvD
NP_344419.1
15899814
Sulfolobus solfataricus


ilvD
AAT48208.1
48994964
Escherichia coli


ilvD
NP_462795.1
16767180
Salmonella typhimurium


ilvD
XP_958280.1
85090149
Neurospora crassa









FIG. 2, Step G—Propanal Reductase

The alcohol dehydrogenase enzyme candidates described above are also suitable for catalyzing the reduction of propanal to propanol.
4.3 Example III—Enhanced Yield of 1,3-Propanediol and/or Glycerol from Carbohydrates Using Methanol
Exemplary methanol metabolic pathways for enhancing the availability of reducing equivalents are provided in FIG. 1.
1,3-propanediol and/or glycerol production can be achieved in a recombinant organism by the pathway shown in FIG. 3. Exemplary enzymes for the conversion of glucose to 1,3-propanediol and/or glycerol by this route include 3A) a glyceraldehyde-3-phosphate reductase; 3B) a glycerol-3-phosphate phosphatase or a glycerol kinase; 3C) a glycerol dehydratase; 3D) a 3-hydroxypropanal reductase; 3E) a dihydroxyacetone phosphate phosphatase or a dihydroxyacetone kinase; 3F) a dihydroxyacetone reductase; and 3G) a dihydroxyacetone phosphate reductase. 1,3-propanediol production can be carried out by 3A, 3B, 3C and 3D; 3G, 3B, 3C and 3D; or 3E, 3F, 3C and 3D. Glycerol production can be carried out by 3A and 3B; 3G and 3B; or 3E and 3F.
The additional reducing equivalents obtained from the methanol metabolic pathways provided herein improve the yields of 1,3-propanediol and glycerol when utilizing a carbohydrate-based feedstock. 1,3-propanediol or glycerol production can be achieved in a recombinant organism by alternative pathways as shown in FIG. 3. In the first route, glyceraldehyde-3-phosphate is reduced to glycerol-3-phosphate. Glycerol-3-phosphate is subsequently dephosphorylated to glycerol by either a phosphatase or a glycerol kinase enzyme. Glycerol can then be secreted as a product or further converted to 1,3-PDO by a diol dehydratase and a 3-hydroxypropanal reductase. Alternately, the glycerol-3-phosphate intermediate is formed by the reduction of dihydroxyacetone phosphate. In yet another route, dihydroxyacetone phosphate is first dephosphorylated to dihydroxyacetone by a kinase or phosphatase. Dihydroxyacetone is then reduced to glycerol, which can be secreted or further converted to 1,3-PDO as described above.
Exemplary enzyme candidates for the transformations shown in FIG. 3 are described below. The following table shows enzyme classes that can perform the steps depicted in FIG. 3.















Label
Function
Step









1.1.1.a
Oxidoreductase (oxo to alcohol)
A, D, F, G



3.1.3.a
Phosphatase
B, E



2.7.2.a
Kinase
B, E



4.2.1.a
Dehydratase
C










FIG. 3, Step A=Glyceraldehyde-3-Phosphate Reductase

Enzymes that reduce aldehydes to alcohols are suitable candidates for the reduction of 3-hydroxypropanal and glyceraldehyde-3-phosphate. Exemplary genes encoding enzymes that catalyze the conversion of an aldehyde to alcohol (i.e., alcohol dehydrogenase or equivalently aldehyde reductase) include alrA encoding a medium-chain alcohol dehydrogenase for C2-C14 (Tani et al., Appl. Environ. Microbiol. 66:5231-5235 (2000)), yqhD and fucO from E. coli (Suizenbacher et al., 342:489-502 (2004)), and bdh I and bdh II from C. acetobutylicum which converts butyryaldehyde into butanol (Walter et al., 174:7149-7158 (1992)). YqhD catalyzes the reduction of a wide range of aldehydes using NADPH as the cofactor, with a preference for chain lengths longer than C(3) (Sulzenbacher et al., 342:489-502 (2004); Perez et al., J Biol. Chem. 283:7346-7353 (2008)). The adhA gene product from Zymomonas mobilisE has been demonstrated to have activity on a number of aldehydes including formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, and acrolein (Kinoshita et al., Appl Microbiol Biotechnol 22:249-254 (1985)). Additional aldehyde reductase candidates are encoded by bdh in C. saccharoperbutylacetonicum and Cbei_1722, Cbei_2181 and Cbei_2421 in C. beijerinckii.













Protein
GenBank ID
GI Number
Organism


















alrA
BAB12273.1
9967138
Acinetobacter sp. train M-1


ADH2
NP_014032.1
6323961
Saccharomyces cerevisiae


yqhD
NP_417484.1
16130909
Escherichia coli


fucO
NP_417279.1
16130706
Escherichia coli


bdh I
NP_349892.1
15896543
Clostridium acetobutylicum


bdh II
NP_349891.1
15896542
Clostridium acetobutylicum


adhA
YP_162971.1
56552132
Zymomonas mobilis


Bdh
BAF45463.1
124221917
Clostridium saccharoperbutylacetonicum


Cbei_1722
YP_001308850
150016596
Clostridium beijerinckii


Cbei_2181
YP_001309304
150017050
Clostridium beijerinckii


Cbei_2421
YP_001309535
150017281
Clostridium beijerinckii









Aldehyde reductase gene candidates in Saccharomyces cerevisiae include the aldehyde reductases GRE3, ALD2-6 and HFD1, glyoxylate reductases GOR1 and YPL113C and glycerol dehydrogenase GCY1 (WO 2011/022651A1; Atsumi et al., Nature 451:86-89 (2008)). The enzyme candidates described previously for catalyzing the reduction of methylglyoxal to acetol or lactaldehyde are also suitable lactaldehyde reductase enzyme candidates.













Protein
GenBank ID
GI Number
Organism


















GRE3
P38715.1
731691
Saccharomyces cerevisiae


ALD2
CAA89806.1
825575
Saccharomyces cerevisiae


ALD3
NP_013892.1
6323821
Saccharomyces cerevisiae


ALD4
NP_015019.1
6324950
Saccharomyces cerevisiae


ALD5
NP_010996.2
330443526
Saccharomyces cerevisiae


ALD6
ABX39192.1
160415767
Saccharomyces cerevisiae


HFD1
Q04458.1
2494079
Saccharomyces cerevisiae


GOR1
NP_014125.1
6324055
Saccharomyces cerevisiae


YPL113C
AAB68248.1
1163100
Saccharomyces cerevisiae


GCY1
CAA99318.1
1420317
Saccharomyces cerevisiae









Enzymes exhibiting 4-hydroxybutyrate dehydrogenase activity (EC 1.1.1.61) also fall into this category. Such enzymes have been characterized in Ralstonia eutropha (Bravo et al., J Forens Sci, 49:379-387 (2004)), Clostridium kluyveri (Wolff et al., Protein Expr. Purif. 6:206-212 (1995)) and Arabidopsis thaliana (Breitkreuz et al., J Biol Chem, 278:41552-41556 (2003)). The A. thaliana enzyme was cloned and characterized in yeast (Breitkreuz et al., J. Biol. Chem. 278:41552-41556 (2003)). Yet another gene is the alcohol dehydrogenase adhI from Geobacillus thermoglucosidasius (Jeon et al., J Biotechnol 135:127-133 (2008)).













Protein
GenBank ID
GI Number
Organism


















4hbd
YP_726053.1
113867564
Ralstonia eutropha H16


4hbd
L21902.1
146348486
Clostridium kluyveri DSM 555


4hbd
Q94B07
75249805
Arabidopsis thaliana


adhI
AAR91477.1
40795502
Geobacillus





thermoglucosidasius









Another exemplary enzyme is methylmalonate semialdehyde reductase, also known as 3-hydroxyisobutyrate dehydrogenase (EC 1.1.1.31). This enzyme participates in valine, leucine and isoleucine degradation and has been identified in bacteria, eukaryotes, and mammals. The enzyme encoded by P84067 from Thermus thermophilus HB8 has been structurally characterized (Lokanath et al., J Mol Biol, 352:905-17 (2005)). The reversibility of the human 3-hydroxyisobutyrate dehydrogenase was demonstrated using isotopically-labeled substrate (Manning et al., Biochem J, 231:481-4 (1985)). Additional genes encoding this enzyme include 3hidh in Homo sapiens (Hawes et al., Methods Enzymol, 324:218-228 (2000)) and Oryctolagus cuniculus (Hawes et al., supra; Chowdhury et al., Biosci. Biotechnol Biochem. 60:2043-2047 (1996)), mmsB in Pseudomonas aeruginosa and Pseudomonas putida, and dhat in Pseudomonas putida (Aberhart et al., J Chem. Soc. [Perkin 1] 6:1404-1406 (1979); Chowdhury et al., Biosci. Biotechnol Biochem. 60:2043-2047 (1996); Chowdhury et al., Biosci. Biotechnol Biochem. 67:438-441 (2003)). Several 3-hydroxyisobutyrate dehydrogenase enzymes have been characterized in the reductive direction, including mmsB from Pseudomonas aeruginosa (Gokarn et al., U.S. Pat. No. 739,676, (2008)) and mmsB from Pseudomonas putida.













Protein
GenBank ID
GI Number
Organism


















P84067
P84067
75345323
Thermus thermophilus


3hidh
P31937.2
12643395
Homo sapiens


3hidh
P32185.1
416872
Oryctolagus cuniculus


mmsB
NP_746775.1
26991350
Pseudomonas putida


mmsB
P28811.1
127211
Pseudomonas aeruginosa


dhat
Q59477.1
2842618
Pseudomonas putida









Other suitable enzyme candidates for hydrolyzing glyceraldehydes-3-phosphate or dihydroxyacetone phosphate is 3-phosphoglycerate phosphatase (EC 3.1.3.38), catalyzing the hydrolysis of 3PG to glycerate. The enzyme is found in plants and has a broad substrate range that includes phosphoenolpyruvate, ribulose-1,5-bisphosphate, dihydroxyacetone phosphate and glucose-6-phosphate (Randall et al., Plant Physiol 48:488-492 (1971); Randall et al., J Biol. Chem. 246:5510-5517 (1971)). Purified enzyme from various plant sources has been characterized but a gene has not been associated with this enzyme to date. Another enzyme with 3-phosphoglycerate phosphatase activity is the phosphoglycerate phosphatase (EC 3.1.3.20) from pig liver (Fallon et al., Biochim. Biophys. Acta 105:43-53 (1965)). The gene associated with this enzyme is not available.
FIG. 3, Step B—Glycerol-3-Phosphate Phosphatase or Glycerol Kinase
Kinase or phosphotransferase enzymes in the EC class 2.7.2 transform carboxylic acids to phosphonic acids with concurrent hydrolysis of one ATP. Such an enzyme is required to form dihydroxyacetone from dihydroxyacetone phosphate and glycerol from glycerol-3-phosphate. Exemplary dihydroxyacetone kinases enzymes (EC 2.7.2.29) include DAK from Pichia angusta and dhaK from Citrobacter freundii (van der Klei et al, Curr Genet, 34:1-11 (1998); Daniel et al, J Bacteriol, 177:4392-401 (1995)). The E. coli enzyme is encoded by dhaKLM (Bachler et al, EMBO J, 24: 283-93 (2005)).
















Protein
GenBank ID
GI Number
Organism





















dhaK
AAC74284.2
87081857
Escherichia coli



dhaL
AAC74283.1
1787449
Escherichia coli



dhaM
NP_415717.1
16129162
Escherichia coli



DAK
AAC27705.1
3171001
Pichia angusta



dhaK
AAB48843.1
493083
Citrobacter






freundii










Glycerol kinase (EC 2.7.2.30) catalyzes the ATP-dependent phosphorylation of glycerol. Exemplary enzymes are encoded by glpK of E. coli (Pettegrew et al, J Biol Chem 263:135-139 (1988), Atlg80460 of Arabidopsis thaliana (Eastmond, Plant J 37:617-24 (2004)), glpK of Enterococcus casseliflavus (Yeh et al, Biochem, 48:346-56 (2009)) and glpK of Haemophilus influenzae (Pawlyk and Pettigrew, Prot Expr Purif 22:52-9 (2001)).













Protein
GenBank ID
GI Number
Organism


















glpK
AAC76908.1
1790361
Escherichia coli


At1g80460
BAH19502.1
222423040
Arabidopsis thaliana


glpK
O34153.3
3122148
Enterococcus casseliflavus


glpK
NP_438851.1
16272633
Haemophilus influenzae









The hydrolysis of glycerol-3-phosphate to glycerol is catalyzed by glycerol-3-phosphatase. Enzymes with this activity include the glycerol-1-phosphatase (EC 3.1.3.21) enzymes of Saccharomyces cerevisiae (GPP1 and GPP2), Candida albicans and Dunaleilla parva (Popp et al, Biotechnol Bioeng 100:497-505 (2008); Fan et al, FEMS Microbiol Lett 245:107-16 (2005)). The D. parva gene has not been identified to date.













Protein
GenBank ID
GI Number
Organism


















GPP1
DAA08494.1
285812595
Saccharomyces cerevisiae


GPP2
NP_010984.1
6320905
Saccharomyces cerevisiae


GPP1
XP_717809.1
68476319
Candida albicans









FIG. 3, Step C—Glycerol Dehydratase

The dehydration of glycerol to 3-hydroxypropanal is catalyzed by a diol dehydratase enzyme with glycerol dehydratase activity. The enzyme candidates described above in Example II for propanediol dehydratase are also applicable here. Exemplary diol dehydratase enzymes include propanediol dehydratase (EC 4.2.1.28), glycerol dehydratase (EC 4.2.1.30) and dihydroxy-acid dehydratase (EC 4.2.1.9). Enzymes may require adenosylcobalamin (B12) as a cofactor or be B12-independent. B12-dependent diol dehydratases contain alpha, beta and gamma subunits, which are all required for enzyme function.
Diol dehydratase or propanediol dehydratase enzymes (EC 4.2.1.28) capable of converting the secondary diol 2,3-butanediol to 2-butanone would be excellent candidates for this transformation. Exemplary 1,2-propanediol dehydratase enzyme candidates are found in Klebsiella pneumoniae (Toraya et al., Biochem. Biophys. Res. Commun. 69:475-480 (1976); Tobimatsu et al., Biosci. Biotechnol Biochem. 62:1774-1777 (1998)), Salmonella typhimurium (Bobik et al., J Bacteriol. 179:6633-6639 (1997)), Klebsiella oxytoca (Tobimatsu et al., J Biol. Chem. 270:7142-7148 (1995)) and Lactobacillus collinoides (Sauvageot et al., FEMS Microbiol Lett. 209:69-74 (2002)). Methods for isolating diol dehydratase gene candidates in other organisms are well known in the art (e.g. U.S. Pat. No. 5,686,276).













Protein
GenBank ID
GI Number
Organism


















pddC
AAC98386.1
4063704
Klebsiella pneumoniae


pddB
AAC98385.1
4063703
Klebsiella pneumoniae


pddA
AAC98384.1
4063702
Klebsiella pneumoniae


pduC
AAB84102.1
2587029
Salmonella typhimurium


pduD
AAB84103.1
2587030
Salmonella typhimurium


pduE
AAB84104.1
2587031
Salmonella typhimurium


pddA
BAA08099.1
868006
Klebsiella oxytoca


pddB
BAA08100.1
868007
Klebsiella oxytoca


pddC
BAA08101.1
868008
Klebsiella oxytoca


pduC
CAC82541.1
18857678
Lactobacillus collinoides


pduD
CAC82542.1
18857679
Lactobacillus collinoides


pduE
CAD01091.1
18857680
Lactobacillus collinoides









Enzymes in the glycerol dehydratase family (EC 4.2.1.30) can also be used to dehydrate 1,2-propanediol. Exemplary gene candidates encoded by gldABC and dhaB123 in Klebsiella pneumoniae (World Patent WO 2008/137403) and (Toraya et al., Biochem. Biophys. Res. Commun. 69:475-480 (1976)), dhaBCE in Clostridium pasteuranum (Macis et al., FEMS Microbiol Lett. 164:21-28 (1998)) and dhaBCE in Citrobacter freundii (Seyfried et al., J Bacteriol. 178:5793-5796 (1996)). Variants of the B12-dependent diol dehydratase from K. pneumoniae with 80- to 336-fold enhanced activity were recently engineered by introducing mutations in two residues of the beta subunit (Qi et al., J Biotechnol. 144:43-50 (2009)). Diol dehydratase enzymes with reduced inactivation kinetics were developed by DuPont using error-prone PCR (WO 2004/056963).













Protein
GenBank ID
GI Number
Organism


















gldA
AAB96343.1
1778022
Klebsiella pneumonia


gldB
AAB96344.1
1778023
Klebsiella pneumonia


gldC
AAB96345.1
1778024
Klebsiella pneumoniae


dhaB1
ABR78884.1
150956854
Klebsiella pneumoniae


dhaB2
ABR78883.1
150956853
Klebsiella pneumoniae


dhaB3
ABR78882.1
150956852
Klebsiella pneumoniae


dhaB
AAC27922.1
3360389
Clostridium pasteuranum


dhaC
AAC27923.1
3360390
Clostridium pasteuranum


dhaE
AAC27924.1
3360391
Clostridium pasteuranum


dhaB
P45514.1
1169287
Citrobacter freundii


dhaC
AAB48851.1
1229154
Citrobacter freundii


dhaE
AAB48852.1
1229155
Citrobacter freundii









If a B12-dependent diol dehydratase is utilized, heterologous expression of the corresponding reactivating factor is recommended. B12-dependent diol dehydratases are subject to mechanism-based suicide activation by substrates and some downstream products. Inactivation, caused by a tight association with inactive cobalamin, can be partially overcome by diol dehydratase reactivating factors in an ATP-dependent process. Regeneration of the B12 cofactor requires an additional ATP. Diol dehydratase regenerating factors are two-subunit proteins. Exemplary candidates are found in Klebsiella oxytoca (Mori et al., J Biol. Chem. 272:32034-32041 (1997)), Salmonella typhimurium (Bobik et al., J Bacteriol. 179:6633-6639 (1997); Chen et al., J Bacteriol. 176:5474-5482 (1994)), Lactobacillus collinoides (Sauvageot et al., FEMS Microbiol Lett. 209:69-74 (2002)), Klebsiella pneumonia (World Patent WO 2008/137403).













Protein
GenBank ID
GI Number
Organism


















ddrA
AAC15871
3115376
Klebsiella oxytoca


ddrB
AAC15872
3115377
Klebsiella oxytoca


pduG
AAB84105
16420573
Salmonella typhimurium


pduH
AAD39008
16420574
Salmonella typhimurium


pduG
YP_002236779
206579698
Klebsiella pneumonia


pduH
YP_002236778
206579863
Klebsiella pneumonia


pduG
CAD01092
29335724
Lactobacillus collinoides


pduH
AJ297723
29335725
Lactobacillus collinoides









B12-independent diol dehydratase enzymes utilize S-adenosylmethionine (SAM) as a cofactor and function under strictly anaerobic conditions. The glycerol dehydrogenase and corresponding activating factor of Clostridium butyricum, encoded by dhaB1 and dhaB2, have been well-characterized (O'Brien et al., Biochemistry 43:4635-4645 (2004); Raynaud et al., Proc. Natl. Acad. Sci U.S.A 100:5010-5015 (2003)). This enzyme was recently employed in a 1,3-propanediol overproducing strain of E. coli and was able to achieve very high titers of product (Tang et al., Appl. Environ. Microbiol. 75; 1628-1634 (2009)). An additional B12-independent diol dehydratase enzyme and activating factor from Roseburia inulinivorans was shown to catalyze the conversion of 2,3-butanediol to 2-butanone (US 2009/09155870).













Protein
GenBank ID
GI Number
Organism







dhaB1
AAM54728.1
27461255
Clostridium butyricum


dhaB2
AAM54729.1
27461256
Clostridium butyricum


rdhtA
ABC25539.1
83596382
Roseburia inulinivorans


rdhtB
ABC25540.1
83596383
Roseburia inulinivorans









Dihydroxy-acid dehydratase (DHAD, EC 4.2.1.9) is a B12-independent enzyme participating in branched-chain amino acid biosynthesis. In its native role, it converts 2,3-dihydroxy-3-methylvalerate to 2-keto-3-methyl-valerate, a precursor of isoleucine. In valine biosynthesis the enzyme catalyzes the dehydration of 2,3-dihydroxy-isovalerate to 2-oxoisovalerate. The DHAD from Sulfolobus solfataricus has a broad substrate range and activity of a recombinant enzyme expressed in E. coli was demonstrated on a variety of aldonic acids (KIM et al., J. Biochem. 139:591-596 (2006)), The S. solfataricus enzyme is tolerant of oxygen unlike many diol dehydratase enzymes. Substrate (1) has not been tested to date. The E. coli enzyme, encoded by ilvD, is sensitive to oxygen, which inactivates its iron-sulfur cluster (Flint et al., J. Biol. Chem. 268:14732-14742 (1993)). Similar enzymes have been characterized in Neurospora crassa (Altmiller et al., Arch. Biochem. Biophys. 138:160-170 (1970)) and Salmonella typhimurium (Armstrong et al., Biochim. Biophys. Acta 498:282-293 (1977)).













Protein
GenBank ID
GI Number
Organism







ilvD
NP_344419.1
15899814
Sulfolobus solfataricus


ilvD
AAT48208.1
48994964
Escherichia coli


ilvD
NP_462795.1
16767180
Salmonella typhimurium


ilvD
XP_958280.1
85090149
Neurospora crassa









FIG. 3, Step D—3-Hydroxypropanal Reductase Enzymes that reduce aldehydes to alcohols are suitable candidates for the reduction of 3-hydroxypropanal and glyceraldehyde-3-phosphate. Exemplary genes encoding enzymes that catalyze the conversion of an aldehyde to alcohol (i.e., alcohol dehydrogenase or equivalently aldehyde reductase) include alrA encoding a medium-chain alcohol dehydrogenase for C2-C14 (Tani et al., Appl. Environ. Microbiol. 66:5231-5235 (2000)), yqhD and fucO from E. coli (Sulzenbacher et al., 342:489-502 (2004)), and bdh I and bdh II from C. acetobutylicum which converts butyryaldehyde into butanol (Walter et al., 174:7149-7158 (1992)). YqhD catalyzes the reduction of a wide range of aldehydes using NADPH as the cofactor, with a preference for chain lengths longer than C(3) (Sulzenbacher et al., 342:489-502 (2004); Perez et al., J Biol. Chem. 283:7346-7353 (2008)). The adhA gene product from Zymomonas mobilisE has been demonstrated to have activity on a number of aldehydes including formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, and acrolein (Kinoshita et al., Appl Microbiol Biotechnol 22:249-254 (1985)). Additional aldehyde reductase candidates are encoded by bdh in C. saccharoperbutylacetonicum and Cbei_1722, Cbei_2181 and Cbei_2421 in C. beijerinckii.













Protein
GenBank ID
GI Number
Organism


















alrA
BAB12273.1
9967138
Acinetobacter sp. strain M-1


ADH2
NP_014032.1
6323961
Saccharomyces cerevisiae


yqhD
NP_417484.1
16130909
Escherichia coli


fucO
NP_417279.1
16130706
Escherichia coli


bdh I
NP_349892.1
15896543
Clostridium acetobutylicum


bdh II
NP_349891.1
15896542
Clostridium acetobutylicum


adhA
YP_162971.1
56552132
Zymomonas mobilis


bdh
BAF45463.1
124221917
Clostridium saccharoperbutylacetonicum


Cbei_1722
YP_001308850
150016596
Clostridium beijerinckii


Cbei_2181
YP_001309304
150017050
Clostridium beijerinckii


Cbei_2421
YP_001309535
150017281
Clostridium beijerinckii









Aldehyde reductase gene candidates in Saccharomyces cerevisiae include the aldehyde reductases GRE3, ALD2-6 and HFD1, glyoxylate reductases GOR1 and YPL113C and glycerol dehydrogenase GCY1 (WO 2011/022651A1; Atsumi et al., Nature 451:86-89 (2008)). The enzyme candidates described previously for catalyzing the reduction of methylglyoxal to acetol or lactaldehyde are also suitable lactaldehyde reductase enzyme candidates.













Protein
GenBank ID
GI Number
Organism


















GRE3
P38715.1
731691
Saccharomyces cerevisiae


ALD2
CAA89806.1
825575
Saccharomyces cerevisiae


ALD3
NP_013892.1
6323821
Saccharomyces cerevisiae


ALD4
NP_015019.1
6324950
Saccharomyces cerevisiae


ALD5
NP_010996.2
330443526
Saccharomyces cerevisiae


ALD6
ABX39192.1
160415767
Saccharomyces cerevisiae


HFD1
Q04458.1
2494079
Saccharomyces cerevisiae


GOR1
NP_014125.1
6324055
Saccharomyces cerevisiae


YPL113C
AAB68248.1
1163100
Saccharomyces cerevisiae


GCY1
CAA99318.1
1420317
Saccharomyces cerevisiae









Enzymes exhibiting 4-hydroxybutyrate dehydrogenase activity (EC 1.1.1.61) also fall into this category. Such enzymes have been characterized in Ralstonia eutrophy (Bravo et al., J Forens Sci, 49:379-387 (2004)), Clostridium kluyveri (Wolff et al., Protein Expr. Purif. 6:206-212 (1995)) and Arabidopsis thaliana (Breitkreuz et al., J Biol Chem, 278:41552-41556 (2003)). The A. thaliana enzyme was cloned and characterized in yeast (Breitkreuz et al., J. Biol. Chem. 278:41552-41556 (2003)). Yet another gene is the alcohol dehydrogenase adhI from Geobacillus thermoglucosidasius Peon et al., J Biotechnol 135:127-133 (2008)).













Protein
GenBank ID
GI Number
Organism


















4hbd
YP_726053.1
113867564
Ralstonia eutropha H16


4hbd
L21902.1
146348486
Clostridium kluyveri DSM 555


4hbd
Q94B07
75249805
Arabidopsis thaliana


adhI
AAR91477.1
40795502
Geobacillus





thermoglucosidasius









Another exemplary enzyme is methylmalonate semialdehyde reductase, also known as 3-hydroxyisobutyrate dehydrogenase (EC 1.1.1.31). This enzyme participates in valine, leucine and isoleucine degradation and has been identified in bacteria, eukaryotes, and mammals. The enzyme encoded by P84067 from Thermus thermophilus HB8 has been structurally characterized (Lokanath et al., J Mol Biol, 352:905-17 (2005)). The reversibility of the human 3-hydroxyisobutyrate dehydrogenase was demonstrated using isotopically-labeled substrate (Manning et al., Biochem J, 231:481-4 (1985)). Additional genes encoding this enzyme include 3hidh in Homo sapiens (Hawes et al., Methods Enzymol, 324:218-228 (2000)) and Oryctolagus cuniculus (Hawes et al., supra; Chowdhury et al., Biosci. Biotechnol Biochem. 60:2043-2047 (1996)), mmsB in Pseudomonas aeruginosa and Pseudomonas putida, and dhat in Pseudomonas putida (Aberhart et al., J Chem. Soc. [Perkin 1] 6:1404-1406 (1979); Chowdhury et al., Biosci. Biotechnol Biochem. 60:2043-2047 (1996); Chowdhury et al., Biosci. Biotechnol Biochem. 67:438-441 (2003)). Several 3-hydroxyisobutyrate dehydrogenase enzymes have been characterized in the reductive direction, including mmsB from Pseudomonas aeruginosa (Gokarn et al., U.S. Pat. No. 739,676, (2008)) and mmsB from Pseudomonas putida.













Protein
GenBank ID
GI Number
Organism


















P84067
P84067
75345323
Thermus thermophilus


3hidh
P31937.2
12643395
Homo sapiens


3hidh
P32185.1
416872
Oryctolagus cuniculus


mmsB
NP_746775.1
26991350
Pseudomonas putida


mmsB
P28811.1
127211
Pseudomonas aeruginosa


dhat
Q59477.1
2842618
Pseudomonas putida









FIG. 3, Step E—Dihydroxyacetone Phosphate Phosphatase or Dihydroxyacetone Kinase

Kinase or phosphotransferase enzymes in the EC class 2.7.2 transform carboxylic acids to phosphonic acids with concurrent hydrolysis of one ATP. Such an enzyme is required to form dihydroxyacetone from dihydroxyacetone phosphate and glycerol from glycerol-3-phosphate. Exemplary dihydroxyacetone kinases enzymes (EC 2.7.2.29) include DAK from Pichia angusta and dhaK from Citrobacter freundii (van der Klei et al, Curr Genet, 34:1-11 (1998); Daniel et al., J Bacteriol, 177:4392-401 (1995)). The E. coli enzyme is encoded by dhaKLM (Bachler et al, EMBO J, 24: 283-93 (2005)).













Protein
GenBank ID
GI Number
Organism


















dhaK
AAC74284.2
87081857
Escherichia coli


dhaL
AAC74283.1
1787449
Escherichia coli


dhaM
NP_415717.1
16129162
Escherichia coli


DAK
AAC27705.1
3171001
Pichia angusta


dhaK
AAB48843.1
493083
Citrobacter freundii









The conversion of dihydroxyacetone phosphate to dihydroxyacetone is catalyzed by dihydroxyacetone phosphate phosphatase. The acid phosphatase of Xenopus laevis was shown to catalyze the hydrolysis of a wide range of acid phosphatases including dihydroxyacetone phosphate (Filburn, Arch Biochem Biophys 159:683-93 (1973)). The gene associated with this enzyme is not known.
Other suitable enzyme candidates for hydrolyzing glyceraldehydes-3-phosphate or dihydroxyacetone phosphate is 3-phosphoglycerate phosphatase (EC 3.1.3.38), catalyzing the hydrolysis of 3PG to glycerate. The enzyme is found in plants and has a broad substrate range that includes phosphoenolpyruvate, ribulose-1,5-bisphosphate, dihydroxyacetone phosphate and glucose-6-phosphate (Randall et al., Plant Physiol 48:488-492 (1971); Randall et al., J Biol. Chem. 246:5510-5517 (1971)). Purified enzyme from various plant sources has been characterized but a gene has not been associated with this enzyme to date. Another enzyme with 3-phosphoglycerate phosphatase activity is the phosphoglycerate phosphatase (EC 3.1.3.20) from pig liver (Fallon et al., Biochim. Biophys. Acta 105:43-53 (1965)). The gene associated with this enzyme is not available.
The enzyme alkaline phosphatase (EC 3.1.3.1) hydrolyses a broad range of phosphorylated substrates to their corresponding alcohols. These enzymes are typically secreted into the periplasm in bacteria, where they play a role in phosphate transport and metabolism. The E. coli phoA gene encodes a periplasmic zinc-dependent alkaline phosphatase active under conditions of phosphate starvation (Coleman Annu. Rev. Biophys. Biomol. Struct. 21:441-83 (1992)). Similar enzymes have been characterized in Campylobacter jejuni (van Mourik et al., Microbiol. 154:584-92 (2008)), Saccharomyces cerevisiae (Oshima et al., Gene 179:171-7 (1996)) and Staphylococcus aureus (Shah and Blobel, J. Bacteriol. 94:780-1 (1967)). Enzyme engineering and/or removal of targeting sequences may be required for alkaline phosphatase enzymes to function in the cytoplasm.













Protein
GenBank ID
GI Number
Organism


















phoA
NP_414917.2
49176017
Escherichia coli


phoX
ZP_01072054.1
86153851
Campylobacter jejuni


PHO8
AAA34871.1
172164
Saccharomyces





cerevisiae


SaurJH1_2706
YP_001317815.1
150395140
Staphylococcus aureus









FIG. 3, Step F—Dihydroxyacetone Reductase

Dihydroxyacetone reductase (EC 1.1.1.6 and 1.1.1.156) or glycerol dehydrogenase enzymes have been characterized in numerous organisms. An exemplary NADPH-dependent dihydroxyacetone reductase is encoded by gld2 of Hypocrea jecorina (Liepins et al, FEBS J 273:4229-4235 (2006)). NADH-dependent enzymes include gldA of E. coli and dhaD of Klebsiella pneumoniae (Altaras and Cameron., Appl Env Microbiol., 65:1180-1185 (1999)). The glycerol dehydrogenase GCY1 of Saccharomyces cerevisiae is also suitable here (WO 2011/022651A1).













Protein
GenBank ID
GI Number
Organism


















Gld2
Q0GYU4
121924008
Hypocrea jecorina


GCY1
CAA99318.1
1420317
Saccharomyces cerevisiae


gldA
AAC76927.2
87082352
Escherichia coli


dhaD
ABO15720.1
126513217
Klebsiella pneumoniae









FIG. 3, Step G—Dihydroxyacetone Phosphate Reductase

The reduction of dihydroxyacetone phosphate to glycerol-3-phosphate is catalyzed by numerous enzymes including glycerol-3-phosphate dehydrogenase, glycerol dehydrogenase, galactitol 2-dehydrogenase D-xylulose reductase and glycerol-1-phosphate dehydrogenase. Exemplary glycerol-3-phosphate dehydrogenase enzymes with demonstrated dihydroxyacetone phosphate reductase activity include GPD1 of Saccharomyces cerevisiae (Carnbon et al, Appl Environ Microbiol 72:4688-94 (2006)) and GPDH of Osmerus mordax (Liebscher et al, Physiol Biochem Zool 79:411-23 (2006)). The galactitol dehydrogenase of Rhodobacter sphaeroides also has this activity (Carius et al, J Biol Chem, 25:20006-14 (2010)). The glycerol dehydrogenase enzyme of Emericella nidulans also catalyzes this reaction (Schuurink et al, J Gen Microbiol 136:1043-50 (1990)).













Protein
GenBank ID
GI Number
Organism


















GPD1
CAA98582.1
1430995
Saccharomyces cerevisiae


GatDH
ACM89305.1
223413895
Rhodobacter sphaeroides


gldB
Q7Z8L1
74619179
Emericella nidulans









4.4 Example IV—Methods of Using Formaldehyde Produced from the Oxidation of Methanol in the Formation of Intermediates of Central Metabolic Pathways for the Formation of Biomass
Provided herein are exemplary pathways, which utilize formaldehyde produced from the oxidation of methanol (see, e.g., FIG. 1, step J) in the formation of intermediates of certain central metabolic pathways that can be used for the formation of biomass. Exemplary methanol metabolic pathways for enhancing the availability of reducing equivalents, as well as the producing formaldehyde from methanol (step J), are provided in FIG. 1.
One exemplary pathway that can utilize formaldehyde produced from the oxidation of methanol (e.g., as provided in FIG. 1) is shown in FIG. 4, which involves condensation of formaldehyde and D-ribulose-5-phosphate to form hexylose-6-phosphate (h6p) by hexylose-6-phosphate synthase (FIG. 4, step A). The enzyme can use Mg2+ or Mn2+ for maximal activity, although other metal ions are useful, and even non-metal-ion-dependent mechanisms are contemplated. H6p is converted into fructose-6-phosphate by 6-phospho-3-hexyloisomerase (FIG. 4, step B).
Another exemplary pathway that involves the detoxification and assimilation of formaldehyde produced from the oxidation of methanol (e.g., as provided in FIG. 1) is shown in FIG. 5 and proceeds through dihydroxyacetone. Dihydroxyacetone synthase is a special transketolase that first transfers a glycoaldehyde group from xylulose-5-phosphate to formaldehyde, resulting in the formation of dihydroxyacetone (DHA) and glyceraldehyde-3-phosphate (G3P), which is an intermediate in glycolysis (FIG. 5, step A). The DHA obtained from DHA synthase is then further phosphorylated to form DHA phosphate by a DHA kinase (FIG. 5, step B). DHAP can be assimilated into glycolysis and several other pathways.
FIG. 4, Steps A and B—Hexylose-6-phosphate synthase (Step A) and 6-phospho-3-hexyloisomerase (Step B)
Both of the hexylose-6-phosphate synthase and 6-phospho-3-hexyloisomerase enzymes are found in several organisms, including methanotrops and methylotrophs where they have been purified (Kato et al., 2006, BioSci Biotechnol Biochem. 70(1):10-21. In addition, these enzymes have been reported in heterotrophs such as Bacillus subtilis also where they are reported to be involved in formaldehyde detoxification (Mitsui et al., 2003, AEM 69(10):6128-32, Yasueda et al., 1999. J Bac 181(23):7154-60. Genes for these two enzymes from the methylotrophic bacterium Mycobacterium gastri MB19 have been fused and E. coli strains harboring the hps-phi construct showed more efficient utilization of formaldehyde (Orita et al. 2007, Appl Microbiol Biotechnol. 76:439-445). In some organisms, these two enzymes naturally exist as a fused version that is bifunctional.
Exemplary candidate genes for hexylose-6-phopshate synthase are:













Protein
GenBank ID
GI number
Organism


















Hps
AAR39392.1
40074227
Bacillus methanolicus MGA3


Hps
EIJ81375.1
387589055
Bacillus methanolicus PB1


RmpA
BAA83096.1
5706381
Methylomonas aminofaciens


RmpA
BAA90546.1
6899861
Mycobacterium gastri


YckG
BAA08980.1
1805418
Bacillus subtilis









Exemplary gene candidates for 6-phospho-3-hexyloisomerase are:













Protein
GenBank ID
GI number
Organism


















Phi
AAR39393.1
40074228
Bacillus methanolicus MGA3


Phi
EIJ81376.1
387589056
Bacillus methanolicus PB1


Phi
BAA83098.1
5706383
Methylomonas aminofaciens


RmpB
BAA90545.1
6899860
Mycobacterium gastri









Candidates for enzymes where both of these functions have been fused into a single open reading frame include the following.













Protein
GenBank ID
GI number
Organism







PH1938
NP_143767.1
14591680
Pyrococcus horikoshii OT3


PF0220
NP_577949.1
18976592
Pyrococcus furiosus


TK0475
YP_182888.1
57640410
Thermococcus kodakaraensis



NP_127388.1
14521911
Pyrococcus abyssi


MCA2738
YP_115138.1
53803128
Methylococcus capsulatas









FIG. 5, Step A—Dihydroxyacetone Synthase

Another exemplary pathway that involves the detoxification and assimilation of formaldehyde produced from the oxidation of methanol (e.g., as provided in FIG. 1) is shown in FIG. 5 and proceeds through dihydroxyacetone. Dihydroxyacetone synthase is a special transketolase that first transfers a glycoaldehyde group from xylulose-5-phosphate to formaldehyde, resulting in the formation of dihydroxyacetone (DHA) and glyceraldehyde-3-phosphate (G3P), which is an intermediate in glycolysis (FIG. 5, step A). The DHA obtained from DHA synthase is then further phosphorylated to form DHA phosphate by a DHA kinase (FIG. 5, step B). DHAP can be assimilated into glycolysis and several other pathways.
The dihydroxyacetone synthase enzyme in candida boidinii uses thiamine pyrophosphate and Mg2+ as cofactors and is localized in the peroxisome. The enzyme from the methanol-growing carboxydobacterium, Mycobacter sp. strain JC1 DSM 3803, was also found to have DHA synthase and kinase activities (Ro et al., 1997, JBac 179(19):6041-7). DHA synthase from this organism also has similar cofactor requirements as the enzyme from C. boidinii. The Kms for formaldehyde and xylulose 5-phosphate were reported to be 1.86 mM and 33.3 microM, respectively. Several other mycobacteria, excluding only Mycobacterium tuberculosis, can use methanol as the sole source of carbon and energy and are reported to use dihydroxyacetone synthase (Part et al., 2003, JBac 185(1):142-7.













Protein
GenBank ID
GI number
Organism


















DAS1
AAC83349.1
3978466
Candida boidinii


HPODL_2613
EFW95760.1
320581540
Ogataea





parapolymorpha DL-1





(Hansenula





polymorpha DL-1)



AAG12171.2
18497328
Mycobacter sp.





strain JC1 DSM





3803









FIG. 5, Step B—Dihydroxyacetone (DHA) Kinase

DHA obtained from DHA synthase is further phosphorylated to form DHA phosphate by a DHA kinase. DHAP can be assimilated into glycolysis and several other pathways. Dihydroxyacetone kinase has been purified from Ogataea angusta to homogeneity (Bystrkh, 1983, Biokhimiia, 48(10):1611-6). The enzyme, which phosphorylates dihydroxyacetone and, to a lesser degree, glyceraldehyde, is a homodimeric protein of 139 kDa. ATP is the preferred phosphate group donor for the enzyme. When ITP, GTP, CTP and UTP are used, the activity drops to about 30%. In several organisms such as Klebsiella pneumoniae and Citrobacter fruendii (Daniel et al., 1995, JBac 177(15):4392-40), DHA is formed as a result of oxidation of glycerol and is converted into DHAP by the kinase DHA kinase of K. pneumoniae has been characterized (Jonathan et al, 1984, JBac 160(1):55-60). It is very specific for DHA, with a Km of 4 μM, and has two apparent Km values for ATP, one at 25 to 35 μM, and the other at 200 to 300 μM. DHA can also be phosphorylated by glycerol kinases but the DHA kinase from K. puemoniae is different from glycerol kinase in several respects. While both enzymes can phosphorylate dihydroxyacetone, DHA kinase does not phosphorylate glycerol, neither is it inhibited by fructose-1,6-diphosphate. in Saccharomyces cerevisiae, DHA kinases (I and II) are involved in rescuing the cells from toxic effects of dihydroxyacetone (Molin et al., 2003, J Biol Chem. 17; 278(3):1415-23).
In Escherichia coli, DHA kinase is composed of the three subunits DhaK, DhaL, and DhaM and it functions similarly to a phosphotransferase system (PTS) in that it utilizes phosphoenolpyruvate as a phosphoryl donor (Gutknecht et al., 2001, EMBO J. 20(10):2480-6). It differs in not being involved in transport. The phosphorylation reaction requires the presence of the EI and HPr proteins of the PTS system. The DhaM subunit is phosphorylated at multiple sites. DhaK contains the substrate binding site (Garcia-Alles et al., 2004, 43(41):13037-45; Siebold et al., 2003, PNAS. 100(14):8188-92). The KM for dihydroxyacetone for the E. coli enzyme has been reported to be 6 μM. The K subunit is similar to the N-terminal half of ATP-dependent dihydroxyacetone kinase of Citrobacter freundii and eukaryotes.
Exemplary DHA kinase gene candidates for this step are:













Protein
GenBank ID
GI number
Organism


















DAK1
P54838.1
1706391
Saccharomyces





cerevisiae S288c


DAK2
P43550.1
1169289
Saccharomyces





cerevisiae S288c


D186_20916
ZP_16280678.1
421847542
Citrobacter freundii


DAK2
ZP_18488498.1
425085405
Klebsiella pneumoniae


DAK
AAC27705.1
3171001
Ogataea angusta


DhaK
NP_415718.6
162135900
Escherichia coli


DhaL
NP_415717.1
16129162
Escherichia coli


DhaM
NP_415716.4
226524708
Escherichia coli









4.5 Example V—Methods for Handling Anaerobic Cultures
This example describes methods used in handling anaerobic cultures.
A. Anaerobic Chamber and Conditions.
Exemplary anaerobic chambers are available commercially (see, for example, Vacuum Atmospheres Company, Hawthorne Calif.; MBraun, Newburyport Mass.). Conditions included an O2 concentration of 1 ppm or less and 1 atm pure N2. In one example, 3 oxygen scrubbers/catalyst regenerators were used, and the chamber included an O2 electrode (such as Teledyne; City of Industry Calif.). Nearly all items and reagents were cycled four times in the airlock of the chamber prior to opening the inner chamber door. Reagents with a volume>5 mL were sparged with pure N2 prior to introduction into the chamber. Gloves are changed twice/yr and the catalyst containers were regenerated periodically when the chamber displays increasingly sluggish response to changes in oxygen levels. The chamber's pressure was controlled through one-way valves activated by solenoids. This feature allowed setting the chamber pressure at a level higher than the surroundings to allow transfer of very small tubes through the purge valve.
The anaerobic chambers achieved levels of O2 that were consistently very low and were needed for highly oxygen sensitive anaerobic conditions. However, growth and handling of cells does not usually require such precautions. In an alternative anaerobic chamber configuration, platinum or palladium can be used as a catalyst that requires some hydrogen gas in the mix. Instead of using solenoid valves, pressure release can be controlled by a bubbler. Instead of using instrument-based O2 monitoring, test strips can be used instead.
B. Anaerobic Microbiology.
Serum or media bottles are fitted with thick rubber stoppers and aluminum crimps are employed to seal the bottle. Medium, such as Terrific Broth, is made in a conventional manner and dispensed to an appropriately sized serum bottle. The bottles are sparged with nitrogen for  ̃30 min of moderate bubbling. This removes most of the oxygen from the medium and, after this step, each bottle is capped with a rubber stopper (such as Bellco 20 mm septum stoppers; Bellco, Vineland, N.J.) and crimp-sealed (Bellco 20 mm). Then the bottles of medium are autoclaved using a slow (liquid) exhaust cycle. At least sometimes a needle can be poked through the stopper to provide exhaust during autoclaving; the needle needs to be removed immediately upon removal from the autoclave. The sterile medium has the remaining medium components, for example buffer or antibiotics, added via syringe and needle. Prior to addition of reducing agents, the bottles are equilibrated for 30-60 minutes with nitrogen (or CO depending upon use). A reducing agent such as a 100×150 mM sodium sulfide, 200 mM cysteine-HCl is added. This is made by weighing the sodium sulfide into a dry beaker and the cysteine into a serum bottle, bringing both into the anaerobic chamber, dissolving the sodium sulfide into anaerobic water, then adding this to the cysteine in the serum bottle. The bottle is stoppered immediately as the sodium sulfide solution generates hydrogen sulfide gas upon contact with the cysteine. When injecting into the culture, a syringe filter is used to sterilize the solution. Other components are added through syringe needles, such as B12 (10 μM cyanocobalamin), nickel chloride (NiCl2, 20 microM final concentration from a 40 mM stock made in anaerobic water in the chamber and sterilized by autoclaving or by using a syringe filter upon injection into the culture), and ferrous ammonium sulfate (final concentration needed is 100 μM—made as 100-1000× stock solution in anaerobic water in the chamber and sterilized by autoclaving or by using a syringe filter upon injection into the culture). To facilitate faster growth under anaerobic conditions, the 1 liter bottles were inoculated with 50 mL of a preculture grown anaerobically. Induction of the pA1-lacO1 promoter in the vectors was performed by addition of isopropyl β-D-1-thiogalactopyranoside (IPTG) to a final concentration of 0.2 mM and was carried out for about 3 hrs.
Large cultures can be grown in larger bottles using continuous gas addition while bubbling. A rubber stopper with a metal bubbler is placed in the bottle after medium addition and sparged with nitrogen for 30 minutes or more prior to setting up the rest of the bottle. Each bottle is put together such that a sterile filter will sterilize the gas bubbled in and the hoses on the bottles are compressible with small C clamps. Medium and cells are stirred with magnetic stir bars. Once all medium components and cells are added, the bottles are incubated in an incubator in room air but with continuous nitrogen sparging into the bottles.
Throughout this application various publications have been referenced. The disclosures of these publications in their entireties, including GenBank and GI number publications, are hereby incorporated by reference in this application in order to more fully describe the state of the art to which this invention pertains. Although the invention has been described with reference to the examples and embodiments provided above, it should be understood that various modifications can be made without departing from the spirit of the invention.

## Claims

1. A non-naturally occurring microbial organism comprising:
(A) a methanol metabolic pathway, wherein said non-naturally occurring microbial organism comprises at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme expressed in a sufficient amount to enhance the availability of reducing equivalents in the presence of methanol or metabolize methanol as a carbon source for biosynthesis of 1,2-propanediol or n-propanol, wherein said methanol metabolic pathway comprises:
(i) a methanol methyltransferase and a methylenetetrahydrofolate reductase;
(ii) a methanol dehydrogenase; or
(iii) a methanol dehydrogenase and a formaldehyde activating enzyme; and one of:

(B) a 1,2-propanediol pathway wherein the non-naturally occurring microbial organism comprises at least one exogenous nucleic acid encoding a 1,2-propanediol pathway enzyme expressed in a sufficient amount to produce 1,2-propanediol, wherein said 1,2-propanediol pathway comprises the 1,2 propanediol pathway enzymes:
(i) 2A, 2B, and 2C; or
(ii) 2A, 2D, and 2E; or

(C) a n-propanol pathway wherein the non-naturally occurring microbial organism comprises at least one exogenous nucleic acid encoding a n-propanol pathway enzyme expressed in a sufficient amount to produce n-propanol, wherein said n-propanol pathway comprises n-propanol pathway enzymes:
(i) 2A, 2B, 2C, 2F, and 2G; or
(ii) 2A, 2D, 2E, 2F, and 2G;

wherein 2A is a methylglyoxal synthase that enzymatically converts dihydroxyacetone phosphate to methylglyoxal, 2B is a methylglyoxal reductase (acetol-forming) that enzymatically converts methylglyoxal to acetol, 2C is an acetol reductase that enzymatically converts acetol to 1,2-propanediol, 2D is a methylglyoxal reductase (lactaldehyde-forming) that enzymatically converts methylglyoxal to lactaldehyde, 2E is a lactaldehyde reductase that converts lactaldehyde to 1,2-propanediol, 2F is a 1,2-propanediol dehydratase that converts 1,2-propanediol to propanal, and 2G is a propanal reductase that converts propanal to propanol.

2. The non-naturally occurring microbial organism of claim 1, wherein
the non-naturally occurring microbial organism comprises two or three exogenous nucleic acids, each encoding a 1,2-propanediol pathway enzyme.

3. The organism of claim 1, wherein the methanol metabolic pathway comprises:
(i) a methanol methyltransferase, a methylenetetrahydrofolate reductase, a methylenetetrahydrofolate dehydrogenase, a methenyltetrahydrofolate cyclohydrolase, and a formyltetrahydrofolate deformylase;
(ii) a methanol methyltransferase, a methylenetetrahydrofolate reductase, a methylenetetrahydrofolate dehydrogenase, a methenyltetrahydrofolate cyclohydrolase and a formyltetrahydrofolate synthetase;
(iii) a methanol dehydrogenase, a methylenetetrahydrofolate dehydrogenase, a methenyltetrahydrofolate cyclohydrolase and a formyltetrahydrofolate deformylase;
(iv) a methanol dehydrogenase, a methylenetetrahydrofolate dehydrogenase, a methenyltetrahydrofolate cyclohydrolase and a formyltetrahydrofolate synthetase;
(v) a methanol dehydrogenase and a formaldehyde dehydrogenase;
(vi) a methanol dehydrogenase, a S-(hydroxymethyl)glutathione synthase, a glutathione-dependent formaldehyde dehydrogenase and a S-formylglutathione hydrolase;
(vii) a methanol dehydrogenase, a glutathione-dependent formaldehyde dehydrogenase and a S-formylglutathione hydrolase;
(viii) a methanol dehydrogenase, a formaldehyde activating enzyme, a methylenetetrahydrofolate dehydrogenase, a methenyltetrahydrofolate cyclohydrolase and a formyltetrahydrofolate deformylase; or
(ix) a methanol dehydrogenase, a formaldehyde activating enzyme, a methylenetetrahydrofolate dehydrogenase, a methenyltetrahydrofolate cyclohydrolase and a formyltetrahydrofolate synthetase.

4. The non-naturally occurring microbial organism of claim 1, wherein:
said non-naturally occurring microbial organism comprises two, three, four, five, six or seven exogenous nucleic acids, each encoding a methanol metabolic pathway enzyme.

5. The non-naturally occurring microbial organism of claim 1, further comprising a formaldehyde assimilation pathway, wherein said non-naturally occurring microbial organism comprises at least one exogenous nucleic acid encoding a formaldehyde assimilation pathway enzyme expressed in a sufficient amount to produce an intermediate of glycolysis and/or a metabolic pathway that can be used in the formation of biomass, and wherein said formaldehyde assimilation pathway comprises:
(A) a hexulose-6-phosphate synthase and a 6-phospho-3-hexuloisomerase; or
(B) a dihydroxyacetone synthase and a dihydroxyacetone kinase.

6. The non-naturally occurring microbial organism of claim 1, wherein-said organism is a species of bacteria, yeast, or fungus.

7. A method for producing 1,2-propanediol or n-propanol; the method comprising culturing the respective non-naturally occurring microbial organism of claim 1 under conditions and for a sufficient period of time to produce 1,2-propanediol or n-propanol.

8. The non-naturally occurring microbial organism of claim 1, wherein the at least one exogenous nucleic acid encoding a methanol metabolic pathway enzyme is a heterologous nucleic acid.

9. The non-naturally occurring microbial organism of claim 1, wherein the at least one exogenous nucleic acid encoding a 1,2-propanediol pathway enzyme is a heterologous nucleic acid.

10. The non-naturally occurring microbial organism of claim 1, wherein the non-naturally occurring microbial organism comprises two, three, four or five exogenous nucleic acids, each encoding a n-propanol pathway enzyme.

11. The non-naturally occurring microbial organism of claim 1, wherein the at least one exogenous nucleic acid encoding a n-propanol pathway enzyme is a heterologous nucleic acid.

12. The non-naturally occurring microbial organism of claim 1, wherein the non-naturally occurring microbial organism comprises one or more gene disruptions, the one or more gene disruptions occurring in one or more endogenous genes encoding protein(s) or enzyme(s) involved in native production of ethanol, glycerol, acetate, lactate, formate, CO2, and/or amino acids, by the non-naturally occurring microbial organism, and wherein the one or more gene disruptions confer(s) increased production of 1,2-propanediol or n-propanol in the non-naturally occurring microbial organism.

13. The non-naturally occurring microbial organism of claim 12, wherein the one or more endogenous enzymes involved in native production of ethanol, glycerol, acetate, lactate, formate, CO2 and/or amino acids by said microbial organism have attenuated enzyme activity or expression levels.

14. The non-naturally occurring microbial organism of claim 3, wherein the methanol metabolic pathway further comprises:
(A) a formate dehydrogenase;
(B) a formate hydrogen lyase; or
(C) a formate hydrogen lyase and a hydrogenase.

15. The non-naturally occurring microbial organism of claim 5, wherein the intermediate of glycolysis and/or a metabolic pathway is:
(A) a hexulose-6-phosphate, a fructose-6-phosphate, or a combination thereof;
or
(B) a dihydroxyacetone, a dihydroxyacetone phosphate, or a combination thereof.

16. The non-naturally occurring microbial organism of claim 5, wherein the non-naturally occurring microbial organism comprises two exogenous nucleic acids, each encoding a formaldehyde assimilation pathway enzyme.

17. The non-naturally occurring microorganism of claim 6, wherein the non-naturally occurring microbial organism is selected from the group consisting of:
(A) Escherichia coli, Klebsiella oxytoca, Anaerobiospirillum succiniciproducens, Actinobacillus succinogenes, Mannheimia succiniciproducens, Rhizobium etli, Bacillus subtilis, Corynebacterium glutamicum, Gluconobacter oxydans, Zymomonas mobilis, Lactococcus lactis, Lactobacillus plantarum, Streptomyces coelicolor, Clostridium acetobutylicum, Pseudomonas fluorescens, and Pseudomonas putida; or
(B) Saccharomyces cerevisiae, Schizosaccharomyces pombe, Kluyveromyces lactis, Kluyveromyces marxianus, Aspergillus terreus, Aspergillus niger, Pichia pastoris, Rhizopus arrhizus, and Rhizopus oryzae.

18. The method of claim 7, wherein the method further comprises separating the 1,2-propanediol or n-propanol from other components in the culture.

19. The method of claim 18, wherein the separation comprises extraction, continuous liquid-liquid extraction, pervaporation, membrane filtration, membrane separation, reverse osmosis, electrodialysis, distillation, crystallization, centrifugation, extractive filtration, ion exchange chromatography, size exclusion chromatography, adsorption chromatography, or ultrafiltration.

20. The method of claim 7, wherein the non-naturally occurring microbial organism is cultured in a medium comprising biomass, glucose, xylose, arabinose, galactose, mannose, fructose, sucrose, starch, glycerol, methanol, carbon dioxide, formate, methane, or any combination thereof as a carbon source.

21. The method of claim 7, wherein the non-naturally occurring microbial organism is cultured in a medium comprising methanol as a carbon source.

22. The method of claim 7, wherein the non-naturally occurring microbial organism is cultured in a medium consisting essentially of methanol as a carbon source.

23. The method of claim 7, wherein the non-naturally occurring microbial organism is cultured in a substantially anaerobic culture medium.