bluuebunny/crossref_metadata_2025 huggingface dataset:
Feedback Regulation of 3-Deoxy-
d
-
arabino
-Heptulosonate 7-Phosphate Synthetase from a Marine Bacterium,
Vibrio
MB22
Authors: Chludzinski Andrew M. , Salter Donald S. , Nasser DeLill
Published: January 2020

A marine bacterium,
Vibrio
MB22, has been studied to determine the pattern of feedback regulation of the first enzyme unique to the biosynthesis of the aromatic amino acids, 3-deoxy-
d
-
arabino
-heptulosonate 7-phosphate (DAHP) synthetase. The crude extract was used to study response of the enzyme to various salts as well as possible feedback inhibitors. Ethylenediaminetetraacetic acid was found to be inhibitory to enzyme activity, and only CoCl
2
, of the salts tested, allowed full recovery as well as apparent stimulation of the DAHP synthetase activity. The DAHP synthetase activity was inhibited solely by the aromatic amino acids, tyrosine, tryptophan, and phenylalanine, of the possible effectors tested. Further work demonstrated the existence of three isozymes of DAHP synthetase, each primarily inhibited by one of the aromatic amino acids.
Requirement of Adenosine 3′,5′-Cyclic Phosphate for Formation of the Phage Lambda Receptor in
Escherichia coli
Authors: Yokota Takeshi , Kasuga Tokuhiko
Published: January 2020

Adenosine 3′,5′-cyclic phosphate is indispensable for formation of the phage lambda receptor in
Escherichia coli
K-12.
Ferredoxin- and Nicotinamide Adenine Dinucleotide-Dependent H
2
Production from Ethanol and Formate in Extracts of S Organism Isolated from “Methanobacillus omelianskii”
Authors: Reddy C. Adinarayana , Bryant M. P. , Wolin M. J.
Published: January 2020

S organism ferments ethanol to acetate and H
2
but grows poorly on ethanol unless the partial pressure of H
2
is kept low, as when it is grown in combination with an H
2
-utilizing methanogenic bacterium. The present study shows that S organism contains an alcohol dehydrogenase and a formate dehydrogenase, both of which require nicotinamide adenine dinucleotide (NAD) for activity. Hydrogen is evolved from NADH generated by these activities via a ferredoxin-dependent oxidation of NADH to NAD and H
2
. NADH:NADP oxido-reductase activity was also demonstrated. The relationship of these activities to the growth of S organism is discussed.
Metabolism of Pyrimidines and Pyrimidine Nucleosides by
Salmonella typhimurium
Authors: Beck Christoph F. , Ingraham John L. , Neuhard Jan , Thomassen Elisabeth
Published: January 2020

The pathways by which uracil, cytosine, uridine, cytidine, deoxyuridine, and deoxycytidine are metabolized by
Salmonella typhimurium
are established. The various 5-fluoropyrimidine analogues are shown to exert their toxic effects only after having been converted to the nucleotide level, and these conversions are shown to be catalyzed by the same enzymes which similarly convert the natural substrates. Methods for isolating mutant strains blocked in various steps of metabolism of pyrimidine bases and nucleosides are described.
Initiation of Spore Germination in Glycolytic Mutants of
Bacillus subtilis
Authors: Prasad Chandan , Diesterhaft Martin , Freese Ernst
Published: January 2020

Enzyme activities of glycolysis and glyconeogenesis are present in spores of
Bacillus subtilis
, the rate-limiting step of glucose (GLC) metabolism being its phosphorylation. GLC allows initiation of germination in the presence of fructose (FRU) and asparagine (ASN), not because it is used via the Embden-Meyerhof path, but because it is oxidized in the nonphosphorylated form via the spore-specific GLC dehydrogenase. Spores of mutants lacking GLC-phosphoenolpyruvate transferase, FRU-6-P-kinase, or phosphoglucoisomerase activity can still be initiated by the above substrate combination. Furthermore, GLC can be replaced by 2-deoxy-GLC, which is also oxidized by GLC-dehydrogenase, but not by α- or β-methylglucoside, which are not substrates of this enzyme. GLC probably acts by reducing nicotinamide adenine dinucleotide (or nicotinamide adenine dinucleotide phosphate), which is used for some metabolic reaction other than the cytochrome-linked electron transport system, since inhibitors of this system do not inhibit initiation. Spores of a mutant lacking FRU-1-P-kinase activity can no longer be initiated by GLC+FRU+ASN, but they do respond to the combination of GLC+mannose+ASN. Since spores of a FRU-6-P-kinase (or phosphoglucoisomerase) mutant can still respond to either FRU or mannose, FRU-6-P (or some derivative) apparently is needed for initiation (in addition to reduced nicotinamide adenine dinucleotide and an amino donor). Alanine can initiate germination in spores of all of the above mutants, indicating that it can form all required compounds. However, in a mutant lacking P-glycerate kinase activity, alanine initiates only after a long lag and at a slow rate, indicating that some compound in the upper metabolic subdivision is required for initiation, in agreement with the above findings. All initiating agents of
B. subtilis
probably produce the same required compound(s) by different metabolic routes.
Relationship Between Age of Culture and Occurrence of the Pigments of Photosystem II of Photosynthesis in Heterocysts of a Blue-Green Alga
Authors: Thomas Joseph
Published: January 2020

Microspectrophotometric examination of the pigments in vivo of heterocysts of
Anabaena
sp. L-31 has shown that most heterocysts of 2-day-old cultures possess only very small amounts, if any, of c-phycocyanin, allo-phycocyanin, and c-phycoerythrin, the main pigments comprising photosystem II of photosynthesis. The quantities of these pigments, however, increase with age of cultures, and by the end of 5 days the majority of heterocysts contain comparatively large amounts. The culmination of this sequential development is observed in most heterocysts of 7- to 15-day-old cultures when the full complement of photosystem II pigments is present. The spectral characteristics at this stage are similar to those of vegetative cells and suggest a dedifferentiation of heterocysts.
Regulation of Nitrate Reductase in
Neurospora crassa
: Regulation of Transcription and Translation
Authors: Subramanian K. N. , Sorger G. J.
Published: January 2020

A technique employing cycloheximide and actinomycin D has been used for the separation of transcription and translation during the induction of nitrate reductase in
Neurospora crassa
. Nitrate reductase is found to be synthesized in low efficiency when nitrate is not provided during both transcription and translation. Nitrate reductase synthesis is enhanced by nitrate. Nitrate is found to induce nitrate reductase by enhancing the increase of the capacity to synthesize nitrate reductase, and ammonia is found to repress nitrate reductase, by inhibiting the induced increase of the capacity to make the enzyme, or by making it unstable in vivo, or both. The effect of ammonia is partially reversed by nitrate. The addition of ammonium tartrate or the removal of nitrate during translation of the induced capacity to synthesize nitrate reductase is found to result in the inactivation of nitrate reductase in vivo. A low level of nitrate in the medium is found to be sufficient for enhancing the induced increase of the capacity to synthesize nitrate reductase, but a higher level of nitrate is required to stabilize the enzyme after its formation. The induced capacity to synthesize nitrate reductase is relatively stable in the presence or absence of nitrate, but not in the presence of ammonia.
Purification and Partial Characterization of a Bacteriocin from
Serratia marcescens
Authors: Foulds John
Published: January 2020

Bacteriocin JF246 has been purified from mitomycin C-induced
Serratia marcescens
cells by salt extraction, ammonium sulfate fractionation, and chromatography on QAE-Sephadex and SP-Sephadex. The purified material is homogeneous on polyacrylamide gel electrophoresis in the presence of 2% sodium dodecyl sulfate or 6
m
urea. In the absence of these agents, the bacteriocin associates into aggregates which can be dissociated with 0.4
m
NaCl. The bacteriocin is probably composed of a single subunit with a molecular weight of 64,000 daltons. Analytical studies show the bacteriocin to be essentially protein in nature containing less than one residue of glucose or phosphorus per 64,000 daltons.
Lytic Replication of Coliphage Lambda in
Salmonella typhosa
Hybrids
Authors: Baron L. S. , Ryman I. R. , Johnson E. M. , Gemski P.
Published: January 2020

Hybrids between
Escherichia coli
K-12 and
Salmonella typhosa
which conserved a continuous K-12 chromosomal diploid segment extending from
pro
through
ara
to the
strA
locus were sensitive to plaque formation by wild-type λ. These partially diploid
S. typhosa
hybrids could be lysogenized with λ and subsequently induced to produce infectious phage particles. When the K-12 genes were segregated from a lysogenic
S. typhosa
hybrid, phage-productive ability was no longer detectable due to loss of a genetic region necessary for vegetative replication of λ. However, λ prophage was shown to persist in a quiescent state in the
S. typhosa
hybrid segregant with phage-productive ability being reactivated after replacement of the essential K-12 λ replication region. Low-frequency transduction and high-frequency transduction lysates containing the
gal
+
genes of
S. typhosa
were prepared by induction of λ-lysogenic
S. typhosa
hybrids indicating that the
att
λ site is chromosomally located in
S. typhosa
in close proximity to the
gal
locus as in
E. coli
K-12. After propagation in
S. typhosa
hybrids, λ was subject to restriction by
E. coli
K-12 recipients, thus establishing that
S. typhosa
does not perform the K-12 modification of λ deoxyribonucleic acid. Hybrids of
S. typhosa
, however, did not restrict λ grown previously on
E. coli
K-12. The K-12 genetic region required for λ phage production in
S. typhosa
was located within min 66 to min 72 on the genetic map of the
E. coli
chromosome. Transfer of an F-merogenote encompassing the 66 to 72 min
E. coli
chromosomal region to λ-insensitive
S. typhosa
hybrids enabled them to replicate wild-type λ. The λ-insensitive
S. typhosa
hybrid, WR4255, which blocks λ replication, can be mutagenized to yield mutant strains sensitive to λ
vir
and λ
imm
434. These WR4255 mutants remained insensitive to plaque formation by wild-type λ.
Ribosome Maturation of
Escherichia coli
Growing at Different Growth Rates
Authors: Michaels George A.
Published: January 2020

The data reported here are consistent with the hypothesis that the rate of ribosome assembly in vivo approximates a constant fraction of the generation time for the four rates studied. This conclusion is indicated by the following. (i) There is an increased lag period before radioisotopically labeled uracil appears in 23 and 16
S
ribosomal ribonucleic acid of 70
S
ribosomes as a function of growth rate. (ii) The time necessary for
3
H-uracil in the 43
S
ribonucleoprotein precursor to the 50
S
subunit to assume a position at 50
S
in sucrose gradients is greatly increased inversely to the growth rate.
Arginine Control of Transcription of
argECBH
Messenger Ribonucleic Acid in
Escherichia coli
Authors: Krzyzek Richard , Rogers Palmer
Published: January 2020

The level of messenger ribonucleic acid specific for the
argECBH
gene cluster (
arg
-mRNA) of
Escherichia coli
was measured by deoxyribonucleic acid-ribonucleic acid hybridization in a number of strains. During the first 10 min after removal of arginine (derepression), the rate of
arg
-mRNA accumulation was six to ten times greater than that found in arginine-repressed
argR
+
cells. In the absence of arginine,
l
-canavanine (200 μg/ml) repressed
arg
-mRNA synthesis to a level only 20 to 30% lower than that found after arginine deprivation. High levels of
arg
-mRNA were produced by
argR
−
strains with or without added arginine. Within about 2 min after arginine addition to
argR
+
cells, the rate of synthesis of
arg
-mRNA reached the repressed level. Likewise, 2.5 min after rifampin addition, all transcription of
arg
-mRNA was completed. These data are consistent with the view that arginine signals repression by inhibiting the initiation of transcription of
arg
-mRNA mediated in some way by the
argR
gene. The kinetics of
arg
-mRNA accumulation and the kinetics of completion of transcription together with the profile of hybridizable
arg
-mRNA in sucrose density gradients (major component 16
S
) suggest that the
argECBH
gene cluster is transcribed in short pieces rather than as a single unit.
Mechanism of
d
-Cycloserine Action: Alanine Racemase from
Escherichia coli
W
Authors: Lambert Mary P. , Neuhaus Francis C.
Published: January 2020

The antibiotic
d
-cycloserine is an effective inhibitor of alanine racemase. The lack of inhibition by
l
-cycloserine of alanine racemase from
Staphylococcus aureus
led Roze and Strominger to formulate the cycloserine hypothesis. This hypothesis states that
d
-cycloserine has the conformation required of the substrates on the enzyme surface and that
l
-cycloserine cannot have this conformation. Alanine racemase from
Escherichia coli
W has been examined to establish whether these observations are a general feature of all alanine racemases. The enzyme (molecular weight = 95,000) has Michaelis-Menten constants of 4.6 × 10
−4
m
and 9.7 × 10
−4
m
for
d
- and
l
-alanine, respectively. The ratio of
V
max
in the
d
- to
l
-direction is 2.3. The equilibrium constant calculated from the Haldane relationship is 1.11 ± 0.15. Both
d
- and
l
-cycloserine are competitive inhibitors with constants (
K
i
) of 6.5 × 10
−4
m
and 2.1 × 10
−3
m
, respectively. The ratio of
K
m
d
-alanine to
K
i
d
-cycloserine is 0.71, and the ratio of
K
m
l
-alanine to
K
i
l
-cycloserine is 0.46. Since
l
-cycloserine is an effective inhibitor, it is concluded that the cycloserine hypothesis does not apply to the enzyme from
E. coli
W.
Extracellular Alkaline Amylase from a
Bacillus
Species
Authors: Boyer E. W. , Ingle M. B.
Published: January 2020

A selective medium was used to isolate a bacterium (
Bacillus
species NRRL B-3881) that produced extracellular alkaline amylase in an alkaline medium (
p
H 9.5). Maximal enzyme yield was obtained in an aerated medium after 21 hr at 36 C. The enzyme was purified 18-fold by ultrafiltration and ammonium sulfate precipitation. Three active isoenzymes (one major and two minor) of alkaline amylase were detected by disc electrophoresis in polyacrylamide gel. The enzyme was only 12% inactivated by 20 m
m
ethylenediaminetetraacetic acid after 1 hr at
p
H 9.2 and 32 C. The optimal temperature was 50 C at
p
H 9.2, and the optimal
p
H was 9.2 at 50 C. The enzyme was stable between
p
H 7.5 and 10. It had an endomechanism of substrate encounter. The products produced from amylose and amylopectin had the β-configuration. Cyclomaltoheptaose was hydrolyzed to maltotriose, maltose, and glucose. The main final product produced from amylose and amylopectin was β-maltose; the other final products were maltotriose and small quantities of glucose and maltotetraose. The predominant product at early stages of hydrolysis was maltotetraose; other products were maltose through maltonanaose.
Nature of the Elimination of the Penicillinase Plasmid from
Staphylococcus aureus
by Surface-Active Agents
Authors: Sonstein Stephen A. , Baldwin J. N.
Published: January 2020

Growth of
Stapylococcus aureus
in various ionic surface-active agents resulted in loss of the ability to produce penicillinase, whereas growth in nonionic surface-active agents had no effect on penicillinase production. The curing effect of various alkyl sulfates was found to be dependent upon the chain length. Curing by surface-active agents could be inhibited by magnesium. Reciprocal transduction experiments showed that curing by a surface-active agent was a property of the plasmid, not of the bacterial strain in which the plasmic resides.
Autolysis of Microbial Cells: Salt Activation of Autolytic Enzymes in a Mutant of
Staphylococcus aureus
Authors: Gilpin Richard W. , Chatterjee Anadi N. , Young Frank E.
Published: January 2020

The effect of various salts on the autolysis of cell wall of a ribitol teichoic acid-deficient mutant of
Staphylococcus aureus
H (strain 52A5 carrying
tar-1
) was compared with the parent strain. In the presence of high concentrations of certain salts such as 1.0
m
NaCl, the mutant undergoes autolysis with the release of osmotically sensitive spheroplasts. The parent strain is not affected by these conditions. The stimulation of lysis is related to an activation of
N
-acylmuramyl-
l
-alanine amidase.
Phenoloxidase Activity in Mycelia Carrying Modifier Mutations That Affect Sporocarp Development in
Schizophyllum commune
Authors: Leonard Thomas J.
Published: January 2020

Phenoloxidase activity was studied in mycelia carrying mutations that affect sporocarp formation. The results suggest that phenoloxidase activity may be essential to, but is not sufficient for, the fruiting response in
Schizophyllum
.
Integration Site of Noninducible Coliphage 186
Authors: Woods Walter H. , Egan J. Barry
Published: January 2020

From conjugational data, the attachment site for noninducible coliphage 186 (
att
186) was located between the origins of Hfr strains KL16 and KL98, and close to the
pheA
gene in
Escherichia coli
K-12. P1 transductions indicated that
att
186 lies at 51 min on the standard genetic map of
E. coli
, with the order
cysC-nalB-att
186-
pheA
. The presence of prophage 186 in the donor destroyed linkage between
nalB
and
pheA
, which is taken as evidence for the integration of the 186 prophage between these genes.
Partial Characterization of Phosphoribosyl Transferase, Phosphoribosyl Anthranilate Isomerase, and Indole Glycerol Phosphate Synthase from
Serratia marcescens
Authors: Potts J. M. , Drapeau G. R.
Published: January 2020

The molecular organization of the enzymes phosphoribosyl (PR) transferase, phosphoribosyl anthranilate (PRA) isomerase, and indole glycerol phosphate (InGP) synthase of the tryptophan biosynthetic pathway of
Serratia marcescens
was investigated and compared with that reported in other enteric bacteria. PRA isomerase and InGP synthase activities were found to reside in a single polypeptide chain, a situation analogous to that in
Escherichia coli, Salmonella typhimurium
, and
Aerobacter aerogenes
. This bifunctional enzyme was purified to near homogeneity. Its molecular weight was estimated to be 48,000. PR transferase was found unassociated with PRA isomerase and InGP synthase after gel filtration and ion-exchange chromatography. Whereas in other enteric organisms PR transferase has been reported to form an aggregate with anthranilate synthase, it is a distinct entity in
S. marcescens
.
Cell Division and Prophage Induction inEscherichia coli: Effects of Pantoyl Lactone and Various Furan Derivatives
Authors: Kirby Edward P. , Ruff W. L. , Goldthwait David A.
Published: January 2020

Strain T-44 is a thermosensitive mutant ofEscherichia coliin which both cell division and prophage repression are altered at elevated temperatures. The effects of various ribosides, pantoyl lactone, and the furfural derivatives nitrofurazone and 5-methyl furfural suggest that some low-molecular-weight compound is important in the control of cell division and prophage repression in this strain. This low-molecular-weight compound may have a five-membered oxygen-containing ring as part of its structure.
Inducible Uptake System for β-Carboxy-
cis, cis
-muconate in a Permeability Mutant of
Pseudomonas putida
Authors: Meagher Richard B. , McCorkle George M. , Ornston M. K. , Ornston L. N.
Published: January 2020

A procedure for the large-scale enzymatic synthesis of β-carboxymuconate is described. When used as a growth substrate, β-carboxymuconate selected for mutant strains of
Pseudomonas putida
that were permeable to polycarboxylic acid intermediates of the β-ketoadipate pathway. One mutant organism, strain PRS2110, was investigated in detail. It differed from the parental strain in that it possessed a β-carboxymuconate uptake system that was formed when the compound was supplied exogenously to the cells. The uptake system was not induced by β-carboxymuconate supplied endogenously during growth with
p
-hydroxybenzoate. These observations suggested that β-carboxymuconate was contained within a physical compartment of enzymes during growth with
p
-hydroxybenzoate. Support for this hypothesis came from the demonstration that enzymes of the β-ketoadipate pathway were held together by weak chemical interactions during the chromatography of crude extracts of benzoategrown
P. putida
on diethylaminoethyl-cellulose columns.
Relationship Between Permeability, Cell Division, and Murein Metabolism in a Mutant of
Escherichia coli
Authors: Lazdunski Claude , Shapiro Bennett M.
Published: January 2020

A mutant of
Escherichia coli
has been found to have an increased sensitivity to actinomycin D and to sodium deoxycholate and an unusual morphology which accompanies an abnormality in cellular division. All of these characteristics are suppressed when the strain is grown in the presence of
d
-alanine. This strain, called MAD-1, for murein altered division mutant, exhibits its pleiotropic phenotype only when certain carbon compounds are used as energy sources in minimal medium. Nonpermissive carbon sources, which elicit the disturbed phenotype, include glucose, mannitol, fructose, maltose, and lactose; permissive carbon sources include galactose, glycerol, lactate, and succinate. The mutant is able to transport nonpermissive carbon compounds; 3 mM 3′,5′-cyclic adenosine monophosphate included in the medium does not alter the phenotype seen with growth on glucose. Deoxyribonucleic acid and protein synthesis are normal with respect to cellular mass increase.
d
-Alanine specifically suppresses the pleiotropic phenotype at a concentration six times lower than
l
-alanine, the only other compound found to be effective. There is no abnormality in the
K
m
or
V
max
of
l
-alanine racemase or
d
-alanine-
d
-alanine synthetase of MAD-1 compared to its parent, CR34. MAD-1 is more susceptible to growth inhibition by penicillin or cycloserine than its parent, and is exquisitely sensitive to lysis in the presence of sodium deoxycholate or lysozyme. When cell wall biosynthesis is inhibited, MAD-1 lyses much more rapidly than CR34, even after it has been phenotypically suppressed by growth on
d
-alanine. The incorporation of
l
-alanine and diaminopimelic acid into the peptidoglycan of the mutant and wild type is identical;
d
-alanine is incorporated 1.5 times more rapidly into MAD-1 cells grown under nonpermissive conditions. The peptidoglycan fragments seen after digestion with lysozyme were similar for MAD-1 and the wild type. The results are interpreted as being compatible with an increased autolytic rate in MAD-1, caused either by an increase in the quantity or activity of an autolysin, or by an abnormal cell wall which is especially susceptible to autolysis, but which was not detected by analysis of peptidoglycan fragments.
Isolation and Characterization of 2-Keto-3-Deoxyoctonate-Lipid A from a Heptose-Deficient Mutant of
Escherichia coli
Authors: Rooney Seamus A. , Goldfine Howard
Published: January 2020

A heptose-deficient mutant of
Escherichia coli
has been isolated and from it a glycolipid, consisting of lipid A and 2-keto-3-deoxyoctonate (KDO), has been extracted with diisobutylketone-acetic acid-water. Based on β-hydroxymyristic acid, the extractable glycolipid accounts for a major portion of the total lipid A in this mutant. A glycolipid, purified from the lipid extract by a combination of silicic acid and Sephadex LH-60 chromatography, contains glucosamine, phosphate, KDO, acetyl groups, and fatty acids in the following molar ratios: 1:2:2:1.7:5. These components account for over 80% of the lipid by weight. The fatty acid pattern of the glycolipid is typical of lipid A, the major component being β-hydroxymyristic acid. The lipid also contains an amino sugar which appears to be 4-amino-4-deoxyarabinose. With the use of an ion-exchange paper chromatographic technique, gram-negative bacteria can be rapidly screened for the presence of this glycolipid. The mutant is believed to have a leaky defect in either biosynthesis of heptose or its incorporation into lipopolysaccharide. The lipopolysaccharide from the mutant contains only about a third as much heptose, glucose, and galactose as the parent CR34, a K-12 derivative. Chemical analysis and phage typing suggest that CR34 contains an incomplete core polysaccharide devoid of glucosamine.
Requirement for Protein Synthesis inrec-Dependent Repair of Deoxyribonucleic Acid inEscherichia coliafter Ultraviolet or X Irradiation
Authors: Ganesan Ann K. , Smith Kendric C.
Published: January 2020

Deprivation of amino acids required for growth or treatment with chloramphenicol or puromycin after irradiation reduced the survival of Rec+cells ofEscherichia coliK-12 which had been exposed to either ultraviolet (UV) or X radiation. In contrast, these treatments caused little or no reduction in the survival of irradiatedrecAorrecBmutants. The effect of chloramphenicol on the survival of X-irradiated cells was correlated with an inhibition of repair of single-strand breaks in irradiated deoxyribonucleic acid (DNA), previously shown to be controlled byrecAandrecB. In UV-irradiated cells no effect of chloramphenicol was detected on the repair of single-strand discontinuities in DNA replicated from UV-damaged templates, a process controlled byrecAbut not byrecB. From this we concluded that inhibiting protein synthesis in UV or X-irradiated cells may interfere with some biochemical step in repair dependent upon therecBgene. When irradiated Rec+cells were cultured for a sufficient period of time in minimal growth medium before chloramphenicol treatment their survival was no longer decreased by the drug. After X irradiation this occurred in less than one generation time of the unirradiated control cells. After UV irradiation it occurred more slowly and was only complete after several generation times of the unirradiated controls. These observations indicated that replication of the entire irradiated genome was probably not required forrec-dependent repair of X-irradiated cells, although it might be required forrec-dependent repair of UV-irradiated cells.
Intergenotic Transformation of the
Bacillus subtilis
Genospecies
Authors: Wilson Gary A. , Young Frank E.
Published: January 2020

A multiple auxotrophic derivative of
Bacillus subtilis
168 (strain BR151 carrying
lys-3, trpC2, metB10
) was transformed with deoxyribonucleic acid (DNA) isolated from
B. subtilis
168,
Bacillus amyloliquefaciens
H,
B. subtilis
HSR,
Bacillus pumilus
, and
Bacillus licheniformis
. Transformation with heterologous DNA occurred at a very low frequency for the three auxotrophic markers. Heterologous transformation to rifampin resistance was 100 to 1,000 times more efficient than transformation to prototrophy. Transformants from the various heterologous exchanges were used to prepare donor DNA. The fragment of integrated DNA from the heterologous (foreign) species, termed the “intergenote,” was capable of transforming BR151 with an efficiency almost equal to that of homologous DNA. When BR151 DNA contained the Rfm

R

(rifampin resistance) intergenote from
B. amyloliquefaciens
H, the frequency of transformation was frequently greater than that of the homologous DNA. Accompanying this increased efficiency was a marked change in the physiology of the cells. The growth rate of the transformants carrying this intergenote was approximately one-half that of either parental strain. Thus, in a prokaryotic transformation system, adverse side effects can occur after incorporation of a segment of foreign DNA.
Effect of Maltose on Glucoamylase Formation by
Aspergillus niger
Authors: Barton Larry L. , Georgi Carl E. , Lineback David R.
Published: January 2020

Low levels of glucoamylase are produced when
Aspergillus niger
is grown on sorbitol, but substitution of the latter by glucose, maltose, or starch results in greater formation of glucoamylase as measured by enzymatic activity. Both glucoamylase I and glucoamylase II are formed in a yeast extract medium; however, glucoamylase I appears to be the only form produced when ammonium chloride is the nitrogen source. Maltose or isomaltose (1.4 × 10

−
4

m

), but no other disaccharides or monosaccharides, dextrins, dextrans, or starches, stimulated glucoamylase formation when added to mycelia pregrown on sorbitol-ammonium salts. The induction of glucoamylase by maltose was independent of sulfate concentration but showed a dependency on low
p
H and the absence of utilizable carbon sources.
Influence of Nutrition on the Morphology of a Strain of
Bifidobacterium bifidum
Authors: Husain Intisar , Poupard James A. , Norris Robert F.
Published: January 2020

A mucoid variant of
Bifidobacterium bifidum
was converted from its normal curved rod or bifid form to a highly branched form when grown in a chemically defined minimal medium. Branching could be prevented by the addition of a mixture of
dl
-alanine,
dl
-aspartic acid,
l
(+)-glutamic acid, and
dl
-serine, but not when any one of these four amino acids was omitted. Although sodium chloride induced pleomorphism, calcium ions were ineffective in suppressing the appearance of these pleomorphic forms. None of the cell wall precursors tested, viz.,
N
-acetyl-
d
-glucosamine, α-ε-diaminopimelic acid, and muramic acid, inhibited branching.
Specificity of Interaction Between the First Enzyme for Histidine Biosynthesis and Aminoacylated Histidine Transfer Ribonucleic Acid
Authors: Vogel Tikvah , Meyers Marilyn , Kovach John S. , Goldberger Robert F.
Published: January 2020

The specificity of the interaction between phosphoribosyltransferase and partially purified preparations of various species of transfer ribonucleic acid (tRNA) was investigated with the use of a filter binding assay. The enzyme showed a higher affinity for histidyl-tRNA than for arginyl- or glutamyl-tRNA. Competition experiments revealed that the enzyme does not distinguish between the aminoacylated and deacylated forms of arginine tRNA or glutamic acid tRNA, since all the binding of the aminoacylated tRNA could be inhibited by deacylated tRNA. The enzyme does, however, distinguish between the aminoacylated and deacylated forms of histidine tRNA. Approximately 70% of the binding of aminoacylated histidine tRNA is specific, since only 30% of the binding could be inhibited by deacylated tRNA. The possibility that the regulatory role of phosphoribosyltransferase is carried out as a complex with histidyl-tRNA is consistent with these data.
Isoleucine and Valine Metabolism in
Escherichia coli
XIX. Inhibition of Isoleucine Biosynthesis by Glycyl-Leucine
Authors: Haar Raymond A. Vonder , Umbarger H. E.
Published: January 2020

The inhibition of growth of the K-12 strain of
Escherichia coli
by glycyl-
l
-leucine observed originally by Simmonds and co-workers was investigated. The inhibition was reversed by isoleucine and those precursors of isoleucine beyond threonine in the biosynthetic pathway. Threonine reversed the inhibition poorly. With heavy cell suspensions, the inhibition was transient: the onset of growth followed the disappearance of the dipeptide from the medium and the appearance of glycine and leucine. Glycyl-leucine was shown to be an inhibitor of threonine deaminase (EC 4.2.1.16
l
-threonine hydro-lyase [deaminating]). One kind of glycyl-leucine-resistant mutant had a threonine deaminase that was resistant to isoleucine and glycyl-leucine inhibition. The pattern of glycyl-leucine inhibition is compared with those of inhibition by isoleucine and by the weaker inhibitors leucine and valine.
Deletion Mapping of the Genes Coding for HPr and Enzyme I of the Phosphoenolpyruvate: Sugar Phosphotransferase System in
Salmonella typhimurium
Authors: Cordaro J. Christopher , Roseman Saul
Published: January 2020

Sugars transported by a bacterial phosphoenolpyruvate:sugar phosphotransferase system (PTS) require two soluble proteins: HPr, a low-molecular-weight phosphate-carrier protein, and enzyme I. The structural genes coding for HPr (
ptsH
) and Enzyme I (
ptsI
) are shown to be cotransducible in
Salmonella typhimurium
. The gene order of this region of the
Salmonella
chromosome is
cysA-trzA-ptsH-ptsI
...(
crr
). A method for the isolation of
trzA-pts
deletion is described. One class of
pts
deletions extends through
ptsH
and into
ptsI
; a second class includes both
ptsH
and
ptsI
and extends into or through the
crr
gene. The
crr
gene either codes for or regulates the synthesis of a third PTS protein (factor III) which is sugar-specific. A hypothesis is presented for a mechanism of deletion formation.
Site of Action of Lipid A on Mitochondria
Authors: Kato Masahiko
Published: January 2020

Lipopolysaccharide (LPS) of a number of gram-negative bacteria affected mitochondrial respiration and phosphorylation when it was preincubated with the mitochondrial suspension. The structural part responsible for this activity of LPS is the lipid moiety (lipid A), because the lipid A prepared from either the LPS of
Escherichia coli
or the endotoxic glycolipid of a heptose-less mutant (R595) of
Salmonella minnesota
affected mitochondrial oxidative phosphorylation as did LPS, whereas the polysaccharide moiety was inactive. Preincubation of the mitochondrial suspension with lipid A resulted in (i) inhibition of respiration and accompanying phosphorylation in the presence of either succinate or a number of reduced nicotinamide adenine dinucleotide-linked substrates, (ii) decrease of respiratory control, (iii) inhibition of the transfer of electrons at coupling site II without decrease of efficiency of phosphorylation, and the uncoupling at coupling site III, and (iv) stimulation of adenosine triphosphatase and the inhibition of 2,4-dinitrophenol-induced adenosine triphosphatase.
Restoration of Reduced Nicotinamide Adenine Dinucleotide Phosphate-Nitrate Reductase Activity of a
Neurospora
Mutant by Extracts of Various Chlorate-Resistant Mutants of
Escherichia coli
Authors: MacGregor Carolyn H. , Schnaitman Carl A.
Published: January 2020

Acid-treated extracts of
Escherichia coli
were tested for their ability to restore reduced nicotinamide adenine dinucleotide phosphate-nitrate reductase activity to an extract of a
Neurospora nit-1
mutant which produces a defective enzyme. With wild-type
E. coli
this complementation activity was more readily detected in the cytoplasmic fraction, although the nitrate reductase activity was found primarily in the particulate fraction.
chlB
mutants of
E. coli
appeared to have more complementation activity in the cytoplasm than was observed in the wild type, but no activity in the particulate fraction. The other
chl
mutants had little or no activity in either fraction. These results suggest that
chlB
mutants can produce a component or cofactor which is missing in the other mutants and in the
Neurospora
mutant, but cannot transfer it to the nitrate reductase enzyme.
Recombination Among Three Mitochondrial Genes in Yeast (
Saccharomyces cerevisiae
)
Authors: Kleese R. A. , Grotbeck R. C. , Snyder J. R.
Published: January 2020

Eight crosses involving three different mitochondrial genes were made in
Saccharomyces cerevisiae
. All three genes were linked, but an unambiguous linkage map could not be constructed.
Hyperprotease-Producing Mutants of
Bacillus subtilis
Authors: Higerd Thomas B. , Hoch James A. , Spizizen John
Published: January 2020

A number of mutants of
Bacillus subtilis
producing high levels of extracellular protease have been isolated. Analysis of culture supernatants of these mutants has shown that the total amount of proteolytic activity is elevated from 16- to 37-fold over the wild strain. The elevated activity was due to a simultaneous increase in both the neutral and alkaline protease. All of the mutants genetically analyzed were found linked to the
argC4
marker by PBS-1 transduction analysis.
Properties of RP4, an R Factor Which Originated in
Pseudomonas aeruginosa
S8
Authors: Saunders J. R. , Grinsted John
Published: January 2020

RP4, an R factor derived from
Pseudomonas aeruginosa
S8 and specifying resistance to carbenicillin, neomycin, kanamycin, and tetracycline, could be isolated as an extrachromosomal satellite of covalently closed circular DNA (CCC-DNA) of molecular weight about 62 million and of buoyant density 1.719 g/cm
3
(60% guanine plus cytosine). When RP4 was compared by hybridization with RP1, an R factor originating in another strain of
P. aeruginosa
, it was shown that RP4 contains most, if not all, of the base sequences of RP1, and also additional sequences not found in RP1.
Changes in Free Amino Acid Production and Intracellular Amino Acid Pools of
Bacillus licheniformis
as a Function of Culture Age and Growth Media
Authors: Clark V. L. , Peterson D. E. , Bernlohr R. W.
Published: January 2020

Changes in the endogenous intracellular amino acid pool and total free amino acid production in
Bacillus licheniformis
grown in minimal media were investigated. The total intracellular pool increased during exponential growth and then decreased rapidly after the end of growth. Most of the amino acids were present at low concentrations, but glutamate and alanine comprised 60 to 90% of the total intracellular free amino acid at most times during the growth cycle. It was concluded that, in addition to providing monomers for protein synthesis, the intracellular amino acid pool may be maintained for the storage of energy-providing metabolic intermediates and possibly as a balance to the ionic strength of the medium. The total free amino acid production by the cell was found to be dependent upon the composition of the salts medium as well as the culture age under conditions in which the carbon and nitrogen sources were the same. A 10-fold increase in extracellular amino acid was observed as the cells changed from vegetative to sporulation metabolism, mostly due to the extrusion of intracellular amino acid. The impact of this increase upon amino acid uptake and pulse-labeling studies using unwashed cells is discussed.
Purification of Mycobacterial Deoxyribonucleic Acid
Authors: Hill Elizabeth B. , Wayne Lawrence G. , Gross Wendy M.
Published: January 2020

Impurities believed to be polysaccharides have been found in mycobacterial deoxyribonucleic acid (DNA) preparations. Agar-gel diffusion of the DNA preparations against concanavalin A indicated the presence of three polysaccharides and was used to follow the purification procedures. The polysaccharides appeared to be the same for all strains studied. Precipitation of DNA with cetyltrimethylammonium bromide was used to separate impurities from some DNA preparations. The presence of the contaminants was found to affect markedly the determination of the guanine plus cytosine content according to a method dependent on the ratio of absorbancies at 260 and 280 nm; the impurities did not affect the determination by the method of thermal denaturation. The presence of a DNA-polysaccharide complex is suggested.
Studies on a Thermophilic Bacillus: Its Isolation, Properties, and Temperature Coefficient of Growth
Authors: Ward J. , Cockson A.
Published: January 2020

A thermophilic bacillus with minimal, optimal, and maximal growth temperatures of 40, 64.5, and 72 C, respectively, was isolated from soil. Biochemical and morphological studies place the isolate in group 1 of the classification of Walker and Wolf. After adaption to nitrate broth, the temperature coefficient for growth was found to be 20,400 cal/mol. When the temperature coefficient for growth of the isolate, psychrophilic bacteria, mesophilic bacteria, and a strain of
Bacillus stearothermophilus
are compared, there is no correlation with optimal temperature. The form of the Arrhenius equation, as used by some workers, is commented on.
Physiological Studies on
Vitreoscilla stercoraria
Authors: Mayfield D. C. , Kester A. S.
Published: January 2020

Vitreoscilla stercoraria
ATCC 15218 was studied to elucidate some of its physiological characteristics. The initial optimal
p
H for the organism was found to be 7.5 to 7.7. The characteristics of the growth curve of the organism showed that its growth in shake cultures is by increasing trichome number up to approximately 15 hr and by increasing trichome length after 15 hr. Nutritional studies indicated that it is auxotrophic for biotin, thiamine, and
l
-arginine, and it appears to be an obligate amino acid utilizer because only protein hydrolysates or known amino acid mixtures would support growth.
Action of Phospholipase A
2
and Phospholipase C on
Bacillus subtilis
Protoplasts
Authors: Den Kamp J. A. F. Op , Kauerz M. T. , Van Deenen L. L. M.
Published: January 2020

Protoplasts prepared from
Bacillus subtilis
by lysozyme digestion lysed in the presence of pure pancreatic phospholipase A
2
. The phospholipids cardiolipin, phosphatidylethanolamine, phosphatidylglycerol and lysylphosphatidylglycerol, which are present in the membrane, are degraded by phospholipase A
2
only after removal of the cell wall, giving free fatty acids and lyso derivatives. The four phospholipids are hydrolyzed equally well at a given enzyme concentration. Differences in the phospholipid composition of the protoplasts were obtained by variations in the growth medium, time of harvesting, and preincubation time with lysozyme. The extent of hydrolysis appeared to depend on the initial phospholipid composition. A relative increase in acidic phospholipids in the membrane facilitated the action of phospholipase A
2
, whereas the rate of hydrolysis was diminished when protoplasts were tested which contained a relatively high amount of positively charged phospholipid. Pure phospholipase C from
B. cereus
preferentially hydrolyzed phosphatidyl-ethanolamine in the
B. subtilis
membrane. More than 80% of this phospholipid was converted into diglyceride, whereas only 30% of the cardiolipin was hydrolyzed. Such a loss of phospholipids, however, was not followed by lysis of the protoplasts. Liposomes were prepared from the lipid extracts of
B. subtilis
and incubated with both phospholipases. The hydrolysis pattern of the phospholipids in these model membrane systems was identical to the hydrolysis pattern of the phospholipids in the protoplast membrane. Phospholipase A
2
hydrolyzed all the phospholipids in the liposomes equally well, whereas phospholipase C preferentially degraded phosphatidylethanolamine.
Transformation and Deoxyribonucleic Acid Size: Extent of Degradation on Entry Varies with Size of Donor
Authors: Morrison D. A. , Guild W. R.
Published: January 2020

The fate of label introduced as donor deoxyribonucleic acid (DNA) into competent cells of
Diplococcus pneumoniae
was determined immediately after entry at 25 C, as a function of the size of the donor DNA. Part of the label is found to be acid soluble, part has been incorporated into chromosomal DNA, apparently through reincorporation of degraded donor DNA, and part is found in single strands of length smaller than that of the input donor DNA strands. The last fraction apparently constitutes the precursor for integration of intact donor genetic markers and is referred to as the intact fraction. For large donor DNA the intact fraction contains over 80% of the total intracellular label, but the median strand length has been reduced to 2.2 × 10
6
daltons. For small donor molecules (1 × 10
5
to 6 × 10
5
daltons per strand) the fraction intact increases with donor size from 10 to 50% of the total intracellular label, and the median strand length of this fraction is half that of the donor strands. By combining these results with earlier data on the size dependence of the yield of transformants per unit of total intracellular donor label, we have calculated the probability that a marker in the intact fraction will be integrated, as a function of the length of the donor strand after entry. This probability has a linear dependence on strand length for activities below 40% of maximum, and extrapolates to zero activity at 77,000 daltons per strand.
Template Specificity of Ribonucleic Acid Polymerase in Asporogenous Mutants of
Bacillus subtilis
Authors: Brevet Jean , Sonenshein Abraham L.
Published: January 2020

Asporogenous mutants of
Bacillus subtilis
were examined for the change in template specificity of ribonucleic acid (RNA) polymerase characteristic of wild-type cells undergoing sporulation. Mutants blocked at stages II, III, and IV showed a changed specificity of the enzyme after the end of growth and were in this respect indistinguishable from the wild type. The RNA polymerase of eight stage-zero mutants (out of nine tested) which possess mutations that map at six distinct loci retained the template specificity of vegetative cells.
Serological Study of Nocardia by Using Mycobacterial Precipitation Reference Systems
Authors: Ridell Malin , Norlin Margareta
Published: January 2020

Forty-six nocardia strains and ten strains labeled “
Mycobacterium
” were analyzed with the comparative immunodiffusion technique, employing as reference material nine mycobacterial precipitation systems, each one representing a different species. Three precipitinogens were common for many of the tested strains and the mycobacterial reference strains. The serological analyses indicated the possibility of differentiating two groups within
Nocardia
depending on the characteristics of one of the common precipitinogens. Five of eight tested
Nocardia farcinica
strains showed a serologically close relationship with the mycobacteria and might be regarded as belonging to this genus. The “
M
.”
pellegrino
and “
M
.”
rhodochrous
strains, however, did not react with the antimycobacterial sera to a higher degree than did the tested nocardia strains.
Rapid Regulation of an Anthranilate Synthase Aggregate by Hysteresis
Authors: Kane J. F. , Holmes W. M. , Smiley K. L. , Jensen R. A.
Published: January 2020

The anthranilate synthase aggregate from
Bacillus subtilis
is composed of two nonidentical subunits, denoted E and X, which are readily associated or dissociated. A complex of subunit E and X can utilize glutamine or ammonia as substrates in the formation of anthranilate. Partially purified subunit E is capable of using only ammonia as the amide donor in the anthranilate synthase reaction. The stability of the EX complex is strongly influenced by glutamine and by the concentrations of the subunits. Glutamine stabilizes the aggregate as a molecular species in which the velocity of the glutamine-reactive anthranilate synthase is a linear function of protein concentration. In the absence of glutamine the aggregate is readily dissociated following dilution of the extract; that is, velocity concaves upward as a function of increasing protein concentration. Reassociation of the EX complex is characterized by a velocity lag (or hysteretic response) before steady-state velocity for the glutamine-reactive anthranilate synthase is reached. We propose that association and dissociation of the anthranilate synthase aggregate may be physiologically significant and provide a control mechanism whereby repression or derepression causes disproportionate losses or gains in activity by virtue of protein-protein interactions between subunits E and X.
Biotin Deficiency in
Arthrobacter globiformis
: Comparative Cell Ultrastructure and Nonreplacement of the Vitamin by Structurally Unrelated Compounds
Authors: Chan E. C. S. , Zyk B. , Gomersall M.
Published: January 2020

The development of aberrant cell forms of
Arthrobacter globiformis
425 due to biotin deficiency was followed by electron microscopy of ultrathin sections. Upon comparison with normal cell growth, aberrant cells developed in the early logarithmic growth phase. Several membrane-bound bodies were embedded in a thick matrix, showing that cell division was impaired. Mesosomes and cytoplasmic membranes were still present in the abnormal cell although the normal cell wall was absent. This condition persisted throughout the growth cycle. This pattern of morphological development was correlated with changes in macromolecular composition of the cells. Various structurally unrelated compounds were tested for their ability to replace biotin. These included aspartic acid, oxalacetic acid, coenzyme A, oleic acid, linoleic acid, linolenic acid, and Tween 80. Only Tween 80 was able to spare biotin to a limited degree. However, this sparing action was eliminated in the presence of avidin.