bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Temperature of Incubation and Type of Growth Medium on Pigmentation inSerratia marcescens
Authors: Williams Robert P. , Gott Cora L. , Qadri S. M. Hussain , Scott Randolph H.
Published: January 2020

Maximal amounts of prodigiosin were synthesized in either minimal or complete medium after incubation of cultures at 27 C for 7 days. Biosynthesis of prodigiosin began earlier and the range of temperature for formation was greater in complete medium. No prodigiosin was formed in either medium when cultures were incubated at 38 C; however, after a shift to 27 C, pigmentation ensued, provided the period of incubation at 38 C was not longer than 36 hr for minimal medium or 48 hr for complete medium. Washed, nonpigmented cells grown in either medium at 38 C for 72 hr could synthesize prodigiosin when suspended in saline at 27 C when casein hydrolysate was added. These suspensions produced less prodigiosin at a slower rate than did cultures growing in casein hydrolysate at 27 C without prior incubation at 38 C. Optimal concentration of casein hydrolysate for pigment formation by suspensions was 0.4%; optimal temperature was 27 C. Anaerobic incubation, shift back to 38 C, killing cells by heating, or chloramphenicol (25 μg/ml) inhibited pigmentation. Suspensions of washed cells forming pigment reachedpH 8.0 to 8.3 rapidly and maintained thispH throughout incubation for 7 days. Measurements of viable count and of protein, plus other data, indicated that cellular multiplication did not occur in suspensions of washed cells during pigment formation. By this procedure utilizing a shift down in temperature, biosynthesis of prodigiosin by washed cells could be separated from multiplication of bacteria.
Valine Accumulation by α-Aminobutyric Acid-Resistant Mutants of
Serratia marcescens
Authors: Kisumi Masahiko , Komatsubara Saburo , Chibata Ichiro
Published: January 2020

α-Aminobutyric acid, norvaline, and norleucine, which are analogues of branched-chain amino acids, inhibited the growth of
Serratia marcescens
. The inhibitory effect of these three analogues was counteracted by branched-chain amino acids. A number of mutants resistant to these analogues were isolated. α-Aminobutyric acid-resistant (
abu-r
) mutants markedly accumulated
l
-valine in the culture medium, but the other analogue-resistant mutants did not. Acetohydroxy acid synthetase, which seems to be rate-limiting for the biosynthesis of
l
-valine, was derepressed in
abu-r
mutants. One of the
abu-r
mutants, no. 140, which accumulated over 8 mg of
l
-valine per ml, had about a 20-fold increase in the enzyme level. Most of the
abu-r
mutants had acetohydroxy acid synthetase activity which was sensitive to feedback inhibition by
l
-valine to the same extent as in the parent strain. However, the enzyme of two of
abu-r
mutants was less sensitive to
l
-valine, and one of the two was the best valine accumulator.
Regulation of Thymidine Metabolism inEscherichia coliK-12: Studies on the Inducer and the Coordinateness of Induction of the Enzymes
Authors: Bonney Robert J. , Weinfeld Herbert
Published: January 2020

A study was made of the regulation of three enzymes that act sequentially in the metabolism of thymidine inEscherichia coliK-12. Under a variety of conditions, two of the enzymes, thymidine phosphorylase and deoxyribose-5-phosphate aldolase, were found to be synthesized coordinately. However, the third enzyme, phosphodeoxyribomutase, was synthesized noncoordinately with the other two enzymes under the same conditions. In addition, the mutase could be fully induced, whereas basal levels of the phosphorylase and the aldolase were maintained. These findings indicate that two operons comprise the genes concerned with the reversible pathway leading from thymidine to acetaldehyde and glyceraldehyde-3-phosphate. In addition to thymidine, it was found that acetaldehyde was an external inducer of these enzymes. The results of induction experiments performed on wild-type cells and mutants defective in the mutase or the aldolase, with thymidine or acetaldehyde as exogenous inducers, strongly suggest that deoxyribose-5-phosphate is more proximal to the intracellular inducer than is thymidine, deoxyribose-1-phosphate, or acetaldehyde.
Effect of Glutamate on Exogenous Citrate Catabolism of
Neisseria meningitidis
and of Other Species of
Neisseria
Authors: Hill James C.
Published: January 2020

Resting cell suspensions of
Neisseria meningitidis
group B (strain 2091) do not catabolize citrate as the sole substrate to an appreciable degree. When another substrate, such as glutamate, is also present to furnish energy for transport, citrate metabolism is greatly stimulated. Within limits, the amount of CO
2
produced from citrate is proportional to the amount of glutamate added. When the cells are disrupted, citrate is degraded at a rapid rate and the stimulatory effect of glutamate is completely eliminated. Pronounced stimulation of citrate metabolism by glutamate was demonstrated in 12 of 13 strains of
N. meningitidis
tested and only 1 of 6 strains of
N. lactamicus
. The remaining strains of
N. lactamicus
and one each of
N. gonorrhoeae, N. flavescens
, and
N. flava
did not utilize significant amounts of citrate in the absence or presence of glutamate.
N. catarrhalis
shared with
Mima polymorpha
and
Moraxella glucidolytica
a capability to catabolize citrate at a rapid rate without added glutamate. It is concluded that tests of glutamate-stimulated citrate metabolism may contribute to species characterization in the genus
Neisseria
.
Activities of Tricarboxylic Acid Cycle Enzymes, Glyoxylate Cycle Enzymes, and Fructose Diphosphatase in Bakers' Yeast During Adaptation to Acetate Oxidation
Authors: Gosling J. P. , Duggan P. F.
Published: January 2020

Bakers' yeast oxidizes acetate at a high rate only after an adaptation period during which the capacity of the glyoxylate cycle is found to increase. There was apparently no necessity for the activity of acetyl-coenzyme A synthetase, the capacity of the tricarboxylic acid cycle, or the concentrations of the cytochromes to increase for this adaptation to occur. Elevation of fructose 1,6 diphosphatase occurred only when acetate oxidation was nearly maximal. Cycloheximide almost completely inhibited adaptation as well as increases in the activities of isocitrate lyase and aconitate hydratase, the only enzymes assayed.
p
-Fluorophenylalanine was partially effective and chloramphenicol did not inhibit at all. The presence of ammonium, which considerably delayed adaptation of the yeast to acetate oxidation, inhibited the increases in the activities of the glyoxylate cycle enzymes to different degrees, demonstrating noncoordinate control of these enzymes. Under the various conditions, the only enzyme activity increase consistently related to the rising oxygen uptake rate was that of isocitrate lyase which apparently limited the activity of the cycle.
Influence of Ribosides on Ultraviolet Resistance of
Escherichia coli
: Role of Deoxyribonucleic Acid Synthesis in the Ultraviolet Resistance Enhancement After Amino Acid Prestarvation
Authors: Sedliaková Milena , Štefunková Eva , Bernátová Ľubica
Published: January 2020

Changes in the resistance of cells of
Escherichia coli
B/r Hcr
+
thy
−
trp
−
to ultraviolet radiation were investigated after the following pretreatments: (i) amino acid starvation which, according to previous conclusions, enabled the cells to complete replication cycles of deoxyribonucleic acid (DNA); (ii) amino acid starvation during which the synthesis of DNA was arrested by the addition of 50 μg of cytidine per ml. The results showed that the enhancement of resistance observed after amino acid prestarvation was in correlation with the amount of DNA which was synthesized during the amino acidless period. The enhancement of resistance can be abolished by the addition of the riboside at any phase of the starvation period. This shows that the enhancement of resistance was not a consequence of the total inhibition of metabolism but of unbalanced growth which evoked the completion of replication cycles of DNA.
Differentiation of the Ribosomal Protein Compositions in the GenusEscherichiaand Its Related Bacteria
Authors: Osawa Syozo , Itoh Takuzi , Otaka Eiko
Published: January 2020

Compositions of the ribosomal proteins of 60 bacterial strains belonging to the genusEscherichiaand its related genera were examined by use of a column of carboxymethyl cellulose. The ribosomes were classified into seven groups and were further differentiated into several types (subgroups) according to their protein compositions. It was shown that ribosomal protein composition is a useful characteristic for studies of bacterial taxonomy.
Characterization of the Late Steps of Microbial Heme Synthesis: Conversion of Coproporphyrinogen to Protoporphyrin
Authors: Jacobs N. J. , Jacobs J. M. , Brent P.
Published: January 2020

Cell-free extracts of various cytochrome-containing, heterotrophic microorganisms were examined for ability to convert coproporphyrinogen to protoporphyrin. Extracts of
Escherichia coli
and
Pseudomonas denitrificans
readily accumulated large amounts of protoporphyrin when assayed under aerobic conditions. However, protoporphyrin did not accumulate under either aerobic or anaerobic conditions of assay or in the presence of various supplements in extracts of the aerobe
Micrococcus lysodeikticus
, the facultative anaerobe
Staphylococcus aureus
, or the anaerobe
Vibrio succinogenes
. Protoporphyrin also accumulated when extracts of
E. coli
and
P. denitrificans
were incubated aerobically with the early heme precursor, δ-amino levulinic acid (ALA). This protoporphyrin accumulation was markedly stimulated by the iron chelator,
o
-phenanthroline. Extracts of
S. aureus
and
M. lysodeikticus
accumulated coproporphyrin, but not protoporphyrin when incubated with ALA. The enzyme system in extracts of
E. coli
which converts coproporphyrinogen to protoporphyrin under aerobic conditions of assay was also partially characterized. This conversion was stimulated by the iron chelator,
o
-phenanthroline, the respiratory inhibitor, cyanide, and the reducing agent, thioglycolate. Dialysis of the extract did not diminish enzyme activity. Certain alternate electron acceptors and nitrite caused a marked inhibition of the conversion. These results indicate that this late step in heme synthesis, the conversion of coproporphyrinogen to protoporphyrin, can be readily demonstrated in extracts of some, but not all, cytochrome-containing bacteria and that the aerobic conversion in
E. coli
exhibits many characteristics similar to those demonstrated for the aerobic conversion previously studied in liver mitochondria.
Metabolism of T4 Bacteriophage Ghost-Infected Cells: Effect of Bacteriophage and Ghosts on the Uptake of Carbohydrates inEscherichia coliB
Authors: Winkler Herbert H. , Duckworth Donna Hardy
Published: January 2020

Ghosts of T4 bacteriophage inhibit the uptake of thiomethyl-β-galactoside (TMG), α-methylglucoside, glucose-6-phosphate, and glycerol inEscherichia coliB. The transport of orthonitrophenyl-β-galactoside (ONPG) is also inhibited to a lesser degree and without alteration of the apparentKmof transport. These effects of ghosts parallel those of energy poisons on these systems. However, nooneenergy poison can produce such pronounced inhibitory effects in all these systems. The effect of the intact phage in these systems was either absent or very slight relative to the ghost. The effect of ghosts on the uptake of TMG was not immediate; at 10 C, no effect of the ghosts was apparent for at least 2 min. This suggests that a step, more temperature dependent than the attachment of the ghost, is necessary for the inhibitory action. The intracellular level of adenosine triphosphate (ATP) in the ghost-infected cells fell to less than 25% of the control value, and the ATP lost from the cell appeared in extracellular medium. Phage, on the other hand, caused no decrease in the intracellular ATP level. This loss of ATP from the cells after ghost infection suggests an alteration of the barrier properties of the membrane so that ATP can leave the cell; however, the accessibility of extracellular ONPG to intracellular β-galactosidase does not increase. The dissimilarity of the actions of phage and ghosts on all properties examined does not support the model that the initial events in their infections are identical but that the intact phage, unlike the ghost, can provide information for the repair of its effects.
Ribosomal Helices: Formation in
Escherichia coli
During Acidic Growth
Authors: Nauman Robert K. , Silverman David J. , Voelz Herbert
Published: January 2020

Ribosomal helices are formed in 100% of
Escherichia coli
cells during extended growth in a medium of low buffering capacity. During this time, the
p
H of the medium gradually decreases from 7.0 to about 5.0. Transfer of cells into preconditioned or acidified medium does not result in helix formation unless acidification is gradual and during active growth. Concomitant with helix formation is a decrease of all major biosynthetic activities and cessation of cell motility. The larger polyribosomes become converted into an inactive helical form and sediment in sucrose gradients with the wall-membrane complex.
Genetic Recombination in
Micromonospora
Authors: Beretta Maria , Betti Mirella , Polsinelli Mario
Published: January 2020

Biochemical mutants were obtained from
Micromonospora chalcea, M. purpurea
, and
M. echinospora
by using ultraviolet radiation or nitrosoguanidine. Crosses carried out between complementary nutritional mutants of the same species showed positive genetic interaction. Data are reported which indicate that the interaction between the crossed strains is due to genetic recombination. No evidence for interspecific genetic recombination was found.
Reactivative Action of Ethylenediaminetetraacetic Acid or Dipicolinic Acid on Inactive Glucose Dehydrogenase Obtained from Heated Spores of
Bacillus subtilis
Authors: Hachisuka Y. , Tochikubo K.
Published: January 2020

Partially purified inactive glucose dehydrogenase obtained from spores which were heated at 87 or 90 C for 30 min is converted to an active from by the addition of ethylenediaminetetraacetic acid, dipicolinic acid, or some salts. The molecular weight of the inactive glucose dehydrogenase in the heated spores is about one-half of that of the active glucose dehydrogenase in the intact resting spores. The possibility is discussed that the active glucose dehydrogenase in the intact resting spores divides into subunits and is converted to stable and inactive form during heating of spores at a particular range of temperature (87 to 90 C).
Regulation of the β-Ketoadipate Pathway in
Alcaligenes eutrophus
Authors: Johnson B. F. , Stanier R. Y.
Published: January 2020

The regulation of the synthesis of the inducible enzymes that mediate the reactions of the β-ketoadipate pathway in
Alcaligenes eutrophus
has been examined by determining the inductive responses of the wild type and of mutants derived from it to metabolites of the pathway. The system of control differs in many respects from those which operate in the genera
Pseudomonas
and
Acinetobacter
.
Homology of Ribosomal Ribonucleic Acid of Diverse Bacterial Species with
Escherichia coli
and
Bacillus stearothermophilus
Authors: Pace B. , Campbell L. Leon
Published: January 2020

Hybridization competition experiments were used to examine the ribosomal ribonucleic acid (rRNA) homologies of 22 bacteria and 3 higher organisms with
Escherichia coli
and
Bacillus stearothermophilus
. Although little or no homology was observed with the higher organisms, the bacteria showed a wide range of homologies. Organisms whose rRNA showed closer homology to
E. coli
rRNA showed less rRNA homology to
B. stearothermophilus
rRNA and vice versa.
Wax D from Different Bovine Strains ofMycobacterium
Authors: Migliore D. , Augier J. , Boisvert H. , Jollès P.
Published: January 2020

Wax DP, a peptido-glycolipid found in extracts ofMycobacterium tuberculosisvar.hominis, was not found in extracts of three strains of still-grownM. tuberculosisvar.bovis(BCG, Marmorek and Dupray). However, extracts from three other bovine strains (Behring, LA and BB) did yield waxes DP, and these did not differ as to their molar ratios of alanine/glutamic acid/diaminopimelic acid from human waxes DP.
New Method for Extraction of Ribonucleic Acid and Polyribosomes from
Schizosaccharomyces pombe
Authors: Birnboim H. C.
Published: January 2020

A new method for extracting ribosomal ribonucleic acid (RNA) and polyribosomes from
Schizosaccharomyces pombe
, a fission yeast, has been developed. Cells grown in the presence of 2-deoxyglucose were found to be more sensitive to the action of Glusulase; a short period of treatment (10 to 20 min) at 0 C was sufficient to convert the cells to osmotically sensitive structures. From these, ribosomal RNA and polyribosomes were readily prepared.
Structure of the Cell Wall of
Bacillus stearothermophilus:
Mode of Action of a Thermophilic Bacteriophage Lytic Enzyme
Authors: Welker N. E.
Published: January 2020

The mode of action of a bacteriophage lytic enzyme on cell walls of
Bacillus stearothermophilus
(NCA 1503-4R) has been investigated. The enzyme is an endopeptidase which catalyzes the hydrolysis of the
l
-alanyl-
d
-glutamyl linkage in peptide subunits of the cell wall peptidoglycan. Preliminary studies on the soluble components in lytic cell wall digests indicate that the glycan moiety is composed of alternating glucosamine and muramic acid; one half of the muramic acid residues contain the tripeptide,
l
-alanyl-
d
-glutamyldiaminopimelic acid, and the remaining residues contain the tetrapeptide,
l
-alanyl-
d
-glutamyldiaminopimeyl-
d
-alanine. Almost one half of the peptide subunits are involved in cross-linkages of chemotype I. A structure for the cell wall peptidoglycan is proposed in the light of these findings.
Purification and Properties of 3-Deoxy-
d
-Arabinoheptulosonic Acid-7-Phosphate Synthetase (phe) from a λ
aroG
+
Transductant of
Escherichia coli
Authors: Simpson R. J. , Davidson B. E. , Dopheide T. A. A. , Andrews S. , Pittard J.
Published: January 2020

By incorporating
aroG
, the structural gene for 3-deoxy-
d
-arabinoheptulosonic acid-7-phosphate (DAHP) synthetase (phe), into the genome of a heat-inducible
susR60
mutant of phage lambda, it has been possible to increase the intracellular levels of DAHP synthetase (phe) in a lysogenized strain of
Escherichia coli
some 15-fold over levels found in the wild-type strain. By using this strain, the enzyme has been purified approximately 2,000-fold compared with wild type, and various kinetic parameters of the purified enzyme have been studied. In contrast to previous reports, the inhibition by phenylalanine was found to exhibit sigmoidal kinetics, suggestive of cooperative interactions between phenylalanine binding sites. Stimulation of enzyme activity by Co
2+
was minimal (14%).
Deoxyribonucleic Acid-Ribonucleic Acid Hybridization Studies on the
l
-Arabinose Operon of
Escherichia coli
B/r
Authors: Wilcox Gary , Singer Judith , Heffernan Laurel
Published: January 2020

An increase in the rate of synthesis of
ara
-specific messenger ribonucleic acid as measured by deoxyribonucleic acid-ribonucleic acid hybridization has been detected in the induced wild-type (
ara
+
) strain of
Escherichia coli
B/r as compared with the uninduced control, thus providing evidence that regulation of the positively controlled
l
-arabinose operon is at the level of transcription.
In Vivo and In Vitro Action of New Antibiotics Interfering with the Utilization of
N
-Acetyl-Glucosamine-
N
-Acetyl-Muramyl-Pentapeptide
Authors: Lugtenberg E. J. J. , Van Schijndel-Van Dam Arna , Van Bellegem T. H. M.
Published: January 2020

Recent literature on the antibiotics enduracidin, moenomycin, prasinomycin, and 11.837 RP suggested an interaction with murein synthesis. Incubation of sensitive strains from
Bacillus cereus
and
Staphylococcus aureus
in a “wall medium” containing labeled
l
-alanine showed that all four antibiotics inhibited the incorporation of alanine into murein and gave rise to accumulation of radioactive uridine diphosphate-
N
-acetyl-muramyl (UDP-MurNAc)-pentapeptide. Peptidoglycan was synthesized when the particulate enzyme of
B. stearothermophilus
was incubated with the murein precursors UDP-
N
-acetyl-glucosamine (UDP-GlcNAc) and UDP-MurNAc-pentapeptide. The newly formed polymer was less accessible for lysozyme and more strongly bound to the acceptor than the same product from the
Escherichia coli
particulate enzyme. After incubation in the presence of penicillin, a greater part of the peptidoglycan was lysozyme sensitive and more loosely bound to the acceptor. The antibiotics enduracidin, moenomycin, prasinomycin, and 11.837 RP inhibited peptidoglycan synthesis by the
B. stearothermophilus
particulate enzyme. The rate of synthesis of GlcNAc-MurNAc(-pentapeptide)-P-P-phospholipid was independent from the addition of these antibiotics, but its utilization was strongly inhibited. With the present results, it is not possible to distinguish the mechanisms of action of enduracidin, moenomycin, prasinomycin, and 11.837 RP from the mechanisms of action of vancomycin and ristocetin.
Confirmation of the Identification of the Major C-29 Hydrocarbons of
Sarcina lutea
Authors: Albro Phillip W.
Published: January 2020

Although there is agreement on the fact that
Sarcina lutea
strain FD-533 has branched C-29 monoalkenes as major hydrocarbon components, there is disagreement in the literature as to the nature of the branching. This has been resolved by analyses of the fatty acids produced by permanganate-periodate treatment of each of the resolvable hydrocarbon fractions making up the C-29 complex. The three major components are identified as doubly branched, Δ
13
species with two iso terminations, one iso and one anteiso termination, and two anteiso terminations.
Metabolism of Phosphatidylglycerol, Lysylphosphatidylglycerol, and Cardiolipin of
Staphylococcus aureus
Authors: Short Steven A. , White David C.
Published: January 2020

Staphylococcus aureus
accumulated cardiolipin (CL) and lost phosphatidylglycerol (PG) during the stationary phase of growth. The minor lipids, phosphatidylethanolamine and phosphatidylglucose, also accumulated, whereas the lysylphosphatidylglycerol (LPG) content of the membrane remained constant as stationary phase continued. During exponential growth, the proportions and total content of phospholipids per cell remained constant. The metabolism of the phospholipids was examined under these conditions. In pulse-chase experiments, the phospholipids lost
14
C from the glycerols slower than
32
P. When the phospholipids were labeled with
14
C glycerol, the unacylated glycerols of PG and LPG lost
14
C, whereas the diacylated glycerols either accumulated or did not lose
14
C. In all experiments, the PG showed a more rapid metabolism than the LPG. When staphylococcal CL was hydrolyzed by
Haemophilus parainfluenzae
CL-specific phospholipase D into phosphatidic acid (PA) and PG, the incorporation of
32
P into both of the phosphates of CL was found to be parallel at both the PG and PA ends of the molecule. However, the specific activity of the
32
P at the PA end was twice that at the PG end of the molecule. The PG end of the CL apparently came from a portion of the cellular PG pool with about 20% the specific activity of the total cellular PG. The turnover of two of the glycerols of the PG portion of CL was like that of the cellular PG. The diacylated glycerol of the PG and of CL and of the membrane PG showed neither turnover nor incorporation of
14
C. Half of the radioactivity was lost from the middle glycerol of CL and the free glycerol of the cellular PG in one bacterial doubling. The diacylated glycerol from the other end of the CL molecule (the PA end) lost radioactivity almost as rapidly as the middle glycerol for 10 min. After the initial rapid loss, the turnover slowed to a rate 10 times slower than the middle glycerol, indicating that the
14
C was actually accumulating at this end of the molecule. The phosphates and glycerols involved in the hydrolysis and resynthesis of the CL molecule during exponential growth in
S. aureus
apparently come from different pools of PG.
Pseudomonas putida Tryptophan Synthetase: Partial Sequence of the α Subunit
Authors: Crawford Irving P. , Yanofsky Charles
Published: January 2020

There is 50% identity in the sequences of the first 50 residues of the α chains of
Escherichia coli
and
Pseudomonas putida
. No deletions or additions of residues are found in this region, except for the N-terminal methionine residue which is missing in the polypeptide isolated from
P. putida
. Most of the residues which differ are chemically dissimilar, and half of them are specified by codons which differ by more than a single base. The two residues known by mutational analysis to be essential for catalysis in
E. coli
are conserved in
P. putida
. The potential taxonomic usefulness of information of this sort is analyzed.
Early Intermediate State of Transforming Deoxyribonucleic Acid During Uptake by
Bacillus subtilis
Authors: Morrison D. A.
Published: January 2020

Examination of the effects of ethylenediaminetetraacetic acid (EDTA) on uptake of transforming deoxyribonucleic acid (DNA) by
Bacillus subtilis
allowed definition of a new intermediate state of transforming DNA during uptake. Markers in this state, termed “EDTA-resistant,” are bound to the cell, are sensitive to inactivation by deoxyribonuclease, but may become deoxyribonuclease-resistant despite the addition of excess EDTA. Markers become EDTA-resistant quadratically with time after the addition of DNA to a competent culture, but linearly after exposure of competent cells to a brief pulse of DNA. An attractive model consistent with these findings is that EDTA blocks only the initiation of entry of a molecule of DNA.
Transposition of the
lac
Region to the
gal
Region of the
Escherichia coli
Chromosome: Isolation of λ
lac
Transducing Bacteriophages
Authors: Ippen K. , Shapiro J. A. , Beckwith J. R.
Published: January 2020

Defective and plaque-forming λ
lac
transducing phages have been isolated from bacterial strains in which the lactose operon has been genetically transposed to the galactose locus.
Heat Stabilities of Ribosomal Subunits and Reassociated Ribosomes from
Bacillus stearothermophilus
Authors: Friedman S. Marvin
Published: January 2020

Absorbance-temperature profiles reveal that both the 30
S
and 50
S
ribosomal subunits from
Bacillus stearothermophilus
are more thermostable than the comparable
Escherichia coli
particles. Thermophile ribosomes formed by the reassociation of subunits do not display functional heat stability.
Metabolism of Benzoic Acid by Bacteria: 3,5- Cyclohexadiene-1,2-Diol-1-Carboxylic Acid Is an Intermediate in the Formation of Catechol
Authors: Reiner Albey M.
Published: January 2020

3,5-Cyclohexadiene-1,2-diol-1-carboxylic acid (1,2-dihydro-1,2-dihydroxy-benzoic acid) is converted enzymatically to catechol in cell extracts fromAcinetobacter, Alcaligenes, Azotobacter, and threePseudomonasspecies. This enzymatic activity is present only in cultures which have been grown in the presence of benzoic acid, and which convert benzoic acid to catechol rather than to protocatechuic acid. The reaction is assayed by the concomitant formation of reduced nicotinamide adenine dinucleotide from nicotinamide adenine dinucleotide. The conversion of [14C]benzoic acid to [14C]dihydrodihydroxybenzoic acid is demonstrated in cell extracts. A scheme for the conversion of benzoic acid to catechol in bacteria is presented, involving the formation of dihydrodihydroxybenzoic acid from benzoic acid by a dioxygenase which is unstable in cell extracts, followed by the dehydrogenation and decarboxylation of dihydrodihydroxybenzoic acid to catechol by a previously undescribed enzyme. Experiments with anthranilic acid and phthalic acid suggest that dihydrodihydroxybenzoic acid is a metabolite unique to benzoic acid metabolism. Two new methods for assaying benzoic acid dioxygenase are suggested.
Oxidation of Nicotinic Acid by a
Bacillus
Species: Purification and Properties of Nicotinic Acid and 6-Hydroxynicotinic Acid Hydroxylases
Authors: Hirschberg Rona , Ensign J. C.
Published: January 2020

The enzymes of a
Bacillus
species that hydroxylate nicotinic acid to 6-hydroxynicotinic acid and 6-hydroxynicotinic acid to 2,6-dihydroxynicotinic acid were purified and characterized. The purified enzymes contained approximately two molecules of flavine and eight molecules of iron per molecule of enzyme. The enzymes were large (molecular weight, 400,000 to 450,000) and appeared to consist of subunits.
Escherichia coli
K-12 Mutants Altered in the Transport of Branched-Chain Amino Acids
Authors: Guardiola John , Iaccarino Maurizio
Published: January 2020

Two mutants of
Escherichia coli
K-12 are described which are resistant to the inhibition that valine exerts on the growth of
E. coli
. These mutants have lesions at two different loci on the chromosome. One of them,
brnP
, is linked to
leu
(87% cotransduction) and is located between
leu
and
azi
represented on the map at 1 min; the other,
brnQ
, is linked to
phoA
(96% cotransduction), probably between
proC
and
phoA
and represented at 10 min. These mutants are resistant to valine inhibition but are sensitive to dipeptides containing valine. Since it is known that dipeptides are taken up by
E. coli
through a transport system(s) different from those used by amino acids, this sensitivity to the peptides suggests an alteration in the active transport of valine. The mutants are resistant to valine only if leucine is present in the growth medium; the uptake of valine is less in both mutants than it is in wild-type
E. coli
, and it is reduced even further if leucine is present. Under these conditions the total uptake of valine is almost completely abolished in the
brnQ
mutant. The
brnP
mutant takes up about 60% as much valine as does the wild type, but no exogenous valine is incorporated into proteins. The apparent
K
m
and
V
max
of isoleucine, leucine, and valine for the transport system are reported; the
brnP
mutant, when compared to the wild type, has a sevenfold higher
K
m
for isoleucine and a 17-fold lower
K
m
for leucine; the
V
max
for the three amino acids is reduced in the
brnQ
mutant, up to 20-fold for valine. The transport of arginine, aspartic acid, glycine, histidine, and threonine is not altered in the
brnQ
mutant under conditions in which that of the branched amino acids is. Evidence is reported that
O
-methyl-threonine enters
E. coli
through the transport system for branched amino acids, and that thiaisoleucine does not.
Structural Effects onArthrobacterMethylene Hydroxylase Activity
Authors: Hayasaka Steven , Klein D. A.
Published: January 2020

Arthrobacter4-44-2 (ATCC 25581), capable of subterminal oxidation ofn-hexadecane to 2-, 3-, and 4-alcoholic and ketonic products, was examined for the ability of this methylene hydroxylase capability to be induced and repressed and for structural relationships influencing methylene function oxidation. Induction was best carried out by use ofn-alkanes from 10 to 16 carbons in length and was especially strong with methylcyclohexane among cyclic compounds tested. Induction was not observed with several related alcohols, 1-unsaturated compounds, or methoxy and ethoxy compounds tested. After induction,n-alkanes 14 and 16 carbons in length were transformed to the corresponding internal oxidation products; however, no activity was observed with even-carbon alkanes of shorter chain length. Hexadecene-1 and all alcohols tested, including cyclododecanol, were transformed to corresponding ketonic or aldehydic products. Cyclic compounds tested, including cyclododecane, were not oxidized by induced cells, suggesting that a methyl group plays a role in orientation of the substrate for the methylene hydroxylation but that the methyl function was not as critical after completion of the hydroxylation step regardless of structural configuration. Acetate strongly repressed induction ofn-hexadecane methylene hydroxylase activity. Inducibility of methylene hydroxylase activity was confirmed by use of cell-free systems with methylcyclohexane as an inducer. A stimulation of methylene hydroxylase activity by addition of reduced pyridine nucleotides and ferrous ion was indicated.
Influences of Various Amino Acids on Tryptophan-Mediated Control of the Tryptophan Biosynthetic Enzymes in
Escherichia coli
Authors: Stubbs John D. , Stubbs E. Ann
Published: January 2020

Lysates of
Escherichia coli
Ymel obtained from cultures grown in the absence of tryptophan in minimal medium supplemented with 0.1% casein hydrolysate show an approximate fivefold increase in steady-state specific activity of both anthranilate synthetase and tryptophan synthetase A protein relative to cultures grown in nonsupplemented medium. In the presence of repressing levels of exogenous tryptophan, growth of cultures in casein hydrolysate-supplemented medium results in a noncoordinate enhancement of repression of 10-fold for anthranilate synthetase and twofold for tryptophan synthetase A protein. Similar, but less pronounced, effects are shown for strain W3110. Strains possessing tryptophan regulator gene mutations do not exhibit this first effect, but do yield an approximate twofold decrease in specific activity of both enzymes when grown in medium supplemented with tryptophan and casein hydrolysate. A stimulation of derepression of both enzymes in strain Ymel equivalent to that induced by casein hydrolysate can be reproduced by growth in minimal medium supplemented with threonine, phenylalanine, tyrosine, serine, glutamic acid, and glutamine. Doubling time in this medium is not significantly different from that in minimal medium. An enhancement of repression which partially mimics that observed on growth in medium supplemented with tryptophan plus casein hydrolysate is obtained when Ymel is grown on medium supplemented with tryptophan plus methionine. Threonine or phenylalanine plus tyrosine as separate medium supplements are independently capable of producing a 1.4-fold or 3.4-fold stimulation, respectively, but in combination only the phenylalanine plus tyrosine effect is manifested unless serine and glutamic acid or glutamine are included. Our data show that expression of the tryptophan biosynthetic enzymes can be significantly influenced in vivo as a result of growth in medium supplemented with a variety of amino acids.
2-Keto-3-Deoxygluconate 6-Phosphate Aldolase Mutants of
Escherichia coli
Authors: Fradkin Judith E. , Fraenkel D. G.
Published: January 2020

A new mutation in
Escherichia coli
, giving inability to grow on gluconic, glucuronic, or galacturonic acids, has been identified as complete deficiency of 2-keto-3-deoxygluconate 6-phosphate (KDGP) aldolase activity. The genetic map position of the locus,
eda
, is about 35 min. The inability to grow on the uronic acids was expected, because the aldolase is on the sole known pathway of their metabolism. However, inability to grow on gluconate was less expected, because the hexose monophosphate shunt might be used, as happens in mutants blocked in the previous step,
edd
, of the Entner-Doudoroff pathway. The likely explanation of gluconate negativity is inhibition by accumulated KDGP, because gluconate is inhibitory to growth on other substances, and one type of gluconate revertant is
eda
−
,
edd
−
. KDGP is probably the inducer of KDGP aldolase.
Nicotinamide Adenine Dinucleotide-Dependent and Nicotinamide Adenine Dinucleotide-Independent Lactate Dehydrogenases in Homofermentative and Heterofermentative Lactic Acid Bacteria
Authors: Doelle Horst W.
Published: January 2020

Three homofermentative (
Lactobacillus plantarum
B38,
L. plantarum
B33,
Pediococcus pentosaceus
B30) and three heterofermentative (
Leuconostoc mesenteroides 39, L. oenos
B70,
Lactobacillus brevis
) lactic acid bacteria were examined for the presence or absence of nicotinamide adenine dinucleotide (NAD)-dependent and NAD-independent
d
- and
l
-lactate dehydrogenases. Two of the six strains investigated,
P. pentosaceus
and
L. oenos
, did not exhibit an NAD-independent enzyme activity capable of reducing dichlorophenol indophenol. The
p
H optima of the lactic dehydrogenases were determined. The NAD-dependent enzymes from homofermentative strains exhibited optima at
p
H 7.8 to 8.8, whereas values from 9.0 to 10.0 were noted for these enzymes from heterofermentative organisms. The optima for the NAD-independent enzymes were between 5.8 and 6.6. The apparent Michaelis-Menten constants determined for both NAD and the substrates demonstrated the existence of a greater affinity for
d
- than
l
-lactic acid. A comparison of the specific NAD-dependent and NAD-independent lactate dehydrogenase activities revealed a direct correlation of the
d/l
ratios of these activities with the type of lactic acid produced during the growth of the organism.
Spore Appendages and Taxonomy of
Clostridium sordellii
Authors: Rode L. J. , Pope Leodocia , Filip Camille , Smith Louis Ds.
Published: January 2020

Twenty-five strains of
Clostridium sordellii
were divided into two groups on the basis of spore fine structure. Sixteen strains formed spores with smooth tubular appendages, and nine strains formed spores which lacked appendages. The other properties of the 25 strains were relatively constant. Since the minor strain variability which was encountered did not correlate with spore appendage status, fragmentation of this species on the basis of spore appendage status is not advocated.
Alkaline Sucrose Gradient Sedimentation of Chromosomal Deoxyribonucleic Acid from
Escherichia coli
PolA
+
and PolA
−
Strains During Thymine Starvation
Authors: Sedgwick Steven G. , Bridges Bryn A.
Published: January 2020

Single-strand breaks were not detected in the deoxyribonucleic acid of
Escherichia coli
after thymine starvation for up to 180 min, even in a sensitive PolA
−
strain.
Fatty Acids of
Thiobacillus thiooxidans
Authors: Levin Richard A.
Published: January 2020

Fatty acid spectra were made on
Thiobacillus thiooxidans
cultures both in the presence and absence of organic compounds. Small additions of glucose or acetate had no significant effect either on growth or fatty acid content. The addition of biotin had no stimulatory effect but did result in slight quantitative changes in the fatty acid spectrum. The predominant fatty acid was a C
19
cyclopropane acid.
Regulation of Penicillinase Synthesis: a Mutation in
Staphylococcus aureus
Unlinked to the Penicillinase Plasmid That Reduces Penicillinase Inducibility
Authors: Zyskind J. Weaver , Imsande John
Published: January 2020

A mutant of
Staphylococcus aureus
strain 655 was isolated that is restricted in penicillinase induction. Wild-type plasmids that bear penicillinase determinants could not be fully induced in this mutant, 655
par-1;
hence, the responsible mutation is not located on the plasmid. Mutant plasmid PI
258
penI443
, which produces penicillinase constitutively in wild-type cells, was fully constitutive for penicillinase production when it was harbored by mutant 655
par-1
. Therefore, the bacterial mutation does not interfere directly with the transcription of the
penZ
gene or translation of the penicillinase messenger ribonucleic acid. Mutant plasmid PII
147
penI220
was fully inducible in the mutant bacterium, even though the wild-type plasmid PII
147
was only partially inducible in the
par-1
mutant. Thus, in the presence of inducer, complementation appears to occur between the product of the
par-1
gene and the product of the
penI220
gene. These results suggest that the
par-1
gene codes for a penicillinase antire-pressor.
Transmethylation of Sterols in Aerobically Adapting
Saccharomyces cerevisiae
Authors: Starr P. R. , Parks L. W.
Published: January 2020

The transmethylation of methyl-
14
C-methionine and methyl-
14
C-adenosylmethionine into the nonsaponifiable lipids of anaerobically grown yeast during adaptation to aerobic conditions was investigated. The rate and extent of methyl transfer increased with aeration time and was dependent upon the presence of a fermentable carbon source and O
2
. Methionine and adenosylmethionine uptake rates increased in adaptation buffer but did not seem to be the rate-limiting factor for transmethylation under the conditions studied. Thinlayer chromatography of the nonsaponifiable fraction after exposure to label showed the labeled product to be ergosterol. Samples taken after short-term exposure to label were composed of two labeled steroidal products, one with kinetics of an ergosterol precursor.
Competence Mutants II. Physical and Biological Fate of Donor Transforming Deoxyribonucleic Acid
Authors: Postel Edith Horn , Goodgal Sol H.
Published: January 2020

Transformation-deficient (
com
−
) mutants, which are able to bind donor transforming deoxyribonucleic acid (DNA) without yielding a significant number of transformants, were studied with regard to the fate of donor DNA. In no case was there any detectable degradation into acid-soluble radioactivity after donor DNA uptake. Physical experiments showed that some of these mutants are deficient in their ability to associate donor DNA with the recipient's chromosome (
dad
−
mutants, for donor association defective), whereas others are able to form what appear to be normal donor-recipient complexes. In spite of physical evidence for integration, none of the
dad
−
mutants contains biologically active recombinant DNA, suggesting that they might be deficient in the recombination process (
dab
−
mutants, for donor association biologically defective). Donor biological activity is not replicated in any of the mutant strains, and in some cases there is a 10-fold reduction of donor transforming DNA within 60 min after DNA uptake.
Unusual Valyl-Transfer Ribonucleic Acid Synthetase Mutant of
Escherichia coli
Authors: Anderson James J. , Neidhardt Frederick C.
Published: January 2020

Escherichia coli
strain NP2907 was isolated as a spontaneous mutant of strain NP29, which possesses a thermolabile valyl-transfer ribonucleic acid (tRNA) synthetase. The valyl-tRNA synthetase of the new mutant, unlike that of its immediate parent, retains enzymatic activity in vitro but differs from the wild-type enzyme in stability and apparent
K
m
for adenosine triphosphate. The new mutant locus,
valS
-102, cotransduces with
pyrB
at the same frequency as does the parental locus,
valS
-1. Cultures of strain NP29 cease growth immediately in any medium when shifted from 30 to 40 C. The new mutant grows normally at 30 C, and upon a shift to 40 C growth quickly accelerates exactly as for normal cells. Exponential growth, however, cannot be sustained at 40 C. At a point characteristic for each medium, growth becomes linear with time. This transition occurs almost immediately in rich media and after 1.5 generations in glucose minimal medium. Net synthesis of valyl-tRNA synthetase ceases in the new mutant as soon as the temperature is raised to 40 C, irrespective of the growth medium. We conclude that it is the amount of valyl-tRNA synthetase activity that limits the rate of growth in the linear phase at 40 C. This property of the mutant makes it possible to evaluate the in vivo efficiency of this enzyme at different growth rates and thereby to determine the concentration that is necessary for a given rate of protein synthesis. The results of our measurements indicate that cells of
E. coli
growing in minimal medium normally possess a functional excess of valyl-tRNA synthetase with respect to protein synthesis and to repression of threonine deaminase.
Release of the β-Galactosidase-Synthesizing System from Ultraviolet Catabolite Repression by Cyclic 3′,5′-Adenosine Monophosphate, Dark Repair, Photoreactivation, and Cold Treatment
Authors: Swenson P. A.
Published: January 2020

Recovery from the inhibitory effect of ultraviolet irradiation on the induced synthesis of β-galactosidase was studied in
Escherichia coli
B/r. When irradiated cells (520 ergs/mm
2
at 254 nm) were induced and incubated in minimal medium supplemented with Casamino Acids (conditions of catabolite repression), the ability to form enzyme was greatly reduced for about 100 min and then recovery began. The inhibition observed immediately after ultraviolet irradiation was partially reversed by cyclic 3′,5′-adenosine monophosphate (cyclic AMP) or by photoreactivation treatment. Inhibition was reduced if the cells were given cold treatment (5 C) before or during irradiation; the kinetics of induced enzyme formation in each case were similar to those of irradiated cells receiving cyclic AMP. These kinetics suggest that the cold treatments, like cyclic AMP, cause the release of the β-galactosidase-synthesizing system from catabolite repression. When irradiated cells were incubated for various times before cyclic AMP or photoreactivation treatment, some reversal of the inhibition of induced enzyme formation was obtained, but by 100 min the treatments were ineffective. Because 100 min was also the time at which dark recovery of enzyme formation began, the recovery process was interpreted to be the result of completion of DNA repair, which, in turn, released the β-galactosidase-synthesizing system from catabolite repression.
Deoxyribonucleic Acid of
Anaplasma marginale
Authors: Senitzer D. , Dimopoullos G. T. , Brinkley B. R. , Mandel M.
Published: January 2020

Deoxyribonucleic acid from isolated marginal bodies and calf erythrocytes infected with
Anaplasma marginale
is found to be double stranded and to contain 51 moles per cent guanine plus cytosine.
Deoxyribonucleic Acid Homologies of Some So-Called “
Hydrogenomonas
” Species
Authors: Ralston Ericka , Palleroni N. J. , Doudoroff M.
Published: January 2020

Evidence based on deoxyribonucleic acid homology supports the abandonment of the genus
Hydrogenomonas. Pseudomonas facilis
(formerly
Hydrogenomonas facilis
) is closely related to the nonautotrophic species
P. delafieldii. P. facilis
and
Alcaligenes eutrophus
(often called
H. eutropha
) are not related to each other or to other hydrogen bacteria and pseudomonads studied.
Function of Ubiquinone in
Escherichia coli:
a Mutant Strain Forming a Low Level of Ubiquinone
Authors: Newton N. A. , Cox G. B. , Gibson F.
Published: January 2020

A ubiquinone-deficient mutant of
Escherichia coli
K-12 forming 20% of the normal amount of ubiquinone was compared with a normal strain. This lowered concentration of ubiquinone is still four times the concentration of cytochrome
b
1
. The mutant strain grew more slowly than the normal strain on a minimal medium with glucose as sole source of carbon and gave a lower aerobic growth yield than the normal strain. The reduced nicotinamide adenine dinucleotide (NADH) oxidase rate in membranes from the mutant strain was 40% of the oxidase rate in membranes from the normal strain, and the percentage reduction of cytochrome
b
1
in the aerobic steady state, with NADH as substrate, was increased in membranes from the mutant strain. It is concluded that ubiquinone is required for maximum oxidase activity at the relatively high concentration (27 times that of cytochrome
b
1
) found in normal cells. The results are discussed in relation to a scheme previously advanced for ubiquinone function in
E. coli
.
Suppression of a Mutation Disruptive to Nuclear Migration in
Schizophyllum
by a Gene Linked to the
B
Incompatibility Factor
Authors: Koltin Y. , Stamberg Judith
Published: January 2020

A gene which can suppress a specific mutation disruptive to nuclear migration in
Schizophyllum
is described. It controls the rate of migration of invading nuclei through the mutant mycelium, thus suppressing the mutant character. The gene is located between the two loci of the
B
incompatibility factor.