bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation and Partial Characterization of an Immunogenic Moiety Obtained fromSalmonella typhimurium
Authors: Venneman Martin R. , Bigley Nancy J.
Published: January 2020

Ribosomal preparations obtained fromSalmonella typhimuriumby differential centrifugation and sodium dodecyl sulfate (SDS) treatment of the bacillary lysate were found to be immunogenic in F1hybrid (C3H/HeJ × DBA/2J) and albino Swiss mice, as determined by progressive host survival. The immunity obtained was independent of the need for adjuvant and dependent on the dosage of immunogen given. Immunizations with the ribosomal preparations induced an immune response comparable to that obtained by vaccination with living organisms and significantly greater than that obtained by immunization with heat-killed salmonellae, purified lipopolysaccharide, or crude and SDS-treated endotoxin preparations. No effect on the immunogenicity of the ribosomal fraction was observed by enzymatic treatment with trypsin, Pronase, deoxyribonuclease, and pancreatic ribonuclease. Linear sucrose density gradient resolution of the preparations showed that the immunogenicity of the ribosomal fraction was not unique to any one of its subcomponents. Ethyl alcohol-precipitated, crude ribonucleic acid preparations obtained from the ribosomal and sucrose density-resolved ribosomal preparations were found to induce an immune response comparable to that obtained by immunization with the entire ribosomal fraction. Dialysis in doubly distilled demineralized water slightly reduced the immunogenicity of the preparation; however, comparable dialysis in 10−4mMgCl2-phosphate buffer did not. Chemical assays of the preparations found to be immunogenic were performed.
Influence of Carbon or Nitrogen Starvation on Amino Acid Transport in
Pseudomonas aeruginosa
Authors: Kay W. W. , Gronlund Audrey F.
Published: January 2020

Pseudomonas aeruginosa
was shown to utilize the majority of commonly occurring amino acids for growth as either the sole carbon or the sole nitrogen source. During carbon or nitrogen deprivation, the rates of transport of most of the amino acids remained unchanged; however, the transport rates for glutamate, alanine, and glycine increased under these conditions and the transport rates for leucine and valine decreased. Normal transport rates for these amino acids were resumed immediately upon the addition of the required nutrient. In the absence of an external source of carbon or of nitrogen, pool amino acids underwent rapid degradation.
14
C-Amino acid pulse experiments indicated that the constitutive amino acid catabolic enzymes, normally present in the organism during growth with glucose as the carbon source, were responsible for rapid pool losses. Nutrient starvation in the presence of chloramphenicol did not prevent amino acid catabolism. This enzymic activity is interpreted as providing
P. aeruginosa
with a selective advantage for survival during conditions of carbon or nitrogen starvation.
Distribution and Serological Specificity of Sialidase Produced by Various Groups of Streptococci
Authors: Hayano Seiki , Tanaka Atsuko , Okuyama Yusuke
Published: January 2020

The occurrence of a streptococcal sialidase (designated St-sialidase) in culture fluids of various streptococci was investigated. St-sialidase was found to occur in strains belonging to groups A, B, C, E, G, H, and L, and the unclassified strains,
Streptococcus sanguis
and
Streptococcus uberis
. St-sialidase of group A was confined predominantly to types 4 and 22. St-sialidases, extracted from the culture fluids of some selected strains, were antigenic, eliciting the formation of antibody which effectively neutralized the enzymatic activity of the enzyme. Antisera to the St-sialidases of groups A, B, C, E, G, and L, and
Streptococcus sanguis
were produced in rabbits. The St-sialidases of groups A, B, and E streptococci were serologically distinct and group-specific. The St-sialidases from groups C, G, and L were serologically homologous, but distinct from St-sialidases of the other groups. Antiserum to the enzyme of strain 10557 (
S. sanguis
) cross-reacted with the St-sialidase of strain 9927 (
S. uberis
).
Differential Effect of Respiratory Inhibitors on Ergosterol Synthesis bySaccharomyces cerevisiaeDuring Adaptation to Oxygen
Authors: Adams B. G. , Parks L. W.
Published: January 2020

The effect of different respiratory inhibitors on the ergosterol content of microaerobically grown non-proliferating yeast cultures was monitored during adaptation to oxygen. It was found that dinitrophenol, azide, and cyanide, which act on the mechanism of the respiratory chain, cause a marked stimulation of sterol production. Acriflavine and chloramphenicol, which affect the synthesis of the respiratory apparatus, caused a delay in the onset of ergosterol synthesis or a marked decrease in sterol content. The data obtained provide presumptive evidence that a component of sterol formation is synthesized on the 70Sribosomal system of the mitochondrion and induced in the presence of oxygen.
Developmental Regulation of Alkaline Phosphatase in
Dictyostelium discoideum
Authors: Loomis William F.
Published: January 2020

The kinetics of accumulation of alkaline phosphatase activity were determined in cells of wild-type and morphologically aberrant mutant strains of
Dictyostelium discoideum
induced to develop synchronously on membrane supports. The enzyme specific activity increased slowly in wild-type cells until culmination when a dramatic rise in specific activity occurred. The patterns of accumulation in the mutant strains, as well as previous electrophoretic analysis, suggest that the two phases of accumulation may result from the synthesis of distinct isozymes. The rapid accumulation of alkaline phosphatase was found to require concomitant protein synthesis. Ribonucleic acid synthesis, on the other hand, could be inhibited during the 8 hr immediately preceding culmination without affecting the amount of enzyme accumulated. When ribonucleic acid synthesis was inhibited earlier in development, the accumulation of alkaline phosphatase was reduced. Comparison of these results with work on other developmentally controlled enzymes suggests that both transcriptional and translational control occurs during development of
D. discoideum
. The accumulation of alkaline phosphatase was shown to require specific cellular topography during culmination, suggesting that intercellular interactions which allow synthesis of alkaline phosphatase occur at that stage.
l
-Arabinose Binding Protein from
Escherichia coli B/r
Authors: Hogg R. W. , Englesberg E.
Published: January 2020

A protein which is capable of binding
l
-arabinose-
1
-
14
C
has been isolated from
l
-arabinose-induced cultures of
Escherichia coli
B/r. Analysis for this
l
-arabinose-binding protein (ABP) in a number of
l
-arabinose-negative mutants suggests that the ABP is not coded for by any of the known genetic units of the
l
-arabinose complex yet is under the control of the regulator gene
araC
. The ABP has been purified and found to bind
l
-arabinose,
d
-fucose,
d
-xylose, and
l
-ribulose with decreasing affinities. The

K
m

for
l
-arabinose is 5.7 × 10
−6
m
. The molecular weight, as determined by equilibrium centrifugation, was found to be 32,000. The protein was observed to have many features that liken it to other recently isolated binding proteins that have been implicated in the active transport of small molecules.
Cotransduction and Cotransformation of Genetic Markers in
Bacillus subtilis
and
Bacillus licheniformis
Authors: Tyeryar Franklin J. , Taylor Martha J. , Lawton William D. , Goldberg Ivan D.
Published: January 2020

Bacteriophage SP-15, a large generalized transducing phage of
Bacillus
, was compared with phages PBS-1 and SP-10 for the ability to cotransduce pairs of genetic markers exhibiting different degrees of linkage. When auxotrophs of
B. subtilis
W-23 were used as recipients, SP-15 and PBS-1 effected a much higher frequency of cotransduction than did SP-10 with markers that were not closely linked. With more closely linked loci, the differences were not as great. SP-15 cotransduced linked markers at a higher mean frequency than PBS-1, suggesting that SP-15 is able to transfer a larger fragment of the
Bacillus
genome than any phage heretofore described. The frequency of the joint transfer of genetic markers in
B. licheniformis
was lower via transforming deoxyribonucleic acid than by transduction with phage SP-10. The availability of three procedures for genetic exchange—transduction by SP-15 and SP-10 as well as transformation—each of which reveals a different degree of linkage, makes
B. licheniformis
9945A especially amenable to genetic analysis.
Catabolite Repression Gene of
Escherichia coli
Authors: Tyler Bonnie , Wishnow Rodney , Loomis W. F. , Magasanik Boris
Published: January 2020

A catabolite repression gene (
cat
) which alters the sensitivity of
Escherichia coli
to catabolite repression has been mapped by transduction and shown to be located between the
pyrC
and
purB
genes. When the
cat-1
mutation was studied in a number of genetic backgrounds, the results showed that this mutation affects the synthesis of more than one catabolic enzyme but does not completely eliminate catabolic repression under all conditions. It is suggested that this mutation may cause a block in the accumulation of the catabolite effector. Our experiments show that this effector is not glucose-6-phosphate.
Regulation of the Potassium to Sodium Ratio and of the Osmotic Potential in Relation to Salt Tolerance in Yeasts
Authors: Norkrans Birgitta , Kylin Anders
Published: January 2020

By using the isotope pairs
22
Na-
24
Na and
42
K-
86
Rb, the uptake and retention of Na and K was studied in the salt-tolerant
Debaryomyces hansenii
and in the less tolerant
Saccharomyces cerevisiae
at NaCl levels of 4 m
m
and 0.68, 1.35, and 2.7
m
in the medium. The ratio of K to Na is much higher in the cells than in the media, and higher in
D. hansenii
than in
S. cerevisiae
under comparable conditions. The difference between the two species is due to a better Na extrusion and a better uptake of K in
D. hansenii
. The kinetics of ion transport show that at about the time when extrusion of Na could be demonstrated in
D. hansenii
, K-Rb previously lost to an easily washable compartment of the cells was reabsorbed in both organisms. More H
+
was given off from
S. cerevisiae
than from
D. hansenii
in the course of these events. The findings fit the working hypothesis tested, which regards salt tolerance as partly dependent on the ability to mobilize energy to extrude Na from the cells and to take up K. The volume changes in
S. cerevisiae
are greater and are more slowly overcome than those in
D. hansenii
. The total salt level of the cells is not sufficient to counteract the osmotic potential of the medium, so that additional osmoregulatory mechanisms must be involved in determining halotolerance.
Phenol and Benzoate Metabolism by
Pseudomonas putida:
Regulation of Tangential Pathways
Authors: Feist Carol F. , Hegeman G. D.
Published: January 2020

Catechol occurs as an intermediate in the metabolism of both benzoate and phenol by strains of
Pseudomonas putida
. During growth at the expense of benzoate, catechol is cleaved
ortho
(1,2-oxygenase) and metabolized via the β-ketoadipate pathway; during growth at the expense of phenol or cresols, the catechol or substituted catechols formed are metabolized by a separate pathway following
meta
(2,3-oxygenase) cleavage of the aromatic ring of catechol. It is possible to explain the mutually exclusive occurrence of the
meta
and
ortho
pathway enzymes in phenol- and benzoate-grown cells of
P. putida
on the basis of differences in the mode of regulation of these two pathways. By use of both nonmetabolizable inducers and blocked mutants, gratuitous synthesis of some of the
meta
pathway enzymes was obtained. All four enzymes of the
meta
pathway are induced by the primary substrate, cresol or phenol, or its analogue. Three enzymes of the
ortho
pathway that catalyze the conversion of catechol to β-ketoadipate enol-lactone are induced by
cis,cis
-muconate, produced from catechol by 1,2-oxygenase-mediated cleavage. Observations on the differences in specificity of induction and function of the two pathways suggest that they are not really either tangential or redundant. The
meta
pathway serves as a general mechanism for catabolism of various alkyl derivatives of catechol derived from substituted phenolic compounds. The
ortho
pathway is more specific and serves primarily in the catabolism of precursors of catechol and catechol itself.
Exopolysaccharide Colanic Acid and Its Occurrence in the
Enterobacteriaceae
Authors: Grant W. D. , Sutherland I. W. , Wilkinson J. F.
Published: January 2020

A study of strains from the genera
Salmonella, Escherichia
, and
Aerobacter
has shown that under appropriate conditions many strains produce an exopolysaccharide slime of identical composition, which has been identified as colanic acid on the basis of its chemical composition and its sensitivity to certain bacteriophage-induced depolymerase enzymes. Chemical analysis shows that the polysaccharide contains
O
-acetyl groups in addition to the sugars glucose, galactose, fucose, and glucuronic acid. Mild acid hydrolysis has led to the isolation of a β-glucosylfucose in addition to glucuronic acid containing oligosaccharides. Many strains were found to synthesize colanic acid under normal conditions of growth or under conditions favoring polysaccharide synthesis, whereas others only synthesized colanic acid when the control mechanism was derepressed by
p
-fluorophenylalanine.
Carbohydrate Metabolism During Morphogenesis of
Coprinus lagopus
(
sensu
Buller)
Authors: Rao P. S. , Niederpruem D. J.
Published: January 2020

The occurrence and properties of enzymes of carbohydrate metabolism were studied during dikaryotic fruiting of the mushroom
Coprinus lagopus
. Enzymes of hexose monophosphate catabolism, sugar alcohol (polyol) dehydrogenases (DH), and trehalase occurred throughout development. The ratio of xylitol DH to sorbitol DH was greater than unity in both monokaryotic mycelium and dikaryotic fruit body caps, whereas this ratio decreased in the stipe (stalk) tissue. Xylitol DH and sorbitol DH were both dependent upon nicotinamide adenine dinucleotide (NAD) and showed maximal activity at
p
H 9. Two separate enzymes were suspected on the basis of preferential utilization of the NAD analogue, thionicotinamide-NAD, by xylitol DH, and this feature was consistent throughout development. An appraisal of the carbohydrate pool revealed trehalose and glucose, with the former predominant in the stipe and the latter in excess in the cap of dikaryotic fruit bodies. Trehalase activity in dialyzed enzyme extracts showed
p
H optima at acid and alkaline
p
H levels in monokaryotic mycelium, dikaryotic stipes, and cap tissues.
6-Phosphogluconolactonase Mutants of
Escherichia coli
and a Maltose Blue Gene
Authors: Kupor S. R. , Fraenkel D. G.
Published: January 2020

Mutants lacking an enzyme of the oxidative branch of the hexose monophosphate shunt, 6-phosphogluconolactonase (
pgl
), have been selected as a new class of glucose-negative derivatives of a phosphoglucose isomerase (
pgi
) mutant. Glucose negativity is not as complete as in mutants lacking phosphoglucose isomerase and glucose-6-phosphate dehydrogenase.
Pgi
+
,
pgl
−
strains have been constructed by transduction and grow almost normally on glucose. Genetic mapping shows that
pgl
lies between
chlD
and
att
-λ, in the same position as and identical with a
blu
gene described by Adhya and Schwartz. These
blu
mutants grown on maltose were recognized by their property to turn blue after treatment with iodine. It is not known how phosphogluconolactonase deficiency causes this reaction; it might be related to accumulation of 6-phosphogluconolactone.
Incorporation of 5-Methyl- and 5-Hydroxy-Tryptophan into the Protein of
Bacillus subtilis
Authors: Barlati Sergio , Ciferri Orio
Published: January 2020

Addition of the tryptophan analogues 5-methyl-tryptophan, 5-hydroxy-tryptophan, and 7-aza-tryptophan, during tryptophan starvation of a tryptophan auxotroph of
Bacillus subtilis
, stimulated amino acid incorporation. Two of the analogues tested, 5-methyl-tryptophan and 5-hydroxy-tryptophan, competed with each other, but their addition did not prevent tryptophan incorporation into acid-insoluble material. The incorporation of tryptophan and 5-hydroxy-tryptophan was stimulated when a mixture of phenylalanine and tyrosine was present in the medium. The two analogues 5-methyl-tryptophan and 5-hydroxy-tryptophan were recovered in protein hydrolysates of analogue-grown cultures, and there is evidence suggesting that the analogues are not chain terminators. Neither analogue prevented the polysome degradation that occurs during tryptophan starvation.
Mechanism of 3-Methylanthranilic Acid Derepression of the Tryptophan Operon in
Escherichia coli
Authors: Held William A. , Smith Oliver H.
Published: January 2020

3-Methylanthranilic acid (3MA) inhibits growth and causes derepression of the tryptophan biosynthetic enzymes in wild-type strains of
Escherichia coli
. Previous reports attributed this effect to an inhibition of the conversion of 1-(
o
-carboxyphenylamino)-1-deoxyribulose 5-phosphate to indole-3-glycerol phosphate and a consequent reduction in the concentration of endogenous tryptophan. Our studies have shown that 3MA-resistant mutants linked to the tryptophan operon have a feedback-resistant anthranilate synthetase; mutants with an altered indole-3-glycerol phosphate synthetase were not found. 3MA or 7-methylindole can be metabolized to 7-methyltryptophan, and 3MA, 7-methylindole, and 7-methyltryptophan lead to derepression of the tryptophan operon. Furthermore, 3MA-resistant mutants are also resistant to 7-methylindole derepression. These results strongly suggest that the primary cause of derepression by 3MA is through its conversion to 7-methyltryptophan, which can inhibit anthranilate synthetase, thereby decreasing the concentration of endogenous tryptophan. Unlike 5- or 6-methyltryptophan, 7-methyltryptophan does not appear to function as an active corepressor.
Bacterial Distribution of the Use of Succinyl and Acetyl Blocking Groups in Diaminopimelic Acid Biosynthesis
Authors: Weinberger Steven , Gilvarg Charles
Published: January 2020

The use of acetate, rather than succinate, as a blocking group in diaminopimelate biosynthesis has been found only in species of the genus
Bacillus
.
Effects of Temperature on Activation, Germination, and Outgrowth of
Bacillus megaterium
Spores
Authors: Levinson Hillel S. , Hyatt Mildred T.
Published: January 2020

The effects of temperature on the activation, glucose-induced germination, and outgrowth of
Bacillus megaterium
QM B1551 spores were investigated. There was no evidence for discontinuities in the response of spores to temperature in these processes reflecting reported thermal anomalies in the physical structure of water. Increasing the temperature of heat activation (aqueous suspensions, 5 min) increased the germinability of spores. Activation, as measured by extent of germination, was optimal after heating at 62 to 78 C, and the rate of spore germination was maximal after heat activation at 64 to 68 C. Increasing the temperature of activation above 68 C depressed the germination rate and increased the time lag before this rate was reached. Germination occurred over a wide range of temperatures, but was optimal between 28 and 38 C. The highest rate of germination was at 38 C; at lower incubation temperatures, the maximum attained rate was lower and the lag in attaining this rate was extended. Outgrowth (postgerminative development through the first cell division) of the germinated spores in Brain Heart Infusion (BHI) occurred in at least two phases—a temperature-dependent lag phase followed by a relatively temperature-independent phase of maximum outgrowth rate, during which increase in optical density was a linear function of time. Outgrowth time (time required for doubling of the initial optical density), essentially dependent on the time for completion of the lag phase, was shortest at temperatures between 34 and 40 C. The temperature-dependent lag phase was completed in a rich medium (e.g., BHI) but not in the glucose germination medium, suggesting that the endogenous reserves of the germinated spore were inadequate to support the metabolic synthetic events occurring during this period.
Defined Nongrowth Media for Stage II Development of Competence in
Haemophilus influenzae
Authors: Herriott R. M. , Meyer E. M. , Vogt M.
Published: January 2020

The composition of a defined nongrowth medium used in stage II development of competence of
Haemophilus influenzae
affects the course of this development. The development of competence in two nongrowth media, M-IV and M-V, is rapid, logarithmic, and independent of the cell concentration. This last property indicates that there is probably no transfer of a competence factor from competent to noncompetent cells, in contrast to results reported for other organisms. Levels of competence reached in these completely defined media are such that 1 to 5% of the cells are transformed in the presence of an excess of marked deoxyribonucleic acid. The method of evaluating competence, which depends on the frequency of multiple independent transformations, has been reexamined. This and other methods are compared on samples taken from a culture during development of competence.
Comparative Ultrastructure of the Thiobacilli
Authors: Shively J. M. , Decker G. L. , Greenawalt J. W.
Published: January 2020

The ultrastructure of seven
Thiobacillus
species was studied. The structure of their cell envelopes is similar, if not identical, to that found in other gram-negative bacteria. Obvious differences were noted in the middle layer of the cell envelope of the seven cultures. Polyhedral inclusion bodies were apparent in four of the organisms:
T. thioparus, T. neapolitanus, T. intermedius
, and
T. thiooxidans
. Lamellar bodies, similar to those present in certain photosynthetic bacteria were found in a few cells of
T. thioparus
. Structures resembling mesosomes were discovered in
T. dinitrificans
. A few cells of
T. intermedius
possessed paracrystalline bodies. Other inclusions, probably volutin and polysaccharide, were present in some of the cultures.
Induction of Enzymes in Dormant Spores of
Aspergillus oryzae
Authors: Sinohara Hyogo
Published: January 2020

In dormant conidia of
Aspergillus oryzae
, α-amylase, invertase, and glucose dehydrogenase were induced by their respective inducers. Neither germination nor swelling occurred during this period.
Active Transport of Glucose-1-Phosphate in
Agrobacterium tumefaciens
Authors: Fukui Sakuzo , Miyairi Sachio
Published: January 2020

The presence of an active transport system for glucose-1-phosphate in
Agrobacterium tumefaciens
was demonstrated from the following observations. (i) The bacterium could grow on a medium containing glucose-1-phosphate as carbon source; (ii) the entry of glucose-1-phosphate into the resting cells occurred against concentration gradient obeying Michaelis-Menten kinetics; and (iii) the entry reaction was energy-dependent. The transport system for glucose-1-phosphate was formed inducibly by growing the organism on a glucose-1-phosphate or sucrose medium. From the inhibition and kinetics studies it was found that the transport system had a high specificity for glucose-1-phosphate with a high affinity,
K
m
value of 4.5 × 10
−6
m
at
p
H 8.2. The existence of glucose-1-phosphate binding factor was proved in the shock fluid which was prepared from the cells grown on both glucose-1-phosphate and sucrose media by osmotic shock.
Purification and Properties of a Fructose-1,6-Diphosphate-Activated Lactate Dehydrogenase from
Streptococcus faecalis
Authors: Wittenberger Charles L. , Angelo Noreen
Published: January 2020

An
l
-(+)-lactate dehydrogenase was purified approximately 35-fold from crude extracts of
Streptococcus faecalis
. The purified enzyme had an absolute and specific requirement for fructose-1,6-diphosphate (FDP) for catalytic activity. The concentration of FDP required for 50% maximal activity was about 0.045 m
m
. The activator was bound to the enzyme more effectively at
p
H 5.8 than it was at a neutral or alkaline
p
H. Activation appeared to involve a conformational change in the enzyme which made the substrate and coenzyme sites more accessible to the respective reactants. Among the evidence supporting this hypothesis was the fact that FDP lowered significantly the apparent
K
m
for both pyruvate and reduced nicotinamide adenine dinucleotide. Moreover, the enzyme, which was quite heat stable in the absence of any of the reactants, was rendered heat labile by FDP.
Isolation and Characterization of a Mutant ofEscherichia coliBlocked in the Synthesis of Putrescine
Authors: Hirshfield I. N. , Rosenfeld H. J. , Leifer Z. , Maas W. K.
Published: January 2020

A mutant ofEscherichia coliis described which is defective in the conversion of arginine to putrescine. The activity of the enzyme agmatine ureohydrolase is greatly reduced, whereas the activity of the other two enzymes of the pathway, the constitutive arginine decarboxylase and the inducible arginine decarboxylase, are within the normal range. The growth behavior of the mutant reflects the enzymatic block. It grows well in the absence of arginine, but only poorly in the presence of arginine. Under the former conditions, putrescine can be formed from ornithine as well as arginine, whereas under the latter conditions, because of feedback control, it can be formed only from arginine.
Potassium-Dependant Mutants of
Escherichia coli
K-12
Authors: Epstein Wolfgang , Davies Martin
Published: January 2020

Mutants of
Escherichia coli
K-12 that grow more slowly in media containing low concentrations of K have been isolated. All independent mutants of this type which have been studied carry a mutation in a small region of the bacterial chromosome between the
supE
and
gal
loci. The growth rate of the mutants is the same as that of the parental strains in medium containing more than 1 m
m
K, but is only 50% that of the parent when the K concentration is reduced to 0.1 m
m
. The mutants do not appear to have a primary alteration in K transport, and are therefore referred to as K-dependent. The abbreviation
kdp
is proposed for this class of mutant.
Cellular Metabolism in Genetic Transformation of Pneumococci: Requirement for Protein Synthesis During Induction of Competence
Authors: Tomasz Alexander
Published: January 2020

Metabolic inhibitors have differential effects on various phases of genetic transformation in pneumococci. Evidence is presented suggesting that, in addition to the competence factor, another specific protein or class of proteins is essential for the development of cellular “competence.” The precise role of this protein(s) in genetic transformation is not known, but it seems essential for some function subsequent to the interaction of competence factor and cells.
Pathways of Anaerobic Acetate Utilization in
Escherichia coli
and
Aerobacter cloacae
Authors: Higgins Thomas E. , Johnson Marvin J.
Published: January 2020

Acetate-
1
-
14
C
was added to anaerobic glucose-fermenting cultures of
Escherichia coli
and
Aerobacter cloacae
. In the
E. coli
culture, lactate formation occurred late in the fermentation, when the rate of production of formate and acetate had decreased. The occurrence of acetate label in the lactate indicated formation of pyruvate from acetyl-coenzyme A (CoA) and formate. In the
A. cloacae
cultures, substantial amounts of acetate label were found in the 2,3-butanediol formed. Evidence is presented that the label could have entered the diol only by conversion of formate and acetyl-CoA into pyruvate. The observed levels of radioactivity in the diol indicated that during diol formation the reaction yielding formate and acetyl-CoA from pyruvate CoA was operating close to equilibrium. The shift in metabolism from formation of acetate, ethyl alcohol, and formate to the formation of butanediol or lactate appears to be due basically to an approach to equilibrium of the pyruvate-splitting reaction, whatever the induction mechanism by which the shift is implemented.
Early Host Damage in the Infection Cycle of
Bdellovibrio bacteriovorus
Authors: Rittenberg Sydney C. , Shilo Moshe
Published: January 2020

The effects of bdellovibrio infection on host permeability and respiration were investigated by measuring respiration rates and the rate of
o
-nitrophenyl-β-
d
-galactopyranoside hydrolysis during the course of single infection cycles of
Bdellovibrio bacteriovorus
strain 109 growing on
Escherichia coli
ML 35 (
lac i
−
z
+
y
−
). The data show that among the very early consequences of parasite attack on the host are an increase in permeability and a general disruption of respiratory activity of the host, and it is suggested that both phenomena stem from early damage to host membrane. The rapid onset of damage after inception of the cycle and the failure of streptomycin to prevent the damage indicate that complete penetration of the parasite into the host is not a requirement for the observed effects. The data also show that bdellovibrio does not use host energy-generating mechanisms for its growth and suggest that the parasites may have a search mechanism that permits them, to some degree, to distinguish between infected and uninfected hosts.
Purification of Phosphomannanase and Its Action on the Yeast Cell Wall
Authors: McLellan William L. , McDaniel Lloyd E. , Lampen J. Oliver
Published: January 2020

An improved assay for phosphomannanase (an enzyme required for the preparation of yeast protoplasts) has been developed based on the release of mannan from yeast cell walls. A procedure for the growth of
Bacillus circulans
on a large scale for maximal production of the enzyme is described. The culture medium containing the secreted enzyme was concentrated, and the enzyme was purified by protamine sulfate treatment, ammonium sulfate fractionation, gel filtration on P-100, and isoelectric density gradient electrophoresis. Although the enzyme was purified to apparent homogeneity, it still contained laminarinase activity which could not be separated by size or charge. The two enzymatic activities also exhibited two isoelectric points (
p
H 5.9 and 6.8) on ampholine electrophoresis. The laminarinase was not active on yeast glucan. The enzyme preparation was shown to remove mannan from yeast without removing glucan. Electron microscopic observation supports the idea that this mannan is the outer layer of the yeast wall. Phosphomannanase will produce protoplasts from yeast when supplemented with relatively low amounts of snail enzyme. This activity is present in snail enzyme but appeares to be rate-limiting when snail enzyme alone is used. Phosphomannanase has proven useful for studying the macromolecular organization of polymers in the yeast cell wall.
Adenosine Triphosphate Pools in
Methanobacterium
Authors: Roberton A. M. , Wolfe R. S.
Published: January 2020

Certain aspects of adenosine triphosphate (ATP) metabolism in the strict anaerobe
Methanobacterium
strain M.o.H. have been investigated. Results of growth yield studies suggest that ATP conservation is very inefficient (0.06 mole of ATP per mole of hydrogen) under the conditions used to grow the bacterium in a fermentor. Experiments designed to demonstrate net ATP formation in cell-free extracts were negative. In whole-cell studies, substances which decreased ATP pool levels and increased adenosine monophosphate (AMP) pool levels were air, chloroform, 2,4-dinitrophenol, carbonylcyanide-
m
-chlorophenylhydrazone, and pentachlorophenol. The results suggest that the latter compounds act either as inhibitors of electron transport or as uncouplers of an energy-linked process. All the above compounds also inhibit methane formation in cell-free extracts, an ATP-requiring process. Methods are described for estimation of ATP, adenosine diphosphate (ADP), and AMP in whole cells, with a sensitivity in the range of 10 to 200 pmoles. An apparatus for quick sampling from an anaerobic suspension of whole cells also is described.
Mode of Action of Pectic Enzymes II. Further Purification of Exopolygalacturonate Lyase and Pectinesterase from
Clostridium multifermentans
Authors: Miller L. , Macmillan J. D.
Published: January 2020

Exopolygalacturonate lyase and pectinesterase from
Clostridium multifermentans
were purified 156-fold and 178-fold, respectively, by gel filtration chromatography on Sephadex G-200. The activities of both enzymes coincided in a single protein peak. Profiles of the two activities also coincided in diethylaminoethyl-cellulose chromatography and zonal centrifugation. These studies indicated that the esterase and the lyase were either complexed or similar molecular species. The former seems more probable because of the relatively high molecular weight. Both activities were most stable at
p
H 6.0. The esterase was inactivated rapidly at
p
H 5 or 7. Lyase preparations were freed of pectinesterase activity by heating for 30 min at 38 C and
p
H 7.0.
Formation of Protoporphyrin from Coproporphyrinogen in Extracts of Various Bacteria
Authors: Jacobs N. J. , Jacobs J. M. , Brent P.
Published: January 2020

The enzyme system capable of converting coproporphyrinogen to protoporphyrin was demonstrated in the soluble fraction of extracts of
Pseudomonas fluorescens
grown aerobically, of
P. denitrificans
grown anaerobically under denitrifying conditions, and of
Escherichia coli
grown both aerobically and anaerobically. Protoporphyrin accumulation by each of these extracts occurred only if the assay was conducted aerobically. Attempts to replace this oxygen requirement with several alternate electron acceptors were not successful. The conversion of coproporphyrinogen to protoporphyrin could not be demonstrated in extracts of the heme-containing organisms
Staphylococcus epidermidis
and
Bacillus subtilis
.
Basis of Pyruvate Inhibition in
Thiobacillus thiooxidans
Authors: Rao G. Sivaji , Berger L. R.
Published: January 2020

Addition of 10
−3
m
pyruvic acid to cultures of
Thiobacillus thiooxidans
, at
p
H 2.3, results in its rapid intracellular accumulation and in the cessation of sulfur oxidation, CO
2
fixation, and oxygen consumption; at
p
H 7.0, pyruvate neither inhibits oxygen uptake nor accumulates appreciably intracellularly. Pyruvate does not affect CO
2
fixation in cell-free extracts. The data suggest that the cells of
T. thiooxidans
are passively permeable to pyruvic acid at low
p
H. Thus entry of pyruvic acid causes accumulation of pyruvate with a concomitant decrease in intracellular
p
H.
UGA Nonsense Mutations in
Salmonella typhimurium
Authors: Roth John R.
Published: January 2020

Salmonella typhimurium
strain LT-2 carries a weak UGA suppressor activity. This activity prevents the detection of some UGA mutants as auxotrophs and probably accounts for the rarity of
his
UGA mutants in this strain. A selection method is described which permits the isolation of these rare
his
UGA mutants. Map distribution of
his
UGA mutations is normal, and their polarity effects are indistinguishable from the polarity effects of amber and ochre mutations at similar locations. Isolation and properties of a prototrophic
his
UGA mutant are described. UGA mutants are common among
lac
mutants isolated from
Salmonella
strains carrying an F′
lac
episome. Apparently the suppressor activity is insufficient to prevent detection of
lac
UGA mutants. It is not yet clear whether the suppressor activity plays an important role in normal cell physiology.
Mutants of
Salmonella typhimurium
Lacking Phosphoenolpyruvate Carboxykinase and α-Ketoglutarate Dehydrogenase Activities
Authors: Carrillo-Castañeda Guillermo , Ortega Manuel V.
Published: January 2020

Two auxotrophic mutants (SM16 and SM51) of
Salmonella typhimurium
, which for aerobic growth, with hexoses as carbon source, required lysine and methionine (SM51 required also nicotinic acid), were isolated and characterized. The requirement for the amino acids disappeared in anaerobiosis. Neither lipoate nor 4-hydroxybenzoate was effective in supporting aerobic growth of the mutants. The lysine and methionine requirement for aerobic growth was due to the absence in the mutants of the enzymatic activities of the α-ketoglutarate dehydrogenase complex. The mutants could not use succinate as carbon source even after enrichment of the growth medium with acid-hydrolyzed casein and yeast extract. No phosphoenolpyruvate carboxykinase activity was found in the mutants, a phenomenon which explained their inability to use succinate. By interrupted conjugation and by transduction experiments, the positions of the three affected loci,
pck, suc
, and Nic, were located at approximately 17 to 19 min of the
S. typhimurium
chromosome; they were found to be closely linked. From different criteria, it appears as if the genetic lesions present in both mutants are due to deletion of a small chromosome fragment.
Segregation into and Replication of Plasmid Deoxyribonucleic Acid in Chromosomeless Segregants of
Escherichia coli
Authors: Inselburg Joseph
Published: January 2020

The progeny cells of
Escherichia coli
strain P678-54, which normally do not contain deoxyribonucleic acid (DNA), were found to carry DNA when the parental cell carried colicin factor E1 (Col E1). The DNA found in the normally DNA-less segregants was shown to be Col E1 DNA, which is present primarily as a covalently closed circular molecule that can undergo more than one complete cycle of replication.
Genetic and Metabolic Controls for Sulfate Metabolism in
Neurospora crassa:
Isolation and Study of Chromate-Resistant and Sulfate Transport-Negative Mutants
Authors: Marzluf George A.
Published: January 2020

Mutants of
Neurospora
resistant to chromate were selected and all were found to map at a single genetic locus designated as
cys-13
. The chromate-resistant mutants grow at a wild-type rate on minimal media but are partially deficient in the transport of inorganic sulfate, especially during the conidial stage. An unlinked mutant,
cys-14
, is sensitive to chromate but transports sulfate during the mycelial stage at only 25% of the wild-type rate;
cys-14
also grows at a fully wild-type rate on minimal media. The double-mutant strain,
cys-13;cys-14
, cannot utilize inorganic sulfate for growth and completely lacks the capacity to transport this anion. The only biochemical lesion that has been detected for the double-mutant strain is its loss in capacity for sulfate transport.
Neurospora
appears to possess two distinct sulfate permease species encoded by separate genetic loci. The transport system (permease I) encoded by
cys-13
predominates in the conidial stage and is replaced by sulfate permease II, encoded by the
cys-14
locus, during outgrowth into the mycelial phase. The relationship of these new mutants to
cys-3
, a regulatory gene that appears to control their expression, is discussed.
Nitrate Reductase and Soluble Cytochrome
c
in
Spirillum itersonii
Authors: Gauthier Dorothy K. , Clark-Walker G. D. , Garrard W. T. , Lascelles June
Published: January 2020

The addition of nitrate to cultures of
Spirillum itersonii
incubated under low aeration produced a diauxic growth pattern in which the second exponential phase was preceded by the appearance of nitrite in the medium. The organism also grew anaerobically in the presence of nitrate. Nitrate reductase activity could be demonstrated in cell-free extracts by use of reduced methyl viologen as the electron donor. The enzyme was located in the supernatant fraction after centrifugation of extracts for 2 hr at 40,000 ×
g
, and it sedimented as a single peak when centrifuged in a sucrose gradient. Nitrate reductase activity was found in cells grown with low aeration without nitrate, but was increased about twofold by addition of nitrate. Enzyme activity was negligible in cells grown with high aeration. The proportion of soluble cytochrome
c
was increased two- to threefold in cells grown with nitrate. The specific activities of nitrate reductase and soluble cytochrome
c
rose when nitrate or nitrite was added to cell suspensions incubated with low aeration; nitrite was more effective than nitrate during the early stages of incubation. A nitrate reductase-negative mutant synthesized increased amounts of soluble cytochrome
c
in response to nitrate or to nitrite in the cell suspension system. It is concluded that enhanced synthesis of soluble cytochrome
c
does not require the presence of a functional nitrate reductase.
Inhibition of the Induced Formation of Tryptophanase in
Escherichia coli
by Near-Ultraviolet Radiation
Authors: Swenson P. A. , Setlow R. B.
Published: January 2020

Induced formation of tryptophanase in
Escherichia coli
B/r is temporarily inhibited by near-ultraviolet (UV) irradiation. The inhibition is greater when irradiation is at 5 C than when at room temperature. Hence, the inhibition is the result of a photochemical, rather than photoenzymatic, alteration of some cellular component. The action spectrum has a peak in the region of 334 nm and is similar to that for growth delay. However, inhibition of tryptophanase formation is more sensitive to near-UV irradiation than are growth, respiration, and the induced formation of β-galactosidase. Thus, for tryptophanase the lack of formation cannot be due to general inhibition of metabolism. Pyridoxal phosphate absorbs in the near-UV region of the spectrum and is a cofactor for tryptophanase, but this enzyme in induced cells is not inactivated by near UV-radiations. An experiment in which toluene-treated suspensions from irradiated and unirradiated cells were mixed showed that irradiation does not cause the formation of an inhibitor of tryptophanase activity. The possibility remains that the absorption of radiant energy by pyridoxal phosphate interferes with the synthesis of tryptophanase.
Fatty Acids from Vegetative Cells and Spores of
Bacillus stearothermophilus
Authors: Yao M. , Walker H. W. , Lillard D. A.
Published: January 2020

In spores of
Bacillus stearothermophilus
produced at 45 and 55 C, branched-chain fatty acids predominated in the former and straight-chain acids in the latter.
Partial Purification of an Extracellular Leptospiral Lipase
Authors: Chorvath Branko , Fried Melvin
Published: January 2020

Sequential procedures involving ethanol precipitation, ultracentrifugation, and molecular sieve chromatography in deoxycholate permitted 140-fold purification of a leptospiral lipase.
Cardiolipin-Specific Phospholipase D Activity in
Haemophilus parainfluenzae
Authors: Ono Yoshie , White David C.
Published: January 2020

A highly active phospholipase D that is specific for cardiolipin was detected in the gram-negative bacterium
Haemophilus parainfluenzae
. Previously reported phospholipase D preparations have come exclusively from higher plants. The bacterial enzyme hydrolyzed cardiolipin to phosphatidyl glycerol and phosphatidic acid. During the incubation, phosphatidic acid disappeared. Phosphatidyl ethanolamine, methylated phosphatidyl ethanolamines, phosphatidyl choline, and phosphatidyl glycerol were not hydrolyzed when cardiolipin was rapidly hydrolyzed.
Composition of the Cellular Envelopes of
Anabaena cylindrica
Authors: Dunn John H. , Wolk C. Peter
Published: January 2020

Comparative chemical analyses were made of the walls of vegetative cells, heterocysts, and spores, and of the mucilage of
Anabaena cylindrica
. The wall of the vegetative cell is composed predominantly of amino compounds, with a mannose-rich carbohydrate component comprising only 18% of the dry weight. In contrast, 62% of the heterocyst wall and 41% of the spore wall is carbohydrate. The carbohydrate moieties of the heterocyst wall and spore wall are similar in that the ratio of glucose, mannose, galactose, and xylose is approximately 75:20:3:4 in both walls. It appears that, during the differentiation of a vegetative cell into either a spore or a heterocyst, a glucose-rich wall polysaccharide is produced that is different from the polysaccharide component of the wall of the vegetative cell and of the sheath. In the case of the heterocyst, the wall was estimated to account for approximately 52% of the dry weight of the whole cell.
Isolation and Analysis of the Nucleic Acids and Polysaccharides from
Clostridium welchii
Authors: Darby G. K. , Jones A. S. , Kennedy J. F. , Walker R. T.
Published: January 2020

A method previously described for the use of bentonite in the isolation of the nucleic acids from two gram-positive organisms was applied to the isolation of the nucleic acids from two strains of
Clostridium welchii
. The nucleic acids were separated from polysaccharides by the fractional precipitation of their cetyltrimethyl-ammonium salts from sodium chloride solution, and the base composition of the nucleic acids was determined. One strain of
C. welchii
investigated (NCTC 10578) was shown to produce considerable quantities of an acidic and also a weakly acidic or neutral polysaccharide; the other strain (ATCC 10543) gave very small quantities of the latter but none of the former polysaccharide. The monosaccharide composition of these polysaccharides was determined and the acidic polysaccharide was shown to resemble dermatan sulfate.
Marine Vibrios Associated with Bacillary Necrosis, a Disease of Larval and Juvenile Bivalve Mollusks
Authors: Tubiash Haskell S. , Colwell Rita R. , Sakazaki Riichi
Published: January 2020

The etiological agents of bacillary necrosis, a disease of larval and juvenile bivalve mollusks, are designated members of the genus
Vibrio
.
Metabolism of Some Polyols byRhizobium meliloti
Authors: de Drets G. Martínez , Arias A.
Published: January 2020

The utilization ofd-mannitol,d-arabitol, andd-sorbitol byRhizobium melilotiwas studied in extracts from mannitol-grown cells. Two different polyol dehydrogenases were induced by any of these polyols: (i) a nicotinamide adenine dinucleotide (NAD)-arabitol dehydrogenase and (ii) a NAD-sorbitol dehydrogenase, whereas polyol phosphate dehydrogenases were absent.d-Arabitol dehydrogenase was observed to act on bothd-arabitol andd-mannitol, butd-sorbitol dehydrogenase acted specifically ond-sorbitol.d-Arabitol was oxidized tod-xylulose,d-mannitol andd-sorbitol were oxidized tod-fructose. An adenosine triphosphate-linked hexokinase which acts ond-fructose and absence of hexose isomerase were also detected in this organism.
Termination of Deoxyribonucleic Acid in
Escherichia coli
by 2′,3′-Dideoxyadenosine
Authors: Toji Lorraine , Cohen Seymour S.
Published: January 2020

2′,3′-Dideoxyadenosine was previously shown to be lethal to
Escherichia coli
and to inhibit deoxyribonucleic acid (DNA) synthesis irreversibly in this organism. It was also shown that triphosphate of this analogue terminates DNA chains in an in vitro system. Data presented here show that the nucleoside is relatively insensitive to
E. coli
adenosine deaminase and is converted intracellularly into the dideoxynucleotide, including the triphosphate. Thymine nucleotide pools were not reduced in inhibited bacteria, nor did preformed DNA break down. Some adenine was liberated from the dideoxyadenosine on incubation, and the latter was incorporated into ribonucleic acid. Nevertheless, about 4,000 molecules of the dideoxynucleoside were incorporated into DNA per cell. The dideoxynucleotide occurred in DNA chains in a terminal position, liberated selectively by venom phosphodiesterase. The possible nature of the lethal event is discussed.
Temporal Separation of Transcription and Translation in
Neurospora
Authors: Turner J. R. , Terry K. , Matchett W. H.
Published: January 2020

Cells of
Neurospora
accumulated capacity for synthesis of kynureninase in the presence of cycloheximide and a suitable inducer. The capacity was expressed only when the cells were returned to a medium which allowed net synthesis of protein to resume. Subsequent expression did not require synthesis of ribonucleic acid (i.e., was not inhibited by actinomycin D) or the presence of inducer. The relative level of capacity, as judged by the initial rate of appearance of enzyme, increased linearly for 70 min in cells incubated in the presence of inducer plus antibiotic.