bluuebunny/crossref_metadata_2025 huggingface dataset:
Competence-Inducing Factor of
Bacillus stearothermophilus
Authors: Streips Uldis N. , Welker N. E.
Published: January 2020

An incompetent mutant (4S Com
−
) does not release competence-inducing factor (CF) into the culture medium and is not infected with TP-1C phage deoxyribonucleic acid (DNA) unless CF is added to the transfection assay. A TP-1C phage-resistant mutant (4S Ton-r) releases relatively large amounts of CF into the culture medium but is not infected with TP-1C phage DNA, even in the presence of CF. The production of CF by the wild type or Ton-r mutant and the ability of the wild type or Com
−
mutant to react with CF does not occur after these cultures have grown at 67 C for 1 hr or longer. A preliminary characterization of the CF is described. The autolytic enzyme or the temperate phage of the wild type and the Ton-r and Com
−
mutants do not have competence-inducing activity.
Factors Affecting Transfection in
Bacillus stearothermophilus
Authors: Streips Uldis N. , Welker N. E.
Published: January 2020

The conditions for the infection of
Bacillus stearothermophilus
4S with TP-1C phage deoxyribonucleic acid (DNA) are described. Cells from log-phase cultures are the most susceptible to phage DNA infection (transfection). A cellular component (competence factor) which enhances transfection is released into the culture medium during the transition period between the log and stationary phase of growth. Transfection is stimulated in the order of decreasing effectiveness, by Fe
3+
, Mn
2+
, and Mg
2+
. The efficiency of transfection is the highest in cells growing at 60.5 C and does not occur in cells growing at 67 C although the cells are growing normally. A cellular component (competence factor) of this organism, which is released into the culture medium, advances by 40 min some step in the uptake of phage DNA.
Dielectric Study of the Physical State of Electrolytes and Water Within
Bacillus cereus
Spores
Authors: Carstensen Edwin L. , Marquis Robert E. , Gerhardt Philipp
Published: January 2020

Dielectric measurements revealed that dormant spores of
Bacillus cereus
have extremely low conductivities at high frequencies (50 MHz) and so must contain remarkably low concentrations of mobile ions both within the core and in the surrounding integuments. Activation, germination, and outgrowth were all accompanied by increases in conductivity of the cells and their suspending medium, and this result indicated that intracellular electrolytes had become ionized and leaked from the spores. High-frequency dielectric constants of spores were consistent with normal states for cell water. These values increased during successive stages of development from dormant spore to vegetative bacillus, and they could be directly related to increases in cell water content. In all, the results refuted a model of the dormant spore involving freely mobile, ionized electrolytes and supported a model involving electrostatically bound electrolytes.
Structure and Arrangement of Flagella in Species of the Genus
Beneckea
and
Photobacterium fischeri
Authors: Allen Richard D. , Baumann Paul
Published: January 2020

Species of marine bacteria belonging to the genus
Beneckea
and strains of
Photobacterium fischeri
were negatively stained and examined by means of the electron microscope to determine the structure and arrangement of their flagella. All of the species of the genus
Beneckea
had single, polar, sheathed flagella when grown in liquid medium. When grown on solid medium, most strains of
B. campbellii
and
B. neptuna
and all strains of
B. alginolytica
and
B. parahaemolytica
had unsheathed, peritrichous flagella in addition to the single, sheathed, polar flagellum. The remaining species,
B. nereida, B. pelagia
, and
B. natriegens
, had a single, polar, sheathed flagellum when grown on solid medium. Strains of
P. fischeri
had sheathed flagella arranged in polar tufts. Only one group (B-2) of marine bacteria included in this study was found to have polar, unsheathed flagella.
Observations on the Rhodanese Activity of
Desulfotomaculum nigrificans
Authors: Burton Carolyn P. , Akagi J. M.
Published: January 2020

Rhodanese activity, partially purified from
Desulfotomaculum nigrificans
, was shown to reside in a protein fraction separate from thiosulfate reductase.
Effect of Sulfhydryl Reagents on the Ribosomes of
Bacillus subtilis
Authors: Ranu Rajinder Singh , Kaji Akira
Published: January 2020

The effect of various sulfhydryl reagents on the ribosomes of
Bacillus subtilis
was studied. The 70
S
ribosomes were completely dissociated into 30
S
and 50
S
subunits by appropriate concentrations of
p
-chloromercuribenzoic acid (PCMB) and 5,5′-dithio-
bis
-(2-nitro-benzoic acid). The
N
-ethylmaleimide and iodoacetamide failed to dissociate the ribosomes even at relatively high concentrations. The rate of dissociation of ribosomes by PCMB varied with the concentration of ribosomes. A progressive decrease in the rate of dissociation was observed as the concentration of ribosomes in the reaction mixture was increased. The PCMB-induced ribosomal subunits were unable to reassociate into 70
S
monomers unless they were dialyzed against buffer containing β-mercaptoethanol. On the average, four molecules of PCMB per 70
S
ribosome and two molecules of PCMB per each 30
S
and 50
S
subunit were bound. The number of PCMB molecules bound per ribosome did not change with increasing concentrations of PCMB, even though higher concentrations of PCMB resulted in dissociation of ribosomes into subunits.
Repression of 3-Deoxy-
d
-Arabinoheptulosonic Acid-7-Phosphate Synthetase (trp) and Enzymes of the Tryptophan Pathway in
Escherichia coli
K-12
Authors: Camakaris J. , Pittard J.
Published: January 2020

Mutant strains of
Escherichia coli
K-12 have been isolated in which the synthesis of 3-deoxy-
d
-arabinoheptulosonic acid-7-phosphate (DAHP) synthetase (trp) is partially constitutive. The mutation causing derepression is closely linked to
aroH
[the structural gene for DAHP synthetase (trp)] and occurs in a locus designated
aroJ
. The
aroJ
mutation is not recessive in an
aroJ
+
/
aroJ
−
diploid strain, as the synthesis of DAHP synthetase (trp) is still derepressed in this strain. On the basis of its close linkage to
aroH
and its continued expression in an
aroJ
+
/
aroJ
−
diploid, it is postulated that
aroJ
is an operator locus controlling the expression of the structural gene
aroH
. In support of this conclusion, the synthesis of anthranilate synthetase is still normally repressible in
aroJ
−
strains, whereas, in
trpR
−
strains, both DAHP synthetase (trp) and anthranilate synthetase are synthesized constitutively. The synthesis of DAHP synthetase (trp) remains repressible in an operator-constitutive mutant of the tryptophan operon. In two
trpS
mutants which possess defective tryptophanyl transfer ribonucleic acid synthetase enzymes, neither DAHP synthetase (trp) nor anthranilate synthetase derepress under conditions in which the defective synthetase causes a decrease in growth rate. On the other hand, an effect of the
trpS
mutant alleles on the level of anthranilate synthetase has been observed in strains which are derepressed for the synthesis of this enzyme, because of a mutation in the gene
trpR
. Possible explanations for this effect are presented.
Immunochemical Comparison of
l
-Asparaginases from
Serratia marcescens
and
Escherichia coli
Authors: Phillips Arthur W. , Boyd John W. , Ferguson Donald A. , Marucci A. Alvin
Published: January 2020

Immunochemical properties of
l
-asparaginases from
Serratia marcescens
and
Escherichia coli
were compared by means of quantitative precipitin reactions and quantitative microcomplement-fixation reactions employing homologous and heterologous antisera. The enzyme preparations used in these tests produced one arc of precipitate upon immunoelectrophoresis. According to our results with the precipitin and micro-complement fixation reactions, both enzymes are related immunochemically. On the basis of these tests, distinct structural differences exist between the two enzymes. From results with the micro-complement fixation test, we estimated that the two enzymes could differ by 10 to 15 amino acid residues.
Mutants ofEscherichia coliSensitive to Antibiotics
Authors: Ennis Herbert L.
Published: January 2020

Mutants ofEscherichia colisensitive to the antibiotic synergistin A, an inhibitor of protein synthesis, were isolated. These mutants were pleiotropic, being also sensitive to a large number of unrelated antibiotics and to lysis by detergents. These pleiotropic responses indicated that the mutations affected cell wall or membrane synthesis. Consequently, selection for antibiotic-sensitive mutants constitutes a useful means for isolating cell wall or membrane mutants.
Bactericidal Action of 2-Hydroxy-3-(Cyclohexylpropyl)-1,4-Naphthoquinone on
Bacillus megaterium
Authors: Olenick John G. , Cook Thomas M. , Hahn Fred E.
Published: January 2020

The antimalarial drug, 2-hydroxy-3-(cyclohexylpropyl)-1,4-naphthoquinone (NQ), at concentrations of approximately 10
−5
m
(3 μg/ml), was bactericidal for the gram-positive bacterium,
Bacillus megaterium
. Only a few other gram-positive bacteria were sensitive to this drug. All growth inhibitory concentrations of NQ were also bactericidal for
B. megaterium
, and even resting suspensions of cells were killed. The incorporation of radioactive-labeled leucine, thymidine, uracil, and diaminopimelic acid into protein, deoxyribonucleic acid, ribonucleic acid, and the cell wall polymer was arrested immediately and completely upon addition of NQ to cultures in exponential growth. NQ produced a delayed effect on aerobic respiration and no change in the rate of oxygen consumption was observed at a time when all major biosyntheses had failed.
3
H-NQ was demonstrated to bind strongly and preferentially to the bacterial cell membrane. This simultaneous shutdown of all major categories of in vivo macromolecular syntheses points to an effect of NQ upon membrane-centered energy supplying reactions or transport of essential nutrients, or both.
Properties of Nonheme Iron in a Cell Envelope Fraction from
Escherichia coli
Authors: Kim I. C. , Bragg P. D.
Published: January 2020

The reaction with
o
-phenanthroline of nonheme iron found in cell envelope fractions from
Escherichia coli
has been investigated. About 20% of the total nonheme iron reacts directly with
o
-phenanthroline. This iron appears to be in the ferric state but is reducible by protein sulfhydryl groups in the presence of the chelating agent. A further 20% of the nonheme iron will react with
o
-phenanthroline only in the presence of dithionite. Succinate can replace dithionite but only produces about 35% of the reaction given by dithionite. The reduction of cytochrome
b
1
of the respiratory chain by succinate shows similar behavior to the reaction of iron with
o
-phenanthroline in the presence of succinate. Both of these components react completely only in the presence of 2-heptyl-4-hydroxyquinoline-
N
-oxide. The remaining 60% of the nonheme iron of the cell envelope will not react with
o
-phenanthroline even in the presence of dithionite or 6
m
urea. Triton X-100 with dithionite will permit a small part (10%) of this iron to react with
o
-phenanthroline. The iron which does not react with
o
-phenanthroline is not associated with succinate, reduced nicotinamide adenine dinucleotide, or
d
-lactate dehydrogenases.
Location and Orientation of the
phoA
Locus on the
Escherichia coli
K-12 Linkage Map
Authors: Nakata Atsuo , Peterson George R. , Brooks E. Lucille , Rothman Frank G.
Published: January 2020

The order of gene loci in the
phoA-phoR
region of the
Escherichia coli
K-12 linkage map was demonstrated to be
lac phoA proC phoR
. The end of the
phoA
locus corresponding to the amino terminus of alkaline phosphatase was shown to be the end nearer
proC
. Translation (and transcription) of
phoA
is therefore in the anticlockwise direction relative to the conventional
E. coli
linkage map.
Effects of Temperature Variation on the Fatty Acid Composition of
Candida utilis
Authors: McMurrough I. , Rose A. H.
Published: January 2020

The fatty acid compositions of various cultures of the yeast
Candida utilis
NCYC 321 were analyzed by gas-liquid chromatography of the methyl esters obtained from the lipids in chloroform-methanol extracts of the cells. Over a wide range of growth conditions
C. utilis
contained mainly 16:0, 16:1, 18:1, 18:2, and 18:3 fatty acids in variable proportions. The most variable aspect of the fatty-acid composition of
C. utilis
was in the relative proportions of 18:1, 18:2, and 18:3 acids. During batch growth at 30 C, the relative proportions of 18:3 decreased, whereas 18:1 increased as the cultures aged. Batch cultures grown at low temperatures maintained higher proportions of 18:3 acids than cultures grown at 30 C. When stationary cultures were replenished with fresh medium under aerobic conditions, there was an abrupt increase in the proportion of 18:3 with a concomitant decrease in 18:1 acids in the cells. The fatty acid composition of cells grown in a chemostat at 30 C did not vary much in response to changes in either the growth rate or the growth-limiting substrate. Chemostat-grown cells contained highest proportions of 18:3 acid when grown under conditions of glucose-limitation at low temperatures.
Unusual Effects of Reducing Agents on
o
-Diphenoloxidase of
Mycobacterium leprae
Authors: Prabhakaran Kochukunju
Published: January 2020

Reducing agents had no effect on the oxidation of 3,4-dihydroxyphenylalanine (DOPA) to quinone by
Mycobacterium leprae;
no quinone formation by
o
-diphenoloxidase of mammalian or plant origin was detected under similar experimental conditions. Ascorbic acid and reduced glutathione prevented further oxidation and polymerization of the quinone to melanin by
M. leprae;
cysteine was less effective. In the presence of reducing agents, the quinone (indole-5,6-quinone) formed from DOPA by
M. leprae
was not reduced back to diphenol. On the other hand, the quinone (dopachrome) produced from DOPA by mammalian or plant phenolase was rapidly decolorized by reducing agents. Oxidized glutathione and cystine had little effect on
o
-diphenoloxidase from all of the three sources. Cyanide, which completely inhibited mammalian and plant phenolases, had only a partial effect on the enzyme in the bacilli. Various lines of evidence suggest that the properties of
o
-diphenoloxidase in
M. leprae
are different from those of similar enzymes obtained from other sources.
Phospholipids of Virus-Induced Membranes in Cytoplasm of
Escherichia coli
Authors: Ohnishi Yoshinari
Published: January 2020

Infection of
Escherichia coli
with amber mutants of phage fd, in contrast to infection with wild-type phage, leads to cell death and the proliferation of intracytoplasmic membranes observed in electron micrographs at the poles of the cells. The accumulation of membranes correlates with changes in structural phospholipids, especially a marked increase in the apparent rate of formation and total amount of cardiolipin (from 4 to 20% of total radioactive phospholipids), and a compensating decline in phosphatidylethanolamine.
Regulation and Mechanism of Phosphoribosylpyrophosphate Synthetase: Repression by End Products
Authors: White Mary N. , Olszowy Joyce , Switzer R. L.
Published: January 2020

Phosphoribosylpyrophosphate (PRPP) synthetase participates in the biosynthesis in bacteria of purine nucleotides, pyrimidine nucleotides, tryptophan, and histidine. The regulation of the synthesis of PRPP synthetase in
Salmonella typhimurium
was studied. Addition of end products to the growth medium, singly or in combination, resulted in small decreases in the specific activity of PRPP synthetase, but levels of the enzyme were never decreased to less than half of those found when the bacteria were grown on minimal medium. Growth of the bacteria on several different carbon sources or starvation for phosphate had little effect on the specific activity of PRPP synthetase. Over-production of histidine in a histidine regulatory mutant, which would be expected to result in a depletion of intracellular PRPP pools, did not alter PRPP synthetase specific activity. PRPP synthetase levels were examined in auxotrophic strains of
S. typhimurium
that had been starved for the end products of PRPP. In each case derepression of an enzyme in the biosynthetic pathway for the limiting end product was demonstrated. However, only alterations in the levels of pyrimidine bases in the culture medium brought about derepression and repression of PRPP synthetase. Excess pyrimidines do not completely repress the enzyme. Deprivation of exponentially growing cells for pyrimidines by growth of an auxotrophic mutant on media containing orotic acid, which enters the cells slowly, resulted in a 10-fold derepression of PRPP synthetase. Derepression of PRPP synthetase during uracil starvation was prevented by chloramphenicol. The PRPP synthetase activities of extracts from repressed and derepressed cells responded in identical fashion to heat inactivation, cellulose acetate electrophoresis at several
p
H values, and in kinetic experiments.
Effect of Growth Temperature on the Lipid Composition of
Thermus aquaticus
Authors: Ray Paul H. , White David C. , Brock Thomas D.
Published: January 2020

The complex lipids of
Thermus aquaticus
include phospholipids, glucolipids, carotenoids, and vitamin K
2
isoprenologues. The phospholipids account for 30% of the total lipids and have been identified as phosphatidylethanolamine (4%), phosphatidylglycerol (3%), phosphatidylinositol (10%), cardiolipin (3%), and phosphatidic acid (1%). The major phospholipid contained three fatty acids, a long-chain unsaturated amine, and one glycerol per phosphate and accounted for 80% of the lipid phosphate. The carotenoids accounted for 60% of the membrane lipid. The majority of the carotenoids were very polar. Mono- and diglucosyldiglyceride and the 35-, 40-, and 45-carbon vitamin K
2
isoprenologues were also identified. All these lipids were localized in the membrane of
T. aquaticus
. When the growth temperature was increased from 50 to 75 C and measured at 5 C intervals, there was a progressive increase in the total lipid content. The phospholipids increased 2-fold, the carotenoids increased 1.8-fold, and the glucolipids increased 4-fold between cells grown at 50 C and 75 C. The vitamin K
2
level did not change. The proportions of the individual lipids within each lipid class remained constant as the temperature of growth was raised. Metabolic studies indicated turnover of the diacyl phospholipids during pulse-chase experiments at rates comparable with mesophilic bacteria. The major phospholipid and the carotenoids did not turn over.
On the Process of Cellular Division in
Escherichia coli
VI. Use of a Methocel-Autoradiographic Method for the Study of Cellular Division in
Escherichia coli
Authors: Lin E. C. C. , Hirota Y. , Jacob F.
Published: January 2020

A technique allowing chain formation by
Escherichia coli
for the analysis of the segregation of certain cellular components by autoradiographic methods has been developed. Deoxyribonucleic acid labeled with
3
H-thymidine does not appear to segregate preferentially with one or another of the bacteria. Membrane lipids labeled with either
3
H-oleate or
3
H-glycerol are evenly distributed among all progeny cells. A similar pattern of distribution of cell wall material is observed when
3
H-diaminopimelate is used as the marker.
Repression of Aromatic Amino Acid Biosynthesis in
Escherichia coli
K-12
Authors: Brown K. D. , Somerville R. L.
Published: January 2020

Mutants of
Escherichia coli
K-12 were isolated in which the synthesis of the following, normally repressible enzymes of aromatic biosynthesis was constitutive: 3-deoxy-
d
-arabinoheptulosonic acid 7-phosphate (DAHP) synthetases (phe and tyr), chorismate mutase T-prephenate dehydrogenase, and transaminase A. In the wild type, DAHP synthetase (phe) was multivalently repressed by phenylalanine plus tryptophan, whereas DAHP synthetase (tyr), chorismate mutase T-prephenate dehydrogenase, and transaminase A were repressed by tyrosine. DAHP synthetase (tyr) and chorismate mutase T-prephenate dehydrogenase were also repressed by phenylalanine in high concentration (10
−3
m
). Besides the constitutive synthesis of DAHP synthetase (phe), the mutants had the same phenotype as strains mutated in the tyrosine regulatory gene
tyrR
. The mutations causing this phenotype were cotransducible with
trpA, trpE, cysB
, and
pyrF
and mapped in the same region as
tyrR
at approximately 26 min on the chromosome. It is concluded that these mutations may be alleles of the
tyrR
gene and that synthesis of the enzymes listed above is controlled by this gene. Chorismate mutase P and prephenate dehydratase activities which are carried on a single protein were repressed by phenylalanine alone and were not controlled by
tyrR
. Formation of this protein is presumed to be controlled by a separate, unknown regulator gene. The heat-stable phenylalanine transaminase and two enzymes of the common aromatic pathway, 5-dehydroquinate synthetase and 5-dehydroquinase, were not repressible under the conditions studied and were not affected by
tyrR
. DAHP synthetase (trp) and tryptophan synthetase were repressed by tryptophan and have previously been shown to be under the control of the
trpR
regulatory gene. These enzymes also were unaffected by
tyrR
.
Control of Vitamin B
6
Biosynthesis in
Escherichia coli
Authors: Dempsey Walter B.
Published: January 2020

Pyridoxineless mutants of
Escherichia coli
B which specifically require pyridoxal or pyridoxamine for growth can be divided into classes according to their growth responses in enriched media. Members of the slowest growing class synthesize vitamin B
6
at the fastest rates when starved for pyridoxal in glycerol minimal medium. After 80 min of synthesis at 4 × 10
−10
moles of vitamin B
6
per mg of cells per hr, the rate increases four- to fivefold and continues at the new rate for several hours. The shift to the new rate is prevented by chloramphenicol, thus suggesting that a derepression mechanism exists to control vitamin B
6
synthesis in addition to the previously discovered feedback control.
Proposal for Classifying Human Strain Navel and Related Simian Mycoplasmas asMycoplasma primatumsp. n
Authors: DelGiudice Richard A. , Carski Theodore R. , Barile Michael F. , Lemcke Ruth M. , Tully Joseph G.
Published: January 2020

Mycoplasmas isolated from simian (Cercopithecus aethiops) tissues were shown to have biological, biochemical, and serological properties and electrophoretic cell protein patterns similar to strain Navel isolated from man 15 years ago. The simian and human Navel strains comprised a single serogroup, distinct from the establishedMycoplasmaandAcholeplasmaspecies of the classMollicutes. It is proposed that strains with the properties described be namedMycoplasma primatum.
Microbial Transformation of Antibiotics: Phosphorylation of Clindamycin byStreptomyces coelicolorMüller
Authors: Coats John H. , Argoudelis Alexander D.
Published: January 2020

Addition of clindamycin to whole-cell cultures ofStreptomyces coelicolorMüller resulted in the loss of in vitro activity against organisms sensitive to clindamycin. Incubation of such culture filtrates with alkaline phosphatase generated a biologically active material identified as clindamycin. Fermentation broths containing inactivated clindamycin yielded clindamycin 3-phosphate, the structure of which was established by physical-chemical and enzymatic studies. Clindamycin was phosphorylated by lysates and partially purified enzyme preparations fromS. coelicolorMüller. These reactions require a ribonucleoside triphosphate and Mg2+. The product of the cell-free reactions was identified as clindamycin 3-phosphate.
Biphasic Growth of
Acetobacter suboxydans
on a Glycerol-Limiting Medium
Authors: Batzing B. L. , Claus G. W.
Published: January 2020

Dihydroxyacetone was quantitatively produced from glycerol during the primary exponential growth phase and depleted during the secondary exponential phase. Although no growth was detected on the basal medium, growth occurred upon addition of dihydroxyacetone.
Inhibition of Ribonuclease II of
Escherichia coli
by Sodium Ions, Adenosine-5′-Triphosphate, and Transfer Ribonucleic Acid
Authors: Venkov P. , Schlessinger D. , Longo D.
Published: January 2020

Ribonuclease II action on polyuridylate is competitively inhibited by transfer ribonucleic acid and noncompetitively inhibited by sodium ions. At low substrate levels, adenosine-5′-triphosphate is also inhibitory.
Biochemical Characterization of the
ctr
Mutants of
Escherichia coli
Authors: Morse Helvise G. , Penberthy William K. , Morse M. L.
Published: January 2020

A test procedure based on complementation in mixed extracts is described for the assay of heat-stable protein and enzyme I of the phosphoenolpyruvate-dependent phosphotransferase system. The test was used to assay a collection of pleiotropic carbohydrate mutants of
Escherichia coli
(
ctr
mutants) and revertants of these mutants. All mutants were found to lack enzyme I of the phosphoenolpyruvate-dependent transferase system. Revertants of these mutants to complete wild phenotype regained enzyme I-forming ability. Reversion to partial wild type was not accompanied by restoration of enzyme I-forming ability.
Total Synthesis of Acetate from CO
2
: Methyltetrahydrofolate, an Intermediate, and a Procedure for Separation of the Folates
Authors: Parker Donald J. , Wu Tsai-Feng , Wood Harland G.
Published: January 2020

Whole-cell preparations of
Clostridium thermoaceticum
were exposed to a short pulse of
14
CO
2
under conditions in which double-labeled acetate was synthesized. Radioactive methyltetrahydrofolate monoglutamate, diglutamate, and triglutamates were isolated from extracts of the cells. The radioactivity was found to be exclusively in the five methyl position. The specific activities of the methyltetrahydrofolate derivatives were very high and were in accord with the proposal that methyltetrahydrofolates are the precursors of the methyl of acetate. A new method of separation of folates employing QAE-Sephadex chromatography and a linear gradient with triethylammonium bicarbonate is presented which completely resolves the common folate monoglutamates and, upon freeze-drying, yields salt-free preparations.
Metabolism of Poly-β-Hydroxybutyrate: Effect of Mild Alkaline Extraction on Native Poly-β-Hydroxybutyrate Granules
Authors: Griebel R. J. , Merrick J. M.
Published: January 2020

Mild alkaline extraction of native poly-β-hydroxybutyrate (PHB) granules results in the solubilization of a protein fraction. Both the solubilized protein fraction and the extracted granules are essentially devoid of PHB synthetase activity unless recombined. The protein fraction has been separated by chromatography into two components (A-I and A-II). A-I but not A-II can be recombined with extracted granules to give rise to PHB synthetase activity. Extracted granules no longer require pretreatment with activator or trypsin but are directly susceptible to hydrolysis by
Rhodospirillum rubrum
depolymerase. Addition of A-II or A-I prevents the direct hydrolysis by depolymerase. The inhibition is reversed by activator or trypsin. We conclude that native granules are associated with a protein inhibitor which prevents the hydrolysis of PHB by depolymerase unless the protein is destroyed by trypsin, removed by alkaline extraction, or modified by activator.
Detection of a Rapidly Metabolizing Portion of the Membrane Cardiolipin in
Haemophilus parainfluenzae
Authors: Tucker Anne N. , White David C.
Published: January 2020

Heterogeneity in the metabolism of cardiolipin (CL) has been detected in
Haemophilus parainfluenzae
. Pulse-chase experiments showed that a portion of the total CL incorporated and then lost
32
P much more rapidly than the rest of the CL in the cells. The metabolism of each phosphate of the CL differed. The phosphate of the phosphatidyl glycerol (PG) portion of the CL had a more active metabolism than the phosphate of the phosphatidic acid portion of the molecule. Only a portion of the PG pool contributed to the formation of CL. Ethylenediaminetetraacetic acid inhibited the CL-specific phospholipase D in vitro and, when added to growing cells, resulted in more rapid PG metabolism, suggesting that CL hydrolysis contributed to the PG pool.
Isolation of Circular Deoxyribonucleic Acid from
Salmonella typhosa
Hybrids Obtained from Matings with
Escherichia coli
Hfr Donors
Authors: Leavitt R. W. , Wohlhieter J. A. , Johnson E. M. , Olson G. E. , Baron L. S.
Published: January 2020

Heterozygous, partial diploid
Salmonella typhosa
hybrids obtained from matings with
Escherichia coli
K-12 Hfr strains were observed to contain supercoiled, circular deoxyribonucleic acid (DNA) when examined by the dye-buoyant density method. Examination of one such
S. typhosa
hybrid after its loss, by segregation, of the inherited
E. coli
genetic markers revealed a concurrent loss of its supercoiled circular DNA. Subsequent remating of this segregant with various
E. coli
Hfr strains resulted in the reappearance of the circular DNA. Molecular weight determinations of circular DNA molecules isolated from a number of
S. typhosa
partial diploid hybrids were made by sucrose density gradient ultracentrifugation and electron microscopy. These studies revealed a range of molecular sizes among the various hybrids examined, but each hybrid exhibited only a single characteristic size for its contained circular DNA. The range of size is consistent with the presence in each hybrid of a different length of
E. coli
chromosome. It was concluded that the
E. coli
Hfr genetic segments transferred to these
S. typhosa
hybrids were conserved, in the diploid state, in the form of supercoiled, circular DNA molecules.
Ureidosuccinic Acid Uptake in Yeast and Some Aspects of Its Regulation
Authors: Drillien Robert , Lacroute François
Published: January 2020

Ureidosuccinic acid (USA) is an intermediary product in pyrimidine biosynthesis. When proline was the sole nitrogen source, USA uptake occurred; however, when ammonium sulfate or glutamic acid was the nitrogen source, uptake was inhibited. Thus, a
ura2
strain which does not synthesize USA would not grow when this substance was supplied on an ammonium sulfate or glutamic acid medium. Mutants are described in which uptake was constitutive on such a medium. Permeaseless mutants for USA have been found, and evidence is presented for permease specificity. It is shown that all constitutive mutants use the same transport system that is missing in the permeaseless mutant. These mutants are constitutive for two permeases: the specific USA permease and the general amino acid permease. The transport system studied here, like the general amino acid transport system, is regulated by nitrogen metabolism. These facts and others suggest that our permease constitutive mutants are impaired in nitrogen metabolism.
Genetic Behavior of R Factors in
Vibrio cholerae
Authors: Yokota Takeshi , Kasuga Tokuhiko , Kaneko Michiharu , Kuwahara Shogo
Published: January 2020

The
fi
+
and
fi
−
R factors are unstable in
Vibrio cholerae
even on selective media containing antibiotics, although a temperature-sensitive kanamycin resistance factor and its recombinants are stably maintained in
V. cholerae
at low temperatures.
Genophore Homologies Among Compatible Nocardiae
Authors: Clark Josephine E. , Brownell George H.
Published: January 2020

Deoxyribonucleic acid (DNA) reassociation analyses were employed to determine the molecular relationships between recombinable nocardiae. Analysis of the compatibility system of
Nocardia erythropolis
Mat-Ce and Mat-cE mating strains demonstrated the existence of extensive homology under both exacting and nonexacting conditions. Labeled
N. erythropolis
Mat-cE DNA reassociated equally as well with the Mat-Ce test DNA as with its own filter-bound DNA. However, the Mat-cE DNA bound only ca. 60% of the Mat-Ce DNA, when the latter was the reference. The existence of unique nucleotide sequences is postulated on the basis of these results as well as of aberrant segregation patterns which have been observed in certain class types of recombinants. Reassociation data reveal that recombinants representing the inheritance of different portions of each of the parental genomes have inherited the unique portion from the Mat-Ce parent.
N. restrictus
AY-B-226 exhibited little relatedness (11 to 32%), and
N. globerula
ATCC 9356 only slightly more (21 to 42%), to either of these mating strains at either exacting or nonexacting temperatures of incubation.
Hydrostatic Pressure Effects on
Escherichia coli
: Site of Inhibition of Protein Synthesis
Authors: Schwarz J. R. , Landau J. V.
Published: January 2020

Utilizing whole-cell preparations of
Escherichia coli
, it appears that 670 atm inhibits protein synthesis during elongation, while not affecting aminoacyl transfer ribonucleic acid formation, polysomal integrity, or amino acid permeability.
Inhibition of Gene Transfer by Antiserum and Identification of Serotypes of Sex Pili
Authors: Harden Valerie , Meynell Elinor
Published: January 2020

Gene transfer by conjugation due to F or R (drug resistance) factors is inhibited by antibody to the sex pili. Serological analysis is able to distinguish between the sex pili determined by closely related sex factors, and the specificity of inhibition of transfer agrees with that previously determined by direct electron microscopical observation of antibody bound to the sex pili (10). Inhibition of transfer can therefore be applied to the identification of wild-type R factors with repressed sex factors that determine too few pili to be examined directly. It can also be used to differentiate the activities of two unrelated sex factors in the same donor bacterium.
Effect of Phenethyl Alcohol on Deoxyribonucleic Acid-Membrane Association in
Escherichia coli
Authors: Masker W. E. , Eberle H.
Published: January 2020

The effect of phenethyl alcohol (PEA) on deoxyribonucleic acid (DNA)-membrane attachment was examined by means of the “M-band” technique of Tremblay, Daniels, and Schaechter. The results of this work indicate that no significant release of DNA from the membrane could be detected after treatment with 0.25% PEA, a concentration previously shown to prevent reinitiation of DNA replication. However, concentrations of 0.5% PEA and greater, which stop DNA replication immediately, appear to release 25 to 80% of the DNA from the membrane.
Penicillin and Cell Wall Synthesis: A Study of
Bacillus cereus
by Electron Microscopy
Authors: Highton Peter J. , Hobbs D. G.
Published: January 2020

The changes in wall structure of a penicillinase micro-constitutive strain of
Bacillus cereus
(569/H/24), on exposure to penicillin, and after its removal by addition of penicillinase, have suggested the following model for the growth of the walls of these cylindrical cells. Longitudinal extension is by addition of material to a large and continuously increasing number of growing points uniformly distributed over the cylindrical surface. Addition is only in the longitudinal direction so that the cell diameter remains constant. Cross walls grow by addition to their inner edge, and on completion the two new rounded ends of the daughter cells are formed by splitting at the outer edge and continued addition at the center. The ends are conserved.
Germination and Outgrowth of Single Spores of
Saccharomyces cerevisiae
Viewed by Scanning Electron and Phase-Contrast Microscopy
Authors: Rousseau Paul , Halvorson Harlyn O. , Bulla Lee A. , Julian Grant St.
Published: January 2020

Single spores of
Saccharomyces cerevisiae
were examined during germination and outgrowth by scanning electron and phase-contrast microscopy. Also determined were changes in cell weight and light absorbance, trehalose utilization, and synthesis of protein and KOH-soluble carbohydrates. These studies reveal that development of the vegetative cell from a spore follows a definite sequence of events involving dramatic physical and chemical modifications. These changes are: initial rapid loss in cellular absorbance followed later by an abrupt gain in absorbance; reduction in cell weight and a subsequent progressive increase; modification of the spore surface with concomitant diminution in refractility; elongation of the cell and augmentation of surface irregularities; rapid decline in trehalose content of the cell accompanied by extensive formation of KOH-soluble carbohydrates; and bud formation.
Thermolabile Triose Phosphate Isomerase in a Psychrophilic
Clostridium
Authors: Shing Yuen Wan , Akagi James M. , Himes Richard H.
Published: January 2020

The psychrophile
Clostridium
sp. strain 69 contains a thermolabile triose phosphate isomerase which is inactivated rapidly in vitro and in vivo at 32 C.
Repair of Pyrimidine Dimer Damage Induced in Yeast by Ultraviolet Light
Authors: Resnick Michael A. , Setlow Jane K.
Published: January 2020

Crude extracts from ultraviolet (UV)-irradiated yeast cells compete with UV-irradiated transforming deoxyribonucleic acid (DNA) for photoreactivating enzyme. The amount of competition is taken as a measure of the level of cyclobutyl pyrimidine dimers in the yeast DNA. A calibration of the competition using UV-irradiated calf thymus DNA indicates that an incident UV dose (1,500 ergs/mm
2
) yielding 1% survivors of wild-type cells produces between 2.5 × 10
4
to 5 × 10
4
dimers per cell. Wild-type cells irradiated in the exponential phase of growth remove or alter more than 90% of the dimers within 220 min after irradiation. Pyrimidine dimers induced in stationary-phase wild-type cells appear to remain in the DNA; however, with incubation, they become less photoreactivable in vivo, although remaining photoreactivable in vitro. In contrast, exponentially growing or stationary-phase UV-sensitive cells (
rad2-17
) show almost no detectable alteration of dimers. We conclude that the UV-sensitive cells lack an early step in the repair of UV-induced pyrimidine dimers.
Deoxyribonucleic Acid Relatedness Among Species of
Erwinia
and Between
Erwinia
Species and Other Enterobacteria
Authors: Brenner Don J. , Fanning G. R. , Steigerwalt A. G.
Published: January 2020

Relatedness in species of
Erwinia
was assessed by determining the extent of reassociation in heterologous deoxyribonucleic acid preparations. Thermal elution chromatography on hydroxyapatite was used to separate reassociated nucleotide sequences from nonreassociated sequences and to determine the thermal stability of related nucleotide sequences. An apparent 15% core of relatedness is present between fire blight, soft-rot, and “atypical”
Erwinia
species. All
Erwinia
species showed low to moderate reaction with representative enteric bacteria.
Glucose-6-Phosphate Dehydrogenase from
Escherichia coli
and from a “High-Level” Mutant
Authors: Banerjee Santimoy , Fraenkel D. G.
Published: January 2020

Glucose-6-phosphate dehydrogenase has been purified to near homogeneity from wild-type
Escherichia coli
K-12 and from a mutant previously found to contain substantially more of the enzyme. The two enzymes are the same in all characteristics studied thus far: specific activity, kinetics, specificity, and subunit size.
Regulation of the Bacterial Cell Wall: Analysis of a Mutant of
Bacillus subtilis
Defective in Biosynthesis of Teichoic Acid
Authors: Boylan R. J. , Mendelson N. H. , Brooks D. , Young F. E.
Published: January 2020

Bacillus subtilis
168ts-200B is a temperature-sensitive mutant of
B. subtilis
168 which grows as rods at 30 C but as irregular spheres at 45 C. Growth at the nonpermissive temperature resulted in a deficiency of teichoic acid in the cell wall. A decrease in teichoic acid synthesis coupled with the rapid turnover of this polymer led to a progressive loss until less than 20% of the level found in wild-type rods remained in spheres. Extracts of cells grown at 45 C contained amounts of the enzymes involved in the biosynthesis and glucosylation of teichoic acids that were equal to or greater than those found in normal rods. Cell walls of the spheres were deficient also in the endogenous autolytic enzyme (
N
-acyl muramyl-
l
-alanine amidase). Genetic analysis of the mutant by PBS1-mediated transduction and deoxyribonucleic acid-mediated transformation demonstrated that the lesion responsible for these effects (
tag-1
) is tightly linked to the genes which regulate the glucosylation of teichoic acid in the mid-portion of the chromosome of
B. subtilis
.
Temperature-Sensitive Mutants of
Escherichia coli
K-12 with Low Activities of the
l
-Alanine Adding Enzyme and the
d
-Alanyl-
d
-Alanine Adding Enzyme
Authors: Lugtenberg E. J. J. , Van Schijndel-van Dam Arna
Published: January 2020

A number of properties of temperature-sensitive mutants in murein synthesis are described. The mutants grow at 30 C but lyse at 42 C. One mutant possesses a temperature-sensitive
d
-alanyl-
d
-alanine adding enzyme, has an impaired rate of murein synthesis in vivo at both 30 and 42 C, and contains elevated levels of uridine diphosphate-
N
-acetyl-muramyl-tripeptide (UDP-MurNAc-
l
-Ala-
d
-Glu-
m
-diaminopimelic acid) at 42 C. The other mutant possesses an
l
-alanine adding enzyme with a very low in vitro activity at both 30 and 42 C. Its in vivo rate of murein synthesis is almost normal at 30 C but is much less at 42 C. When the murein precursors were isolated after incubation of the cells in the presence of
14
C-
l
-alanine, they contained only a fraction of the radioactivity that could be obtained from a wild-type strain. A genetic nomenclature for genes concerned with murein synthesis is proposed.
Conjugation in
Escherichia coli
: Failure to Confirm the Transfer of Part of Sex Factor at the Leading End of the Donor Chromosome
Authors: Walker E. M. , Pittard J.
Published: January 2020

Experiments were carried out attempting to determine whether part of sex factor is transferred at the leading end of the Hfr chromosome during conjugation. In the first experiment, an analysis was made of the donor properties of recombinant strains which had inherited the terminal but not the proximal marker from an Hfr. Secondly, recombinants integrating an extremely proximal marker from an Hfr were examined for the inheritance of a sex factor affinity locus adjacent to this marker. In the third experiment, proximal transfer of the wild-type allele of a temperature-sensitive sex factor mutation was looked for, using as recipient a temperature-sensitive Hfr strain, and as donor a wild-type Hfr isogenic with respect to the site of sex factor integration. In none of these experiments could the presence of sex factor material at the leading end be demonstrated. The results do not rule out the possibility that part of F is transferred proximally but only integrated at a very low frequency. They do, however, conflict with certain findings of other authors which, in the past, have been taken as evidence for the transfer of part of F at the leading end.
Osmotic Stability and Sodium and Potassium Content of L-Forms of
Streptococcus faecalis
Authors: Montgomerie J. Z. , Kalmanson G. M. , Hubert E. G. , Guze L. B.
Published: January 2020

A stable L-form of
Streptococcus faecalis
(T
53
) was transferred in media containing decreasing concentrations of sucrose until it grew in medium without added osmotic stabilizer. This L-form (designated T
53I
) was compared with T
53
from which it was derived. The survival of these two L-forms suspended at different osmolalities showed that maximal survival for T
53I
was 350 to 400 milliosmolal and for T
53
was 900 to 1,000 milliosmolal. Both peaks were at the osmolality of their growth media. Measurement of intracellular potassium and sodium showed that the concentration of these ions was reduced in T
53I
.
Kinetic and Morphological Observations on the Yeast Phase of
Histoplasma capsulatum
During Protoplast Formation
Authors: Carbonell Luis M. , Berliner Martha D. , Gil F.
Published: January 2020

Protoplast formation by
Histoplasma capsulatum
yeasts using high concentrations of MgSO
4
occurs either by lysis of the bud or lysis of the entire cell wall. Both mechanisms may also occur simultaneously. Neither the protoplast emerging through a hole in the cell wall nor the freshly released protoplast has a recognizable cell wall or the remnant of such. The protoplast contains all the organelles of the normal cell except for mesosomes. During protoplast formation the nucleus increases in size and produces several nuclear masses by the invaginations of the internal layer of the nuclear membrane. All these nuclear masses are surrounded by the external layer of the nuclear membrane. Several nuclei with a normal nuclear membrane are formed later.
Organization of Bacteriophage Tail-Like Particles in Cells of
Chromobacterium violaceum
Authors: Rucinsky Thomas E. , Gregory Judith P. , Cota-Robles E. H.
Published: January 2020

A strain of
Chromobacterium violaceum
has been isolated which produces bacteriophage tail-like particles in high numbers. The extracellular morphology and the intracellular arrangement of these particles are described.
Isolation and Phenotypes of Mutants from
Salmonella typhimurium
Defective in Formate Hydrogenlyase Activity
Authors: Chippaux M. , Casse F. , Pascal M.-C.
Published: January 2020

A new method is described for the isolation of different mutants defective in formic dehydrogenase activity measured with benzyl viologen as electron acceptor.
Lowered Respiratory Response to Adenosine Diphosphate of Mitochondria Isolated from a Mutant
B
Strain of
Schizophyllum commune
Authors: Hoffman Robert M. , Raper John R.
Published: January 2020

Mitochondria were isolated from the mycelium of a
B
-factor mutant in
Schizophyllum commune
that was previously shown to have its energy metabolism partially uncoupled. These mitochondria were compared to mitochondria isolated from wild-type mycelia and were found to increase their respiration rate upon addition of adenosine diphosphate to only one-half the extent of the mitochondria of wild-type mycelia.
New Rifampin-Resistant Mutant of
Escherichia coli
Authors: Marshall Sergio , Gillespie David
Published: January 2020

A rifampin-resistant ribonucleic acid (RNA) polymerase mutant,
rif
r
51, derived from a presumptive RNA synthesis mutant of
Escherichia coli
K-12, complements
rif
r
RNA polymerase mutants isolated from other strains of
E. coli
K-12.
Four-Iron (Sulfide) Ferredoxin from
Bacillus polymyxa
Authors: Yoch Duane C. , Valentine Raymond C.
Published: January 2020

Ferredoxin from
Bacillus polymyxa
contains (per mole) four non-heme iron residues, four acid-labile sulfide residues, and four cysteine residues. Its molecular weight is approximately 8,800, and it has an oxidation-reduction potential (E
m
) of −390 mv. It is active as an electron carrier in several ferredoxin-linked enzyme systems.
Genetic Evidence for the Action of Oxathiin and Thiazole Derivatives on the Succinic Dehydrogenase System of
Ustilago maydis
Mitochondria
Authors: Georgopoulos S. G. , Alexandri E. , Chrysayi M.
Published: January 2020

The inhibitory effect of fungitoxic derivatives of 1,4-oxathiin on substrate oxidation by the basidiomycete
Ustilago maydis
is diminished by a single-gene mutation (
oxr
). The difference between mutant and wild type is approximately the same on the basis of inhibition of either growth and operation of the tricarboxylic acid cycle in intact cells or succinate-driven reduction of ferricyanide by mitochondrial preparations. The mutation affects the behavior of the succinic dehydrogenase system of mitochondria not only in the presence but also in the absence of the toxicant, from which it is concluded that some component of the system itself has been modified. The malonate and the antimycin A sensitivity of the
oxr
mutant is similar to that of the wild type but cross-resistance to thiazole derivatives is easily demonstrated.