bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth, Sporulation, and Enzyme Defects of Glucosamine Mutants of
Bacillus subtilis
Authors: Freese Elisabeth B. , Cole Roger M. , Klofat Walther , Freese Ernst
Published: January 2020

Two glucosamine (GCA)-requiring mutants have been isolated which grow on glucose minimal or nutrient sporulation medium only in the presence of either GCA or acetyl-GCA. They lack the
l
-glutamine-
d
-fructose-6-phosphate aminotransferase (EC 2.6.1.13), which is repressible by GCA and whose activity in the standard strain decreases after cessation of growth. But the mutants can grow on GCA as sole carbon and ammonia source, because GCA induces the synthesis of 2-amino-2-deoxy-
d
-glucose-6-phosphate ketol-isomerase (deaminating) (EC 5.3.1.10). With respect to sporulation, the GCA-requiring mutants are in a serious dilemma, as GCA represses the onset of massive sporulation and yet a small amount of GCA-6-phosphate derivatives is necessary to allow sporulation. When GCA is continuously provided in small quantities, sporelike particles are produced which contain little or no spore cortex but a normal spore coat. Apparently, GCA derivatives are needed especially for cortex formation. Many of the sporelike particles can produce colonies after octanol, but not after heat treatment. When they are purified by treatment with lysozyme and sodium dodecylsulfate, they do not show the decrease in optical density at 600 nm typical of germination nor do they produce offspring.
In Vitro Protein Synthesis and Aging in
Rhizoctonia solani
Authors: Obrig T. G. , Gottlieb David
Published: January 2020

A study was made of the ability of cell-free protein synthesis systems from vegetative cells of different age of the fungus
Rhizoctonia solani
to produce polyphenylalanine. Polyuridylic acid-directed phenylalanine incorporation into peptides decreased linearly with cell age. The 105,000 ×
g
supernatant fluid and ribosomal fractions were equally responsible for the total loss of synthetic activity of the older cells. Initial rates of phenylalanyl-transfer ribonucleic acid (tRNA) synthetase activity decreased with increasing cell age, which accounted for the defect of the supernatant fraction. An accelerated degradation of soluble phenylalanyl-RNA was associated with the ribosomes of the older cells. In vitro systems from cells of different age transferred phenylalanine from phenylalanyl-tRNA to polyphenylalanine at similar rates. Of the 15 specific aminoacyl-tRNA synthetases assayed, 5 increased and 5 decreased in specific activity with increased age; 3 others did not change during aging and 2 were below acceptable detectable levels.
Repair of Ultraviolet-Irradiated Transforming Deoxyribonucleic Acid in
Haemophilus influenzae
Authors: Beattie Kenneth L. , Setlow Jane K.
Published: January 2020

Ultraviolet-sensitive and wild-type
Haemophilus influenzae
cells were exposed to irradiated and unirradiated transforming deoxyribonucleic acid (DNA) containing a marker which can be linked to another marker in the cells. Lysates were made after various times of incubation and assayed for transforming activity on an excisionless recipient. Repair can be noted as an increase in activity from the irradiated donor DNA after its linkage to the recipient DNA. No repair can be observed in a mutant which is unable to integrate transforming DNA. There is a little repair in another mutant which is unable to excise pyrimidine dimers.
H. influenzae
cells also repair nondimer damage, as judged by the increase in activity observed in lysates made with irradiated and maximally photoreactivated DNA.
Physiological Comparison of
l
-Serine Dehydratase and Tryptophanase from
Bacillus alvei
Authors: Griffiths S. K. , DeMoss R. D.
Published: January 2020

Tryptophanase from
Bacillus alvei
also possesses serine dehydratase activity. A comparison of this enzyme with
l
-serine dehydratase [
l
-serine hydro-lyase (deaminating), EC 4.2.1.13] in toluene-treated whole cell preparations of the organism was undertaken. Tryptophanase is a constitutive enzyme in
B. alvei
. The dehydratase undergoes a repression-derepression-repression sequence as the
l
-serine level in the growth medium is increased from 0 to 0.1
m
. Tryptophanase activity is decreased in organisms grown in medium containing glucose. Both enzymes are repressed in organisms grown in glycerol-containing medium.
l
-Serine dehydratase has a
p
H optimum of 7.5 in potassium phosphate buffer; tryptophanase functions optimally in this buffer at
p
H 8.2. Both enzymes lose activity in the presence of tris(hydroxymethyl)aminomethane buffer. Either K
+
or NH
4
+
is required for full tryptophanase activity, but Na
+
is markedly inhibitory. These three cations are stimulatory to
l
-serine dehydratase activity. Both enzymes are subject to apparent substrate inhibition at high concentrations of their respective amino acids, but the inhibition of tryptophanase activity can be completely overcome by the removal of indole as it is formed. The dehydratase does not catalyze cleavage of
d
-serine,
l
-threonine, or α-substituted serine analogues at the concentrations tested. However, activity of the enzyme in cleaving
l
-serine is competitively inhibited by
d
-serine, indicating that the
d
-isomer can occupy an active site on the enzyme. The enzyme catalyzes cleavage of some β-substituted serine analogues.
Base Composition of Deoxyribonucleic Acid of the Temperature-Sensitive Kanamycin-Resistant R Factor, R
ts
1
Authors: Goto Nobuichi , Yoshida Yoko , Terawaki Yoshiro , Nakaya Rintaro , Suzuki Kenji
Published: January 2020

The buoyant density of deoxyribonucleic acid (DNA) from the temperature-sensitive R factor, R
ts
1, was determined by CsCl density-gradient centrifugation. R
ts
1 was found to consist of a single species of DNA of density 1.705 g/cm
3
, which corresponds to a base composition of 45% guanine plus cytosine. This value is distinct from the densities previously reported for other R factors, suggesting that R
ts
1 represents a new molecular class of R factors.
Properties of the Inducible Hydroxyproline Transport System of
Pseudomonas putida
Authors: Gryder Rosa M. , Adams Elijah
Published: January 2020

Features of the transport system for hydroxyproline in a strain of
Pseudomonas putida
were studied. A mutant, lacking hydroxyproline-2 epimerase and unable to metabolize hydroxy-
l
-proline, was shown to transport and accumulate this compound after induction. Both entry and exit rates were examined, and kinetic constants for the reaction were determined. Increasing the induction time from 0.5 to 3 hr increased the entry rate three- to fourfold but had only a small and variable effect on the exit rate. Entry followed saturation kinetics. For hydroxy-
l
-proline, the
K
m
and
V
max
values were found to be 3 × 10
−5
m
and 6 μmoles per g (dry weight) per min, respectively. The
K
m
and
V
max
for the epimer allohydroxy-
d
-proline were 10
−3
m
and 0.1 μmole per g (dry weight) per min. Entry rates into “loaded” and “unloaded” cells were found to be the same. Exit was shown to be first order over the range of internal substrate concentrations measured. Exit rates were measured by several different methods and found to be independent of external substrate concentration. The first-order exit rate constant was computed to be 0.23 min
−1
. Several metabolic inhibitors were examined for their effect on transport. The inhibitory action of
N
-ethyl maleimide was shown to be greatly reduced if cells were allowed to accumulate hydroxy-
l
-proline before exposure to the inhibitor. A number of other amino acids interfered with the transport of hydroxy-
l
-proline; the greatest effect was produced by
l
-alanine and
l
-proline.
Aerobic Heterotrophic Bacteria Indigenous to
p
H 2.8 Acid Mine Water: Predominant Slime-Producing Bacteria in Acid Streamers
Authors: Dugan Patrick R. , MacMillan Carol B. , Pfister Robert M.
Published: January 2020

Five gram-negative bacteria, two gram-positive bacteria, and one yeast were isolated from “acid streamers” taken from acid mine water. One gram-positive rod which has been tentatively identified as a
Bacillus
species appeared to be the predominant organism in the streamers. This isolate produced copious amounts of extracellular polymer at 10 C in the laboratory and was considered to be the primary source of polymer in the “acid streamer” slime matrix. The organism grew slowly at
p
H 2.8 in mine water media, but the optimal
p
H was approximately 7.0.
Ultrastructure and Cell Division of a Facultatively Parasitic Strain of
Bdellovibrio bacteriovorus
Authors: Burnham Jeffrey C. , Hashimoto T. , Conti S. F.
Published: January 2020

Some aspects of cell development and division of
Bdellovibrio bacteriovorus
strain UKi2 were examined by use of electron microscopic techniques. Under saprophytic and parasitic conditions of growth, the comma-shaped cells enlarge, elongate, and form helical filaments. The mechanism of division appears to consist of an asymmetrical constriction of the filamentous cell by the cytoplasmic membrane, accompanied by a breakdown of the outer layers of the cell wall in the division region. During regeneration of the cell wall, the flagellum and flagellar sheath are formed. The development of the flagellum of the daughter cell is initiated prior to separation of the newly formed cells from the filament. Observations of
B. bacteriovorus
UKi2 grown under saprophytic and parasitic conditions indicate that development and ultrastructure are similar in both modes of growth.
Control of Deoxyribonucleic Acid and Ribonucleic Acid Synthesis in Pyrimidine-Limited
Escherichia coli
Authors: Dennis Patrick P. , Herman Robert K.
Published: January 2020

The effects of pyrimidine limitation on chromosome replication and the control of ribosomal and transfer ribonucleic acid syntheses were investigated. Chromosome replication was studied by autoradiography of
3
H-thymine pulse-labeled cells. Pyrimidine limitation did not affect the fraction of cells incorporating radioactive thymine during a short pulse, indicating that when growth is limited by the supply of pyrimidine, the time required for chromosome duplication increases in proportion to the time required for cell duplication. Control of ribosomal RNA and transfer RNA syntheses was examined by chromatographing cell extracts on methylated albumin kieselguhr columns. When growth was controlled by carbon-nitrogen limitation, the ratio of tRNA to total RNA remained roughly constant at growth rates above 0.5 doublings per hour. During pyrimidine limitation, however, the control of rRNA synthesis was apparently dissociated from the control of tRNA synthesis: the ratio of tRNA to total RNA increased as the growth rate decreased.
Staphylococcus aureus
H Autolytic Activity: General Properties
Authors: Takebe Itaru , Singer Howard J. , Wise Edmund M. , Park James T.
Published: January 2020

Staphylococcus aureus
strain H has an autolytic activity which can be found in the cell wall but is most easily obtained from high-speed supernatant fractions of broken-cell preparations. As measured either turbidimetrically or radioactively, this activity is much greater on murein extracted from penicillin-treated cells than on murein extracted from normal cells.
Induction of Pleomorphy and Calcium Ion Deficiency inLactobacillus bifidus
Authors: Kojima Masami , Suda Shozo , Hotta Susumu , Hamada Koyata
Published: January 2020

The induction of pleomorphism ofLactobacillus bifidusby NaCl was completely inhibited by CaCl2. When the organism was cultivated in calcium-free medium, growth of the bifid form was exclusively observed. Supplementation of calcium ion in the medium caused bacilloid growth. Chemical analyses indicated that calcium content of the bifid form organisms was significantly less than that of the bacilloid form; i.e., in the former type, there was an approximately 30% decrease of calcium in the whole cells, and an 82% decrease in the cell wall, as compared with the respective content of the latter. These results indicate a suppressing role of calcium ion in the induction of pleomorphism ofL. bifidus. Besides calcium content, sugar and amino acid compositions were shown to be different between the bifid and bacilloid forms. In the cell wall especially, the content of glucose in the bifid form was larger than that in the bacilloid form. Methionine and phenylalanine were present in the bifid form, but not in the bacilloid form. Cell walls of the bifid form organisms lacked a larger molecular weight peptidoglycan (7.5S) which was clearly detected in the bacilloid form. Evidence has been given for the relationships of calcium ion and cell wall components to the pleomorphism inL. bifidus.
Comparative Study of Isoenzyme Formation of Bacterial β-Galactosidase
Authors: Erickson Robert P. , Steers Edward
Published: January 2020

The enzyme β-galactosidase was studied in crude extracts of
Escherichia coli
3300,
E. coli
grown on a selenium and sulfur medium,
Salmonella typhimurium
F-lac,
Serratia marcescens
F-lac,
S. marcescens
P-lac,
Proteus mirabilis
F-lac,
P. mirabilis
P-lac,
Aeromonas formicans
, and
Streptococcus lactis
. The isoenzymes could be demonstrated by an alternative histochemical technique. Different isoenzyme patterns were found to be determined by the β-galactosidase structural gene and not by the cytoplasm within which the β-galactosidase was formed. In addition, the β-galactosidases from strains which form isoenzymes were more stable to heat and urea treatments than the enzyme formed by those organisms which produce reduced amounts of, or no, isoenzyme.
Sequence of Genes Replicated in
Salmonella typhimurium
as Examined by Transduction Techniques
Authors: Nishioka Y. , Eisenstark A.
Published: January 2020

5-Bromouracil (BU) was pulsed into the genome of synchronously growing cells of an F
−
strain of
Salmonella typhimurium
of LT2. BU-labeled genes were transduced with P22 phage to a series of recipient auxotrophs. When BU was incorporated early in the replication cycle, the transducing markers that had hybrid densities were those that lie between 9 and 12 o'clock on the genetic map. When BU was incorporated during the terminal period of the synchronous cycle, the transducing particles had hybrid densities for genes that lie from 1 to 8 o'clock clockwise. When phages were prepared on cells in which the middle period was BU-labeled, transducing particles with hybrid densities appeared for genes that lie in two separate regions: between 7 and 9 o'clock and between 12 and 2 o'clock. Analysis of the map sequences of the transduced BU genes, the relative frequency of transduction for each marker, and the time sequence of replication led to a hypothesis that the origin of replication is near the isoleucine-valine gene on the chromosome map. As for direction of replication, several models were considered, including the possibility that replication may proceed in both directions in the same chromosome. It was also found that the
aroB, cysG
, and
strA
genes are cotransduced and
strA
and
aroC
are also cotransduced. The relative order of the four genes was found to be
aroB, cysG, strA, aroC
, but the orientation in the circular map was not determined.
Mevalonate Metabolism in Supernatant Fractions of Lysates of
Lactobacillus plantarum
Authors: Durr I. F. , Habbal M. Z.
Published: January 2020

The supernatant fractions of lysates of
Lactobacillus plantarum
metabolize mevalonate into lipids. Adenosine triphosphate and uridine, as well as related compounds, and reduced nicotinamide adenine dinucleotide phosphate or reduced nicotinamide adenine dinucleotide stimulate this process. To obtain very active supernatant fractions, the method of lysis is modified to include polyamines during lysozyme treatment of cells and subsequent shocking with citrate buffer.
Evidence for a Second Chemotactic System in the Cellular Slime Mold,
Dictyostelium discoideum
Authors: Bonner J. T. , Hall E. M. , Sachsenmaier W. , Walker B. K.
Published: January 2020

An unknown substance found in bacteria (
Escherichia coli
) is especially effective in attracting the vegetative amoebae of the cellular slime mold,
Dictyostelium discoideum
. However, the aggregating amoebae are not attracted to it at all. On the other hand, the vegetative amoebae show very little chemotactic response to cyclic adenosine monophosphate (cyclic AMP), whereas the aggregating amoebae are exceptionally responsive to it. It is suggested that the new factor may be used in food seeking, whereas cyclic AMP, the chemotactic substance responsible for aggregation, is the acrasin of this species. The important point is that the amoebae are differentially stage-specific in their responses to these two chemotactic agents.
Glycerol Kinase, the Pacemaker for the Dissimilation of Glycerol in
Escherichia coli
Authors: Zwaig N. , Kistler W. S. , Lin E. C. C.
Published: January 2020

The activity of glycerol kinase is rate-limiting in the metabolism of glycerol by cells of
Escherichia coli
. A mutant strain producing a glycerol kinase resistant to inhibition by fructose-1,6-diphosphate grows faster than its wild-type parent on glycerol as the sole source of carbon and energy. The amount of intracellular fructose-1,6-diphosphate was determined for wild-type cells growing exponentially on glycerol. The water content of such cells was also determined, allowing calculation of the intracellular concentration of fructose-1,6-diphosphate. This value, 1.7 m
m
, is adequate to exert substantial inhibition on the wild-type glycerol kinase. The desensitization of glycerol kinase to feedback inhibition also enhances the power of glycerol to exert catabolite repression, both on the enzymes of the glycerol system itself and on those of the lactose system. However, desensitization of glycerol kinase alone does not eliminate the phenomenon of diauxic growth in a glucose-glycerol medium. Biphasic growth in such a medium is abolished if the altered enzyme is produced constitutively. The constitutive production of the mutant kinase at high levels, however, renders the cells vulnerable to glycerol. Thus, when the cells have been grown on a carbon source with a low power for catabolite repression, e.g., succinate, sudden exposure to glycerol leads to overconsumption of the nutrient and cell death.
Repair of Alkylation Damage: Stability of Methyl Groups in
Bacillus subtilis
Treated with Methyl Methanesulfonate
Authors: Prakash Louise , Strauss Bernard
Published: January 2020

Bacillus subtilis
was not inactivated and was able to replicate even though approximately 3 × 10
4
methyl groups added by methyl methanesulfonate (MMS) were bound to the deoxyribonucleic acid (DNA) of each organism. No significant loss of methyl groups from the DNA occurred for several generations upon incubation of methylated wild-type or MMS-sensitive cells. Single-strand breaks were not observed in the DNA from cells treated at this low MMS dose. Higher doses of MMS resulted in significant killing of both wild-type and MMS-sensitive strains, and the DNA extracted from such treated cells sedimented more slowly than control DNA through alkaline sucrose gradients, indicating the presence of breaks or apurinic sites (or both). These breaks were repaired upon incubation of wild-type but not of MMS-sensitive strains. Repair of damage induced by alkylating agents is probably the repair of breaks which occur as a consequence of high levels of alkylation.
Growth and Development of Competence in the Group H Streptococci
Authors: Lawson John W. , Gooder Harry
Published: January 2020

The growth and development of competence by group H streptococci, strain Challis, were compared in synthetic, semisynthetic, and complex media with respect to the cultural conditions required, time of onset and persistence of competence and transformation efficiency. Provided that cultural conditions were strictly controlled in the synthetic system, transformation frequencies of 1% or above were routinely observed. The initial
p
H must be between 7.3 and 7.6, and the addition of freshly prepared bicarbonate ion was required. Furthermore, competence was sensitive to the degree of initial agitation of the culture. There was no evidence that “step-down” or “unbalanced” growth conditions were required. Competence could be provoked in the incompetent strain Wicky, growing in complex or semisynthetic media, by the addition of heat-killed or filtered cultures of strain Challis prepared during the competent period of growth in synthetic medium.
K
+
-Dependent Deplasmolysis of a Marine Pseudomonad Plasmolyzed in a Hypotonic Solution
Authors: Thompson J. , Costerton J. W. , MacLeod Robert A.
Published: January 2020

When cells of a marine pseudomonad were washed with a solution consisting of 0.3
m
NaCl, 0.05
m
MgSO
4
, and 0.01
m
KCl (complete salts), they maintained their normal morphology. When washed with a solution of 0.05
m
MgSO
4
, they became plasmolyzed as indicated by both phase and electron microscopy. Suspensions of cells washed with 0.05
m
MgSO
4
showed an increase in optical density (OD) when 0.3
m
NaCl was added, and this was followed by a decrease in OD upon the further addition of 0.01
m
KCl. Salts of other monovalent cations were not effective in replacing K
+
in producing the OD decrease. Phase-contrast microscopy revealed that the increase in OD was accompanied by a decrease in cell size, and the decrease in OD, by an increase in the cell size. Both phase and electron microscopy showed that the K
+
-dependent decrease in OD was accompanied by deplasmolysis of the cells. Na
+
was required in the suspending medium in addition to K
+
to obtain deplasmolysis. The intracellular K
+
concentration in cells which had been washed with complete salts and which had retained their normal morphology was found to be 0.290
m
. In cells plasmolyzed by washing with 0.05
m
MgSO
4
, the intracellular K
+
concentration was 0.004
m
. Deplasmolyzed cells contained 0.330
m
K
+
. The membrane profile of plasmolyzed cells was retained when protoplasts were formed. The protoplasts became spherical if incubated in a solution permitting the deplasmolysis of the parent cells. The evidence obtained indicates that plasmolysis and deplasmolysis under the conditions described was due to the loss and gain, respectively, of K
+
by the cells. The effect of Na
+
could be ascribed to its capacity to control the porosity of the cytoplasmic membrane of this organism.
Metabolism of Valine by the Filamentous Fungus
Arthrobotrys conoides
Authors: Gupta Rishab K. , Pramer David
Published: January 2020

Uptake of valine by
Arthrobotrys conoides
was an active process and was independent of its incorporation into cellular protein. Chemical fractionation of cells supplied with
14
C-
l
-valine for different time intervals revealed that the amino acid initially entered a pool of metabolic intermediates and was extractable with cold trichloroacetic acid. After a 4-min interval, some intracellular valine was incorporated into cell proteins, but most underwent metabolic transformation to a variety of products that included carboxylic acids and other amino acids. Carbon derived from valine was not localized in the lipid or nucleic acid fraction of cells, but some was completely oxidized and recovered as metabolic
14
CO
2
. Autoradiograms of paper and thin-layer chromatograms of acid hydrolysates of cellular protein identified the following amino acids as having originated from valine: glutamate, aspartate, alanine, and leucine. Similar analysis of cold trichloroacetic acid extracts established that
14
C supplied as
l
-valine had been transformed also to α-ketoisovalerate, isobutyrate, propionate, succinate, malate, oxalacetate, pyruvate, and α-ketoglutarate. Pathways for transformation of the carbon skeleton of valine to various metabolic products are proposed.
Kinetics of Initiation of Germination of
Bacillus pumilus
Spores by Hydrostatic Pressure
Authors: Clouston J. G. , Wills Pamela A.
Published: January 2020

The kinetics of initiation of germination and inactivation by hydrostatic pressure of phosphate-buffered
Bacillus pumilus
spores is shown to be a consecutive first-order process at 25 C. The effect of increasing pressure at constant temperature was studied, and rate constants were derived by using the criteria of heat resistance, refractility, and stainability. The calculated volume change of activation (Δ
V
‡) was −139 ± 6 cm
3
/mole for loss of heat resistance, −158 ± 8 cm
3
/mole for the loss of refractility, and −153 ± 4 cm
3
/mole for the change in permeability to dilute stains for the pressure range 800 to 1,010 atm at 25 C. It is suggested that the spore exists as a Donnan phase and that pressure triggers germination by influencing the equilibrium.
Relation Between Deoxyribonucleic Acid and Intracytoplasmic Membranes in
Escherichia coli
O111a
1
Authors: Altenburg Betty C. , Suit Joan C.
Published: January 2020

The possibility of a relationship between intracytoplasmic membranes and deoxyribonucleic acid (DNA) in
Escherichia coli
O111a
1
has been investigated. To facilitate this investigation, a simple enzymatic assay for the amount of internal membrane present in a culture was developed. This assay was then used to show that the appearance of intracytoplasmic membranes is accompanied by an increase in the DNA content of the cells. Electron micrographs have confirmed this observation and have shown DNA to be in contact with the intracytoplasmic membranes. Extensive membranes were observed at sites of apparently unsuccessful attempts at cell division. These observations led to the conclusion that the internal membrane formed by strain O111a
1
represents “extra” membrane, which is functional in that it contains sites for DNA replication, but is produced in excess because the organism is somehow defective in its regulation of membrane synthesis.
Electron Microscopic Study of Lipopolysaccharide from an Avian Strain of
Escherichia coli
O18
Authors: Lopes J. , Inniss W. E.
Published: January 2020

The fine structure of lipopolysaccharide (LPS), isolated from an avian strain of
Escherichia coli
O18, was examined by electron microscopy. In positively stained preparations, ribbonlike structures with frequent branching were observed as previously reported (4). Two densely stained parallel lines were occasionally seen associated with a ribbon. When negative staining was employed, the LPS appeared as a branching ribbon with one central and two lateral zones divided by two relatively dense parallel lines running the complete length of the ribbon. The lateral zones were probably due to the O-antigenic side chains of the LPS. This interpretation was supported by the fact that the electron microscopic structure of the LPS from two rough strains,
E. coli
K-12 Gal 23 and
Salmonella tuphimurium
TV119 RII, both lacking the O-specific side chains, did not possess the outer lateral zones.
Electron Transport in Halophilic Bacteria: Involvement of a Menaquinone in the Reduced Nicotinamide Adenine Dinucleotide Oxidative Pathway
Authors: Marquez Ernest D. , Brodie Arnold F.
Published: January 2020

The reduced nicotinamide adenine dinucleotide oxidative pathway of a halophilic bacterium was found to contain a light-sensitive (360 nm) compound, menaquinone-8, which serves as a cofactor in the nicotinamide adenine dinucleotide
+
-linked pathway.
Regulation of Nitrate Reductase in the Basidiomycete
Ustilago maydis
Authors: Lewis C. M. , Fincham J. R. S.
Published: January 2020

Nitrate reductase was induced in
Ustilago maydis
by growth in medium containing only nitrate as the nitrogen source. Ammonium ions repressed the enzyme and led to a rapid loss of activity. Ammonium did not inhibit the enzyme in vitro; although amino acids partially did so, this cannot account for the rapid loss of in vivo activity which occurred when the ammonium was added. Experiments with cycloheximide and actinomycin D, together with measurements of protein turnover, suggested that nitrate reductase is actively broken down when cells with fully induced activity are transferred to medium containing ammonium ions.
Genetic Exchange Between
Escherichia coli
Strains in the Mouse Intestine
Authors: Jones Randall T. , Curtiss Roy
Published: January 2020

Germ-free mice contaminated with selected
Escherichia coli
strains were used for experiments designed to demonstrate gene transfer and recombinant formation in vivo. The well-characterized conjugation system of
E. coli
K-12 was examined in these experiments. Contamination of germ-free mice with a polyauxotrophic F
−
strain followed by the addition of isogenic Hfr, F′, or F
+
strains resulted in the appearance of all recombinant classes at frequencies that would be expected from an in vitro mating experiment. Inheritance of unselected donor markers occurred at frequencies that were dependent on linkage relationships established in experiments in vitro. The presence of
Lactobacillus
had no influence on gene transfer and recombinant formation in an F′ × F
−
in vivo mating. The R factor ROR-1 was transferred from
E. coli
strain M7-18 to an
E. coli
F
−
strain in the mouse intestine.
Chromosomal Location and Properties of Radiation Sensitivity Mutations in
Bacillus subtilis
Authors: Hoch James A. , Anagnostopoulos C.
Published: January 2020

Transformation and transduction crosses involving
recA1, recB2
, and
urv-1
mutations have shown that these mutations belong to three distinct unlinked genetic loci. The precise position of these loci on the
Bacillus subtilis
chromosome map has been determined. The behavior of
recB2
strains in transformation studies suggested a dominance of
recB2
+
function over
recB2
and an early expression of this phenotype during transformation. Strains bearing two ultraviolet sensitivity markers possess a phenotype characteristic of the marker with the most adverse effect on recombination. The possibility that the effects of the two mutations are additive was also considered. Results are also presented which show that a phage-induced enzyme is not responsible for the high transducibility of
recA1
strains.
Induction of the Lactose Transport System in a Lipid-Synthesis-Defective Mutant of
Escherichia coli
Authors: Hsu Chuen Chin , Fox C. Fred
Published: January 2020

In order to relate the biogenesis of the lactose transport system to lipid synthesis, a glycerol-requiring mutant of
Escherichia coli
K-12 with a specific defect in
l
-glycerol-3-phosphate synthesis was isolated and characterized. The defective enzyme is the biosynthetic
l
-glycerol-3-phosphate dehydrogenase [
l
-glycerol-3-phosphate: NAD (P) oxidoreductase, EC 1.1.1.8] which functions as a dihydroxyacetone phosphate reductase to provide
l
-glycerol-3-phosphate for lipid synthesis. In this mutant, removal of glycerol from the growth medium results in inhibition of the synthesis of protein, deoxyribonucleic acid, and phospholipid. Inhibition of phospholipid synthesis immediately follows glycerol removal, whereas the inhibition of deoxyribonucleic acid and protein synthesis is preceded by a short lag period. Glycerol starvation does not change the turnover pattern of previously synthesized phospholipids. The blocking of lipid synthesis by glycerol starvation causes a drastic decrease in inducibility of β-galactoside transport activity relative to β-galactosidase, indicating that induction of lactose transport requires de novo lipid synthesis.
Interaction of Concanavalin A with an Arabinogalactan from the Cell Wall ofMycobacterium bovis
Authors: Goldstein I. J. , Misaki Akira
Published: January 2020

The arabinogalactan isolated from the cell wall ofMycobacterium bovisreacts to form a precipitate with concanavalin A, the phytohemagglutinin of the jack bean. A typical precipitin-like curve is obtained when increasing amounts of the polysaccharide are added to a constant quantity of concanavalin A. Inhibitor studies suggest that concanavalin A reacts with the arabinogalactan by interacting with the C-2, C-3, and C-5 hydroxyl groups of the α-d-arabinofuranosyl residues situated at the chain ends of this polysaccharide.
Complexing of Fatty Acids by Triton WR1339 in Relation to Growth of
Mycobacterium tuberculosis
Authors: Hedgecock Loyd W.
Published: January 2020

Mycobacterium tuberculosis
grew in the presence of toxic concentrations of free fatty acids when an adequate amount of triton WR1339 was added to the medium. Triton produced a solubilizing effect on turbid suspensions of fatty acids, indicating the formation of a detergent-lipid complex. Oleic acid complexed with triton served as a source of carbon for growth of
M. tuberculosis
.
Quantitation of the Action of Ethylenediaminetetraacetic Acid and Tris(hydroxymethyl)aminomethane on a Gram-Negative Bacterium by Vancomycin Adsorption
Authors: Haslam Donald F. , Best Gary K. , Durham Norman N.
Published: January 2020

Changes in the cell wall of a species of
Flavobacterium
can be quantitated by measuring vancomycin adsorption. Treatment of the cells with ethylenediaminetetraacetic acid or tris(hydroxymethyl)aminomethane (or both) increased adsorption of the antibiotic.
Unusual Reducing Sugar from
Coccidioides immitis
Authors: Scheer E. , Terai T. , Kulkarni S. , Conant N. F. , Wheat R. W. , Lowe E. P.
Published: January 2020

Documentation is offered for the identification of 3-
O
-methyl-mannose as one of several neutral sugars found in defatted arthrospore and mycelial cell walls of
Coccidioides immitis
.
Defective Excision Repair of Pyrimidine Dimers in the Ultraviolet-Sensitive
Escherichia coli ras
−
Mutant
Authors: Walker James R.
Published: January 2020

The
ras
−
mutant of
Escherichia coli
K-12 is sensitive to ultraviolet (UV) light but only slightly sensitive to X-irradiation (1.5-fold increase). Other phenotypic properties include normal recombination ability and normal host cell reactivation ability but an abnormally high frequency of UV-induced mutation. The response of the
ras
−
mutant to UV has been studied biochemically. After low doses of UV, the
ras
−
mutant degraded excessive amounts of deoxyribonucleic acid, and long delays in resumption of deoxyribonucleic acid synthesis occurred. Pyrimidine dimers were excised at the normal rate. Although the mutant had the capability of initiating repair replication, the process was not completed after the high UV dose required to allow detection of repair replication. The
ras
−
mutant, after low UV doses, left three to four times as many single-strand breaks not rejoined as did the wild-type strain.
Cytochrome Content of Two Pseudomonads Containing Mixed-Function Oxidase Systems
Authors: Peterson Julian A.
Published: January 2020

The cytochrome and nonheme iron protein content of two pseudomonads,
Pseudomonas oleovorans
and
P. putida
, containing mixed function oxidase systems was examined. The mixed function oxidase system of
P. oleovorans
and
P. putida
had previously been shown to be present in cells which had been grown on hexane and camphor, respectively, as energy source. The content of protoheme was found to increase significantly when the organisms were grown on the substrates for mixed function oxidation. The nonheme iron protein content increased significantly in the case of
P. putida
and was constant in
P. oleovorans
. The cytochrome
c
content was essentially constant in both pseudomonads. The content of cytochrome P-450 in
P. putida
increased from an immeasurably low amount to 0.15 nmoles per mg (dry weight). The content of cytochrome
o
in
P. oleovorans
increased by a factor of 4.5.
P. oleovorans
was not found to contain detectable quantities of cytochrome P-450 either in the presence or absence of the mixed function oxidase system.
Spermidine Requirement for
Bacillus thuringiensis
Ribosomes in Cell-Free Phenylalanine Incorporation
Authors: Changchien Li-Ming , Aronson John N.
Published: January 2020

A cell-free system from
Bacillus thuringiensis
was found to actively incorporate phenylalanine into hot trichloroacetic acid-precipitable material in the presence of synthetic polynucleotide, ribosomes, S-100 supernatant, an energy-generating system, and guanosine triphosphate. Phenylalanine incorporation was absolutely dependent on the presence of spermidine in addition to magnesium ions, even when highly purified ribosomes were used. The spermidine effect could not be attributed to inhibition of nucleases. The ribosomal and supernatant fractions from
Escherichia coli
and
B. thuringiensis
could be substituted for each other in this system. The spermidine requirement was shown to be limited to the
B. thuringiensis
ribosome fraction.
Growth ofSaccharomycopsisSchiönning Under Continuous Gassing
Authors: Buecher Edward J. , Phaff Herman J.
Published: January 2020

Two strains ofSaccharomycopsis guttulata, JB-1 and JB-3, isolated from stomach contents of domestic rabbits, were grown under different gas phases, and their growth rates were compared. Strain JB-1 grew exponentially at a maximal growth rate under a continuous gas phase of 15% CO2, 2% O2in nitrogen. High cell yields with low cell granulation were obtained. The growth rates were almost the same between oxygen concentrations of 0.25 and 20% at 15% CO2. Poor growth and early cell granulation occurred in the absence of oxygen at 15% CO2. Growth increased at 2% O2in direct proportion to the carbon dioxide concentration up to 10 to 15% CO2. A very high carbon dioxide content (e.g. 98%) was somewhat inhibitory. Cell granulation always occurred during the maximal stationary phase in media atpH 4, but was relatively slight atpH 5.6 or higher. Strain JB-3 responded to various gas phases in a similar manner except that it grew slowly in the absence of oxygen at 15% CO2(pH 4). The effect of an optimal gas phase on the growth of strain JB-1 was examined in relation to other environmental conditions. In the presence of 15% CO2, 2% O2, this strain grew exponentially in yeast autolysate-Proteose Peptone-glucose medium at 37 C atpH 2, 4, and 5.6 at approximately the same rate; the growth rate was somewhat lower atpH 6.2. Under similar conditions, strain JB-1 grew at 30 C andpH 4 at one-sixth its maximal growth rate. Cell granulation was greatly reduced at this temperature. With adequate CO2strain JB-1 also grew at a reduced rate in a yeast autolysate medium previously reported not to support growth. Results indicate that continuous gassing with an optimal gas phase increases the growth rate to the extent that the growth rate surpasses the death rate by a significant margin; as a result, granulated cells can be avoided almost entirely in the log phase.
Presence of Binding Site for α-Amylase and of Masking Protein for This Site on Mycelial Cell Wall of
Aspergillus oryzae
Authors: Yabuki Minoru , Fukui Sakuzo
Published: January 2020

Mycelial cell wall of
Aspergillus oryzae
M-13 grown in an α-amylase-forming medium could not bind α-amylase (Taka-amylase A, EC 3.2.1.1). However, by treatment with 1.0
n
NaOH at 100 C for 30 min, the wall gained the ability to bind α-amylase. This phenomenon was caused by removal of a factor (designated as masking factor) which masked the binding site for α-amylase. The masking factor was purified as a preparation giving a single peak in both ultracentrifugation (1.6
S
) and by gel electrophoresis (
M
BPB
, 1.0). Approximately 20 μg of the purified factor, bound to 10 mg of the alkali-treated mycelial cell wall, prevented the binding of approximately 100 μg of α-amylase or released approximately 100 μg of α-amylase which previously was bound to the alkali-treated wall. These findings indicate that the factor has much higher affinity than α-amylase for the binding site on the mycelial wall. The masking factor was inducibly formed accompanying the secretion of α-amylase.
Inhibitory Effect of Diphtheria Toxin on Amino Acid Incorporation in
Escherichia coli
Cell-Free System
Authors: Tsugawa Akiko , Ohsumi Yoshinori , Kato And Iwao
Published: January 2020

The mechanism of action of diphtheria toxin in an
Escherichia coli
cell-free protein-synthesizing system was examined. When the washed ribosomes were incubated with toxin before addition of messenger ribonucleic acid (RNA), peptide syntheses of
14
C-phenylalanine directed by polyuridylic acid or phage R17 RNA were strongly inhibited by a small amount of toxin. Whereas, if the soluble fraction (105,000 ×
g
supernatant fraction) was preincubated with toxin, no effect of toxin occurred either on the induced protein synthesis or on the activity of guanosine triphosphatase even in the presence of nicotinamide adenine dinucleotide. The binding of
3
H-formylmethionyl-transfer RNA to
E. coli
ribosomes directed by either R17 RNA or trinucleotide AUG was also decreased by toxin. These findings suggest that diphtheria toxin may prevent the binding of messenger RNA by successfully competing with the AUG for ribosomal binding sites. Sucrose-density gradient studies support this concept by showing the decrease in binding of
3
H-labeled R17 RNA to
E. coli
ribosomes exposed to toxin.
Purification and Some Properties of Two Boticins
Authors: Ellison Jane S. , Kautter Judith A.
Published: January 2020

Two bacteriocins (boticins) were elaborated without induction by strain S5, a nontoxigenic variant of
Clostridium botulinum
type E. After separation of the two active entities by gel filtration on Sephadex G-50, a large particle with boticin activity was isolated by density gradient ultracentrifugation, and a small soluble boticin was purified by continuous curtain electrophoresis and chromatography on sulfoethyl-Sephadex. Large and small boticins were purified 200- and 3,000-fold, respectively, with yields of 50% or more. The small boticin, a basic substance with molecular weight under 30,000, was the predominant species; the large boticin, a negatively charged particle with particle weight greater than 40 × 10
6
, represented less than 20% of the total activity. Both purified boticins were resistant to heat and were attacked by proteolytic enzymes, but the large boticin was less thermostable and less sensitive to proteolytic enzymes than was the smaller variety. The activity of the large boticin was not reduced by treatment with urea or deoxyribonuclease. Both boticins exhibited sporostatic and bactericidal activities for
C. botulinum
type E, strain 070. A suspension of type E strain 070 vegetative cells was rendered nonviable within 9 min by the small boticin. The lethal action of this bacteriocin was not reversed by trypsin.
Penicillinase (β-Lactamase) Induction in
Bacillus licheniformis
Under Pseudogratuitous Conditions by 2-(2′-Carboxyphenyl)-Benzoyl-6-Aminopenicillanic Acid
Authors: Bettinger George E. , Lampen J. Oliver
Published: January 2020

Induction of penicillinase (β-lactamase) in
Bacillus licheniformis
749 by 2-(2′-carboxyphenyl)-benzoyl-6-aminopenicillanic acid (CBAP) was examined, since this compound was reported to be a gratuitous inducer of penicillinase in
Staphylococcus aureus
. The specific activity of enzyme optimally induced by CBAP is slightly more than that formed in response to cephalosporin C and threefold the level induced by benzylpenicillin. The optimal inducer concentration of CBAP was not inhibitory toward the growth of penicillinase-deficient mutants, unlike benzylpenicillin or cephalosporin C which showed marked toxicities. CBAP is hydrolyzed by the
Bacillus
penicillinase, but as indicated by its “physiological efficiency” (
V
max
/
K
m
), CBAP is a poor substrate at low concentrations. At very high concentrations, CBAP inhibited benzylpenicillin hydrolysis. The overall effectiveness of CBAP as an inducer can be attributed to its low “physiological efficiency” which enables the use of nontoxic levels of CBAP for induction without its rapid hydrolysis. Although CBAP is not a true gratuitous inducer, operationally it approaches gratuity for induction of
B. licheniformis
penicillinase better than other known inducers.
Isolation, Characterization, and Genetic Analysis of Mutator Genes in
Escherichia coli
B and K-12
Authors: Liberfarb Ruth M. , Bryson Vernon
Published: January 2020

Twenty-one Mut mutants were obtained from
Escherichia coli
B (B/UV) and K-12 (JC355) after treatment with mutagens. These Mut strains are characterized by rates of mutation to streptomycin resistance and T-phase resistance which are significantly higher than the parental (Mut
+
) rates. Mutator genes in 12 strains have been mapped at three locations on the
E. coli
chromosome: one close to the
leu
locus; five close to the
purA
locus; and six close to
cysC
. In addition, eight mutator strains derived from
E. coli
B/UV are still unmapped. Some effort was made to deduce the mode of action of the mutator genes. These isolates have been examined for possible defects in deoxyribonucleic acid repair mechanisms (dark repair of ultraviolet damage, host-cell reactivation, recombination ability, repair of mitomycin C damage). By using transductional analysis, it was found that the ultraviolet sensitivity of NTG119 and its mutator property results from two separate but closely linked mutations. PurA
+
transductants that receive
mut
from NTG119 or NTG35 are all more sensitive to mitomycin C than is the PurA recipient. Unless transduction selects for sensitivity, a probable interpretation is that defective repair of mitomycin C-induced damage is related to the mode of action of
mut
in these transductants and the donor. Abnormal purine synthesis may be involved in the mutability of some strains with cotransduction of the mutator properly and
purA
(100% cotransduction for NTG119). Three mutators are recombination-deficient and may have a defective step in recombination repair. One maps near three
rec
genes close to
cysC
.
Transformation Between
Haemophilus influenzae
and
Haemophilus parainfluenzae
Authors: Beattie Kenneth L. , Setlow Jane K.
Published: January 2020

Heterospecific transformation between
Haemophilus influenzae
and
H. parainfluenzae
is from one to more than six orders of magnitude lower than homospecific transformation, depending on the marker assayed. However, the physical integration of deoxyribonucleic acid (DNA) in heterospecific compared with homospecific transformation is only slightly decreased. Measurement of integration of ultraviolet-irradiated heterospecific transforming DNA suggests that compared with homospecific DNA a longer piece of heterospecific transforming DNA must undergo pairing for integration to occur. Heterospecific transforming DNA behaves towards ultraviolet inactivation of biological activity as though it had undergone some previous inactivation. The efficiency of heterospecific transformation can be improved by light sonic treatment of the DNA or by the use of DNA containing markers which originated from the heterospecific recipient. The presence of an excision mechanism in the recipient cell does not affect killing or marker efficiency in heterospecific transformation. The data indicate that the low frequency of transformation between
H. influenzae
and
H. parainfluenzae
results mostly from lethality. It is proposed that integration of heterospecific transforming DNA results in alterations in the base sequence of the recipient genome which cannot be repaired. Transcription and translation of the altered DNA could result in synthesis of nonfunctional essential proteins.
Chromosomal Location of the C Gene Involved in the Biosynthesis of Nicotinamide Adenine Dinucleotide inEscherichia coliK-12
Authors: Tritz Gerald J. , Matney Thomas S. , Chandler J. L. R. , Gholson R. K.
Published: January 2020

A gene involved in the synthesis of nicotinamide adenine dinucleotide has been found to be cotransducible with the genes involved in the utilization of arabinose (ara) and the biosynthesis of leucine (leu) and pantothenate (pan). Cotransduction frequency analysis places thisnadClocus betweenleuandpanat approximately minute 1.5 on the genetic map ofEscherichia coli. This gene codes for the enzyme, quinolate phosphoribosyl transferase, which catalyzes the conversion of quinolinic acid to nicotinic acid mononucleotide.