bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Phenylbutazone on Phagocytosis and Intracellular Killing by Guinea Pig Polymorphonuclear Leukocytes
Authors: Strauss Robert R. , Paul Benoy B. , Sbarra Anthony J.
Published: January 2020

The anti-inflammatory drug phenylbutazone has been found to inhibit both engulfment and intracellular killing of
E. coli
by guinea pig peritoneal polymorphonuclear (PMN) leukocytes. The bactericidal activity of leukocytic homogenates was also inhibited by the drug. Addition of the drug at various time intervals to a phagocytic reacting system caused an almost immediate cessation of bactericidal activity. Metabolic studies showed that the drug sharply curtailed glucose-
l
-
14
C
and
14
C-formate oxidation of both resting and phagocytizing PMN leukocytes. These data indicated an effect upon the hexose monophosphate shunt and H
2
O
2
formation. Further investigation showed that the sites of inhibition were on glucose-6-phosphate and 6-phosphogluconate dehydrogenase. These inhibitions resulted in decreased H
2
O
2
production. It is suggested that H
2
O
2
activates lysosomes and subsequently complexes with the lysosomal enzyme, myeloperoxidase. This complex is a potent bactericidal agent in the phagocyte.
Fractionated Strands of Bacterial Deoxyribonucleic Acid III. Transformation Efficiencies and Rates of Phenotypic Expression
Authors: Peterson John M. , Guild Walter R.
Published: January 2020

Preferential binding of guanine-rich ribopolymers to one of the complementary strands of denatured deoxyribonucleic acid (DNA) of
Diplococcus pneumoniae
permitted the fractionation of the complements in CsCl density gradients. Phenotypic expression of the newly acquired genes for four drug resistances was more rapid in cells transformed by the heavy fractions than in those transformed either by light fractions or by unfractionated DNA. The efficiencies of transformation with the two complements were nearly equal for the four markers tested. Both efficiency and expression results were the same whether we assayed the residual activity or the activity obtained by annealing the fractions with excess recipient DNA.
Coproporphyrinogenase in a Respiration-deficient Mutant of Yeast Lacking All Cytochromes and Accumulating Coproporphyrin
Authors: Miyake Setsuko , Sugimura Takashi
Published: January 2020

In an earlier report, a respiration-deficient mutant of yeast which lacks all cytochromes and hemoproteins and accumulates coproporphyrin was described. This respiration-deficient mutant was temperature-sensitive and resulted from the single chromosomal gene(
cyt
). In this study, the activity of coproporphyrinogenase, catalyzing the conversion of coproporphyrinogen to protoporphyrinogen, was assayed in the
cyt
mutant and wild strains. Coproporphyrinogenase activity was 10 times higher in the
cyt
mutant than in the wild strains. Cells of the
cyt
mutant grown at 20 C had less activity than those grown at 35 C. The Michaelis constants,
p
H optima, and temperature activations of the enzymes of the
cyt
mutant and the wild strains were similar. The significance of the higher activity of this enzyme in the
cyt
mutant, in which this enzymatic step is apparently blocked in vivo, is discussed.
Production of
l
-Asparaginase II by
Escherichia coli
Authors: Cedar Howard , Schwartz James H.
Published: January 2020

l
-Asparaginase II was synthesized at constant rates by
Escherichia coli
under anaerobic conditions. The enzyme was produced optimally by bacteria grown between
p
H 7 and 8 at 37 C. Although some enzyme was formed aerobically, between 100 and 1,000 times more asparaginase II was produced during anaerobic growth in media enriched with high concentrations of a variety of amino acids. Bacteria grown under these conditions should provide a rich starting material for the large-scale production of the enzyme. No single amino acid specifically induced the synthesis of the asparaginase, nor did
l
-asparagine, even when it was used as the only source of nitrogen. The enzyme was produced at lower rates in the presence of sugars; glucose was the most inhibitory.
Inhibition of Thymidine Kinase Activity and Deoxyribonucleic Acid Synthesis in L Cells Infected with the Meningopneumonitis Agent
Authors: Lin Hsiu-San
Published: January 2020

The activities of enzymes related to deoxyribonucleic acid (DNA) synthesis were studied in uninfected L cells and in L cells infected with
Chlamydia psittaci
(strain meningopneumonitis). The meningopneumonitis agent multiplied normally but failed to induce the synthesis of thymidine kinase in LM (TK
−
) cells which contain no thymidine kinase in the uninfected state. It was concluded that this microorganism has no thymidine kinase of its own and that it does not depend on the functioning of the host enzyme for synthesizing its DNA. Exposure of clone 5b L cells to the meningopneumonitis agent was followed by a decline in their thymidine kinase activity to nearly zero levels, whereas the levels of uridine kinase and thymidylate synthetase remained unchanged. Inhibition of thymidine kinase activity in L cells occurred soon after infection and required new protein synthesis by the meningopneumonitis agent. This inhibition occurred before inhibition of host DNA synthesis, but it was not an essential prelude to the latter inhibition. On the basis of this and previous investigations and in light of present knowledge of the mammalian cell cycle, it was postulated that the meningopneumonitis agent inhibits macromolecular synthesis in L cells by preventing the initiation of a new cell cycle.
Effects of Temperature, Agitation, and Donor Strain on Chromosome Transfer inEscherichia coliK-12
Authors: Wood Thomas H.
Published: January 2020

Recombinant production inEscherichia coliK-12 can be described by three parameters: (i) the distancexof a selected male marker from the donor origin; (ii) the gradient constantk(the probability of interruption of the donor chromosome per unit distance during transfer into a recipient cell); and (iii) the extrapolate numberA(the probability that a donor cell will produce a recombinant inheriting the donor marker contiguous with the origin). It is usually assumed that chromosomal distances can be measured by marker entry times, i.e., that the velocity of chromosome transfervis constant along the chromosome. The dependencies ofk, A, x, andvon temperature, agitation during mating, and donor strain were studied. The transfer velocity of the HfrH chromosomal region from the origin tohisincreases 15-fold between 16 and 43 C, and the chromosomal regions studied have the same temperature dependence that was found for the separate transfer velocities of the O-trpandtrp-hisregions. These data and radiation studies on chromosome transfer indicate that, at a given temperature, chromosomal transfer velocity varies by less than 10% as the distance of any given region from the origin increases. The gradient constantkis temperature-independent between 20 and 45 C if mating times at different temperatures are inversely proportional to the chromosome velocities; also,kis insensitive to agitation during mating and is not decreased by mating on membrane filters. However, the extrapolate numberAis highly temperature-dependent, having its maximum value between 30 and 38 C. These results suggest that the spontaneous interruption of transfer which produces the gradient of transfer is a property of the chromosome itself and not of the fragility of the connection between mating cells.
Locus of the Action of Serum and the Role of Lysozyme in the Serum Bactericidal Reaction
Authors: Feingold David S. , Goldman John N. , Kuritz Harold M.
Published: January 2020

The mechanism of the lethal action of human serum on a rough strain ofEscherichia coliwas investigated by use of serum with and without lysozyme, in medium of low and high osmotic pressure, with cells radioactively labeled in the peptidoglycan polymer, and by electron microscopy. The results suggested that there are two separate components in the bacterial cell wall that afford structural support for the cell. Lysozyme attacked one of these, the peptidoglycan polymer. Serum damaged the other, which is probably the peripherally located lipopolysaccharide-phospholipid complex. The cell wall damage caused by lysozyme-free serum promptly resulted in cell death under usual conditions. In plasmolyzed cells, however, the wall damage was not lethal, presumably because the membrane of the plasmolyzed cell was protected from secondary lethal changes which otherwise occur.
Locus of the Lethal Event in the Serum Bactericidal Reaction
Authors: Feingold David S. , Goldman John N. , Kuritz Harold M.
Published: January 2020

Hypertonic sucrose inhibited the bactericidal activity of lysozyme-free serum against a rough strain ofEscherichia coli. The duration of the inhibition correlated with the duration of plasmolysis caused by the sucrose. Although the lethal action of the serum was delayed, the prompt release of alkaline phosphatase by the cells suggested that nonlethal damage to the cell wall had taken place under these conditions. In contrast, the crypticity of the cells for β-galactosidase did not deteriorate until the viability of the bacteria began to decrease. It is concluded that the primary site of action of serum is at the bacterial cell wall; however, in the absence of lysozyme, the lethal event was subsequent damage to the bacterial cell membrane.
Fine Structure and Composition of the Zoogloeal Matrix Surrounding
Zoogloea ramigera
Authors: Friedman Barry A. , Dugan Patrick R. , Pfister Robert M. , Remsen Charles C.
Published: January 2020

The fingerlike projections, which have been considered to be characteristic of the genus
Zoogloea
, appear to consist of generally globular packets of cells, each surrounded by capsular matrix. The individual packets which surround
Z. ramigera
115 cells appear to adhere one to another by intermeshed fibrils that measure 2 to 5 nm in diameter. The fibril polymer appears to be polyglucose that is susceptible to cellulase. The polymer resembles cellulose in several respects, with the exception that it is soluble in 1
n
NaOH. Although
Z. ramigera
I-16-M does not possess an observable zoogloeal matrix when viewed under a light microscope, chemical data indicate that it does produce cellulase-susceptible polymer. Fibrils can be observed under the electron microscope, which are resistant to 1
n
NaOH and may be cellulose. Less polymer fibrils are observed around isolate I-16-M cells than around isolate 115 cells; the inability to observe the I-16-M material as a zoogloeal matrix under light microscopy may be due to lack of sufficient amount of polymer.
Location of Genes for Motility and Chemotaxis on theEscherichia coliGenetic Map
Authors: Armstrong John B. , Adler Julius
Published: January 2020

InEscherichia coli, the following genes are involved in motility and chemotaxis. TheHgene is the structural gene for flagellin. Mutation in themotgene results in paralysis of the flagella, and mutation in theflagenes leads to an absence of flagella. ThecheA, cheB, andcheCgenes are required for chemotaxis. The chromosomal location of these genes has now been determined. The majority are clustered in a small region arounduvrC, betweenhisandaroD, in the orderhis-cheC-H-uvrC-mot-cheA-cheB-aroD. Theflagenes are located in the same region, and also betweentrpandgal. The results indicate that many of the genes are homologous to those which have been studied inSalmonella typhimurium.
Phospholipids from
Bacillus stearothermophilus
Authors: Card George L. , Georgi Carl E. , Militzer Walter E.
Published: January 2020

The lipids of
Bacillus stearothermophilus
strain 2184 were extracted with chloroform-methanol and separated into neutral lipid and three phospholipid fractions by chromatography on silicic acid columns. The phospholipids were identified by specific staining reactions on silicic acid-impregnated paper, by chromatography of alkaline and acid hydrolysis products, and by determination of acyl ester:glycerol:nitrogen:phosphorus molar ratios. The total extractable lipid was 8% of the dry weight of whole cells and consisted of 30 to 40% neutral lipid and 60 to 70% phospholipid. The phospholipid consisted of diphosphatidyl glycerol (23 to 42%), phosphatidyl glycerol (22 to 39%), and phosphatidyl ethanolamine (21 to 32%). The concentrations of diphosphatidyl glycerol and phosphatidyl glycerol were lower in 2-hr cells than in 4- and 8-hr cells. Whole cells were fractionated by sonic treatment and differential centrifugation. The total lipid content, expressed in per cent of dry weight of each fraction was: whole protoplasts, 10%; membrane fraction, 18%; 30,000 ×
g
particulate fraction, 22%; and 105,000 ×
g
particulate fraction, 26%. The relative phospholipid concentrations in each fraction were about the same. As had been previously reported, none of the phospholipid was stable to alkaline hydrolysis.
Evidence for a Methionine-controlled Homoserine Dehydrogenase in
Salmonella typhimurium
Authors: Cafferata Robert L. , Freundlich Martin
Published: January 2020

Evidence is presented for the existence of a second homoserine dehydrogenase in
Salmonella typhimurium
. The formation, but not the activity, of this enzyme is controlled by methionine. Two distinct homoserine dehydrogenases were separated from wild-type cells by diethylaminoethyl (cellulose) column chromatography. Sucrose gradient ultracentrifugation gave molecular weight estimates for the threonine-regulated enzyme (HSD I) of 220,000 to 240,000 and for the methionine controlled enzyme (HSD II) of 130,000 to 140,000. Approximately 12% of the total HSD activity in wild-type cells was accounted for by HSD II. A threonine-requiring strain of
S. typhimurium
was found to lack HSD I but not HSD II. Under certain conditions, this mutant grew rapidly in minimal medium. Rapid growth in minimal medium was correlated with the appearance of an enzyme with similar characteristics to HSD I. The possible origins of this HSD I-like enzyme are presented.
Phospholipid Metabolism During Changes in the Proportions of Membrane-bound Respiratory Pigments in
Haemophilus parainfluenzae
Authors: White David C. , Tucker Anne N.
Published: January 2020

After a transition from high to low oxygen tension, there was a twofold to 50-fold increase in the content of membrane-bound respiratory pigments of
Haemophilus parainfluenzae
, and there were concurrent changes in the metabolism of the membrane phospholipids: (i) a twofold decrease in the rate of turnover of the phosphate in all the phospholipids; (ii) a shift from simple one-phase, linear incorporation of phosphate into phospholipids to a complex biphasic incorporation of phosphate into phospholipids; and (iii) an increase in the total phospholipids with a slight increase in the proportion of phosphatidylglycerol (PG) and a slight decrease in the proportion of phosphatidylethanolamine (PE). Changes in the rates of incorporation of phosphate into the phospholipids occurred without a change in the rate of bacterial growth. When the compensatory adjustment of the proportions of the respiratory pigments reached a steady state, the total phospholipid, the rate of incorporation of phosphate into phospholipids, and the proportion of PG fell. At steady-state proportions of cytochromes, the proportion of PE and the rate of turnover of the phosphate in the phospholipids increased. All through an incorporation experiment of 1.5 divisions, the specific activity of the phosphate of PG was twice that of phosphatidic acid (PA). The phosphate of PG turned over 1.2 to 1.5 times more rapidly than the phosphate of PA in cells with high and low cytochrome levels. If the PA was an accurate measure of the precursor for the cytidine-5′-diphosphate-diglyceride, which in turn was the precursor of all the lipids, then the results of these experiments suggested that exchange reactions, in addition to synthesis from PA, were involved in phospholipid metabolism. These reactions were more sensitive to changes in oxygen concentration than was the growth rate.
Amino Acid Pool Formation in
Pseudomonas aeruginosa
Authors: Kay W. W. , Gronlund Audrey F.
Published: January 2020

The accumulation and behavior of various amino acids in the pool of
Pseudomonas aeruginosa
(ATCC 9027) were investigated. Patterns of pool formation and maintenance varied with different amino acids tested and were dependent, to a considerable extent, upon the ability of the organism to catabolize the particular amino acid. The establishment of steady-state amino acid pool levels depended upon the activity of the amino acid permease involved and upon the rate of protein synthesis. The presence of a relatively large specific amino acid pool did not affect the formation of a pool of a structurally different amino acid, and a preformed steady-state pool was not displaced by structurally unrelated amino acids. Steady-state amino acid pools decreased rapidly in the presence of inhibitors of energy metabolism and at 0 C. Steady-state internal amino acid pools were found to be in equilibrium with the corresponding external amino acid, present at low levels. A multiplicity of proline pools was demonstrated.
Role ofPasteurella pneumotropicaandMycoplasma pulmonisin Murine Pneumonia
Authors: Brennan Patricia C. , Fritz T. E. , Flynn R. J.
Published: January 2020

Pneumonia caused byMycoplasma pulmonisandPasteurella pneumotropicawas studied in conventional, specific pathogen-free (SPF), and germ-free mice. WhenP. pneumotropicawas serially passed in conventional mice,M. pulmonis, as well asP. pneumotropica, was recovered from mice with gross lesions. WhenM. pulmoniswas serially passed in conventional mice, both organisms were recovered. SPF mice given a nasal instillation ofM. pulmonisalone,P. pneumotropicaalone, or a combination of the two developed pneumonia when both organisms were present. These findings suggested that both organisms contribute to typical murine pneumonia. ThatM. pulmonismight be an L form ofP. pneumotropicawas suggested because some SPF mice inoculated with either organism yielded both on culture. This possibility was investigated with mole per cent guanine plus cytosine (GC) content and nucleic acid hybridization techniques. The GC content ofP. pneumotropicais 42.2 mole per cent and that ofM. pulmonisis 28.6 mole per cent. No specific hybrids between deoxyribonucleic acid (DNA) fromM. pulmonisand DNA fromP. pneumotropicawere detected. This and the wide disparity in GC content showed thatM. pulmonisis not an L form ofP. pneumotropica. In germ-free mice, intranasal instillation with either organism alone produced pneumonia. The lesions produced when each organism was inoculated independently were characterized by areas of consolidation with perivascular and peribronchial lymphocytic infiltration. Qualitatively, the lesions produced when both organisms were inoculated simultaneously more closely resembled those seen in naturally occurring murine pneumonia. Statistical analysis indicated that the quantitative effect of the two organisms was additive. The indirect fluorescent antibody technique was used to locate organisms in lung tissue sections.M. pulmonislocalized in the bronchial epithelium andP. pneumotropicalocalized in the alveolar lesions.
Spirochaeta aurantia
, a Pigmented, Facultatively Anaerobic Spirochete
Authors: Breznak John A. , Canale-Parola E.
Published: January 2020

A strain of
Spirochaeta aurantia
was isolated from mud by a procedure involving migration of the organisms through cellulose ester filter discs (0.3-μm pore diameter) onto the surface of culture plates. The helical cells measured 0.3 by 10 to 20 μm during exponential growth. Electron microscopy showed the presence of two subterminally inserted axial fibrils partially overlapping in a 1-2-1 arrangement. An outer envelope, exhibiting a polygonal substructure, was observed. The spirochete grew either aerobically or anaerobically, with aerobic yields of 9.8 × 10
8
cells per ml and anaerobic yields of 3.0 × 10
8
cells per ml. The organism used carbohydrates, but not amino acids, as energy sources. Amino acids served as sole nitrogen sources, whereas inorganic ammonium salts did not. The presence of biotin and thiamine in the medium was required for growth. Growing cells fermented maltose mainly to carbon dioxide, hydrogen, ethyl alcohol, and acetic acid. Small amounts of formic and lactic acids, acetoin, and diacetyl were produced. Cells of
S. aurantia
growing aerobically produced a yellow-orange pigment. Chemical analysis indicated that the pigment was carotenoid in nature, its main component being lycopene or a similar compound.
S. aurantia
is not closely related to the leptospires, since it lacks both the hemolytic antigen and the hooked ends typical of the latter organisms. Furthermore, the guanine plus cytosine content in the deoxyribonucleic acid of
S. aurantia
(66.8 moles%) differs drastically from that of leptospires.
Direct Measurement of Acetylesterase in Living Protist Cells
Authors: Medzon Edward L. , Brady Marilyn L.
Published: January 2020

The fluorogenic acetylesterase (acetic ester hydrolase EC 3.1.1.6.) substrate, fluorescein diacetate, was used to measure enzyme activity in living protist cells. The visual enzyme assay was done by monitoring fluorochromasia by fluorescent microscopy. Quantitative fluorogenic assays were done by measuring the evolved fluorescein in a fluorometer. Of 59 strains of bacteria, 35 were fluorochromatically positive. Eight of the fluorochromatically negative strains were fluorogenically positive. Of 22 strains of slime molds and fungi, all were fluorochromatically positive. Three out of 12 different algae were fluorochromatically positive. Several unidentified protozoa were also fluorochromatically positive. Four out of six protozoa were fluorochromatically positive. Structures of special interest showing acetylesterase activity were: the growing hyphal tips of fungi, the vacuolated areas of yeast and protozoa, newly formed bacterial spores or immature fungal spores, “mesosome-like” bodies inBacillus megaterium, and the cell membrane and nuclear region of green algae. Yeast protoplasts and bacterial protoplasts and spheroplasts were fluorochromatically positive when derived from positive cells and negative when derived from negative cells. There was no correlation between the possession of a capsule and acetylesterase activity. There was no effect on the viability of bacterial cells incubated in the presence of fluorescein diacetate. Paraoxon inhibited bacterial and yeast enzyme at 10−5m. Eserine (10−5m) and Paraoxon (10−7m) inhibitedB. megateriumenzyme. Sodium acetate at 10−2mdid not inhibit bacterial enzyme. The implications of these findings on the location and expression of esterase activity in living cells are discussed.
Genetic Relationship Between
Sarcina ureae
and Members of the Genus
Bacillus
Authors: Herndon Saundra E. , Bott Kenneth F.
Published: January 2020

Deoxyribonucleic acid-ribonucleic acid (DNA-RNA) and DNA-DNA hybridization studies were performed to determine the degree of genetic relatedness between
Sarcina ureae
and several members of the genus
Bacillus
. DNA-RNA hybridization showed a high degree of homology between
S. ureae
RNA and DNA from
Bacillus
species having a similar guanine plus cytosine content. The DNA from other genera of the family
Micrococcaceae
showed less homology with
S. ureae
RNA than did that of the
Bacillus
species tested; however, this homology was not found between the DNA of
S. ureae
and DNA from these
Bacillus
species or DNA from the other
Micrococcaceae
tested. Transformation with
Bacillus
DNA, infection with representatives from several major classes of
Bacillus
phages, and electrophoretic analysis of proteins in crude extracts of these strains were also attempted as a further test of the genetic relationship between the genera. These experiments did not support the belief that the two groups are closely related genetically.
Aldohexuronic Acid Catabolism by a Soil
Aeromonas
Authors: Farmer J. J. , Eagon R. G.
Published: January 2020

Bacteria which utilize mannuronic acid as an energy source were isolated from nature. One of the organisms, identified as a member of the genus
Aeromonas
, used glucuronate, galacturonate, and mannuronate as the sole source of carbon and energy. Glucuronate- and galacturonate-grown resting cells oxidized both glucuronate and galacturonate rapidly, but mannuronate slowly. Mannuronate-grown cells oxidized all three rapidly, with the rate of mannuronate utilization somewhat lower. Cell-free extracts from glucuronate-, galacturonate-, and mannuronate-grown
Aeromonas
C11-2B contained glucuronate and galacturonate isomerases, fructuronate, tagaturonate, and mannuronate reductases, and mannonate and altronate dehydratases, with the exception of glucuronate-grown cells which lacked altronate dehydratase. Thus, the pathway for glucuronate and galacturonate catabolism for
Aeromonas
was identical to
Escherichia coli
. Glucuronate and galacturonate were isomerized to
d
-fructuronate and
d
-tagaturonate which were then reduced by reduced nicotinamide adenine dinucleotide to
d
-mannonate and
d
-altronate, respectively. The hexonic acids were dehydrated to 2-keto-3-deoxy gluconate which was phosphorylated by adenosine triphosphate to 2-keto-3-deoxy-6-phospho gluconate. The latter was then cleaved to pyruvate and glyceraldehyde-3-phosphate. Mannuronate was reduced directly to
d
-mannonate by a reduced nicotinamide adenine dinucleotide phosphate-linked oxidoreductase.
d
-Mannonate was then further broken down as in the glucuronate pathway. The mannuronate reducing enzyme, for which the name
d
-mannonate:nicotinamide adenine dinucleotide (phosphate) oxidoreductase (
d
-mannuronate-forming) was proposed, was shown to be distinct from altronate and mannoate oxidoreductases. This is the first report of a bacterial oxidoreductase which reduces an aldohexuronic acid to a hexonic acid. The enzyme should prove to be a useful analytical tool for determining mannuronate in the presence of other uronic acids.
Enterotoxin B Synthesis by Replicating and Nonreplicating Cells of
Staphylococcus aureus
Authors: Markus Z. , Silverman G. J.
Published: January 2020

Although 95% of the enterotoxin B produced by
Staphylococcus aureus
appears during the latter part of the exponential phase of growth, growth per se is not necessary for toxin synthesis. A procedure is described whereby a concentrated suspension (at least 6 × 10
10
cells per ml) of a 16-hr culture of
S. aureus
was found to be capable of producing toxin, without replication, when air and glucose were present. This technique allows the growth requirement to be separated from toxin formation. Although higher (100 μg/ml) concentrations of toxin appeared in the medium when nitrogen was present, lower levels (30 μg/ml) were produced in the absence of N-Z-amine A. Toxin production proceeded without any net increase in deoxyribonucleic acid, ribonucleic acid, or protein. Chloramphenicol did not inhibit toxin formation in a nitrogen-free medium. The optimal
p
H for toxin production in a nitrogen-free medium was 8.0 to 8.5; for synthesis in a medium where nitrogen was available, the optimal
p
H was 7.0 to 7.5. Increasing the rate of aeration increased toxin release during growth, but decreased the amount of toxin subsequently produced when the bacteria were resuspended. These results suggest the presence of a precursor pool in the cells collected after 16 hr of growth.
Cultural Characteristics and Fatty Acid Composition of Propionibacteria
Authors: Moss C. Wayne , Dowell V. R. , Farshtchi D. , Raines L. J. , Cherry W. B.
Published: January 2020

The cultural characteristics and cellular fatty acid composition of 40 strains representing 7 species of
Propionibacterium
and of 9 cultures of anaerobic corynebacteria were studied. The cultures were characterized by means of 23 separate cultural and biochemical tests. Cultures of the two genera differed consistently in only two reactions; the propionibacteria did not produce indole or liquefy gelatin, whereas the anaerobic corynebacteria were consistently positive with these tests. The fatty acids were extracted from whole cells and examined as methyl esters by gas-liquid chromatography. The most abundant acid in the seven
Propionibacterium
species was a C
15
-saturated branched-chain acid which was present in both the iso-and anteiso-form. Based on a comparison of the relative abundance of these isomers (i-C
15
and a-C
15
), the species were separated into two groups.
P. freudenreichii
and
P. shermanii
(group one) were similar and contained the a-C
15
isomer as the predominant acid. The i-C
15
isomer was the most abundant acid in the second group (
P. arabinosum, P. jensenii, P. pentosaceum, P. thoenii
, and
P. zeae
). The fatty acid profiles of the anaerobic corynebacteria were somewhat similar to those of the second group of propionibacteria, but were distinct from the profiles of
P. freudenreichii
and
P. shermanii
. The addition of branched-chain amino acids (
l
-leucine and
l
-isoleucine) to the growth medium increased the synthesis of the specific fatty acid(s) structurally related to the added amino acid.
Failure to Inhibit In Vitro or In Vivo Acetycholinesterase with Botulinum Toxin Type A
Authors: Simpson Lance L. , Morimoto Hiromi
Published: January 2020

An attempt has been made to replicate an earlier finding that type A botulinum toxin can inhibit the in vitro activity of acetylcholinesterase. Two methods of enzyme assay were employed, but with neither technique were we able to reproduce the finding of in vitro enzyme inhibition. In fact, an examination of the data from the previous report leads us to question the possibility of the observations that were given. Furthermore, an investigation was carried out to determine if botulinum toxin can exert an inhibiting effect on acetylcholinesterase that is situated in the biological tissue. The answer again is negative. The experimental observations, coupled with several mathematical computations, do not support the notion that botulinum toxin is an acetylcholinesterase inhibitor.
Effect of
p
H on the Immunogenicity of
Mycoplasma pneumoniae
Authors: Pollack J. Dennis , Somerson Norman L. , Senterfit Laurence B.
Published: January 2020

Mycoplasma pneumoniae
harvested from media which had become acid lost the ability both to induce formation of tetrazolium reduction inhibition antibody and to act as antigens in immunodiffusion against human convalescent-phase sera. Incorporation of
N
-tris(hydroxymethyl)-2-aminoethane sulfonic acid and
N
-2-hydroxyethylpiperazine-
N
′-2-ethane sulfonic acid buffers into a new medium containing PPLO Serum Fraction instead of horse serum delayed the
p
H decline. Tris(hydroxymethyl)aminomethane, triethanolamine, and 3,6-endomethylene-1,2,3,6-tetrahydrophthalic acid buffers inhibited growth. Mycoplasmas obtained from buffered cultures retained antigenicity as measured by immunodiffusion and could stimulate tetrazolium reduction inhibition antibody formation in animals.
Bacterial Attachment to a Specific Wound Site as an Essential Stage in Tumor Initiation byAgrobacterium tumefaciens
Authors: Lippincott Barbara B. , Lippincott James A.
Published: January 2020

The number of tumors initiated byAgrobacterium tumefaciensstrain B6 on primary pinto bean leaves was decreased when cells of an avirulent strain (IIBNV6) were included in the inoculum. With sufficient B6 cells to initiate ca. 50% of the maximal number of tumors per leaf, inhibition was detected at a 1:1 ratio of B6 to IIBNV6 cells and increased linearly with the logarithm of the number of IIBNV6. Varying the number of B6 in the presence of a constant number of IIBNV6 or varying the number of both, while maintaining a constant ratio of B6 to IIBNV6, showed that the inhibition was a function of the absolute concentration of each cell type. The data fit a one-particle dose response curve, which indicates that a single IIBNV6 cell can prevent tumor initiation by a single B6 cell. Inhibition was obtained with mixed inocula and when the addition of IIBNV6 preceded B6, but not when B6 preceded IIBNV6. Heat-inactivated IIBNV6 inhibited, as did ultraviolet or heat-inactivated B6. Several unrelated bacteria and certain strains ofAgrobacteriumfailed to inhibit, whereas other related strains gave inhibition. Attachment of IIBNV6 to a specific would site, thus excluding B6 from the site, is proposed to account for these data. A specific complementary binding of a virulent bacterium to a host wound site exposed by the inoculation procedure is suggested as an essential early event in the crown-gall tumor initiation process.
Repair of Ultraviolet Radiation Damage in Sensitive Mutants of
Micrococcus radiodurans
Authors: Moseley B. E. B.
Published: January 2020

Various aspects of the repair of ultraviolet (UV) radiation-induced damage were compared in wild-type
Micrococcus radiodurans
and two UV-sensitive mutants. Unlike the wild type, the mutants are more sensitive to radiation at 265 nm than at 280 nm. The delay in deoxyribonucleic acid (DNA) synthesis following exposure to UV is about seven times as long in the mutants as in the wild type. All three strains excise UV-induced pyrimidine dimers from their DNA, although the rate at which cytosine-thymine dimers are excised is slower in the mutants. The three strains also mend the single-strand breaks that appear in the irradiated DNA as a result of dimer excision, although the process is less efficient in the mutants. It is suggested that the increased sensitivity of the mutants to UV radiation may be caused by a partial defect in the second step of dimer excision.
Initiation of Germination and Inactivation of
Bacillus pumilus
Spores by Hydrostatic Pressure
Authors: Clouston J. G. , Wills Pamela A.
Published: January 2020

The effect of hydrostatic pressures as high as 1,700 atm at 25 C on the heat and radiation resistance of
Bacillus pumilus
spores was studied. Phosphate-buffered spores were more sensitive to compression than spores suspended in distilled water. Measurements of the turbidity of suspensions, the viability, refractility, stainability, dry weight, and respiratory activity of spores, and calcium and dipicolinic acid release were made for different pressures and times. Initiation of germination occurred at pressures exceeding 500 atm and was the prerequisite for inactivation by compression. The rate of initiation increased with increasing pressure at constant temperature. This result is interpreted as a net decrease in the volume of the system during initiation as a result of increased solvation of the spore components.
Electrophoretic Characteristics of Staphylococcal Hyaluronate Lyase
Authors: Abramson Carl , Friedman Herman
Published: January 2020

Partially purified staphylococcal hyaluronidase was studied with respect to its electrophoretic properties by the use of starch slurry or semisolid Noble agar as a matrix. The polarity of enzyme activity was found to be cathodal on starch and anodal on agar gel. The electrophoretic migration of the partially purified enzyme on starch, as a function of
p
H, suggested that the enzyme has an isoelectric point of
p
H 9.5 to 10.
Anthranilate Synthetase, an Enzyme Specified by the Tryptophan Operon of
Escherichia coli
: Purification and Characterization of Component I
Authors: Ito Junetsu , Cox Edward C. , Yanofsky Charles
Published: January 2020

A procedure employed in the purification of anthranilate synthetase component I of
Escherichia coli
is described. The purified component appears homogeneous by starch gel electrophoresis and by sedimentation analysis. A molecular weight of 60,000 was estimated by gel filtration of Sephadex G-100. This value is consistent with the molecular weight estimated from the sedimentation and diffusion coefficients. Purified anthranilate synthetase component I cannot use glutamine as substrate and thus has no activity in the reaction of chorismate +
l
-glutamine → anthranilate; however, it is active when ammonium sulfate is provided as amino donor. Sucrose density gradient analyses showed that ammonium sulfate does not affect the sedimentation velocity of component I. The ultraviolet absorption and fluorescence spectra of the purified component indicated that it contains tryptophan. Peptide pattern and extract complementation evidence suggested that the protein is a single polypeptide chain. Enzyme activity measurements indicated that wild-type
E. coli
produces equimolar amounts of at least four of the five polypeptides specified by the operon. Purified anthranilate synthetase component I is inhibited by
l
-tryptophan.
Covert
fi
−
R Factors in
fi
−
R
+
Strains of Bacteria
Authors: Romero E. , Meynell Elinor
Published: January 2020

The presence of an
fi
−
sex factor can be detected by propagation of the I-specific phage If1. By use of this method of detection, a high proportion of strains with
fi
+
R factors were shown also to carry an
fi
−
factor which was frequently a second R factor. In some doubly R
+
strains, the
fi
+
and the
fi
−
factor were observed to be transferred independently at conjugation.
Morphological, Biochemical, and Serological Studies on 64 Strains of
Actinomyces israelii
Authors: Slack John M. , Landfried Sandra , Gerencser Mary A.
Published: January 2020

A comparative study of 64 strains of
Actinomyces israelii
was done with the use of techniques standardized by the Subgroup on Taxonomy of the Microaerophilic Actinomycetes. Emphasis was placed on the range of variation to assist recognition of clinical isolates and aid in differentiation from
Actinomyces
-like organisms. None of the strains was positive for catalase or indole, or in the Voges-Proskauer test; 90% were methyl red-positive and 62% were nitrate-positive. Acid was produced from: glucose (100%), xylose (100%), salicin (98%), raffinose (95%), lactose (89%), cellobiose (83%), mannose (78%), arabinose (76%), inositol (58%), mannitol (48%), starch (31%), glycogen (0%), glycerol (0%), and rhamnose (0%).
A. israelii
can be identified by the fluorescent-antibody method, but there is no single morphological or biochemical characteristic which can be used for its identification. By both fluorescent-antibody and gel-diffusion techniques, the serological classification of
A. israelii
group D with serotypes 1 and 2 was verified. Eleven serotype 2 strains were compared morphologically, biochemically, and serologically with 53 serotype 1 strains. All but two of the serotype 2 strains produced viscous growth in broth and none fermented arabinose.
Factors Affecting the Intracellular Parasitic Growth of
Bdellovibrio bacteriovorus
Developing Within
Escherichia coli
Authors: Seidler Ramon J. , Starr Mortimer P.
Published: January 2020

A procedure for one-step growth experiments on
Bdellovibrio bacteriovorus
growing parasitically in
Escherichia coli
B was developed. The resulting one-step growth curves showed that, under defined conditions at 30 C, each singly infected
E. coli
host cell, on the average, gave rise to 5.7
Bdellovibrio
cells. This value was confirmed by single-burst experiments and by microscopic observations. In the temperature range of 25 to 38 C, the average burst size and the duration of the latent period were inversely proportional to the temperature. The effect of hydrogen ion concentration on the one-step growth kinetics in this system indicated a broad
p
H optimum, ranging from neutrality to slightly alkaline
p
H values. After
Bdellovibrio
cells and host cells were mixed, there was always a delay (the so-called “lag phase”) before the parasite titer increased in terms of plaque-forming units. Phase-contrast microscopic observations indicated that this delay stems in part from the polyphasic nature of the
Bdellovibrio
life cycle. We propose the following five terms to make explicit the sequence of events in this life cycle: “attachment,” “penetration,” “elongation,” “fragmentation,” and “burst.” Nutritional experiments revealed that
Bdellovibrio
obtains a major fraction of its cellular components from host-cell material. Infection of
E. coli
by
Bdellovibrio
without added Mg
++
or Ca
++
(0.003
m
Mg
++
, 0.002
m
Ca
++
) resulted in partial or total lysis of the host cell soon after infection. Protoplast integrity was necessary for the normal completion of the intracellular growth phase of
Bdellovibrio
in
E. coli
; normal development of the parasite took place only in the presence of Mg
++
or Ca
++
.
Ultrastructure of
Nitrobacter agilis
Grown Under Autotrophic and Heterotrophic Conditions
Authors: Pope L. M. , Hoare D. S. , Smith A. J.
Published: January 2020

Nitrobacter agilis
, grown through seven transfers heterotrophically in the absence of nitrite, was examined in the electron microscope. The ultrastructure of such cells closely resembled that of autotrophically grown
N. agilis
. It was thus futher established that the organisms growing heterotrophically were indeed
N. agilis
and, therefore, that
N. agilis
is a facultative autotroph. Acetate incorporation into poly-β-hydroxybutyrate was confirmed cytologically.
Isolation and Partial Characterization of a Staphylococcal Leukocyte Cytotaxin
Authors: Walker W. S. , Barlet R. L. , Kurtz H. M.
Published: January 2020

A factor which attracts rabbit polymorphonuclear leukocytes both in vitro and in vivo was isolated from the culture filtrate of a strain ofStaphylococcus aureus. The activity of the chemotactic factor was independent of fresh serum and it was nondialyzable. Incubation of the factor with heat-inactivated human serum markedly inhibited its chemotactic property. The factor was heat-labile (80 C, 10 min) in the crude culture filtrate but was heat-stable when partially purified.
Effect of Endotoxin and Cortisone on Synthesis of Ribonucleic Acid and Protein in Livers of Mice
Authors: Shtasel Thelma F. , Berry L. Joe
Published: January 2020

The effect of cortisone and endotoxin, singly and in combination, on ribonucleic acid (RNA) synthesis in livers of adrenalectomized mice was determined. This was accomplished by measuring the incorporation either of inorganic
32
P or of
14
C-orotic acid into the RNA. Under similar conditions, the effect of these agents on the rate of protein synthesis was examined with the use of
14
C-leucine. Bacterial endotoxin was found to augment the uptake of isotope in the RNA and in the protein of the liver. These reactions did not appear to be mediated via the pancreatic hormone insulin, which was found to depress the incorporation of the radioactive compounds into RNA. Cortisone increased the uptake of isotope in liver RNA but depressed the incorporation of leucine into hepatic protein. These results indicate that the previously observed ability of endotoxin to prevent the hormone induction of hepatic enzymes, such as tryptophan oxygenase, is not associated with impaired synthesis of liver RNA or protein.
Number of Transformable Units Per Cell in
Diplococcus pneumoniae
Authors: Porter Ronald D. , Guild W. R.
Published: January 2020

Analysis of frequencies of single and random multiple transformations in
Diplococcus pneumoniae
showed that there are
at least two
transformable units per cell of the
total
population in highly competent cultures. If 100% of the cells are competent in these cases, the units may be interpreted as the strands of one duplex deoxyribonucleic acid recipient chromosome. The theory is developed to allow for extension to more complex situations.
Enteric Pathogens in Monkeys
Authors: Good Robert C. , May Bessie D. , Kawatomari Toshio
Published: January 2020

From 1964 to 1967, 6,646 monkeys, representing 10 primate species, were examined for
Shigella
and
Salmonella
infections upon arrival at the National Center for Primate Biology. Of these animals, 12% were infected with
Shigella
, and 75% of the
Shigella
isolates were
S. flexneri
4. The incidence of
Salmonella
infections decreased from 12 to 3% during the period of study. Epidemiological studies of animals in the colony for 90 days or more indicated no seasonal variation in the occurrence of
Shigella
and
Salmonella
. Many of the isolates from incoming monkeys as well as from laboratory-conditioned animals were resistant to chloramphenicol, dihydrostreptomycin, and tetracycline. The possible operation of drug-resistance factors in these infections is discussed.
Genetic Analysis of the Glutamate Permease in
Escherichia coli
K-12
Authors: Marcus Menashe , Halpern Yeheskel S.
Published: January 2020

The glutamate permeation system in
Escherichia coli
K-12 consists of three genes:
gltC, gltS
, and
gltR
. The genes
gltC
and
gltS
are very closely linked, and are located between the
pyrE
and
tna
loci, in the following order:
tna, gltC, gltS, pyrE; gltR
is located near the
metA
gene. The three
glt
genes constitute a regulatory system in which
gltR
is the regulator gene responsible for the formation of repressor,
gltS
is the structural gene of the glutamate permease, and
gltC
is most probably the operator locus. The synthesis of glutamate permease is partially repressed in wild-type K-12 strains, resulting in the inability of these strains to utilize glutamate as the sole source of carbon. Derepression due to mutation at the
gltC
locus enables growth on glutamate as a carbon source both at 30 C and at 42 C. Temperature-sensitive
gltR
mutants capable of utilizing glutamate for growth at 42 C but not at 30 C were found to be derepressed for glutamate permease when grown at 42 C and partially repressed (wild-type phenotype) upon growth at 30 C. These mutants produce an altered thermolabile repressor which can be inactivated by mild heat treatment (10 min at 44 C) in the absence of growth.
Dark Recovery Processes in
Escherichia coli
Irradiated with Ultraviolet Light II. Effect of
uvr
Genes on Liquid Holding Recovery
Authors: Ganesan Ann K. , Smith Kendric C.
Published: January 2020

The
uvr
mutations of
Escherichia coli
K-12 decrease the ability of cells to survive ultraviolet light (UV), to excise pyrimidine dimers from their deoxyribonucleic acid and to reactivate bacteriophage exposed to UV. The
rec
mutations decrease the ability of the cells to survive UV and to undergo genetic recombination. Certain
rec
mutations, including
recA1, rec-12, recA13
, and
rec-56
, are necessary for the expression of liquid-holding recovery (LHR), observed as an increase in colony-forming ability when irradiated cells are held in buffer in the dark. These
rec
mutations appear to act indirectly to permit the detection of LHR rather than to affect its occurrence directly. We have tested the effect of
uvr
markers on LHR in cells containing one of these
rec
mutations. Recombinants containing
rec-56
together with a
uvr
marker were constructed and tested for LHR. None of the 39 recombinants examined, carrying
uvrA6, uvrB5
, or
uvrC34
, showed LHR. Three
rec
−
uvr
−
strains were also tested for photoreactivation. In all three, photoreactivation was observed, indicating that they contained detectable amounts of pyrimidine dimers. Our results are consistent with the idea that
uvr
mutations inactivate LHR, and suggest that LHR reflects excision-dependent repair of pyrimidine dimers.
Target Analysis of Mitochondrial Genetic Units in Yeast
Authors: Allen N. E. , MacQuillan Anthony M.
Published: January 2020

Target analyses of the induction of ρ
−
mutants indicated that the cytoplasm of an aerobic nonrepressed yeast contains approximately 20 mutable units, whereas repressed cells exhibit approximately 3. Aerobic adaptation of fully repressed cells brings about an increase in these cytoplasmic units which continues after maximal respiration has been reached. This increase can be correlated with the increase in numbers of stained mitochondria. The data are interpreted with reference to mitochondrial deoxyribonucleic acid.