bluuebunny/crossref_metadata_2025 huggingface dataset:
Lethal Toxin of
Bacillus cereus
I. Relationships and Nature of Toxin, Hemolysin, and Phospholipase
Authors: Johnson Charles E. , Bonventre Peter F.
Published: January 2020

Bacillus cereus
phospholipase was characterized as a phospholipase C by the analysis of lecithin degradation products by thin-layer and paper chromatography. Methanol in the growth menstruum inhibited completely the synthesis of phospholipase C, whereas the synthesis of lethal toxin and hemolysin were only partially inhibited. Dialysis of preformed
B. cereus
products against ethyl alcohol and methanol did not inactivate hemolytic, phospholipase C, or lethal activity. The hemolytic and lethal activities of culture filtrates were completely abolished by trypsin, but phospholipase C activity was resistant to inactivation. Lethal and phospholipase C properties of culture filtrates were resistant to inactivation at 45 C, whereas the hemolytic activity was completely destroyed. Lethal, hemolytic, and phospholipase C activities appeared simultaneously in a complex growth menstruum, but the kinetics of synthesis were different in all cases. Resolution of
B. cereus
filtrates on columns of Sephadex showed that the phospholipase C, hemolysin, and lethal toxin are distinct proteins. Evidence is also presented which suggests a correlation between the synthesis of
B. cereus
toxin and the period of transition from vegetative growth to sporulation. The activity of each
B. cereus
product was cation-independent, as opposed to cation-dependency of the phospholipase C and lethal activities of
Clostridium perfringens
α-toxin. Immunological cross-reactivity between the
B. cereus
products and
C. perfringens
α-toxin was not apparent; indeed, they were shown to be antigenically distinct.
Formation of Adenosine Cyclic 3′,5′-Phosphate by Nonproliferating Cells and Cell-free Extract of
Brevibacterium liquefaciens
Authors: Ide Misao , Yoshimoto Akihiro , Okabayashi Tadashi
Published: January 2020

The formation of adenosine cyclic 3′,5′-phosphate by
Brevibacterium liquefaciens
ATCC 14929 was studied with the use of nonproliferating cells and cell-free extract. With nonproliferating cells provided by deprivation of sulfate, the formation of this nucleotide was accelerated by adding some amino acids and sugars. Among amino acids tested, alanine and asparagine were most effective. Pentoses were more favorable than hexoses and other sugars. Formation of adenosine cyclic 3′,5′-phosphate was observed also with chloramphenicol-treated cells. Experiments on cell-free extract showed that addition of alanine or pyruvate stimulated the formation of adenosine cyclic 3′,5′-phosphate from adenosine-5′-triphosphate. When alanine was added to the cell-free system, shaking of the reaction mixture further increased the amount of the nucleotide, but pyruvate was far more effective than alanine. No synergistic effect of alanine and pyruvate was observed. Some enzyme activity was observed which decomposed adenosine cyclic 3′,5′-phosphate, but it was weak as compared with adenyl cyclase activity in the presence of pyruvate. From the results obtained, it appears that pyruvate may act as an activating factor of adenyl cyclase in
Brevibacterium liquefaciens
.
Thiamine-dependent Accumulation of Tetramethylpyrazine Accompanying a Mutation in the Isoleucine-Valine Pathway
Authors: Demain A. L. , Jackson M. , Trenner N. R.
Published: January 2020

A mutant of
Corynebacterium glutamicum
was found to accumulate high concentrations of a material which crystallized upon cooling of the broth. The compound was identified as tetramethylpyrazine. The mutant was found to require isoleucine, valine, leucine, and pantothenate for growth. All four requirements probably result from the loss of a single enzyme of the isoleucine-valine pathway. Since similar mutants of
Neurospora crassa
accumulate acetoin, the present mutant probably forms tetramethylpyrazine from acetoin. Accumulation of tetramethylpyrazine was dependent upon addition of thiamine. This observation is consistent with the known activity of diphosphothiamine as a cofactor for the formation of acetolactate (a precursor of acetoin) from pyruvate.
14
C Incorporation into the Fatty Acids and Aliphatic Hydrocarbons of
Sarcina lutea
Authors: Tornabene T. G. , Oró J.
Published: January 2020

An initial investigation into the mechanism of hydrocarbon biosynthesis in
Sarcina lutea
was performed by measuring the amounts of
14
C incorporated into the hydrocarbons and fatty acids by use of a combination gas chromatograph and high-temperature gas-flow ionization apparatus. Uniformly labeled
l
-isoleucine-
14
C
was predominantly incorporated into the anteiso-branched chains. Palmitate-
16
-
14
C
gave evidence that a direct correlation may exist between the nonpolar end of the palmitate and the biosynthesis of hydrocarbons and carotenoids. The label from palmitate-
1
-
14
C
was incorporated into the various hydrocarbon groups as a compound, derived from the polar end of the palmitate, consisting of more than two carbon atoms. Palmitate-
16
-
14
C
and -
1
-
14
C
gave no detectable evidence that transformed products were incorporated into other fatty acids. Sodium acetate-
2
-
14
C
and uniformly labeled
l
-leucine-
14
C
gave evidence of a nonspecific incorporation into both the aliphatic hydrocarbons and fatty acids of
Sarcina lutea
.
Suppression of Radiation Sensitivity and Capsular Polysaccharide Synthesis in
Escherichia coli
K-12 by Ochre Suppressors
Authors: Markovitz Alvin , Baker Bruce
Published: January 2020

A class of suppressors effective on nonsense polarity mutations suppresses several independent mutations in a gene (
capR
) that controls ultraviolet-radiation sensitivity and capsular polysaccharide synthesis. Since these ochre suppressors function at the level of translation of messenger ribonucleic acid into protein, the results provide evidence that the product of the
capR
gene is a protein.
Segregation of Deoxyribonucleic Acid in Bacteria: Association of the Segregating Unit with the Cell Envelope
Authors: Chai Ning-Chun , Lark Karl G.
Published: January 2020

Cells of the gram-positive organism
Lactobacillus acidophilus
R-26 were labeled with
3
H-thymine to measure the segregation of radioactive deoxyribonucleic acid (DNA) into daugher cells. Such cells were found to contain 8 conserved units of DNA which would correspond to two replicating chromosomes per cell. Fluorescent antibody (FA) against this organism was used to demonstrate that portions of the cell surface (2 to 4 units per cell) were conserved during growth and division. The permanent association of DNA with these conserved cell surface units was measured by combining autoradiography with FA techniques. DNA synthesized immediately before FA labeling was not associated with the fluorescent cell surface, whereas DNA synthesized a generation previously was. The results are consistent with a model in which DNA becomes permanently fixed to the cell surface when it is first used as a template.
Fine Structure of the Cytomembranes of
Nitrosocystis oceanus
Authors: Remsen Charles C. , Valois Frederica W. , Watson Stanley W.
Published: January 2020

Thin-sectioned, negatively stained, and freeze-etched preparations of
Nitrosocystis oceanus
cytomembranes were compared. The cytomembranes in freeze-etched cells were covered with 80- to 120-A particles. When cells were disrupted and differentially centrifuged, various membrane and particle fractions were obtained. Negatively stained membrane fragments from the pellet centrifuged at 3,000 ×
g
showed 70- to 80-A stalked particles, whereas those from the pellet centrifuged at 39,000 ×
g
exhibited a crystalline array of subunits with a 30- to 40-A periodicity. High-speed supernatant and pellet fractions centrifuged at greater than 39,000 ×
g
contained 40- to 120-A free particles but no membranes. In chemically fixed cells, 40-A particles were found embedded in the matrix of membranes. Results suggest that the larger 80- to 120-A particles are enzyme complexes, whereas the smaller 30- to 40-A particles represent a structural protein or a lipoprotein of the membrane.
Metabolic Requirements for Microcycle Sporogenesis of
Bacillus megaterium
Authors: Holmes P. K. , Levinson Hillel S.
Published: January 2020

Spores of
Bacillus megaterium
QM B1551 germinated, elongated, and resporulated (microcycle sporogenesis) in simple chemically defined media which permitted no cell division. The second-stage spores thus produced were heat-stable and required heat activation for germination. The original amount of spore deoxyribonucleic acid tripled before completion of the cycle. Acetate and a small amount of a tricarboxylic acid cycle intermediate were the minimal organic metabolic requirements for microcycle sporogenesis. During this cycle, germinated cells oxidized acetate only after a delay, whether or not glucose was initially present. Spores that were germinated in the absence of a carbon source first oxidized an endogenous substrate, and then developed the ability to oxidize acetate.
Separation of Two Functional Roles of
l
-Alanine in the Initiation of
Bacillus subtilis
Spore Germination
Authors: Wax Richard , Freese Ernst , Cashel Michael
Published: January 2020

Spores of the standard transformable Marburg strain of
Bacillus subtilis
can be initiated to germinate by
l
-alanine alone. We isolated mutants which required for this process, in addition to
l
-alanine, the combination of
d
-glucose +
d
-fructose + K
+
or NH
4
+
ions. In place of fructose, autoclaved or caramelized glucose could be used. Even the standard type strain required the addition of these three agents when
d
-alanine was present or when the temperature was raised. These findings show that
l
-alanine normally performs two functions during initiation, one of which is absent in the mutants or is blocked by
d
-alanine or elevated temperature. One of our mutants was not absolutely dependent on the addition of external
l
-alanine, because it could be initiated at a reduced rate by the sole addition of glucose + K
+
or NH
4
+
. When K
+
or NH
4
+
was replaced by Na
+
, the initiation rate was greatly reduced. The divalent metal ions Mg
++
, Mn
++
, and Ca
++
could not satisfy the cation requirement.
Volatile Fatty Acid Requirements of Cellulolytic Rumen Bacteria
Authors: Dehority B. A. , Scott H. W. , Kowaluk Patricia
Published: January 2020

A gas chromatographic method was developed which could separate the isomers isovaleric and 2-methylbutyric acid. Subsequent analyses revealed that most commercially available samples of these acids were cross-contaminated; however, one sample of each acid was found to be pure by this criterion. The growth response of seven strains of cellulolytic rumen bacteria (three strains of
Bacteroides succinogenes
, three strains of
Ruminococcus flavefaciens
, and one strain of
R. albus
) to additions of isobutyric, isovaleric, 2-methylbutyric, valeric, and combinations of valeric and a branched-chain acid was determined. Strains of
B. succinogenes
required a combination of valeric plus either isobutyric or 2-methylbutyric acid. Isovaleric acid was completely inactive. Either isobutyric or 2-methylbutyric acid was required for the growth of
R. albus
7. Strain C-94 of
R. flavefaciens
grew slowly in the presence of any one of the three branched-chain acids, but a combination of isobutyric and 2-methylbutyric acids appeared to satisfy this organism's growth requirements. None of the individual acids or mixtures of straight- and branched-chain acids allowed growth of
R. flavefaciens
strain C1a which would approach the response obtained from the total mixture of acids. Further work indicated that all three branched-chain acids were required for optimal growth by this strain, although isovaleric acid only influenced the rate of maximal growth. Either 2-methylbutyric or isovaleric acid allowed growth of nearly the same magnitude as that of the positive control for
R. flavefaciens
B34b. The presence of acetic acid had little influence on the rate or extent of growth of any of the strains except
R. albus
7, for which the extent of growth was markedly increased. Determination of the quantitative fatty acid requirements for the three
B. succinogenes
strains indicated that 0.1 μmole of valeric per ml and 0.05 μmole of 2-methylbutyric per ml permitted maximal growth. However, with isobutyric acid as the branched-chain component, strains A3c and B21a required 0.1 μmole/ml in contrast to S-85 which exhibited optimal growth at the 0.05 μmole/ml level. By use of mixtures of isobutyric and 2-methylbutyric acids, good growth of C-94 was obtained at concentrations of 0.1 and 0.01 μmole/ml, respectively. About 0.3 μmole/ml of each acid was required for satisfactory growth of C1a.
Relationship Between Sulfadiazine Resistance and the Failure to Ferment Maltose in
Neisseria meningitidis
Authors: Kingsbury David T.
Published: January 2020

The genetic marker for sulfadiazine resistance was transferred by means of purified deoxyribonucleic acid from sulfadiazine-resistant
Neisseria meningitidis
and
N. perflava
to a sulfadiazine-sensitive strain of
N. meningitidis
. Over 80% of the isolates from these experiments, selected on the basis of sulfadiazine resistance, failed to produce acid from maltose. The same proportion of naturally occurring isolates that are sulfadiazine-resistant failed to ferment maltose. The enzymatic block in 17 isolates tested was the loss of maltose permease activity; in two cases, maltose phosphorylase activity was lost also. The permease was present in these cells, however, and could be activated by the addition of sulfadiazine. The results obtained support the hypothesis that these organisms, in becoming resistant to sulfadiazine, have undergone a single mutation.
Development of Competence in the
Bacillus subtilis
Transformation System
Authors: Bott Kenneth F. , Wilson Gary A.
Published: January 2020

Competence in
Bacillus subtilis
, assayed by the ability of cells to be transformed with bacterial deoxyribonucleic acid (DNA) or transfected by phage DNA, has been shown to occur in a single semisynthetic medium with peak activity occurring 3 hr after the cessation of logarithmic growth. No step-down conditions or culture manipulations were necessary for routine transfection of 1% of the population. The results demonstrate that bacteriophage DNA is a valid assay for studying the development of competence in
B. subtilis
. Predictions of workers using transforming bacterial DNA, who have suggested that competence in
B. subtilis
is associated with a specific phase of growth, are substantiated. The peak of competence is not affected by marked differences in the rate of growth during the logarithmic phase. The effect on development of competence by this procedure of some components (including casein hydrolysate, tryptophan, and histidine) which were routinely included in the transformation medium by other investigators has been determined by use of infectious phage DNA as an assay. We have demonstrated that tryptophan, as well as histidine, increases the transformation frequency—even in strains which do not have auxotrophic demands for these components. Glutamic acid and alanine depress optimal levels of transfection.
Mutants of Yeast Sensitive to Ultraviolet Light
Authors: Snow Richard
Published: January 2020

Six
uvr
mutants of
Saccharomyces cerevisiae
with hypersensitivity to ultraviolet (UV) light were isolated after mutagen treatment with ethylmethanesulfonate. UV sensitivity ranges from moderate to extreme, and four of the mutants are also sensitive to nitrous acid. Ranking in terms of UV sensitivity does not parallel ranking in terms of nitrous acid sensitivity. Homozygous diploid mutant strains are somewhat less sensitive than the corresponding haploids. All mutations are recessive. None of the mutants is sensitive to γ rays, and each shows photoreactivation after UV radiation. Complementation tests and tetrad analysis indicate that each strain represents mutation in a different gene. Two of the
uvr
genes are linked, and two others are centromere-linked.
Failure of Bacterial Endotoxin to Produce the Generalized Shwartzman Reaction in the Syrian Hamster
Authors: Merritt Katharine , Galton Michael
Published: January 2020

The ability of bacterial endotoxin to produce the generalized Shwartzman reaction (GSR) in pregnant and nonpregnant hamsters was investigated. Endotoxins prepared fromEscherichia coliO127:B8,Salmonella enteritidis, andS. typhosa0-901 did not produce the GSR in nonpregnant hamsters. Injection of lead acetate did not make the hamsters susceptible to the GSR producing effects of endotoxin. Endotoxin administered to hamsters on either or both the 14th and 15th day of the 16-day gestation period caused fetal death, but did not provoke the GSR. The immunization of hamsters with boiled suspensions of gram-negative bacteria isolated from hamster feces did not protect against the GSR produced in pregnant hamsters by the injection of the antimitotic drug colchicine late in the gestation period. It appeared that colchicine was acting to produce the GSR by a mechanism other than the release of endogenous endotoxin through the damaged intestinal wall. Ascitic fluid, amniotic fluid, and serum obtained from pregnant hamsters developing the GSR after the administration of colchicine did not provoke the GSR in other pregnant hamsters.
In Vivo Growth and Distribution of Anthrax Bacilli in Resistant, Susceptible, and Immunized Hosts
Authors: Jones William I. , Klein Frederick , Walker Jerry S. , Mahlandt Bill G. , Dobbs James P. , Lincoln Ralph E.
Published: January 2020

Differences in in vivo growth rates of
Bacillus anthracis
in the bodies of infected rats and guinea pigs showed the effect of innate species resistance. The effect of two levels of immunity imposed on these hosts demonstrated that, as the degree of immunity increased, the growth rate of organisms decreased and was accompanied by a decrease in terminal population. It was shown that growth rates in the blood best reflected the population growth in the entire host. Data obtained from the naturally resistant rat that had been immunized with both the Belton-Strange protective antigen and live vaccine demonstrated the role of “toxins” in terminal anthrax. The in vivo morphological changes in anthrax bacilli pointed out errors regarding estimates of true terminal population of organisms when samples for counting were taken postmortem rather than at the time of death.
Sphere-Rod Morphogenesis in
Arthrobacter crystallopoietes
II. Peptides of the Cell Wall Peptidoglycan
Authors: Krulwich Terry A. , Ensign Jerald C. , Tipper Donald J. , Strominger Jack L.
Published: January 2020

Cell walls of
Arthrobacter crystallopoietes
grown as spheres and as rods were solubilized by treatment with the B enzyme from
Chalaropsis
, an
N
-acetylmuramidase. The neutral glycopeptides were then isolated by chromatography on ECTEOLA cellulose. The glycopeptides, consisting of disaccharide-peptide units interlinked by peptide cross-bridges, were fractionated by gel filtration on Sephadex columns into oligomers of various sizes. The size distribution ranged from monomers with no cross-bridges to polymers with a high degree of polymerization, but did not differ significantly between cell walls from cells grown as spheres or rods. Some small differences in the distribution of C- and N-terminal amino acids were found. Analyses revealed that all the peptide bridges in the glycopeptide fractions from rod cell walls were formed by one
l
-alanine residue. In sphere cell walls,
l
-alanine was also found, but, in addition, higher oligomers of the glycopeptide contained glycine in their cross-bridges. These results were confirmed by determinations of C- and N-terminal amino acids released after lysostaphin and AL-1 enzyme digestions and by Edman degradations. Models representing the structures of the sphere and rod cell walls are presented. These structures indicate that the sphere cell wall is probably a more loosely knit macromolecule than is the rod cell wall.
Evidence for the Calvin Cycle and Hexose Monophosphate Pathway in
Thiobacillus ferrooxidans
Authors: Gale Nord L. , Beck Jay V.
Published: January 2020

The enzymes of the Calvin reductive pentose phosphate cycle and the hexose monophosphate pathway have been demonstrated in cell-free extracts of
Thiobacillus ferrooxidans
. This, together with analyses of the products of CO
2
fixation in cell-free systems, suggests that these pathways are operative in whole cells of this microorganism. Nevertheless, the amount of CO
2
fixed in these cell-free systems was limited by the type and amount of compound added as substrate. The inability of cell extracts to regenerate pentose phosphates and to perpetuate the cyclic fixation of CO
2
is partially attributable to low activity of triose phosphate dehydrogenase under the experimental conditions found to be optimal for the enzymes involved in the utilization of ribose-5-phosphate or ribulose-1,5-diphosphate as substrate for CO
2
incorporation. With the exception of ribulose-1,5-diphosphate, all substrates required the addition of adenosine triphosphate (ATP) or adenosine diphosphate (ADP) for CO
2
fixation. Under optimal conditions, with ribose-5-phosphate serving as substrate, each micromole of ATP added resulted in the fixation of 1.5 μmoles of CO
2
, whereas each micromole of ADP resulted in 0.5 μmole of CO
2
fixed. These values reflect the activity of adenylate kinase in the extract preparations. The
K
m
for ATP in the phosphoribulokinase reaction was 0.91 × 10
−3
m
. Kinetic studies conducted with carboxydismutase showed
K
m
values of 1.15 × 10
−4
m
and 5 × 10
−2
m
for ribulose-1,5-diphosphate and bicarbonate, respectively.
Function of the Glyoxylate-condensing Enzymes I. Growth of
Escherichia coli
on
n
-Valeric Acid
Authors: Furmanski Philip , Wegener Warner S. , Reeves Henry C. , Ajl Samuel J.
Published: January 2020

Growth of
Escherichia coli
E-26 on valeric acid results in the formation of a mutant population characterized by the ability to form constitutively several glyoxylate-condensing enzymes. This mutant also differs from the parent organism in the ability to effect rapid growth on a series of short-chain fatty acids. These mutants were utilized in postulating genetic relationships among the various glyoxylate-condensing activities and also in correlating the presence of these enzymes with the ability of the mutants to initiate growth quickly on short-chain fatty acids.
Effects of Mitomycin C and Thymidine Deprivation on Lysogenic and Sensitive Strains of
Bacillus megaterium
Authors: Maisch W. F. , Wachsman J. T.
Published: January 2020

A triple auxotroph of
Bacillus megaterium
strain KM was lysogenized with a phage suspension from
B. megaterium
899a. The lysogenic and phage-sensitive derivatives of KM were found to die at the same exponential rate during thymineless incubation, despite the fact that the lysogenic strain became induced. The lysogenic strain was also induced by mitomycin C, and died at an exponential rate which was approximately twice that of the sensitive strain. With both strains, the lethality of mitomycin C was the same in the presence and absence of thymidine; thymidine was required for maximal phage production. Mitomycin C preferentially inhibited deoxyribonucleic acid (DNA) synthesis of both strains for the first 60 min. The (DNA) synthetic ability of the lysogenic strain was subsequently restored, due to phage production. Since there was no evidence that sensitive strains of KM contained other inducible elements (prophage or probacteriocins), it is concluded that both thymineless death and mitomycin C death can occur via mechanisms not involving induction.
Unrelatedness of
Bacillus amyloliquefaciens
and
Bacillus subtilis
Authors: Welker N. E. , Campbell L. Leon
Published: January 2020

Eight strains of highly amylolytic, sporeforming bacilli (hereafter referred to as
Bacillus amyloliquefaciens
) were compared with respect to their taxonomic relationship to
B. subtilis
. The physiological-biochemical properties of these two groups of organisms showed that
B. amyloliquefaciens
differed from
B. subtilis
by their ability to grow in 10% NaCl, characteristic growth on potato plugs, increased production of α-amylase, and their ability to ferment lactose with the production of acid. The base compositions of the deoxyribonucleic acid (DNA) of the
B. subtilis
strains consistently fell in the range of 41.5 to 43.5% guanine + cytosine (G + C), whereas that of the
B. amyloliquefaciens
strains was in the 43.5 to 44.9% G + C range. Hybrid formation between
B. subtilis
W23 and
B. amyloliquefaciens
F DNA revealed only a 14.7 to 15.4% DNA homology between the two species. Transducing phage, SP-10, was able to propagate on
B. subtilis
W23 and
B. amyloliquefaciens
N, and would transduce
B. subtilis
168 (indole
−
) and
B. amyloliquefaciens
N-10 (arginine
−
) to prototrophy with a frequency of 3.9 × 10
−4
and 2.4 × 10
−5
transductants per plaque-forming unit, respectively. Attempts to transduce between the two species were unsuccessful. These data show that
Bacillus amyloliquefaciens
is a valid species and should not be classified as a strain or variety of
B. subtilis.
Physical States of Staphylococcal α-Toxin
Authors: Arbuthnott John P. , Freer John H. , Bernheimer Alan W.
Published: January 2020

At least three different forms of staphylococcal α-toxin have been shown to exist: soluble active α-toxin (α 3S), soluble inactive α-toxin (α
12s
), and insoluble inactive aggregate. Aggregation to the insoluble, biologically inactive form could be induced by brief heating to 60 C. The aggregate was dissociated by treatment with 8
m
urea with reappearance of biological activity. Subsequent removal of urea by dialysis resulted in some spontaneous reaggregation to the insoluble state. The supernatant fluid obtained after dialysis contained soluble active α-toxin of high specific activity, possessing physical, toxic, and immunological properties closely resembling those of native toxin. The soluble biologically inert component (α
12s
) was identified as a third physical state. Negatively stained preparations of this material, when examined in the electron microscope, showed rings of approximately 100 A outside diameter containing 6 ± 1 subunits.
Fine-Structure Analysis of Intercellular and Intracellular Mitochondrial Diversity in
Saccharomyces cerevisiae
Authors: Federman Micheline , Avers Charlotte J.
Published: January 2020

Crosses were made between haploid wild-type and suppressive petite strains of bakers' yeast to obtain zygotes for analysis of mitochondrial heterogeneity. Wild-type × petite zygotes contained about 40% noncristate mitochondria when immediate mating mixtures were examined. The frequency of defective mitochondria had decreased to an average of 9.2% in 1-week-old zygote isolate cultures, and to 4.4% in slant cultures 1.5 years after initial zygote isolation. The latter value was not significantly different from values obtained with wild × wild zygotes of either age. The noncristate mitochondria were of two types: one lacking inner membrane invaginations or elaborations and the other containing concentrically arranged loops of inner membrane. The significance of these two types of respiration-deficient mitochondria is unknown. The gradual decrease in frequency of noncristate mitochondria, perhaps due to selection pressures in mixed chondriomes, was discussed as a further indication of the semiautonomous nature of the yeast organelle.
Factors Affecting Reproducibility of Numerical Classifications
Authors: Lockhart W. R.
Published: January 2020

Results obtained with reference organisms which had been included in each of three different investigations were compared. Positions of the reference organisms in diagrams based on highest-link numerical groupings varied with the composition of the microbial samples studied, but significant correlations were found between the results of different investigations. Correlations between the overall groupings obtained in different studies were often better than the correlations between actual similarity values computed between specific pairs of organisms. Similarity values based on different sets of features showed significant correlations, regardless of the kinds of features involved or of the number of features (above a minimum of about 40). Correlations between values based on totally different features were nearly as good as those between values based on similar features which had been determined by different investigators.
Experimental Salmonellosis X. Cellular Immunity and Its Antibody in Mouse Mononuclear Phagocytes
Authors: Kurashige Satonori , Osawa Nobutaka , Kawakami Masaya , Mitsuhashi Susumu
Published: January 2020

A cell-associated antibody was detected in the peritoneal mononuclear phagocytes (referred to as monocytes) of mice hyperimmunized with live vaccine ofSalmonella enteritidis, by use of immune transfer and immune adherence hemagglutination techniques. The cellular antibody inhibited the growth of a virulent strain ofS. enteritidiswith the aid of complement and lysozyme on nutrient agar plates. This type of bactericidal antibody could not be detected in the monocytes of mice immunized with killed vaccine ofS. enteritidis. The antibody extracted from the peritoneal monocytes of mice hyperimmunized with live vaccine was identified as a macroglobulin by ultracentrifugal analysis.
Regulation of Glutamine Synthetase X. Effect of Growth Conditions on the Susceptibility of
Escherichia coli
Glutamine Synthetase to Feedback Inhibition
Authors: Kingdon Henry S. , Stadtman E. R.
Published: January 2020

The kinetic properties of
Escherichia coli
glutamine synthetase are markedly influenced by the manner in which the organism is grown. Enzyme obtained from stationary-phase cells grown on glycerol and glutamate is strongely inhibited by each of the eight feedback effectors known to influence this enzyme; however, the enzyme from log-phase cells grown on glucose and growth-limiting concentrations of NH
4
Cl is stimulated by some of these effectors. Of the growth variables examined, nitrogen source and time of harvest were the most important; carbon source and aeration seemed to have no effect. Two purified enzyme preparations have been obtained from cells grown under two different conditions, designated enzymes I and II for convenience. Enzyme I is stimulated by adenosine 5′-monophosphate, histidine, and tryptophan in the transfer assay, whereas enzyme II is strongly inhibited by all effectors tested. Enzyme I has a higher specific activity in the forward assay in the presence of Mg
++
or Co
++
, whereas enzyme II is more active in the presence of Mn
++
.
Reisolation of
Staphylococcus salivarius
from the Human Oral Cavity
Authors: Gordon D. F.
Published: January 2020

Twenty-four strains of gram-positive facultative cocci, arranged primarily in small clusters, were isolated from the surface of the human tongue. With the exception of 14 catalase-negative isolates, these strains were identical in cultural and biochemical characteristics and in deoxyribonucleic acid base composition. All cultures produced viscous growth in both liquid and agar media. They fermented glucose anaerobically, reduced nitrate beyond nitrite, were benzidine-positive, and failed to grow in the presence of 5% NaCl or at 45 C. In addition, they exhibited guanine plus cytosine (G + C) contents of 55.4 to 58.3%. These isolates differed from strains of pediococci, aerococci, and micrococci which were included for comparison. On the basis of G + C content, these organisms appear to be intermediate between micrococci and staphylococci; however, on the basis of anaerobic glucose fermentation, it is suggested that they be placed in the genus
Staphylococcus
. It is proposed that they be recognized as
S. salivarius
.
Mechanisms of Protection of Trehalase Against Heat Inactivation in
Neurospora
Authors: Yu Shih-An , Sussman Alfred S. , Wooley Susan
Published: January 2020

The half-life of trehalase and invertase at 65 and 60 C was found to be much greater when intact ascospores of
Neurospora tetrasperma
were heated, as compared with extracts. By contrast, no protection was afforded these enzymes when they were heated in intact conidia and mycelium of
N. crassa
or
N. tetrasperma
. The protective effect of ascospores for trehalase was further investigated by heating ascospore extracts before and after dialysis. The removal of small molecules by dialysis lowered the heat resistance of trehalase significantly in such extracts. When the dialysate from extracts of mycelium, conidia, or ascospores was added to dialyzed enzyme extracts, that from ascospores was by far the most active. However, the same dialysates had only a small protective effect on invertase. The addition of ashed dialysates did not protect trehalase, and trehalose and glucose protected less effectively than the dialysate.
Purification and Properties of Staphylococcal δ-Hemolysin I. Production of δ-Hemolysin
Authors: Murphy Richard A. , Haque Riaz-Ul
Published: January 2020

Concentrated preparations of staphylococcal δ-hemolysin were obtained by growing selected hemolytic colonies from the 146P strain of
Staphylococcus aureus
on dialysis membranes laid over Brain Liver Heart agar plates at 37 C for 20 hr under 10% CO
2
and harvesting the growth from five such membranes in 1.0 ml of deionized distilled water. Incubation in a humid environment facilitated this harvesting procedure. Incubation longer than 40 hr or incubation under CO
2
higher than 10 to 20% gave lower yields of δ-lysin. Addition of a sugar, fermented by the organisms, resulted in lower yields of δ-hemolysin. Agar, although separated from the growing cells by the dialysis membrane, did potentiate δ-hemolysin production. Addition of 0.1% agar to the inoculum further enhanced this potentiation. δ-Hemolysin produced in broth or semisolid cultures was excessively diluted with the media. Dialysis membranes prevented this dilution and thus yielded concentrated preparations of δ-hemolysin.
Lipopolysaccharides ofSalmonellaT Mutants
Authors: Wheat R. W. , Berst M. , Ruschmann E. , Lüderitz O. , Westphal O.
Published: January 2020

The composition of lipopolysaccharides derived from variousSalmonellaT forms was studied. All T1-form lipopolysaccharides examined contained 14 to 22% each of bothd-galactose and pentose in addition to 4 to 9% each of ketodeoxyoctonic acid, heptose,d-glucosamine, andd-glucose. The pentose was identified asd-ribose. The T2-form lipopolysaccharide examined did not contain a significant amount of pentose, nor more than the usual amounts ofd-galactose. Periodate oxidation of T1 (lipo) polysaccharides followed by NaBH4reduction revealed that ribose was almost quantitatively protected, galactose was destroyed, and threitol and mannose were newly formed. The latter two products probably originated from 4-linked galactose and heptose, respectively. Ribose and galactose were found in specific precipitates of T1 lipopolysaccharide with anti-T1 antiserum but were not found in specific precipitates of alkali-treated T1 lipopolysaccharide and of Freeman degraded polysaccharide with anti-T1 serum Ribose and galactose are present in these degraded preparations in the form of nondialyzable polymers. The T1-form mutant lipopolysaccharides lacked the O-specific sugars constituting the side-chains in the wild-type antigens. They did not produce the soluble O-specific haptenic polysaccharide known to be accumulated in RI strains. With these properties, T1 lipopolysaccharides resemble RII lipopolysaccharides. Like RII degraded polysaccharides, T1-degraded polysaccharides also contained glucosamine. Furthermore, strong cross-reactions were found to exist between T1 and RII lipopolysaccharides in both hemagglutination inhibition assays and in precipitation tests. It is proposed that T1 lipopolysaccharides represent RII lipopolysaccharides to which polymers consisting of ribose and galactose are attached.
Characterization of Mycoplasma Strains from Cats
Authors: Cole B. C. , Golightly L. , Ward J. R.
Published: January 2020

Mycoplasma strains (B1, B2, CS, and S1A) were isolated from the saliva of normal cats. These were compared with a strain (CO) isolated from the eye of a cat with severe conjunctivitis. On the basis of morphology, biochemical reactions, and antigenic composition, two distinct species were recognizable. Strains CO, B1, and B2 were antigenically unrelated to the other species tested; strains CS and S1A possessed antigenic components in common withMycoplasma arthritidis, M. salivarium, M. hominis, type 1, andM. orale, types 1 and 2. It was tentatively suggested that the two cat species be calledM. felisandM. gateae, respectively.
Synchrony of Nuclear Replication in Individual Hyphae of
Aspergillus nidulans
Authors: Rosenberger R. F. , Kessel M.
Published: January 2020

The synchrony of nuclear replication in individual, multinucleate hyphae of
Aspergillus nidulans
has been investigated. Samples were taken from cultures of germinating conidiospores, and the relative frequency of hyphae containing two to eight nuclei was determined. Because the conidiospores are mononucleate, complete synchrony will yield populations of hyphae containing only 2
n
nuclei,
n
being the number of doublings after germination. The appearance of hyphae with total numbers of nuclei other than 2
n
will indicate lack of synchrony. The relative frequency of hyphae not having 2
n
nuclei will depend on the degree of synchrony in the individual hyphae; numerical aspects of this relation are discussed. In two different strains, replication of the nuclei in any one hypha was highly synchronized when the dry weight doubling time was 1.4 to 1.8 hr. As the doubling time was made longer by changing the nitrogen or carbon source, synchrony was progressively lost. At the slowest growth rate tested, the interval between the division of the fastest and the slowest nucleus equaled 48% of the dry weight doubling time. The active replication of some nuclei in a hypha where other nuclei were resting suggested that nuclear duplication in this eukaryotic organism may be controlled by specific initiators.
Autolytic Enzyme System of
Streptococcus faecalis
III. Localization of the Autolysin at the Sites of Cell Wall Synthesis
Authors: Shockman Gerald D. , Pooley Harold M. , Thompson J. Stuart
Published: January 2020

Cell walls from exponential-phase cultures of
Streptococcus faecalis
ATCC 9790 autolyzed in dilute buffers. Walls were isolated from cultures grown in the presence of
14
C-lysine for about 10 generations and then on
12
C-lysine for 0.1 to 0.8 of a generation (prelabeled). These walls released
14
C to the soluble fraction more slowly than they lost turbidity during the initial stages of autolysis. Walls isolated from cultures grown in the presence of
14
C-lysine for only the last 0.1 to 0.4 of a generation (postlabeled) released
14
C to the supernatant fluid more rapidly than they lost turbidity. Autolysin in both pre- and postlabeled walls was inactivated, and such walls were then incubated in the presence of unlabeled walls containing active autolysin. The inactivated walls lost their
14
C label only very slowly until autolysis of the unlabeled walls was virtually complete and release of soluble autolysin was expected. When this experiment was done in the presence of trypsin, a fourfold increase in the autolysis rate resulted, but the same pattern of
14
C release was observed. A parallel release of
14
C and loss of turbidity from pre- or postlabeled walls was observed upon trypsin “activation” and by addition of isolated soluble autolysin to inactivated walls. We conclude that the wall-bound autolysin acts first on the more recently synthesized portion of the wall. Trypsin appears to speed wall autolysis by activating additional latent autolysin in situ at sites in the older portion of the wall.
Neuraminidase ofCorynebacterium diphtheriae
Authors: Moriyama Takafumi , Barksdale Lane
Published: January 2020

Neuraminidase activity has been found in a variety of strains ofCorynebacterium diphtheriae, both toxinogenic and nontoxinogenic. The enzyme has been shown to be intracellular, possibly associated with the cytoplasmic membrane. Toxinogenic strains of the diphtheria bacillus, grown under conditions unsuitable for maximal toxin production, produce neuraminidase, and the enzyme has been purified from cells of the Park Williams no. 8 strain grown under such conditions. Diphtherial toxin and diphtherial neuraminidase have similar molecular weights and remain associated during column chromatography; immunochemically, and in their electrophoretic behavior, they appear distinct.
Occurrence of Chloramphenicol-acetylating Enzymes in Various Gram-negative Bacilli
Authors: Okamoto Suyehiko , Suzuki Yoshiaki , Mise Katsutoshi , Nakaya Rintaro
Published: January 2020

The occurrence of a chloramphenicol-acetylating enzyme, similar to that found in
Escherichia coli
, carrying an R factor was investigated in various gram-negative bacilli. The acetylated products of chloramphenicol were identified by chromatography and quantitatively assayed after benzene extraction. The investigated strains were of the
Salmonella-Arizona
group, the
Klebsiella-Aerobacter
group,
Serratia marcescens
, the
Proteus
group, and
Pseudomonas aeruginosa
, most of which were isolated from 1947 to 1957. Both chloramphenicol-sensitive and -resistant strains were included, but none of them was able to transfer chloramphenicol resistance by conjugation. In the
Proteus
group, a significant level of a chloramphenicol-acetylating enzyme was found in most strains, whether they were sensitive or resistant to chloramphenicol; the resistant strains showed higher levels of the enzyme. Some chloramphenicol-sensitive strains lacked this enzyme. Only the sensitive strains containing the enzyme could easily produce chloramphenicol-resistant mutants with higher enzyme activity. Thus, the chloramphenicol resistance of this group can be reasonably explained on the basis of the chloramphenicol-acetylating enzyme. All of the
Pseudomonas aeruginosa
strains were resistant to chloramphenicol, and most strains showed low levels of the enzyme (which, however, did not appear sufficient to explain their resistance). All of the strains of the other groups (except one strain of
Enterobacter cloacae
) lacked the enzyme, although most strains of the
Klebsiella-Aerobacter
group and of
S. marcescens
were resistant to chloramphenicol. With respect to the origin of the resistance gene of the R factor, it is noteworthy that the strains of
Proteus mirabilis
isolated in 1947 possessed this enzyme before the discovery of chloramphenicol.
Aromatic Amino Acid Biosynthesis: Gene-Enzyme Relationships in
Bacillus subtilis
Authors: Nasser DeLill , Nester E. W.
Published: January 2020

Single step mutants of
Bacillus subtilis
which required either one or all of the aromatic amino acids for growth were isolated. The relevant gene defect was determined for each mutant by enzyme assays in vitro. A mutant deficient in each enzyme step of aromatic amino acid biosynthesis was found with the exceptions of the shikimate kinase and the phenylalanine and tyrosine transaminases. Representative mutants carrying the defective genes were mapped by deoxyribonucleic acid mediated transformation by reference to the aromatic amino acid gene (
aro
) cluster and, alternately, to any of the other unlinked
aro
genes. The genes coding for dehydroquinate synthetase, 3-enol pyruvylshikimate 5-phosphate synthetase, one form of chorismate mutase, and prephenate dehydrogenase are linked to the
aro
cluster. Except for the previously identified linkage between the genes of 3-deoxy-
d
-arabino heptulosonic acid 7-phosphate synthetase and one species of chorismate mutase, the other genes involved in this pathway are neither linked to the
aro
cluster nor to each other.
Association of Experimental Chronic Arthritis with the Persistence of Group A Streptococcal Cell Walls in the Articular Tissue
Authors: Schwab John H. , Cromartie William J. , Ohanian Sarkis H. , Craddock John G.
Published: January 2020

A single injection of isolated fragments of group A streptococcal cell walls into the joints of rabbits stimulated an initial acute reaction which was followed by a prolonged inflammatory process. The chronic process was characterized by hyperplasia of the synovial cells, diffuse infiltration of the villi by macrophages, and focal collections of lymphocytes in the stroma of the villi. These histological changes were similar to those seen in the early stages of rheumatoid arthritis. Antibodies specific for the mucopeptide and group-specific C polysaccharide antigens of group A streptococcal cell walls were labeled with either fluorescein or
125
I, and were used to demonstrate antigen in the synovial tissues. The antigens persisted within macro-phages for at least 5 weeks. Their presence correlated with the evolution of the chronic inflammatory process.
Effects of Oil-treated Mycobacterial Cell Walls on the Organs of Mice
Authors: Barclay William R. , Anacker Robert , Brehmer Werner , Ribi Edgar
Published: January 2020

Intravenous vaccination of mice with oil-treated mycobacterial cell walls resulted in a marked macrophage accumulation in the lungs and spleens of vaccinated animals. Injection of oil emulsion alone or of cell walls alone failed to elicit the macrophage response. Although a correlation existed between the magnitude of the macrophage response and the degree of immunity against aerosol challenge with H37Rv organisms, the findings presented here do not rule out the possibility that qualitative differences may be present in the macrophages of animals vaccinated against tuberculosis. The ability of oil-treated cell walls to elicit an immune response appeared to be a function of the physical association of cell wall fragments and the surface of oil droplets.
Ultrastructural Studies of Microconidium Formation in
Neurospora crassa
Authors: Lowry Robert J. , Durkee Thomas L. , Sussman Alfred S.
Published: January 2020

Microconidiating cultures of “peach-fluffy” (
pe, fl;
Y8743m, L; FGSC #569) were fixed at various times after the initiation of growth and examined with an electron microscope. Hyphae from which microconidia form are markedly vacuolated and show a much more extensive system of rough endoplasmic reticulum than young vegetative hyphae. A bulge in the hypha presages the start of microconidium formation, followed by the rupture of the outermost wall layers. A thick collar forms around the protruding microconidium due to extensive thickening of the inner wall layer of the parent hypha. At this stage, the cytoplasm of the developing microconidium is still continuous with that of the microsporophore cell from which it arises and is contained by a wall which is derived from the thickened collar. The microconidium is finally isolated from the cytoplasm of the microsporophore by a centripetal extension of the collar. Microconidia differ from macroconidia in having a more extensive endoplasmic reticulum and fewer mitochondria, in addition to being smaller and having a single nucleus.
Identification of a Fourth Staphylococcal Enterotoxin, Enterotoxin D
Authors: Casman E. P. , Bennett R. W. , Dorsey A. E. , Issa J. A.
Published: January 2020

A fourth staphylococcal enterotoxin was identified serologically with antiserum to the very crude enterotoxic products of growth of a strain which also produces enterotoxin C, and then with antiserum to the considerably purified enterotoxic antigen of a strain which produces only the new enterotoxin. The identification of this antigen as enterotoxin D was based on the following observations. It was produced by strains which do not produce enterotoxins A, B, or C; it was absent in the growth products of nonenterotoxigenic strains; when appreciably purified, it was associated with emetic activity in the cat, and its biological activity was neutralized only by antisera containing its specific antibody and not by antibodies to enterotoxins A, B, and C. Staphylococcal strain 494 (ATCC 23235) was selected as the prototype strain. The production of this enterotoxin alone and together with enterotoxin A by strains of food-poisoning origin indicates that its role in food poisoning is second in frequency only to that of enterotoxin A. The incidence of production of enterotoxins A, B, C, and D, and of unidentified cat emetic substances by strains from several source categories, is presented.