bluuebunny/crossref_metadata_2025 huggingface dataset:
Differences BetweenBrucellaAntigens Involved in Indirect Hemagglutination Tests with Normal and Tanned Red Blood Cells
Authors: Diaz Ramon , Jones Lois M. , Leong Daniel , Wilson J. B.
Published: January 2020

Brucellaantigens capable of sensitizing normal and tanned sheep red blood cells for indirect hemagglutination were compared with antigens involved in agglutination, gel diffusion, and immunoelectrophoresis. Hyperimmune rabbit sera, before and after absorption with various antigenic preparations from smooth and roughB. abortus, were used in the tests. Normal erythrocytes could be sensitized with an NaOH-treated ether-water extract (EW-T) of smoothBrucella. Tanned erythrocytes could be sensitized with a water-soluble extract from ultrasonically disrupted smooth or roughBrucella. The EW-T produced a single precipitation band and the water-soluble antigens produce 6 to 23 bands in immunoelectrophoresis with unabsorbed sera. After absorption of antisera with water-soluble extracts from smooth or roughBrucellacells or from smooth or rough cell walls, the hemagglutinins for sensitized tanned erythrocytes and the precipitins for water-soluble antigens were removed. Absorption with living smooth or roughBrucellacells or with EW-T did not remove these antibodies. The precipitins and hemagglutinins for the antigen EW-T, and agglutinins for smooth cells, were absorbed by smooth antigens but not by rough antigens. It appears that the antigens which sensitize tanned erythrocytes and diffuse through agar gels are present in both smooth and rough forms and may be situated in the cytoplasm or in the internal part of the cell wall, whereas the agglutinogen and the antigen which attaches to normal erythrocytes are surface antigens found only on the smoothBrucellacell.
Sequence of Events During Germination of Putrefactive Anaerobe 3679 Spores
Authors: Uehara Minoru , Frank Hilmer A.
Published: January 2020

The sequence of changes during germination of putrefactive anaerobe 3679h spores was studied under aerobic conditions in a solution containing
l
-alanine and sodium pyrophosphate. Evidence that specific changes occurred in two distinct regions of the spore is given by data on several criteria that were used to measure germination. During the initial stage of germination, the absorbancy decreased, dipicolinic acid was released, the spores lost their resistance to heat and toxic chemicals, and the spore periphery (cortex) darkened gradually under phase-contrast microscopy. The final stage of germination was characterized by changes in the central spore region (core), notably phase darkening of the spore center and stainability with mercurochrome, and by a slight additional absorbancy decrease.
Growth of
Bacillus coagulans
in Chemically Defined Media
Authors: Marshall Rosemarie , Beers R. J.
Published: January 2020

A nutritional study was made of five strains of
Bacillus coagulans
obtained from various culture collections. These five strains were descendants of two original isolates; three had been derived from one parent culture in years past and the other two were transfers from another parent culture. Therefore, the five cultures should have represented two distinct groups of genetically identical cultures. Three of the strains obtained from one culture collection had become methyl red-negative and sorbitol-negative and had gained abilities to hydrolyze gelatin and ferment arabinose. Nutritional requirements of the five cultures, determined at 37, 45, and 55 C, differed considerably among strains; however, thiamine and biotin were required by all cultures at all temperatures. Aspartic acid was stimulatory at 37 C and was required at 45 C; folic acid, basic amino acids, and certain other nutrilites were required at 55 C. Adenine supplementation was necessary for two strains at 55 C to prevent autolysis; this phenomenon is discussed. The response of these organisms to both serine and the basic amino acids at the three growth temperatures seems especially significant. The media devised for the growth of the five strains of
B. coagulans
used in this study permit excellent growth at three incubation temperatures.
Regulatory Effect of Pyruvate on the Glucose Metabolism of
Clostridium thermosaccharolyticum
Authors: Lee Chin K. , Ordal Z. John
Published: January 2020

Whole cells and cell-free extracts of
Clostridium thermosaccharolyticum
3814 grown in media containing 0.5% glucose or 0.6% pyruvate were evaluated for their metabolic activities toward these compounds. Glucose-grown cells rapidly fermented glucose with the production of gases (CO
2
and H
2
), acids, and alcohol, but they did not ferment pyruvate well. Pyruvate-grown cells, on the other hand, readily fermented pyruvate, while fermenting glucose at a rate of one-half that of pyruvate. An analysis of the enzyme levels in the two cell culture conditions revealed that pyruvate-grown cells had lower levels of most of the glycolytic enzymes and increased levels of the hexose monophosphate pathway enzymes. Incorporation studies with the use of labeled glucose demonstrated that cells do have a control mechanism(s) whereby they can discriminate between a carbon (glucose) and an energy (pyruvate) source, selectively utilizing glucose in the synthetic pathway while obtaining energy from the phosphoroclastic degradation of pyruvate.
Temperature Response in Animals Infected with
Bacillus anthracis
Authors: Walker Jerry S. , Klein Frederick , Lincoln Ralph E. , Fernelius Albert L.
Published: January 2020

Rats, rabbits, swine, guinea pigs, and monkeys were infected with anthrax spores, and their temperature responses were recorded. These were characteristic for a species and appeared independent of resistance or susceptibility of the species toward establishment of the disease. The rabbit appeared unique in that it not only failed to demonstrate a dose-response relationship over an 8-log dose range, but acted independently producing erratic body temperatures depending on spore dose. This limits the usefulness of the rabbit in studying anthrax pathogenesis, and poses questions regarding published data with the rabbit as the test animal.
Tetanus Toxin and Antigenic Derivatives I. Purification of the Biologically Active Monomer
Authors: Murphy Samuel G. , Miller Kent D.
Published: January 2020

A procedure for the isolation of pure tetanus toxin in a lethal monomeric form was developed based on the extraction of whole cells and chromatographic techniques. A crude extract of toxin was obtained by hypertonic extraction of cells from a 72-hr culture of
Clostridium tetani
Massachusetts strain. The extract was precipitated with ammonium sulfate and further purified by sequential use of ion-exchange chromatography and gel filtration. The degree of purification obtained by the fractionation procedures was monitored by polyacrylamide gel electrophoresis. The pure toxin has an average specific activity of 150 × 10
6
mouse MLD per mg of N and 3,000 Lf per mg of N. Immunological purity was demonstrated by a single line on both immunoelectrophoresis and agar double diffusion. One band was obtained on polyacrylamide electrophoresis, as was a single symmetrical peak in the ultracentrifuge and on Sephadex G-100 chromatography. The pure protein has an absorbancy ratio (280/260 mμ) of 2.1 in phosphate buffer (
p
H 7.5).
Radiorespirometric Studies of
Leucothrix mucor
Authors: Raj H. D.
Published: January 2020

Catabolic capabilities of
Leucothrix mucor
were studied by radiorespirometric technique with a liquid scintillation spectrometer. Through measurement of relative rates and total percentages of
14
CO
2
produced, together with the determination of the cellular incorporation of
14
C from different carbon atoms of various labeled substrates, such as simple carbohydrates, intermediary metabolites, and amino acids, the essential characteristics of the primary and secondary pathways operative in this organism were examined. These substrates appeared to be degraded mainly via enzymes of the Entner-Doudoroff pathway in conjunction with the tricarboxylic acid cycle. Estimation of concurrent participation of pathways indicated that 20 to 25% of the administered carbohydrate was catabolized via the pentose phosphate pathway. There was no evidence of the Embden-Meyerhof-Parnas pathway operating in this organism.
Ribosomes and Ribosomal Protein fromNeurospora crassaI. Physical, Chemical, and Immunochemical Properties
Authors: Alberghina F. A. M. , Suskind S. R.
Published: January 2020

Ribosomes fromNeurospora crassa, initially characterized by ultracentrifugal and immunochemical analyses, have been used to prepare ribosomal protein for physical, chemical, and immunochemical study. The acrylamide gel disc electrophoretic profiles ofNeurosporaribosomal protein exhibit a degree of heterogeneity comparable to what has been observed in other systems. Only by chemical modification or by aggregation of the protein do alterations in the profile become apparent. Disulfide-bond formation appears to play a role in the aggregation of ribosomal protein to complexes ofS20,w= 200. The aggregation can be prevented by alkylation of −SH groups, and protein treated in this fashion has a subunit molecular weight of about 20,000 as determined by equilibrium centrifugation. Finger-printing of tryptic peptides indicates that more than one unique sequence of amino acids must be present in ribosomal protein, although gross primary structural heterogeneity is questioned. Antigenic heterogeneity is much less apparent; only a few precipitin bands are resolved by immunodiffusion tests, although complete reactivity of total ribosomal protein is suggested by quantitative precipitin analysis. The antigenically active ribosomal protein components appear to reside in at least two fractions; one is removed readily from the ribosome by CsC1 treatment. Ribosomal protein ofN. crassapossesses antigenic determinants present inE. coliribosomal protein as judged by spur formation in immunodiffusion tests.
Transformation Mapping of the Genes Controlling Tryptophan Biosynthesis in
Bacillus subtilis
Authors: Carlton Bruce C.
Published: January 2020

Forty tryptophan auxotrophs of
Bacillus subtilis
have been placed in six phenotypic classes on the basis of growth responses, accumulation properties, and, in some cases, specific enzymatic defects. Three-point transformation crosses between representative mutants of the six different types have permitted the determination of the orders of the gene loci. In addition, mutational site orders for mutants within each of the classes have been determined by the same techniques. The organization of the cluster of genes controlling tryptophan biosynthesis in
B. subtilis
appears to be essentially analogous to that of
Escherichia coli
and
Salmonella typhimurium
.
Genetic Basis of Colicin E Susceptibility in
Escherichia coli
I. Isolation and Properties of Refractory Mutants and the Preliminary Mapping of Their Mutations
Authors: Hill Caroline , Holland I. B.
Published: January 2020

Colicin E-resistant mutants were isolated in
Escherichia coli
K-12 which, although still apparently possessing the E receptor and adsorbing colicin, were nevertheless insensitive (refractory) to its effect. Eight phenotypic groups were obtained, but some mutants from three of these groups were all shown to map at
gal
, whereas a second refractory locus, giving resistance to E1 alone, mapped close to
thy
. It is suggested that the successful fixation of any of the three distinct colicins of group E may involve a dual role for the cell surface “receptor,” the first for the binding of the protein and the second for the correct orientation of the bound molecule relative to the cytoplasmic membrane. The majority of the refractory mutants isolated may derive from changes in components concerned with the second of these receptor functions. Two groups of mutants, however, refractory to only E1 or E2, probably reflect changes in the intracellular transmission systems which specifically mediate the effects of these two colicins, the changes not allowing transmission through the cytoplasmic membrane to the respective targets of the colicins. The E1 adsorption site was shown to be distinct from that for E2 and E3, indicating an early separation of the colicin E transmission systems.
Effect of Rec
−
Mutations on the Activity of Colicinogenic Factors
Authors: Helinski Donald R. , Herschman Harvey R.
Published: January 2020

The effect of two Rec
−
mutations (AB2463 and JC1553) on the ability of a cell to accept, maintain, and express the colicinogenic factors ColE
1
, ColE
2
, and ColV was examined in
Escherichia coli
. These mutations had no observable effect on the colicinogenic properties of the ColV factor, but prevented the spontaneous and induced production of colicins E
1
and E
2
which are determined by the ColE
1
and ColE
2
factors, respectively. The two Rec
−
mutations had no apparent effect on the ability of the cells to acquire, maintain, or transfer the ColE
1
and ColE
2
factors. These mutations did not affect the expression of immunity by any of the three Col factors. ColE
1
and ColE
2
were also shown to be indirectly induced by mating F
−
cells carrying these Col factors with ultraviolet-irradiated, non-colicinogenic, Hfr and F
+
cells. Indirect induction of colicin production occurred when either an irradiated F
+
Rec
+
or F
+
Rec
−
strain was employed as the donor strain.
Growth Inhibition by Hexoses of a Temperature-Sensitive Thiazoleless Mutant of
Salmonella typhimurium
Authors: Parada Jose L. , Ortega Manuel V.
Published: January 2020

A
Salmonella typhimurium
mutant showing impairment in the utilization of hexoses was isolated after treatment with
N
-methyl-
N
′-nitro-
N
-nitrosoguanidine. At 30 C, it grew with hexoses (glucose, fructose, galactose, mannitol), glycerol, succinate, or acid-hydrolyzed casein. At 37 C, it failed to grow with any of the hexoses. Enzymatic determinations demonstrated, however, that the enzymes of the glycolytic pathway (up to the formation of triose phosphates) were present and active at 25 and 32 C. At 42 C, the mutant did not grow with any of the carbon sources used. At both 37 and 42 C, the mutant grew perfectly well with hexoses if yeast extract was present. The metabolite required for growth was thiamine or, specifically, its thiazole moiety. If glucose was added to a culture growing in glycerol, at 37 C, growth was inhibited. This inhibition was relieved by the addition of thiamine or thiazole. Thus, at 37 C and only in the presence of hexoses, the mutant manifests a requirement for thiazole. This auxotrophy is absolute at 42 C. These data indicate that, in this mutant, some derivative of hexoses inhibits the synthesis of thiazole, and that this inhibition is also dependent on the temperature of incubation. The position in the bacterial chromosome of the genetic locus of this lesion (
thz
−
) was determined by conjugation and found to coincide with the only thiamine (
thi
) locus so far reported.
Sphere-Rod Morphogenesis in
Arthrobacter crystallopoietes
I. Cell Wall Composition and Polysaccharides of the Peptidoglycan
Authors: Krulwich Terry A. , Ensign Jerald C. , Tipper Donald J. , Strominger Jack L.
Published: January 2020

Cell walls of
Arthrobacter crystallopoietes
were prepared from cells grown as spheres and from peptone- and succinate-induced rod stage cells. Undegraded polysaccharide backbones of the peptidoglycans were isolated from myxobacter AL-1 protease digests by ECTEOLA cellulose and Sephadex G-50 chromatography. The polysaccharide backbones of the sphere cell wall peptidoglycan are heterogeneous in their size, and average less than 40 hexosamines per chain. Those of the rod cell walls are homogeneous in size and average 114 to 135 hexosamines per chain.
Comparisons of Cells, Refractile Bodies, and Spores of
Bacillus popilliae
Authors: Mitruka Brij M. , Costilow Ralph N. , Black S. H. , Pepper R. E.
Published: January 2020

Spores of
Bacillus popilliae
from infected larvae and refractile bodies produced in a Trypticase-barbiturate medium were similar but distinct from vegetative cells of this organism in protein, nucleic acid, and enzyme composition. The spores and refractile bodies were found to have catalase activity, some of which was heat-resistant. This enzyme was not found in the vegetative cells. The spores contained dipicolinic acid, but the refractile bodies did not. The latter were similar to cells in having considerably higher levels of phosphate extractable with cold trichloroacetic acid and of poly-β-hydroxybutyrate than had the spores. Electron microscopy demonstrated conclusively that the refractile bodies are distinctly different from either cells or spores of
B. popilliae
. The possibility that these bodies are formed as a result of an aborted sporulation process is discussed.
Arginine Biosynthesis by
Streptococcus bovis
Authors: Niederman R. A. , Wolin M. J.
Published: January 2020

The pathway of arginine biosynthesis in
Streptococcus bovis
was studied by radioactive tracer techniques. Cells were grown anaerobically with
14
CO
2
in a synthetic medium containing NH
4
+
as the sole nitrogen source except for the trace present in nitrogen-containing vitamins. The protein fraction isolated from the labeled cells was acid-hydrolyzed, and
14
C-arginine was isolated from the protein hydrolysate by ion-exchange chromatography. The carboxyl carbon of the isolated arginine was removed with arginine decarboxylase, and the guanidino carbon was removed by simultaneous arginase-urease degradation. By manometric measurement and liquid scintillation counting of the CO
2
released by enzymatic degradation, 50% of the label was found in the carboxyl carbon and 50% in the guanidino carbon. Specific radioactivity determinations indicated that growth on
14
CO
2
resulted in twice as much label in arginine as with aspartate, glutamate, or lysine. These results are consistent with a glutamate → ornithine → citrulline pathway of arginine biosynthesis in
S. bovis
and provide further evidence for the synthesis of glutamate via the tricarboxylic acid cycle reactions from citrate through α-ketoglutarate.
Regulation of Glutamine Synthetase V. Partial Purification and Properties of Glutamine Synthetase from
Bacillus licheniformis
Authors: Hubbard Jerry S. , Stadtman E. R.
Published: January 2020

The glutamine synthetase of
Bacillus licheniformis
has been obtained at about 15% purity. Sucrose gradient centrifugation gave a molecular weight value of approximately 612,000. Both
l
- and
d
-glutamate can be utilized as substrates in the biosynthetic reaction, although the
l
isomer was five times more active. The requirement for adenosine triphosphate (ATP) can be partially replaced by guanosine or inosine triphosphates, but not by cytidine or uridine triphosphates. The Mn
++
was required for activity, and the requirement cannot be satisfied with Mg
++
. Maximal activity of the biosynthetic reaction was observed when ATP and Mn
++
were present in equimolar amounts. An excess of either reactant gave less activity. However, other purine and pyrimidine nucleotides, when added in combination with ATP, can partially substitute for ATP in attaining the equimolar ratio of nucleotide to Mn
++
. A complex of ATP and Mn
++
is the preferred form of substrate. The
B. licheniformis
enzyme catalyzes the glutamyl transfer reaction but at a much slower rate than the
Escherichia coli
glutamine synthetase. Either adenosine diphosphate (ADP) or ATP can activate the glutamotransferase, although ADP is more active.
Regeneration of Ribosomes and Ribosomal Ribonucleic Acid During Repair of Thermal Injury to
Staphylococcus aureus
Authors: Sogin Stephen J. , Ordai Z. John
Published: January 2020

Heating
Staphylococcus aureus
MF31 at 55 C for 15 min renders the organisms unable to reproduce on agar containing 7.5% NaCl (1). The heated organisms exhibited an extended lag period during which the organisms regained their ability to grow on the 7.5% NaCl-agar. Inhibitor and antibiotic data indicated that protein synthesis is not involved in this recovery process but nucleic acid synthesis is suggested (3). The data presented here further substantiate the noninvolvement of protein synthesis during recovery and further demonstrate the site of the thermally induced nucleic acid lesion. Methylated albumin kieselguhr column analysis showed the lesion site to be the ribosomal ribonucleic acid (rRNA). The rRNA is resynthesized during the extended lag period. Sucrose gradient analysis demonstrated that a ribosomal peak was undetectable subsequent to the thermal treatment, but this peak was regenerated during the recovery period.
Comparison of the α-Amylase of
Bacillus subtilis
and
Bacillus amyloliquefaciens
Authors: Welker N. E. , Campbell L. Leon
Published: January 2020

The α-amylase (α-1,4-glucan 4-glucanohydrolase, EC 3.2.1.1) of
Bacillus subtilis
strain W23 is less negatively-charged than the α-amylase of
B. amyloliquefaciens
strain F, as determined by electrophoretic mobility in polyacrylamide gel at
p
H 8.6. The α-amylase of strain W23 is immunologically unrelated to the α-amylase of strain F, as judged by lack of cross-reaction in Ouchterlony immunodiffusion studies. The
p
H range of maximal activity for the enzyme of strain W23 was 5.7 to 6.7, with a maximum at 6.3. The
p
H range of activity for the α-amylase of strain F was 5.5 to 6.5, with a maximum at 5.9. No significant difference was found in the effect of temperature on the activity of the α-amylase of strain W23 and strain F. α-Amylase production by strain W23 occurs throughout the 7-hr growth period, whereas enzyme production by strain F does not begin until the culture enters the stationary phase of growth. The total amounts of enzyme produced by strains W23 and F after 7 hr of growth were 0.3 and 25.5 units/ml, respectively.
Some Novel Mutants of
Saccharomyces cerevisiae
Inhibited by Adenosylmethionine and Adenosylhomocysteine
Authors: Spence Kemet D. , Shapiro Stanley K.
Published: January 2020

These investigations have established the existence of a novel type of non-nutritional mutant (
ai
) which is inhibited in the presence of two naturally occurring cellular compounds. The inhibition is complete at an extracellular concentration at least as low as 0.05 μmole/ml of either adenosylhomocysteine or adenosylmethionine. It is suggested that adenosylhomocysteine is the true inhibitor. The
ai
mutants are phenotypically indistinguishable from the wild type in the absence of inhibitors. The results have shown that, if any direct effect on the methionine biosynthetic pathway exists, it is a secondary rather than the primary effect of the inhibitors. The
ai
mutation does not involve the loss of the adenosylmethionine (or methylmethionine): homocysteine methyltransferase. In addition, the
ai
mutants accumulate, maintain, and utilize adenosylmethionine and methionine in a manner similar to the parental strain. No genetic relationship could be detected between the
ai-1
mutation and several different markers affecting methionine biosynthesis. The
ai-1
mutation was also shown to be genetically recessive. Methionine partially reverses the inhibition caused by adenosylmethionine or adenosylhomocysteine. Neither methylmethionine nor homocysteine reversed the inhibition, which showed that the homocysteine methyltransferase cannot catalyze the synthesis of sufficient methionine under these conditions to simulate the effects of extracellularly supplied methionine. If adenine is present, methionine does not cause reversal of inhibition due to adenosylmethionine or adenosylhomocysteine. From the data presented, it is clear that the
ai
mutation involves some metabolic control mechanism, though the alteration does not appear to be associated primarily with the biosynthesis of methionine.
Microcysts of the Cellular Slime Mold
Polysphondylium pallidum
I. Factors Influencing Microcyst Formation
Authors: Toama Mohamed A. , Raper Kenneth B.
Published: January 2020

Microcyst formation can be induced by increasing the osmotic pressure of the surrounding medium. Certain ions such as K
+
, Ca
++
, or Mg
++
may be needed in the encystment process, and the presence of divalent cations increases the rate of encystment and cyst maturation. Chloride of potassium is optimal for encystment, but other anions of potassium are either less effective or toxic. The optimal
p
H for encystment was found to be
p
H 6.0. The use of agar plates containing KCl revealed the importance to the encystment process of inhibiting cell aggregation. When myxamoebae of
Polysphondylium pallidum
strain Pan-17 are deposited on KCl-agar plates, approximately 20% of the population proceeds through aggregation to sorocarp formation at the concentration of KCl optimal for microcyst formation. However, the same proportion of myxamoebae remains unaligned, or forms defective aggregation centers, if synergistic inhibitors (such as incubation in darkness or at low temperature) are employed in addition to KCl. The possibility that this is due to heterocytosis has been excluded. Accordingly, it is suggested that during the stationary phase approximately 20% of the population becomes committed to forming component cells of fruiting bodies, and that these myxamoebae cannot be induced to form microcysts by exposure to KCl. In
P. pallidum
strains WS-320 on the other hand, the imposition of synergistic inhibitors leads to the total encystment of the cell population. This suggests that, in contrast to Pan-17, the myxamoebae of the latter strain remain potentially equal and exhibit minimal presumptive specialization.
Electron Microscopy of a Strain of
Bordetella bronchiseptica
Authors: Richter G. W. , Kress Yvonne
Published: January 2020

A strain of
Bordetella bronchiseptica
that had been isolated from a rat hepatoma cell culture was investigated by means of electron microscopy. Bacteria were examined after (i) negative staining with phosphotungstate or uranyl acetate, (ii) metal shadowing with platinum-palladium, and (iii) fixation with glutaraldehyde followed by embedding, sectioning, and staining. The multilayered bacterial cell walls appeared lobulated in negatively stained and in metal-shadowed specimens; the lobules were demarcated by grooves, 100 to 200 A in width, but without interruption of continuity in any layer of the cell wall. Cross sections of fixed material revealed wrinkled cell walls in many—but not all—preparations. Bacterial cell membranes and cytoplasm were similar to those of other gram-negative bacilli (e.g.,
Escherichia coli
). Bacteria fixed in 1.5% glutaraldehyde contained intertwined or whorled fibrils, down to about 20 A in thickness. The flagella were peritrichous, measured about 200 A in width, and were composed of braided strands, about 20 A in width.
In Vivo and In Vitro Manifestations of Adrenergic Blockade inBordetella pertussis-vaccinated Mice
Authors: Keller Kenneth F. , Fishel Charles W.
Published: January 2020

The in vivo metabolic events which follow the administration of epinephrine, norepinephrine, or isoproterenol were examined in normal,Bordetella pertussis-vaccinated, and α and β adrenergically blocked mice. The normal hyperglycemic response to epinephrine was suppressed in all experimental groups. The pertussis-sensitized and β-blocked animals produced similar split patterns of altered response not duplicated by the α-blocking compounds. Those catecholamines that normally increase free fatty acids and lactic acid in the circulation failed to do so in the pertussis-sensitized and β-blocked animals; the inhibition of free fatty acid mobilization was also demonstrated with adipose tissue incubated in vitro. An extract of the pertussis organism added to incubation media prevented the catecholamine-induced free fatty acid response. The epinephrine-stabilizing effect of bovine serum albumin (Cohn-fraction V) was observed. The results of these studies further emphasize a correlation between pertussis-sensitized and β-adrenergically blocked mice.
Flavensomycin, an Inhibitor of Enzyme Reactions Involving Hydrogen Transfer
Authors: Gottlieb David , Inoue Yukio
Published: January 2020

The antifungal antibiotic flavensomycin inhibited the oxidation of amino acids and of glucose by
Penicillium oxalicum
. The compound inhibited
l
-amino acid oxidase (EC 1.4.3.2) activity for
l
-leucine and
l
-phenylalanine, and also
d
-amino acid oxidase (EC 1.4.3.3) in the oxidation for
dl
-alanine. The addition of flavin adenine dinucleotide, which is a cofactor for this enzyme, antagonized the action of the antibiotic. Glucose oxidase (EC 1.1.3.4) was also inhibited. The antibiotic inhibited the reduced nicotinamide adenine dinucleotide (NADH
2
) cytochrome
c
reductase (EC 1.6.2.1) as well as the much slower nonenzymatic reduction of this cytochrome by the nucleotide. Reduced cytochrome
c
was also oxidized nonenzymatically by flavensomycin. The antibiotic completely inhibited the action of rabbit muscle lactic dehydrogenase (EC 1.1.1.27) in promoting the reduction of pyruvate by NADH
2
but only slightly affected the reverse reaction. Alcohol dehydrogenase (EC 1.1.1.1) was also similarly inhibited. Flavensomycin prevented the reduction of nicotinamide adenine dinucleotide phosphate by isocitrate in the presence of isocitrate dehydrogenase (EC 1.1.1.42). The hexokinase (EC 2.7.1.1)-catalyzed phosphorylation of glucose, in which the adenosine triphosphate acts as a phosphate donor, was only slightly affected. Flavensomycin also inhibited the action of yeast lactate dehydrogenase (EC 1.1.2.3) on the reduction of cytochrome
c
. High concentrations of cytochrome
c
were antagonistic to this reaction. The results point to an interference with enzymatically controlled hydrogen or electron transfer as the mechanism of the antifungal activity of flavensomycin.
Effect of Thiosulfate on the Photosynthetic Growth of
Rhodopseudomonas palustris
Authors: Rolls James P. , Lindstrom E. S.
Published: January 2020

Cell yields of
Rhodopseudomonas palustris
grown photoheterotrophically in pyruvate-mineral salts medium were increased by the photooxidation of added thiosulfate. However, thiosulfate had no effect on cell yields of cultures grown aerobically in darkness, although thiosulfate was also oxidized. The presence of thiosulfate increased photosynthetic cell yields on a variety of other organic substrates. Growth of cells in thiosulfate-containing medium, or the addition of thiosulfate to cells grown in thiosulfate-free medium, induced the formation of a thiosulfate-oxidizing system which quantitatively photooxidized thiosulfate to sulfate.
R. palustris
grew photoautotrophically with thiosulfate as an oxidizable substrate. Large amounts of supplemental bicarbonate carbon were incorporated when cells were grown photosynthetically in pyruvate-thiosulfate medium. Cells harvested after photoautotrophic or photoheterotrophic growth in fumarate-thiosulfate medium fixed
14
CO
2
at an 8- to 10-fold greater rate when provided with thiosulfate. The evolution of
14
CO
2
from pyruvate-
1
-
14
C
during photoassimilation by
R. palustris
was greatly suppressed by the presence of thiosulfate. The increase in photoheterotrophic cell yields of
R. palustris
caused by the oxidation of thiosulfate may result from assimilation of substrate carbon which is normally evolved as carbon dioxide.
Deoxyribonucleic Acid Homologies Among Species of the GenusNeisseria
Authors: Kingsbury David T.
Published: January 2020

Eleven aerobic species ofNeisseria, aMimasp., and aHerelleasp. were tested for deoxyribonucleic acid (DNA) homology in direct hybridization experiments. DNA labeled with either14C or32P was prepared from five species ofNeisseria. Unlabeled DNA from the various microorganisms was immobilized on membrane filters, which, after pretreatment, were incubated with labeled DNA (4,000 counts per min per filter) for 14 hr at 67 C. The measure of relatedness was expressed as the relative percentage of direct binding compared to that obtained with homologous DNA. All serological types ofN. meningitidis, including the newly proposed types, were homologous to the standard strain ofN. meningitidiswith one possible exception, type Z. The genusNeisseriais heterogeneous in nature, forming at least three distinct groups: first,N. meningitidisandN. gonorrhoeae;second,N. perflava, N. subflava, N. sicca, N. flavescens, andN. flava;third,N. catarrhalisandN. caviae. MimaandHerelleaspecies show no significant homology with theNeisseria.
Taxonomy of Psychrophilic Strains of
Bacillus
Authors: Larkin J. M. , Stokes J. L.
Published: January 2020

The morphological and physiological characteristics of 20 isolates of psychrophilic
Bacillus
were compared with 29 strains representing nine species of mesophilic
Bacillus
and 2 strains of
Sporosarcina ureae
to determine the taxonomic position of the psychrophiles. The psychrophiles formed four distinct groups which were sufficiently different from the mesophiles to warrant their designation as new species of
Bacillus
. The names
B. psychrosaccharolyticus, B. insolitus, B. globisporus
, and
B. psychrophilus
are proposed for the new species.
Proteinase Enzyme System of Lactic Streptococci II. Role of Membrane Proteinase in Cellular Function
Authors: Cowman R. A. , Swaisgood H. E. , Speck M. L.
Published: January 2020

The effect of several environmental conditions on the structure and activity of a membrane-associated proteinase from
Streptococcus lactis
was investigated. The activity of the enzyme varied with
p
H. Before storage at 3 C, maximal activity occurred at
p
H 6.0, but was minimal at this
p
H after storage. At all
p
H values tested, the enzyme was inactivated after storage. After storage at 3 C, the enzyme showed gross structural alterations with a concomitant loss of activity. Gel filtration and sedimentation velocity data indicated that inactivation of the enzyme was the result of aggregation to higher molecular weight forms.
p
-Hydroxymercuribenzoate prevented inactivation of the enzyme during storage by preventing aggregation. Activity was correlated with disaggregation of polymer forms of the enzyme to an active monomer. The storage-inactivated enzyme could be reactivated by treatment of the enzyme with cysteine, glutathione, or ferrous ion. Glutathione enabled stored cells to produce acid at their original rate when subcultured in milk. This was attributed to the effect of glutathione on the membrane proteinase. The data suggested that the biological activity of stored cells may be dependent upon the activity of the membrane proteinase.
Immunochemical Studies on Glutamate Dehydrogenase and on Two Mutant Forms of the Protein
Authors: Roberts David B.
Published: January 2020

Studies on the active product of pepsin digestion of rabbit immunoglobulin G (IgG), F(ab′)
2
produced from antiserum against
Neurospora
glutamate dehydrogenase, showed it to behave in the same way, in both antienzyme and precipitation experiments, as homologous IgG. It is proposed that the inhibition of glutamate dehydrogenase by this antibody preparation is by the same mechanism as proposed for IgG and F
ab
, a change in the configuration of the catalytic site brought about by antibodies. Antibodies prepared against two mutant proteins behaved in antienzyme studies in the same way as antibodies prepared against the wild-type protein. It is thought therefore that the antigenic sites on the mutant proteins which initiate the production of neutralizing antibodies were not affected by the mutation which had changed the catalytic properties of the mutant proteins.
Anaerobic Growth Yields of
Aerobacter cloacae
and
Escherichia coli
Authors: Hernandez Eovaldo , Johnson Marvin J.
Published: January 2020

Aerobacter cloacae
UW-C83 and
Escherichia coli
K-12 were grown under various anaerobic environments. Y

atp

values were calculated by determination of cell weights and analyses for fermentation products. These Y

atp

values are compared with others reported in the literature. Limitation of growth by factors other than adenosine triphosphate supply is discussed.
Experimental Transmission of a Murine Microsporidian in Swiss Mice
Authors: Nelson John B.
Published: January 2020

The production of ascitic fluid and splenomegaly on intraperitoneal injection in weanlings was used as a test for microsporidia after introduction by other routes and in other loci. Oral and cerebral administration was followed only by enlarged spleens which reproduced the ascitic response on passage. Microsporidia were demonstrable by phase microscopy in all fluids. Positive findings were also obtained with liver, kidney, brain, lungs, blood, and urine. Intramuscular and intranasal injection were occasionally followed by ascites, but splenomegaly again predominated. The results of contact experiments indicated that the organisms were not readily communicable either in weanlings or nurslings. Relation of the microsporidian to
Encephalitozoon cuniculi
(
Nosema cuniculi
Lainson et al.) is discussed.
Degradation of Streptococcal Cell Wall Antigens In Vivo
Authors: Schwab John H. , Ohanian S. H.
Published: January 2020

Specific chemical modification of group A polysaccharide antigen to the A-variant structure was demonstrated in the lymphoid organs of mice by autoradiography by use of radioantibodies specific for these structures. Both antigenic moieties persisted and were still discerned 10 weeks after injection of the group A cell wall. In rabbit skin, the group A specificity was altered after a prolonged period. Unlike the situation for the mouse, polysaccharide A was not converted to A-variant structure, but another specificity common to both polysaccharides persisted at the site of injection. Mucopeptide, separated from the polysaccharide of group A cell walls, was eliminated from the site of injection in rabbit skin between 4 and 8 hr after injection. Group D streptococcal cell walls were also rapidly eliminated from tissue, and were no longer detectable 8 hr after injection into rabbit skin or 24 hr after injection into mice. The rapid degradation of these structures was correlated with their susceptibility to lysozyme in vitro and was in contrast to the prolonged persistence of group A cell walls, which were completely resistant to egg white lysozyme. This persistence in tissue correlated with the capacity of group A cell wall fragments to induce a chronic inflammatory process, whereas the isolated mucopeptide or group D cell walls produced only an acute necrotoxic reaction.
Experimental Irradiated Arthrospore Vaccine Against Coccidioidomycosis in Mice
Authors: Pulliam James D. , Converse J. L. , Snyder E. M. , Esterly J. R. , Lowe E. P.
Published: January 2020

An experimental irradiated (
60
Co) arthrospore vaccine against coccidioidomycosis protected approximately 75% of mice from death after an intraperitoneal challenge sufficient to kill approximately 90% of the nonimmunized control mice. Although the majority of the immunized mice became infected with
Coccidioides immitis
, the histologic lesions were substantially less severe than those in the nonimmunized controls, particularly in the pulmonary region. Although arthrospores irradiated with 1, 2, or 3 million roentgens lost their ability to multiply in various laboratory media (probably through interference with cell division), partial conversion to the parasitic phase (spherule) was observed after animal inoculation (rounding out of arthrospores into immature spherules, but without development of endospores). Duration of viability of these structures has yet to be determined.
Antibiotic Susceptibility Patterns as Aids in Classification and Characterization of Gram-negative Anaerobic Bacilli
Authors: Finegold Sydney M. , Harada Noriko E. , Miller Lawrence G.
Published: January 2020

Patterns of susceptibility of gram-negative anaerobic bacilli to antibiotics have been found to be distinctive and of significant help in classification and identification. Five major groups of gram-negative anaerobic bacilli have been defined on the basis of morphological and biochemical criteria. Antibiotic sensitivity patterns conform to these groupings and provide additional taxonomic criteria. The
Bacteroides fragilis
group is resistant to penicillin G, whereas the other groups are generally sensitive.
B. fragilis
strains are relatively sensitive to erythromycin, whereas the
Sphaerophorus necrophorus
group is resistant.
B. melaninogenicus
strains,
B. oralis
, and
Fusobacterium
are all more sensitive to kanamycin and neomycin than the other two groups. Kanamycin is more active against
Fusobacterium
strains than neomycin, but less active against all other groups. Colistin or polymyxin B is useful for distinguishing between the resistant
B. fragilis
and the sensitive
S. necrophorus
. Antibiotic susceptibility determinations may be more readily performed in clinical laboratories than certain biochemical tests recommended for differentiation of the gram-negative anaerobic bacilli and may serve as helpful adjuncts to morphological and biochemical observations in classifying and characterizing these organisms. The use of standardized procedures for antibiotic susceptibility tests is essential if comparable results are to be obtained in different laboratories.
Cryptococcus neoformans
I. Nonencapsulated Mutants
Authors: Bulmer G. S. , Sans M. D. , Gunn C. M.
Published: January 2020

Seven nonencapsulated mutants of
Cryptococcus neoformans
were isolated from an encapsulated strain of human origin. Initially, the mutants were avirulent for mice. After several months of subculturing, six of the seven isolates reverted to the encapsulated state and possessed varying degrees of virulence. The results of these experiments suggest that a strong correlation exists between the presence of a capsule and the virulence of
C. neoformans
.
Cryptococcus neoformansII. Phagocytosis by Human Leukocytes
Authors: Bulmer G. S. , Sans M. D.
Published: January 2020

Twenty-four per cent of the leukocytes from healthy human subjects phagocytized an encapsulated strain ofCryptococcus neoformans. Phagocytosis was approximately three times more effective with nonencapsulated mutants ofC. neoformans. When the mutants reverted to the encapsulated state, the percentages of phagocytosis decreased. These data indicate that cryptococcal polysaccharide inhibits the phagocytosis ofC. neoformansby human leukocytes.
Catabolite Repression in the Facultative Chemoautotroph
Thiobacillus novellus
Authors: LéJohn H. B. , Van Caeseele L. , Lees H.
Published: January 2020

Several fermentable carbon sources were found to give rise to catabolite repression of all enzymes implicated in thiosulfate oxidation in the facultative chemoautotroph,
Thiobacillus novellus
. Glucose was found to elicit a strong repression. Glycerol, lactate, lactose, ribose, and pyruvate caused marked repression. In all cases, the repression could be relieved only by returning the cells to a medium devoid of such fermentable substrates. On the other hand, carbon compounds (amino acids and organic acids) that are metabolizable only aerobically caused transient or no repression of the thiosulfate oxidative system. All of the enzymes believed to participate in thiosulfate oxidation, except tetrathionase, were found to be simultaneously induced and repressed. This would suggest that tetrathionate may not be a necessary intermediate in the thiosulfate-oxidation pathway of
T. novellus
.
Effect of Some Proteins on the Yeast Cell Membrane
Authors: Yphantis D. A. , Dainko J. L. , Schlenk F.
Published: January 2020

Yeast cells,
Candida utilis
, in water suspension and in the absence of electrolytes were found to be very sensitive to several proteins of moderate size, including ribonuclease, protamine, lysozyme, bovine serum albumin, cytochrome
c
, and myoglobin. Viability ceases rapidly, and ultraviolet-absorbing compounds (260 mμ) and the amino acid pool are released into the medium. The ultraviolet-absorbing material appears to be the nucleotide and coenzyme fraction usually extracted by 0.2
n
perchloric acid at low temperature. The ribonucleic acid fraction remains in the cell ghosts and can be released by ribonuclease. The enzymatic properties of some of these proteins have no relation to their damaging effect on the cell membrane. Poly-
l
-lysine shows the same activity.
Urea Production and Putrescine Biosynthesis by
Escherichia coli
Authors: Morris David R. , Koffron Kara L.
Published: January 2020

Cultures of
Escherichia coli
B and K-12 produce urea during growth in minimal medium. Results of isotopic labeling experiments were consistent with the sole source of urea being from the conversion of arginine to putrescine. Since
E. coli
itself has no demonstrable urease activity, the rate of urea production is a measure of the flux through the arginine to putrescine pathway.
Deoxyribonucleic Acid Repair Replication after Ultraviolet Light or X-Ray Exposure of Bacteria
Authors: Billen D. , Hewitt R. R. , Lapthisophon T. , Achey P. M.
Published: January 2020

A comparison of repair synthesis after ultraviolet light (UV) or X-ray exposure was made in
Escherichia coli
strains 15T
−
(555–7) and B/r by use of a D,
15
N,
13
C density labeling system. During the initial 15 min of incubation after UV irradiation, both a “repair” synthesis and a reduced semiconservative deoxyribonucleic acid (DNA) synthesis occurred. In the so-called “physiological” dose range used, the latter was greater than the former. X-irradiation of cells, at doses producing similar levels of cell death as in the UV-exposed cultures, did not lead to a similar repair replication process. However, a density heterogeneity of the DNA synthesized in the initial 10 min after exposure was observed. This is interpreted in terms of X ray-induced DNA degradation. Normal cells showed only a semiconservative type of replication and, therefore, within the limits of resolution of the system used (the incorporation of 1,000 to 5,000 nucleotides per replicating chromosome could be measured), DNA in normal cells did not appear to undergo a repair synthesis involving thymine exchange. These results indicate that not all repair mechanisms mimic that found after UV exposure.
Formation of α-Hydroxyglutaric Acid by
Aspergillus glaucus
Authors: Bleiweis A. S. , Reeves H. C. , Ajl S. J.
Published: January 2020

Aspergillus glaucus
, cultured on sodium propionate-mineral salts medium, incorporates
14
C-glyoxylate into labeled α-hydroxyglutaric acid within 30 sec. Mycelial extracts retain this biosynthetic capacity, which is destroyed by heating. Propionyl-
2
-
14
C
-coenzyme A also in incorporated into labeled α-hydroxyglutaric acid by these mycelial extracts, but to a more limited extent.
14
CO
2
evolution studies, employing differentially labeled
14
C-propionate, indicate C-1 is oxidized by the mold before C-2, and C-2 before C-3. These findings suggest the involvement of α-hydroxyglutaric acid in the catabolism of propionic acid by
A. glaucus
.
Characterization of a Temperature-sensitive Mutant of
Bacillus subtilis
Defective in Deoxyribonucleic Acid Replication
Authors: Mendelson Neil H. , Gross Julian D.
Published: January 2020

In this paper we present a preliminary characterization of a temperature-sensitive mutant of
Bacillus subtilis
which appears to be defective in deoxyribonucleic acid (DNA) replication at high temperature. When log-phase cells of the mutant were transferred from 30 to 45 C, protein synthesis and ribonucleic acid synthesis continued more or less normally for several hours, whereas DNA synthesis continued at a normal rate for only 20 to 30 min and then was drastically reduced. The amount of DNA synthesized prior to this reduction corresponded approximately to the amount of DNA synthesized under conditions of protein synthesis inhibition by the parent or mutant strain. After 1 hr of growth at high temperature, cells of the mutant showed a pronounced drop in viable count. After 30 or 60 min of growth at high temperature, DNA synthesis could be restored by lowering the temperature. A longer period of growth at 45 C led to a loss of reversibility of DNA synthesis. Spores of the mutant synthesized no DNA when germinated at high temperature, although an outgrowing cell appeared. When spores were germinated at low temperature until DNA synthesis began, and then were transferred to high temperature, macromolecular synthesis continued as the log-phase transfer experiments described above.