bluuebunny/crossref_metadata_2025 huggingface dataset:
Yield Coefficients of
Thiobacillus neapolitanus
in Continuous Culture
Authors: Hempfling Walter P. , Vishniac Wolf
Published: January 2020

Thiobacillus neapolitanus
, when grown in continuous culture with thiosulfate limiting growth, possessed an apparent maximal molar growth yield of 8.0 g (dry weight) per mole of thiosulfate. The substrate requirement for energy of maintenance was the highest yet reported, amounting to 21.8 mmoles of thiosulfate per g per hr. The molar growth yield, corrected for this maintenance energy requirement, was 13.9 g (dry weight) per mole of thiosulfate. It was concluded that substrate-level phosphorylation during sulfite oxidation accounted for about 45% of the adenosine triphosphate (ATP) requirement for CO
2
assimilation and maintenance during growth on limiting thiosulfate, that three sites of energy conservation exist in the electron-transport chain terminating in oxygen, and that 7.8 moles of ATP are required to fix and assimilate 1 mole of CO
2
into cell material.
Fatty Acids in the GenusBacillusI. Iso- and Anteiso-Fatty Acids as Characteristic Constituents of Lipids in 10 Species
Authors: Kaneda Toshi
Published: January 2020

Fatty acids produced by 22 strains of 10 species of the genusBacilluswere analyzed on a very efficient and selective gas-liquid chromatographic column. All of the 10 species,alvei, brevis, cereus, circulans, licheniformis, macerans, megaterium, polymyxa, pumilus, andsubtilis, produced eight fatty acids, six branched (anteiso-C15, anteiso-C17, iso-C14, iso-C15, iso-C16, and iso-C17) and two normal (n-C14and n-C16). In all cases, the six branched-chain fatty acids made up over 60% of the total fatty acids. In addition to the eight fatty acids,B. cereusproduced four extra fatty acids, three branched (anteiso-C13, iso-C12, and iso-C13) and one monoenoic-n-C16. Furthermore, there were distinct differences in the relative amounts of fatty acids produced betweenB. cereusand the remaining nine species.B. cereusproduced iso-C15fatty acid in the largest amount on a glucose-yeast extract medium as well as on Pennassay Broth. On the other hand, for the remaining nine species, anteiso-C15fatty acid was the major fatty acid from the glucose-yeast extract medium, whereas the amount of iso-C15fatty acid from Penassay Broth became comparable to that of anteiso-C15fatty acid. Mechanisms and various factors affecting the fatty acid distribution pattern in the 10Bacillusspecies are discussed.
Comparative Glucose Catabolism ofXanthomonasSpecies
Authors: Zagallo A. C. , Wang C. H.
Published: January 2020

Glucose catabolism in eightXanthomonasspecies has been comparatively examined by means of the radiorespirometric method. The basic mechanisms for the respective xanthomonads closely resembled each other. The Entner-Doudoroff pathway, in conjunction with the tricarboxylic acid cycle pathway, was the predominant mechanism for glucose catabolism. A small portion (8 to 16%) of substrate glucose was routed into the pentose phosphate pathway. The hexose cycle pathway did not appear to play any significant role in glucose catabolism of these xanthomonads. The results are also consistent with the well-recognized close phylogenic relationship between xanthomonads and pseudomonads.
Metabolic Characterization of the Genus
Brucella
VI. Growth Stimulation by
i
-Erythritol Compared with Strain Virulence for Guinea Pigs
Authors: Meyer Margaret E.
Published: January 2020

Strains of
Brucella abortus
isolated 20 to 38 years ago and strains recently isolated were assessed for their virulence to guinea pigs and for their ability to grow in half-strength Tryptose Broth with and without
i
-erythritol. The recently isolated strains were virulent and
i
-erythritol enhanced their growth. The aged strains were avirulent and grew equally well in both media. Three of the recently isolated strains were subcultured serially every 24 hr alternately on Tryptose Agar slants and in half-strength Tryptose Broth without
i
-erythritol. After 8 to 13 such transfers, the growth of each strain was equivalent in both media. The subculture on which growth equivalence occurred was retested for virulence. None of the three strains had decreased in its virulence for guinea pigs. The conclusion was drawn that strain virulence for guinea pigs and growth enhancement by
i
-erythritol are independent characteristics.
Drug Resistance of Enteric Bacteria VIII. Chromosomal Location of Nontransferable R Factor inEscherichia coli
Authors: Harada Kenji , Kameda Mitsuo , Suzuki Mitsue , Shigehara Susumu , Mitsuhashi Susumu
Published: January 2020

The R21(TC) factor, obtained by transduction of the R10(TC.CM.SM.SA) factor with phage ε to group ESalmonella, is not transferable by the normal conjugal process. However, when R21(TC)+transductants are infected with the F13factor, the nontransferable R21(TC) factor acquires transmissibility by conjugation. R21(TC)+conjugants ofEscherichia coliK-12, to which only the R21(TC) factor was transmitted by cell-to-cell contact from an F′ R+donor, were still unable to transfer their R21(TC) factor by conjugation. In crosses between Hfr and F−E. coliK-12 strains containing R21(TC), the gene responsible for tetracycline resistance was located on theE. coliK-12 chromosome betweenlacandpro, nearlac.
Oxidation of 1-Tetradecene byPseudomonas aeruginosa
Authors: Markovetz A. J. , Klug M. J. , Forney F. W.
Published: January 2020

Pseudomonas aeruginosastrain Sol 20 was grown on 1-tetradecene as sole carbon source, and a vinyl-unsaturated 14-carbon monocarboxylic acid, 13-tetradecenoic acid, was identified from culture fluid. This acid was not produced whenn-tetradecane served as substrate for growth. Oxidation of the methyl group represents one method of attack on the 1-alkene by this organism. Tentative identification of 2-tetradecanol indicates that an attack on the double bond is also occurring. α, ω-Dienes would not support growth.
Response of Log-phase Cells of
Escherichia coli
to Medium Limited in Both Sulfate and Phosphate
Authors: Bohinski R. C. , Mallette M. F.
Published: January 2020

In a study of the effects of a double nutritional deficiency, washed suspensions of log-phase cells of
Escherichia coli
increased in both turbidity and plate counts when incubated at 35 to 37 C in a medium deficient in sulfate and phosphate and buffered with tris(hydroxymethyl)aminomethane. The population approximately doubled within 6 to 9 hr, whereas the turbidity increased only 28 to 33% in the same period. Ribonucleic acid, deoxyribonucleic acid, and protein levels were followed, and changes were observed with time and deficiency state. Long-term experiments illustrated that a resulting population in a medium deficient in both sulfate and phosphate survived for 4 to 5 days, a longer period than that characteristic of the single deficiencies. Moreover, in media deficient in sulfate,
E. coli
possessed two completely distinct behavior patterns depending on the nature of the buffer used. In addition, a variation of one nutrient with a marked deficiency of the other suggested the existence of a controlling mechanism in
E. coli
which regulated the processes of cell division and survival, depending on the combination of conditions.
Influence of Isoleucine upon Quinomycin Biosynthesis by
Streptomyces
sp. 732
Authors: Yoshida Tadashi , Katagiri Ken
Published: January 2020

When
dl
-isoleucine was added to an ammonium nitrate-maltose medium during cultivation of
Streptomyces
sp. 732, quinomycin B formation was selectively enhanced (from 3 to 70% of the quinomycin mixture) and quinomycin C synthesis was inhibited completely. In addition, two new quinomycins, designated quinomycins D and E, were produced in the presence of isoleucine. These compounds were found to contain
N
-methylalloisoleucine. In experiments with isoleucine enantiomorphs, it was determined that the order of effectiveness for quinomycin B synthesis was
dl
-isoleucine >
d
-isoleucine >
l
-isoleucine. The extent to which quinomycin B synthesis is enhanced depends upon the concentration and the time of addition of isoleucine to the medium. The effect of
dl
-isoleucine was reduced to some extent by the addition of
l
-valine. It is conceivable that amino acids which are precursors of the
N
-methylamino acids in quinomycin can regulate quinomycin formation.
Effect of Abrupt Temperature Shift on the Growth of Mesophilic and Psychrophilic Yeasts
Authors: Shaw Maxwell K.
Published: January 2020

Exponentially growing cultures of mesophilic and psychrophilic yeasts were subjected to abrupt changes in temperature. Temperature shifts made within the range in which the temperature characteristic, μ, is relatively constant (moderate temperatures) immediately induced growth at the normal exponential rate for the new temperature. Prior incubation at temperatures defined as moderate enabled some yeasts to grow for a few generations at temperatures higher than their normal maximal temperature for growth. Shifts made to or from temperatures above or below those in the moderate temperature range resulted in growth rates that were intermediate between the normal steady-state rates for the initial and final temperatures. A period of transient growth rate at the new temperature outside the moderate temperature range seems to be required before normal steady-state growth rates can be attained after such temperature shifts. The psychrophiles gave transient growth rates only below 10 C, whereas the mesophiles gave transient rates below 20 C. However, the psychrophiles cannot be distinguished from the mesophiles on the basis of the temperature characteristic, μ, which was found to be about 12,000 cal/mole for both types.
Adenosine Triphosphate-Linked Control of
Pseudomonas aeruginosa
Glucose-6-Phosphate Dehydrogenase
Authors: Lessie T. , Neidhardt F. C.
Published: January 2020

Extracts of
Pseudomonas aeruginosa
(ATCC 7700) cells grown on glucose, gluconate, or glycerol had enzyme activities related to the Entner-Doudoroff pathway. These activities were present in no more than trace amounts when the bacteria were grown on succinate. Fructose-1,6-diphosphate aldolase could not be detected in extracts of the bacteria grown on any of the above carbon sources. Therefore, it appears that
P. aeruginosa
degrades glucose via an inducible Entner-Doudoroff pathway. The apparent absence of fructose-1,6-diphosphate aldolase in cells growing on succinate suggests that the bacteria can form hexose and pentose phosphates from succinate by an alternate route.
d
-Glucose-6-phosphate dehydrogenase, a branch-point enzyme of the Entner-Doudoroff pathway, was purified 50-fold from glucose-grown cells. Its molecular weight, estimated by sucrose density gradient centrifugation, was found to be approximately 190,000. The enzyme was strongly inhibited by adenosine triphosphate, guanosine triphosphate, and deoxyguanosine triphosphate, which decreased the apparent binding of glucose-6-phosphate to the enzyme. It is suggested that adenine nucleotide-linked control of glucose-6-phosphate dehydrogenase may regulate the overall catabolism of hexose phosphates and prevent their wasteful degradation under certain conditions requiring gluconeogenesis.
Kinetics of Lethal Adsorption of Colicin E2 by
Escherichia coli
Authors: Shannon R. , Hedges A. J.
Published: January 2020

The kinetics of lethal adsorption of colicin E2 by
Escherichia coli
C6 were studied by means of survivor plots. These were determined by a method which allowed rapid sampling of the reaction mixture and estimation of approximate confidence limits for the plotted data. The results were consistent with the predictions of a hypothetical model that assumed a single-hit mechanism of colicin action upon a bacterial population whose cells varied in their number of specific (lethal) receptors for colicin. The possibility of nonlethal adsorption is discussed.
Glucose-Lactose Diauxie in
Escherichia coli
Authors: Loomis William F. , Magasanik Boris
Published: January 2020

Growth of
Escherichia coli
in medium containing glucose, at a concentration insufficient to support full growth, and containing lactose, is diauxic. A mutation in the gene, CR, which determines catabolite repression specific to the
lac
operon, was found to relieve glucose-lactose but not glucose-maltose diauxie. Furthermore, a high concentration of lactose was shown to overcome diauxie in a CR
+
strain. Studies on the induction of β-galactosidase by lactose suggested that glucose inhibits induction by 10
−2
m
lactose. Preinduction of the
lac
operon was found to overcome this effect. The ability of glucose to prevent expression of the
lac
operon by reducing the internal concentration of inducer as well as by catabolite repression is discussed.
Characterization ofMycoplasma pulmonisVariants Isolated from Rabbits II. Basis for Differentiation of Antigenic Subtypes
Authors: Deeb Barbara J. , Kenny George E.
Published: January 2020

The antigen composition ofMycoplasma pulmonisvariants was studied by complement-fixation, agar-gel diffusion, and growth-inhibition tests. Two classes of complement-fixing antigens were demonstrated forM. pulmonisstrains 47 and 63: (i) cross-related, heat-labile, water-soluble antigens, and (ii) high-titered, subtype-specific, heat-stable, water-soluble antigens. Lipid antigens prepared by organic solvent fractionation were low-titered antigens and showed little specificity. With the aid of agar-gel double-diffusion plates, the subtype-specific antigens were found to be precipitated by trichloroacetic acid and to be stable to periodate, but they were inactivated by pronase. Pronase-stable, periodate-labile precipitating antigens were observed as common components between the two variants. Antisera prepared with boiled antigens were found to be serologically active on gel diffusion but lacked neutralizing ability in growth-inhibition tests. Each of three strains ofM. pulmonis(47, 63, ATCC 14267) could be identified as a variant because each strain possessed immunologically distinct heat-stable subtype-specific antigen(s).
Local and Regional Applications of Hydrogen Peroxide in the Control of Clostridial Myositis in Rabbits
Authors: Finney J. W. , Haberman S. , Race G. J. , Balla G. A. , Mallams J. T.
Published: January 2020

The intra-arterial infusion of hydrogen peroxide has been used as a method for producing a hyperoxic environment in experimental animals for the treatment of experimentally induced clostridial myositis. Eighty-five rabbits were employed in this study; 43 were controls and 42 were experimental animals. In the experimental study, 21 animals were treated with hydrogen peroxide by each route of administration. In this group, 52.4% of the animals receiving the intra-arterial infusion and 66.6% receiving intramuscular clysis survived. There were no survivors past 72 hr in the control group.
Bacteriocin Produced by
Bordetella pertussis
Authors: Litkenhous Claudia , Liu P. V.
Published: January 2020

Of the 24 strains of
Bordetella pertussis
examined, 2 produced bacteriocins that inhibited the growth of all but 2 other strains of this species. The two strains producing the bacteriocin and the two resistant strains were rough, whereas all susceptible strains were smooth. The bacteriocin was not active on the
B. parapertussis
or
B. bronchiseptica
strains tested. These bacteriocins appeared to be protein in nature, since they were heat-labile and partially inactivated by trypsin. They were antigenic but the neutralizing antibodies did not precipitate the antigens. Absorption of the antiserum with homologous cell suspensions removed the agglutinating, but not the neutralizing, antibody.
Immunosuppressive Activity of the 3a-1 Fraction of Papain
Authors: Clagett James A. , Engelhard Warren E.
Published: January 2020

The maximal nonlethal dose of the 3a-1 fraction of papain, determined by use of 9-week-old white albino rabbits, was 10 mg per injection, administered intravenously. The immunosuppressive activity of the 3a-1 fraction of papain was studied by its inhibition of sheep red blood cell hemolysin, bacterial agglutinin, and horse serum precipitin. Immune suppression was observed when papain injections preceded antigen injections by 12 to 18 hr. The enzyme preparation was analyzed by use of cellulose acetate and starch-gel electrophoresis and by the micro-Kjeldahl method. Starch-gel electrophoresis of serum samples revealed qualitative alterations in the α
−1
region 7 hr after papain administration. Changes were also observed in the urinary aminopolysaccharide content.
Stability of Ribosomes and Ribosomal Ribonucleic Acid from
Bacillus stearothermophilus
Authors: Friedman S. Marvin , Axel Richard , Weinstein I. Bernard
Published: January 2020

After heating at 65 C, ribosomes isolated from
Bacillus stearothermophilus
were strikingly more heat-stable than comparable preparations from
Escherichia coli
when tested for ability to support polyuridylic acid-directed phenylalanine incorporation at 37 C. The stability of ribosomes was also determined by measurements of hyperchromicity at 259 mμ while heating them from 25 to 90 C. In standard buffer containing 0.01
m
Mg
++
, the T
m
(temperature at the midpoint of total hyperchromicity) of
E. coli
and
B. stearothermophilus
ribosomes was 71 and 81 C, respectively. In a magnesium-free buffer, the T
m
of
E. coli
and
B. stearothermophilus
ribosomes was 44 and 64 C, respectively. Putrescine (0.01
m
) was more effective in stabilizing ribosomes from
B. stearothermophilus
than those from
E. coli
. Spermidine (0.001
m
), on the other hand, was more effective in stabilizing ribosomes from
E. coli
than those from
B. stearothermophilus
. Melting curves of total ribosomal ribonucleic acid (rRNA) from
E. coli
and
B. stearothermophilus
revealed T
m
values of 50 and 60 C, respectively. Putrescine stabilized thermophile rRNA, but had no effect on
E. coli
rRNA. Sucrose density gradients demonstrated that thermophile 23
S
ribonucleic acid was degraded during storage at −20 C; the 23
S
component from
E. coli
was stable under these conditions. The results are discussed in terms of the mechanism of ribosome heat stability and the role of the ribosome in governing the temperature limits for bacterial growth.
Effect of
l
-Methionine and
S
-Adenosylmethionine on Growth of an Adenine Mutant of
Saccharomyces cerevisiae
Authors: Yall Irving , Norrell Stephen A. , Joseph Ronald , Knudsen Richard C.
Published: January 2020

A pink, adenine-requiring yeast utilized adenine, hypoxanthine, or
S
-adenosylmethionine (SAM), in quantities up to 3 μmoles per 100 ml of medium, as equivalent sources of purine for cell growth, but not methylthioadenosine or
S
-adenosylhomocysteine. Utilization of SAM for growth was inhibited by the presence of
l
-methionine in quantities greater than 0.6 μmole per 100 ml of medium. However, 6 μmoles of
l
-methionine had no effect on growth when adenine or hypoxanthine was the source of purine. These sources also reversed the inhibitory effects of 6 μmoles of the amino acid on the utilization of SAM. The presence of 400 μmoles of the amino acid resulted in some inhibition of growth when the organisms were grown with adenine, hypoxanthine, or adenine plus SAM but had no effect on the total uptake of adenine-
8
-
14
C
. Studies on the uptake of radioactivity from a mixture of SAM-adenine-
8
-
14
C
and
3
H-labeled SAM-methyl indicated that these components were taken into the cells at different rates which were altered by the presence of
l
-methionine. The fixation of
35
S from
35
S-labeled adenosylmethionine into the cells was inhibited by the presence of the amino acid. The cells synthesized and accumulated SAM in the presence of 400 μmoles of
l
-methionine plus adenine even when exogenous SAM was supplied. Approximately 47% of radioactivity fixed from exogenous SAM-adenine-
8
-
14
C
and 12% from
3
H-labeled SAM-methyl were found in reisolated SAM.
Glucose and Gluconate Metabolism in an
Escherichia coli
Mutant Lacking Phosphoglucose Isomerase
Authors: Fraenkel D. G. , Levisohn S. R.
Published: January 2020

A single gene mutant lacking phosphoglucose isomerase (
pgi
) was selected after ethyl methane sulfonate mutagenesis of
Escherichia coli
strain K-10. Enzyme assays revealed no
pgi
activity in the mutant, whereas levels of glucokinase, glucose-6-phosphate dehydrogenase, and gluconate-6-phosphate dehydrogenase were similar in parent and mutant. The amount of glucose released by acid hydrolysis of the mutant cells after growth on gluconate was less than 2% that released from parent cells; when grown in the presence of glucose, mutant and parent cells contained the same amount of glucose residues. The mutant grew on glucose one-third as fast as the parent; it also grew much slower than the parent on galactose, maltose, and lactose. On fructose, gluconate, and other carbon sources, growth was almost normal. In both parent and mutant, gluconokinase and gluconate-6-phosphate dehydrase were present during growth on gluconate but not during growth on glucose. Assay and degradation of alanine from protein hydrolysates after growth on glucose-
1
-
14
C
and gluconate-
1
-
14
C
showed that in the parent strain glucose was metabolized by the glycolytic path and the hexose monophosphate shunt. Gluconate was metabolized by the Entner-Doudoroff path and the hexose monophosphate shunt. The mutant used glucose chiefly by the shunt, but may also have used the Entner-Doudoroff path to a limited extent.
Genetic Mapping of Mutations Affecting Phosphoglucose Isomerase and Fructose Diphosphatase in
Escherichia coli
Authors: Fraenkel D. G.
Published: January 2020

The loci on the
Escherichia coli
genome of mutations affecting phosphoglucose isomerase (
pgi
) and fructose diphosphatase (
fdp
) have been determined by conjugation and transduction experiments, chiefly three-factor crosses. The loci for these two constitutive enzymes of central intermediary metabolism lie in the same region of the chromosome, but they are not cotransducible. The order of some markers in this region of the chromosome is
arg
(
ACFH
)
metA pgi malB uvrA fdp pyrB thr
.
Transduction by Bacteriophage P22 in Nonsmooth Mutants ofSalmonella typhimurium
Authors: Gemski P. , Stocker B. A. D.
Published: January 2020

The general transducing phage P22 attacks only smooth (S)Salmonellawith O antigen 12, determined by the oligosaccharide repeating unit constituting the distal part of the somatic lipopolysaccharide (LPS) side chain; non-S mutants, whose LPS contain few or no O repeating units, appear to be resistant. Auxotrophic non-S mutants ofSalmonella typhimuriumLT2 were tested as transductional recipients. Some transductants (0.5 to 5% as many as from S recipients) were obtained from most semirough recipients, either of class D (presumed leakyrouAmutants) or of a class due to mutation nearhis(presumed leakyrouBmutants), and from recipients lacking uridine diphosphogalactose epimerase or phosphomannose isomerase. Transductants were not obtained from severalrouA, rouB, “heptose-negative,” and glucose-1-transferase mutants, nor from most semirough class C mutants, whose LPS side chains each bear a single O oligosaccharide unit. Most transductants evoked from non-S recipients by temperate (c+) phage P22 were nonlysogenic, and virulent P22.c2phage was about as effective as P22.c+in transduction to non-S recipients; probably all P22 transducing particles neither lysogenize nor kill. The extended-host-range mutant P22h gave qualitatively similar results,but evoked 5- to 30-fold more transductants from some non-S recipients than did P22. Probably, the LPS of non-S mutants susceptible to transduction contains a few O-specific oligosaccharide units, conferring a slight ability to adsorb P22 and a greater ability to adsorb P22h.
Phosphorylation in Hydrogen Bacteria
Authors: Bongers Leonard
Published: January 2020

The electron-transport system of cell-free extracts obtained from
Hydrogenomonas
H-20 has been studied with particular reference to phosphorylation associated with the oxyhydrogen reaction. Cell-free preparations of this organism exhibit oxidative phosphorylation with hydrogen and succinate as electron donors. This activity could be uncoupled with a number of agents. Ratios of phosphorylative activity to oxidative activity observed varied from 0.2 to 0.7. Factors affecting the efficiency of phosphorylation were examined. Inhibitor and spectrophotometric studies indicated that phosphorylation with hydrogen as electron donor occurs exclusively at a site in an abbreviated electron transport chain between H
2
and cytochrome
b
. The possible occurrence of a cytochrome
b
oxidase and the requirement for a quinone are discussed, as well as the correlation between the abbreviated pathway and the energy generation by the cell. Evidence is presented which indicates that nicotinamide adenine dinucleotide does not participate in the hydrogen oxidation path which is coupled to adenosine triphosphate formation.
Macromolecule Synthesis in Temperature-sensitive Mutants of Yeast
Authors: Hartwell Leland H.
Published: January 2020

Approximately 400 temperature-sensitive mutants of
Saccharomyces cerevisiae
were isolated. The mutants were unable to form colonies on enriched media at 36 C, but grew normally, or nearly so, at 23 C. The mutants were tested for loss of viability, change in morphology, increase in cell number, and the ability to synthesize protein, ribonucleic acid (RNA), and deoxyribonucleic acid (DNA) after a shift from 23 to 36 C. Mutations were found which resulted in a preferential loss of ability to carry out protein synthesis, RNA synthesis, DNA synthesis, cell division, or cell-wall formation. Diploid cells heterozygous for the temperature-sensitive mutations were constructed and tested for their ability to form colonies at 36 C. Four mutations dominant to their wild-type allele were identified.
Streptococcal Sialidase I. Isolation and Properties of Sialidase Produced by Group K Streptococcus
Authors: Hayano Seiki , Tanaka Atsuko
Published: January 2020

A survey has been made of the activity of a wide variety of standard strains of streptococci against bovine submaxillary mucin. Strain 6646 (group K) and strain D 168A “X” (group M) completely broke down and strain H 60R (group F) incompletely broke down bound sialic acid of bovine submaxillary mucin added to the growth medium. Among these strains, strain 6646 (group K) produced sialidase in the cell and in the culture fluid. An appropriate amount of glucose in the culture medium stimulated growth and the production of enzyme, but an excess of glucose in the culture medium caused abundant growth without production of the enzyme. The streptococcal sialidase was precipitated from the culture fluid by ammonium sulfate at 50% saturation, and further purification was achieved by diethylaminoethyl cellulose chromatography. Ca
++
and Co
++
stimulated the sialidase activity, and Mn
++
, Zn
++
, and ethylenediaminetetraacetate inhibited it. With acetate buffer, the optimal
p
H lay between 5 and 6. Sialic acid was detected in the reaction product of the streptococcal sialidase and bovine submaxillary mucin.
Effect of
Streptococcus pyogenes
on Tissue Cells
Authors: Quinn Robert W. , Lowry P. Nye
Published: January 2020

Human tissue cell lines from each of the three primary germinal sources, ectoderm (conjunctiva and carcinoma of the buccal mucosa), entoderm (intestine and liver), and mesoderm (heart and monocytes) were inoculated with group A
Streptococcus pyogenes, Staphylococcus aureus
, and group D streptococci and were then observed. In addition, the effect of these bacteria on mouse fibroblasts was studied. All of the cell lines appeared to be equally susceptible to damage, but damage to the cells by
S. pyogenes
occurred only when living, actively multiplying bacteria were in contact with the tissue cells. Streptococcal products in the form of “used” growth medium had no observable effect on the cells. Cytopathogenic effects were first noticed about the time one would expect the bacteria to have reached the end of the log phase of growth. No damage to the tissue cells was noted when group A streptococci were separated from the cells by membrane filter diffusion chambers or dialyzing membranes, but a membrane did not protect cells from deleterious effects of staphylococci or group D streptococci. Group A streptococci survived in the tissue culture medium, but multiplication did not occur unless living tissue cells were present.
Phospholipids and Glycolipids of Sterol-requiringMycoplasma
Authors: Smith Paul F. , Koostra Walter L.
Published: January 2020

The phospholipids ofMycoplasma hoministype 2 strain 07 are composed almost entirely of phosphatidyl glycerol. Traces of other glycerophospholipids may exist. No glycolipids are found. The phospholipids ofMycoplasmasp. avian strain J are composed of diphosphatidyl glycerol, which predominates in older cultures, a monoacyl glycerophosphoryl glycerophosphate, which may serve as a precursor of diphosphatidyl glycerol, and phosphatidyl glycerophosphate. This organism also contains cholesteryl glucoside and an unidentified glycolipid which appears to be similar to a monoglucosyl diglyceride. No turnover or radioisotope labeling of the phospholipids occurs during metabolism. This lack of turnover during growth is indicative of a structural role for these glycerophospholipids. A concomitant decrease of monoacyl glycerophosphoryl glycerophosphate and increase of diphosphatidyl glycerol occurs during growth.
Immunoadsorbent for the Isolation of Bacterial Specific Antibodies
Authors: Weetall Howard H.
Published: January 2020

A new method is described for the isolation and purification of large quantities of bacterial specific antibodies. The technique involves the use of polymerized microorganisms as a specific immunoadsorbent. There should be wide application of this method for the purification of antibodies to various types of microorganisms, provided that the polymerization process does not result in the loss of specific antigenic determinants.
Colonial Recognition, a “New” Approach for Rapid Diagnostic Enteric Bacteriology
Authors: Finkelstein Richard A. , Punyashthiti Kannikar
Published: January 2020

The morphology, on MacConkey's agar, of colonies of the bacteria commonly found in enteric specimens is sufficiently characteristic and distinctive, when observed with transmitted oblique illumination and a low-power stereoscopic microscope, to enable identification at the generic (and occasionally the species) level with over 97% accuracy. Application of this technique resulted in great savings of time, manipulative steps, and media compared with the usual procedures of diagnostic enteric bacteriology, and there was an increase in sensitivity without sacrificing accuracy.
Fatty Acid Synthetase of
Saccharomyces cerevisiae
Authors: Klein Harold P. , Volkmann Carol M. , Chao Fu-Chuan
Published: January 2020

A light particle fraction of
Saccharomyces cerevisiae
, obtained from the crude ribosomal material, and containing the fatty acid synthetase, consisted primarily of 27
S
and 47
S
components. This fraction has a protein-ribonucleic acid ratio of about 13. Electron micrographs showed particles ranging in diameter between 100 and 300 A in this material. By use of density gradient analysis, the fatty acid synthetase was found in the 47
S
component. This component contained particles which were predominantly 300 A in diameter and which were considerably flatter than ribosomes, and it consisted almost entirely of protein.
Aerobic Microbial Growth at Low Oxygen Concentrations
Authors: Johnson Marvin J.
Published: January 2020

Sterilizable membrane probes were used to study the relation between oxygen concentration and respiration rate in
Candida utilis
growing on acetate. When the organism was grown in a continuous fermentor at various dissolved oxygen concentrations (0.23 × 10
−6
to 32 × 10
−6
m
), with time allowed for full adaptation to each oxygen concentration, the relationship between oxygen concentration and growth rate simulated Michaelis-Menten behavior, giving an apparent
K
m
for oxygen of 1.3 × 10
−6
m
. When respiration rate was measured at various oxygen concentrations without allowing time for adaptation, it was found that the respiration rate was directly proportional to O
2
concentration at low O
2
concentrations, and independent of O
2
concentration at high O
2
concentrations. Transition from one type of behavior to the other was fairly abrupt. The respiration rate in the presence of excess oxygen depended on the O
2
concentration at which the cells were grown, but the rate at low O
2
concentrations did not. There was evidence that, at low oxygen concentrations, oxygen diffusion through the cell substance limits respiration rate, at least in part.
Deoxyribonucleic Acid Homology and Taxonomy of
Agrobacterium, Rhizobium
, and
Chromobacterium
Authors: Heberlein Gary T. , De Ley J. , Tijtgat R.
Published: January 2020

Hybridization experiments were carried out between high molecular weight, denatured, agar-embedded deoxyribonucleic acid (DNA) and homologous, nonembedded, sheared, denatured
14
C-labeled DNA from a strain of
Agrobacterium tumefaciens
and
Rhizobium leguminosarum
(the reference strains) in the presence of sheared, nonembedded, nonlabeled DNA (competing DNA) from the same or different nomen-species of
Agrobacterium, Rhizobium, Chromobacterium
, and several other organisms. Percentage of DNA homology was calculated from the results. The findings are discussed in relation to previous taximetric studies, present classification schemes, and guanine-cytosine content of the DNA. Strains of
A. tumefaciens, A. radiobacter, A. rubi, A. rhizogenes, R. leguminosarum
, and
R. meliloti
exhibited a mean percentage of DNA homology greater than 50 with the two reference strains.
A. tumefaciens, A. radiobacter
, and
A. rubi
were indistinguishable on the basis of DNA homology, with strain variations for this group involving up to 30% of their base sequences. The remainder of the organisms studied fall into at least six distinct genetic groups: (i)
R. (Agrobacterium) rhizogenes
, which is more homologous to
R. leguminosarum
than to the
A. tumefaciens-A. radiobacter
group; (ii)
R. leguminosarum
; (iii)
R. meliloti
; (iv)
R. japonicum
, which has a mean DNA homology of some 38 to 45% with the reference strains; (v)
Chromobacterium
, which is as genetically remote from the reference strains as, for example,
Pseudomonas
; and (vi)
A. pseudotsugae
strain 180, which has a DNA homology with
A. tumefaciens
and
R. leguminosarum
of only about 10%. Since this latter homology value is similar to what was found after hybridizations between the reference strains and organisms such as
Escherichia coli
and
Bacillus subtilis, A. pseudotsugae
should definitely be removed from the genus.
Role of the Phagocyte in Host-Parasite Interactions VIII. Effect of Whole-Body X Irradiation on Nicotinamides, Lysosomal Enzymes, and Bactericidal Activities of Leukocytes During Phagocytosis
Authors: Selvaraj R. J. , Sbarra A. J.
Published: January 2020

By studying the effects of whole-body X irradiation on phagocytosis, a correlation between the metabolic and bactericidal activities of leukocytes following X irradiation was demonstrated. The total nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) content of polymorphonuclear neutrolphils (PMN) isolated from irradiated guinea pigs increased significantly when compared to nonirradiated controls. The ratio of unreduced to reduced (NAD) generally increased in PMN isolated from irradiated animals. This occurred with both resting and phagocytizing cells. The ratio of unreduced to reduced NADP of resting PMN isolated from irradiated animals had a tendency to increase. However, in phagocytizing cells a significant decrease in the ratio was noted. The total acid and alkaline phosphatase and β-glucuronidase increased up to about 10 days postirradiation. These lysosomal enzymes returned to approximately normal by the 17th day postirradiation. All three lysosomal enzymes (acid and alkaline phosphatases and β-glucuronidase) were released from the granules at a significantly faster rate during phagocytosis after irradiation. The bactericidal activities of PMN isolated from irradiated animals gradually decreased, and in some cases increased growth of the organisms was observed. The uptake or association of bacteria with PMN isolated from irradiated animals varied with the postirradiation time. Generally, a correlation with bactericidal activities could be made. The data indicate that the bactericidal system in phagocytes consists of at least two agents, H
2
O
2
and myeloperoxidase.
Ordered Synthesis of Proteins During Outgrowth of Spores of
Bacillus cereus
Authors: Torriani Annamarie , Levinthal Cyrus
Published: January 2020

The onset of macromolecular synthesis in activated spores of
Bacillus cereus
occurs under conditions in which the amino acids and nucleotides to be used for building proteins and nucleic acids must be derived only from stored pools and turnover of macromolecules of the spore. Upon addition of the factors required to initiate germination,
14
C-uracil is incorporated with a lag of 30 to 60 sec;
14
C-amino acids, with a lag of 3 to 4 min. The progression of protein synthesis during germination has been studied, and the results suggest three phases of development of the protein synthetic pattern of these germinating spores. The initial synthesis which occurs during the early part of germination is limited to only a few proteins. When the initiated spores are put in a medium containing a complete set of growth requirements and outgrowth ensues, the cells synthesize a large number of different proteins so that the distribution of radioactivity into different fractions appears to be a continuous function. At a later time during outgrowth, the distribution of synthetic rates among the different proteins becomes more representative of that found during vegetative growth.
Pesticins III. Expression of Coagulase and Mechanism of Fibrinolysis
Authors: Beesley E. D. , Brubaker R. R. , Janssen W. A. , Surgalla M. J.
Published: January 2020

Mutational loss of pesticin I, a bacteriocin-like substance produced by
Pasteurella pestis
, is known to result in concomitant loss of a coagulase and fibrinolytic factor. No relationship was detected between pesticinogeny and other tested properties either associated with virulence or peculiar to
P. pestis
. Pesticin I was distinguished from the coagulase and fibrinolytic activities on the basis of anatomical distribution, behavior during gel filtration, and sensitivity to heat. Coagulase and the fibrinolytic factor were not differentiated by these criteria. Spontaneous suppressor mutations causing reversion to pesticinogeny were not detected, nor were such mutants obtained by treatment with ultraviolet light or 2-aminopurine. Attempts to demonstrate a common activator of pesticin I, coagulase, or the fibrinolytic factor in extracts of pesticinogenic cells were not successful. These results are in accord with the hypothesis that at least two structural genes for the three activities reside on a replicon distinct from the chromosome proper. Fibrinolytic activity was significantly reduced in the presence of 0.003
m
ε-aminocaproic acid and was nonexistent on fibrin films freed from endogenous plasminogen by treatment with heat. Fibrinolytic activity on heated films could be restored by addition of plasma or serum from six mammalian species. Accordingly, the plague fibrinolytic factor, like staphylokinase or urokinase, promotes the conversion of plasminogen to plasmin.
Growth of the Fission Yeast,
Schizosaccharomyces pombe
, with Late, Eccentric, Lytic Fission in an Unbalanced Medium
Authors: Johnson Byron F.
Published: January 2020

Growth of
Schizosaccharomyces pombe
in batch cultures in a commercial defined medium was found to be normal until the last generation before the stationary phase. Approximately one-half the progeny of the last division lysed. Lysis occurred at breaks in the cell wall at cell-plates whose fission was eccentric. Normal culture cycle patterns were obtained when the medium was balanced by addition of either 0.20 mg of
l
-asparagine per ml or 5.0 mg of KH
2
PO
4
per ml, or both. The lytic effect of growth in the unbalanced medium was compared with similar effects of growth in 2-deoxyglucose. These studies with 2-deoxyglucose in the balanced medium confirmed earlier cytological observations (lysis at all growing points), but showed that the similarities were superficial.
Ultrastructure of the Obligate Halophilic Bacterium
Halobacterium halobium
Authors: Cho K. Y. , Doy Colin H. , Mercer E. H.
Published: January 2020

The fine structure of
Halobacterium halobium
was studied by means of a modified double-fixation technique. The cell envelope is shown to consist of both a “wall” and a plasma membrane. Some electron-dense strands were seen inside the cytoplasm running parallel to the cell envelope. An unusual organelle (or organelles) appeared inside the cytoplasm in the form of parallel striated strands.
Fine Structure of Quiescent and Germinating Aeciospores of
Cronartium fusiforme
Authors: Walkinshaw Charles H. , Hyde James M. , Zandt Janice Van
Published: January 2020

Aeciospores of the long-cycle heteroecious rust fungus,
Cronartium fusiforme
, were found to have an extremely thick cell wall with striking spicules protruding from it. The wall was readily degraded by commercial chitinase, but spicules were unaffected. Quiescent spores contained two nuclei with distinct nuclear membranes possessing many pores. Numerous membrane-bounded lipid bodies were found both in wild-type orange and in white mutant aeciospores. An abundance of irregularly ovoid mitochondria was present in quiescent spores. After glutaraldehydeosmium fixation, the surface of the mitochondria appeared to be covered with ribosomes or microtubules in a paracrystalline array, whereas after permanganate fixation only smooth outer mitochondrial membranes were noted. The latter fixative revealed abundant vesicular endoplasmic reticulum in the spore. Spores incubated at 20 C on agar produced one to five distinct germ tubes within 65 to 180 min. These thin-walled tubes exhibited varying degrees of branching, and reached a total hyphal length of 300 to 500 μ prior to rupturing. Emergence of germ tubes took place through a pore in the spore wall and appeared to be mainly a physical flowing of cytoplasm from the spore into the germ tube without division of nuclei or other cell organelles. On completion of germination, the protoplasm of the germ tube contained both nuclei and nearly all of the other spore contents. Mitochondria had smooth outer membranes, were greatly elongated, and possessed distinct longitudinal cristae. A limited amount of rough endoplasmic reticulum was arranged parallel to the germ tube wall. Other organelles seen in germ tubes were lipid bodies, concentric membrane figures, and numerous ribosomes. Lipid bodies appeared smaller and fewer in number than in quiescent spores.
Phosphohydrolases of a
Bacillus subtilis
Mutant Accumulating Inosine and Hypoxanthine
Authors: Demain Arnold L. , Hendlin David
Published: January 2020

Although adenine-requiring auxotrophs of
Bacillus subtilis
accumulate large quantities of inosine or hypoxanthine, or of both, they do not accumulate inosine-5′-monophosphate (IMP). Experiments directed at understanding this phenomenon were conducted with an adenineless auxotroph and with a mutant derived from it which lacked alkaline phosphohydrolase. It was found that
B. subtilis
contains four different phosphohydrolases. Only one is an extracellular enzyme; it is a 5′-nucleotide phosphohydrolase which can be inhibited by addition of CuSO
4
to the medium. Of the three cellular enzymes, only one, an acid phosphohydrolase, cannot attack 5′-nucleotides; this enzyme is not repressed by inorganic phosphate. One of the two remaining surface-bound enzymes is a nonspecific alkaline phosphohydrolase which attacks both 5′-nucleotides and
p
-nitrophenyl phosphate; this is the only phosphohydrolase that is markedly repressed by inorganic phosphate. The other surface-bound enzyme is a nonrepressible 5′-nucleotide phosphohydrolase with double
p
H optima: one at neutrality and the other near
p
H 9.0. The experiments indicate that the absence of IMP in the extracellular broth is due to degradation of internally accumulated IMP to inosine by the cellular 5′-nucleotide phosphohydrolase.
Protein Synthesis in a Cell-Free Extract from
Staphylococcus aureus
Authors: Mao James C.-H.
Published: January 2020

Cell-free
Staphylococcus aureus
extracts have been prepared which actively incorporate amino acids into protein. The requirements for amino acid incorporation of this preparation were strongly suggestive of de novo protein synthesis, since it showed an absolute requirement for ribosomes, 105,000 ×
g
supernatant fluid, energy source, and magnesium ion. The stability of these extracts was greatly improved by use of dithiothreitol instead of mercaptoethanol as a sulfhydryl protecting reagent. Data were presented to show that the binding of aminoacyl-soluble ribonucleic acid to ribosomes did not require guanosine triphosphate and supernatant enzyme. The major characteristic which distinguishes this system from other cell-free systems is the much higher magnesium concentration required to maintain ribosomes intact and to obtain the maximal incorporation of amino acids. Addition of polyuridylic acid, polyadenylic acid, or polycytidylic acid caused about 60-fold, 30-fold, or 4-fold stimulation of the incorporation of phenylalanine, lysine, or proline, respectively. Studies by density gradient sedimentation indicated that radioactive polyuridylic acid or polyadenylic acid was associated with the monosomes. This complex can actively synthesize polypeptides. On the other hand, the nascent protein synthesized under the direction of endogenous messenger ribonucleic acid was associated with both polysomes and monosomes.
Staphylococcal β-Hemolysin I. Purification of β-Hemolysin
Authors: Maheswaran S. K. , Smith K. L. , Lindorfer Robert K.
Published: January 2020

The purification of staphylococcal β-hemolysin was accomplished by the successive use of three protein fractionation methods. The first method employed was a double precipitation with the use of ammonium sulfate at 65% saturation. The second phase of purification used Sephadex G-100 column fractionation. The third phase utilized either carboxymethyl cellulose or diethylaminoethyl cellulose fractionation. The last two fractionation methods both resulted in the separation of a relatively high concentration of cationic hot-cold lysin and a low concentration of anionic hot-cold lysin. Because of the low concentration of the anionic component, its purity could not be assessed. However, the purity of the cationic component was demonstrated by immunodiffusion, microimmunoelectrophoresis, and by disc polyacrylamide gel electrophoresis. In addition, antisera against purified cationic β-hemolysin yielded one line of precipitate when tested against the original crude β-hemolysin. The purified cationic β-hemolysin was stable in the lyophilized state. Crude β-hemolysin was dermonecrotic, whereas purified cationic β-hemolysin was not dermonecrotic even after Mg++activation.