bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Properties of a Vi Antigen-Degrading Enzyme
Authors: Baker Edgar E. , Whiteside Roberta E.
Published: January 2020

Baker, EdgarE. (Boston University School of Medicine, Boston, Mass.),and Roberta E. Whiteside. Preparation and properties of a Vi antigen-degrading enzyme. J.Bacteriol.89:1217–1224. 1965.—Vi antigen can be hydrolyzed by an inducible enzyme produced by a microorganism isolated from soil. The organism can be identified asBacillus sphaericus. The enzyme in the culture supernatant fluid can be concentrated and partially purified by precipitation with ammonium sulfate at 50% of saturation. The partially purified enzyme is relatively stable. Incubation of the enzyme with Vi antigen causes a rapid loss of serological activity, a decrease in viscosity, the loss of ability to precipitate albumin atpH 4.0, and the production of reducing sugar and hexosamine. Optimal conditions for enzyme action on Vi antigen arepH 8.4 and 40 C. The reaction rate is independent of the substrate concentration. Intact protein and calcium activates the Vi antigen-enzyme system. The enzyme is not inhibited by its reaction products.
Nonphotoreactivating Repair of Ultraviolet Light-Damaged
Micrococcus lysodeikticus
Cells
Authors: Elder Robert L. , Beers Roland F.
Published: January 2020

Elder, Robert
L. (Johns Hopkins University, Baltimore, Md.),
and Roland F. Beers, Jr.
Nonphotoreactivating repair of ultraviolet light-damaged
Micrococcus lysodeikticus
cells. J. Bacteriol.
89:
1225–1230. 1965.—
Micrococcus lysodeikticus
cells are highly resistant to ultraviolet radiation. The shape of the dose-survival curve is consistent with the presence of a repair mechanism. The presence of nontoxic doses of dinitrophenol (0.1 m
m
) or iodoacetate (1 m
m
) before or after radiation decreases the survival number and the initial lag in the dose-kill curve. The extent of decrease in survival after postradiation treatment with these compounds is dependent upon both time and temperature. Organisms that survive radiation show a prolonged lag phase before multiplying. No photoreactivation of the radiated cells can be demonstrated. Ultraviolet-radiated phage show a higher inactivation when plated on host cells of
M. lysodeikticus
treated with dinitrophenol at concentrations which do not affect the infectivity of nonradiated phage. The resistance of these cells to ultraviolet radiation is the result of a very efficient dark-cell repair mechanism that can be blocked by iodoacetate or dinitrophenol.
New Assay for Penicillinase and Some Results on Penicillinase Induction
Authors: Imsande John
Published: January 2020

Imsande, John
(Western Reserve University, Cleveland, Ohio). New assay for penicillinase and some results on penicillinase induction. J. Bacteriol.
89:
1322–1327. 1965.—A rapid, sensitive, and reliable assay of penicillinase activity is described. Studies conducted on the induction of penicillinase, with use of the new assay, show that actinomycin D inhibits growth and the induced synthesis of penicillinase in
Bacillus cereus
569. These inhibitory effects can be reversed to various degrees by deoxyguanosine, depending upon the time lapse between the addition of the antibiotic and the addition of the deoxynucleoside. Inhibition of growth is reversed more readily than inhibition of penicillinase induction, and it is suggested that actinomycin D may preferentially inhibit the induced synthesis of penicillinase. Studies conducted in an attempt to ascertain the role of penicillin in inducing penicillinase formation in
B. cereus
569 suggest that the inducer, penicillin, enhances penicillinase synthesis in some manner in addition to its probable role of inducing the formation of a penicillinase-specific ribonucleic acid messenger.
Kinetics of Synthesis of Various Types of Antigenic Proteins in Cells Infected with Pseudorabies Virus
Authors: Hamada Chuya , Kaplan Albert S.
Published: January 2020

Hamada, Chuya(Albert Einstein Medical Center, Philadelphia, Pa.),and Albert S. Kaplan. Kinetics of synthesis of various types of antigenic proteins in cells infected with pseudorabies virus. J. Bacteriol.89:1328–1334. 1965.—By means of an indirect precipitation test, a determination was made of the rates of synthesis of various types of serologically specific proteins in rabbit kidney cells infected with pseudorabies virus. The rate of synthesis of cell-specific protein decreased after infection. During the early stages of the infective process, proteins which bear no precursor relationship to the viral particles (nonstructural viral proteins) and which cannot be detected in noninfected cells were formed. Almost concurrently with these nonstructural proteins, synthesis of virus precursor proteins began. The synthesis of these proteins preceded the formation of mature virus and continued until the end of the virus growth cycle.
6-Diazo-5-Oxo-
l
-Norleucine Inhibition of
Escherichia coli
Authors: Coggin J. H. , Martin W. R.
Published: January 2020

Coggin, J. H., Jr.
(The University of Chicago, Chicago, Ill.),
and W. R. Martin
. 6-Diazo-5-oxo-
l
-norleucine inhibition of
Escherichia coli
. J. Bacteriol.
89:
1348–1353. 1965.—The glutamine analogue 6-diazo-5-oxo-
l
-norleucine (DON) induced filaments and spheroplasts in
Escherichia coli
during the transition of sensitive populations to a state of resistance. Resistance developed at a frequency suggesting mutant selection. The morphology of cells resistant to 100 μg of DON per ml was indistinguishable from that of sensitive cells. DON-resistant cells exhibited an extended growth lag when cultured in the absence of the drug. This extended lag could be reduced to the lag time of parent sensitive cells by a combination of
d
-glucosamine and inosine or by DON. Viable counts during the lag period of resistant cells indicate that this lag results from a decrease in the number of cells during the first 2 hr of incubation. A combination of
d
-glucosamine and inosine was required for complete prevention of the DON inhibition of sensitive cells. The results indicate that DON not only inhibits de novo purine biosynthesis but that it also prevents hexosamine synthesis and, ultimately, cell-wall synthesis in
E. coli
.
Isolation and Characterization of a Toxic Moiety of Low Molecular Weight fromClostridium botulinumType A
Authors: Gerwing Julia , Dolman Claude E. , Bains Hardial S.
Published: January 2020

Gerwing, Julia(The University of British Columbia, Vancouver, B.C., Canada),Claude E. Dolman, and Hardial S. Bains. Isolation and characterization of a toxic moiety of low molecular weight fromClostridium botulinumtype A. J. Bacteriol.89:1383–1386. 1965.—A toxic moiety of low molecular weight has been isolated from a type A strain ofClostridium botulinum, by a method involving ammonium sulfate precipitation and elution through diethylaminoethyl cellulose atpH 5.6. By means of electrophoresis and ultracentrifugation, the toxic substance was shown to be homogeneous; a molecular weight of 12,200 was calculated.
Significance of Salmonellae Isolated from Apparently Healthy Mice
Authors: Morello Josephine A. , DiGenio Teresa A. , Baker Edgar E.
Published: January 2020

Morello, Josephine
A. (Boston University School of Medicine, Boston, Mass.),
Teresa A. DiGenio, and Edgar E. Baker
. Significance of salmonellae isolated from apparently healthy mice. J. Bacteriol.
89:
1460–1464. 1965.—Three species of
Salmonella
were isolated from three groups of apparently healthy laboratory mice. The host-parasite relationship of one of these, a mutant
S. typhimurium
(lacks I and
i
antigens), was studied to determine the significance of these pathogens. Mice were fed undiluted broth cultures, and the infection was followed by means of fecal and organ cultures and a hemolytic serological test. Tissue invasion occurred during the early stages of the disease, but, within 1 week, the organism usually was localized in the intestinal tract. After 1 month, most of the mice had eliminated the organism completely. Antibody response to this organism was generally variable. Conditions of stress, including heat, cold, and cortisone administration, did not precipitate more severe disease in infected animals. The infection was maintained for longer periods of time in animals housed in groups than in those in individual cages. The presence of such salmonellae in laboratory animals appears to be of limited significance.
Lipids of
Debaryomyces hansenii
Authors: Merdinger Emanuel , Devine Edward M.
Published: January 2020

Merdinger, Emanuel
(Roosevelt University, Chicago, Ill.),
and Edward M. Devine, Jr.
Lipids of
Debaryomyces hansenii
. J. Bacteriol.
89:
1488–1493. 1965.—The separation of neutral lipids and phospholipids from the lipid extract of
Debaryomyces hansenii
NRRL Y-1448 was accomplished by using a single column packed with silicic acid. The neutral lipids comprised 67%, and the phospholipids 33%, of the total lipid extract. Qualitative and quantitative characterization of the lipids was effected by various analytical procedures. Gas chromatography of the fatty acid methyl esters showed 11 acids, of which 59.7% were unsaturated. The most abundant among the unsaturated acids was the monounsaturated C18 acid (50.1%). Among the saturated acids, palmitic acid (23.5%) prevailed. Ratios of fatty acid to glycerol, phosphorus to glycerol, and phosphorus to fatty acid were ascertained for combined cuts from the neutral lipids and the phospholipids. The presence of ergosterol, stigmasterol, and an unidentified sterol was established by gas chromatography. Also present were saturated hydrocarbons containing 16 to 39 carbon atoms, C22 being the most prevalent.
Cytochemical and Electron Microscopical Observations on the Presence and Origin of Adenosine Triphosphatase-Like Activity at the Surface of Two Myxoviruses
Authors: Dawson C. R. , Epstein M. A. , Hummeler K.
Published: January 2020

Dawson
, C. R. (The Middlesex Hospital Medical School, London, England), M. A.
Epstein, and K. Hummeler
. Cytochemical and electron microscopical observations on the presence and origin of adenosine triphosphatase-like activity at the surface of two myxoviruses. J. Bacteriol.
89:
1526–1532. 1965.—HeLa cells infected with either fowl plague virus (FPV) or Newcastle disease virus (NDV) were examined in thin sections by electron microscopy. Preparations were studied both after direct fixation and embedding and after the application of cytochemical staining for enzymes splitting adenosine triphosphate. Viral particles were identified by their size and characteristic structure, and were found to form at the cell surface by budding out through structurally altered plasmalemma. After cytochemical staining for adenosine triphosphatase activity, extracellular FPV or NDV particles lying close against cell membranes with enzyme activity likewise carried this function, whereas those particles which were associated with cell surfaces without reaction product were themselves free from it. This correspondence between enzyme function in cell membranes and the outer viral membranes of newly formed particles adjacent to them indicates that surface enzymatic capability of the host cell survives even when the cell membrane undergoes morphological and antigenic alteration into myxovirus outer membrane.
Genetic Factors in Radiation Resistance of
Bacillus subtilis
Authors: Zamenhof Stephen , Bursztyn Hela , Reddy T. K. Ramachandra , Zamenhof Patrice J.
Published: January 2020

Zamenhof, Stephen
(University of California, Los Angeles),
Hela Bursztyn, T. K. Ramachandra Reddy, and Patrice J. Zamenhof
. Genetic factors in radiation resistance of
Bacillus subtilis
. J. Bacteriol.
90:
108–115. 1965.—A study of several wild cross-transformable strains of
Bacillus subtilis
revealed differences in the resistance of their spores to X rays. Closer study of two such strains revealed differences of the same type when vegetative cells were exposed to X rays or to ultraviolet light (UV). Cell cultures repeatedly exposed to sublethal doses of UV (with cultivation between exposures) became more resistant to UV, presumably by enrichment in a more UV-resistant mutant. A sulfanilamide-resistant mutant of one strain (vegetative cells and spores) was less resistant to ionizing radiation; this sensitivity was transferable by transformation. No difference in radiation-induced mutability could be demonstrated in any of the strains studied. It is concluded that, at least in the cases studied, (i) the differences in radiation resistance of spores of different strains are not just a result of a superimposition of a common spore resistance mechanism(s) but rather are an amplification of genetically determined resistance differences in vegetative cells of these strains; (ii) sulfanilamide-resistance locus (
p
-aminobenzoic acid overproduction locus) is one of the loci of radiation sensitivity; (iii) no evidence was obtained that the differences in radiation resistance of cells or spores can be ascribed to differences in radiation resistance of their deoxyribonucleic acid.
Permeability of
Nitrobacter agilis
to Organic Compounds
Authors: Ida S. , Alexander M.
Published: January 2020

Ida
, S. (Cornell University, Ithaca, N.Y.),
and M. Alexander
. Permeability of
Nitrobacter agilis
to organic compounds. J. Bacteriol.
90:
151–156. 1965.—None of a variety of inorganic ions or organic compounds served as a sole energy source for the growth of
Nitrobacter agilis
, and the test substrates were not oxidized by either intact cells or extracts of the obligate chemoautotroph. The organic substances did not serve as sole carbon sources for the bacterium in a synthetic medium, and they failed to enhance the rate of nitrite oxidation. The organism was permeable to acetate and a number of other simple carbon compounds, however, and exogenously supplied acetate was converted to a number of products. On the basis of these findings, possible reasons are examined for the inability of the chemoautotroph to use exogenous organic compounds as energy or carbon sources.
Mechanism of Polykaryocytosis Associated with Noncytopathic Infection by Measles Virus
Authors: Atherton John G. , Chaparas Sotiros D. , Cremer Martha , Gordon Irving
Published: January 2020

Atherton, JohnG. (University of Southern California, Los Angeles),Sotiros G. Chaparas, Martha Cremer, and Irving Gordon. Mechanism of polykaryocytosis associated with noncytopathic infection by measles virus. J. Bacteriol.90:213–219. 1965.—Infection with a measles virus variant resulted not only in formation of polykaryocytes (PK) but also in formation of multicellular immunofluorescent foci (IFF) in which no cytopathic effect could be detected. The ratio of IFF to PK changed from 27 to 4 during the first passage and remained 4 after a second passage. PK were plaques. Plaque assay was linear in the presence of IFF. To investigate the mechanism of PK formation, radioautography was done on cells pulse-labeled with tritiated thymidine before virus multiplication began. The results showed that PK were formed by fusion; there were no PK whose nuclei contained no label, and the proportion of labeled nuclei (32%) and distribution of grain counts was the same in PK as in uninvolved cells, ruling out nuclear replication without concomitant cytoplasmic membrane formation as the mechanism of formation of these PK. Early in PK development, neutral red uptake was markedly increased (“red” plaques). As PK matured, hyperchromicity disappeared (“white” plaques). This sequence provided an index of rate of evolution of PK. Rate of PK maturation was more rapid at 37 than at 32 C.
Differential Reduction of Tellurite by Growing Colonies of Normal Yeast and Respiration-Deficient Mutants
Authors: Nagai Susumu
Published: January 2020

Nagai, Susumu
(National Women's University, Nara, Japan). Differential reduction of tellurite by growing colonies of normal yeast and respiration-deficient mutants. J. Bacteriol.
90:
220–222. 1965.—A differential reduction of sodium tellurite was observed between normal and respiration-deficient mutant colonies of several species of
Saccharomyces
. Normal colonies turned black in contrast to mutant colonies which remained nearly white when grown on an agar medium containing 30 to 40 mg per liter of tellurite. Schopfer's medium enriched with yeast extract and a mixture of vitamins was most suitable to develop such black-and-white contrast. The difference was far less obvious when the asparagine of this medium was replaced by other nitrogen sources such as glutamate, peptone, or Casamino Acids. Addition of ammonium sulfate to the medium weakened and sometimes completely reversed the contrast. The usefulness of tellurite medium for diagnostic color differentiation of respiration deficiency was considered.
Boundary Between Bacterial Mesophilism and Thermophilism
Authors: Bausum Howard T. , Matney Thomas S.
Published: January 2020

Bausum, Howard
T. (Fort Detrick, Frederick, Md.),
and Thomas S. Matney
. Boundary between bacterial mesophilism and thermophilism. J. Bacteriol.
90:
50–53. 1965.—The temperature boundary between bacterial mesophilism and thermophilism has been identified as 44 to 52 C. Facultative thermophiles growing in the mesophilic range require a brief period of adaptation at intermediate temperatures before gaining the capacity to initiate growth at thermophilic temperatures. Obligate mesophiles cannot grow in the thermophilic temperature range, but obligate thermophiles may show limited growth at temperatures as low as 41 C.
Elution of Acid Phosphatase from the Cell Surface of
Saccharomyces mellis
by Potassium Chloride
Authors: Weimberg Ralph , Orton William L.
Published: January 2020

Weimberg, Ralph
(Northern Regional Research Laboratory, Peoria, Ill.),
and William L. Orton
. Elution of acid phosphatase from the cell surface of
Saccharomyces mellis
by potassium chloride. J. Bacteriol.
90:
82–94. 1965.—Acid phosphatase of
Saccharomyces mellis
may be eluted from intact resting cells by 0.5
m
KCl or other salts. However, the enzyme is not eluted at higher salt concentrations of about 2
m
unless a thiol, such as β-mercaptoethanol, is included in the reaction mixture. These treatments do not significantly affect viability of the cells. Neutral compounds like sorbitol or sucrose cannot substitute for ionic compounds in eluting the enzyme from resting cells. Furthermore, the neutral compounds are also inadequate for stabilizing the protoplast structure. It is suggested that the enzyme is held on the cell surface by a combination of electrostatic forces and disulfide bonds. Thiol alone dissociates protein and carbohydrate from the cell surface, but the eluate has no acid phosphatase activity. Salts also remove protein and carbohydrate from the cell surface, but the amount of protein removed is considerably less than that dissociated by thiol. A concentration of 0.5
m
KCl elutes more protein than does a 2
m
concentration, and enzymatic activity is present only in the 0.5
m
KCl eluate. The carbohydrate eluted by either reagent has been identified as a mannan. Conditions for eluting acid phosphatase from acetonedried cells of
S. mellis
are essentially the same as those for resting cells. Significantly, though, thiol is required at all salt concentrations to dissociate the enzyme. Pretreatment of the cells with thiol, followed by KCl, elutes acid phosphatase, whereas the reverse procedure does not. Acid phosphatase is excreted by growing cells of
S. mellis
into growth media if the medium contains 0.25
m
KCl. The total yield of enzymatic activity may be 8 to 10 times greater than is usually present on derepressed cells grown in a salt-free medium. The enzyme can be precipitated from the culture fluid with acetone. The acetone-precipitated fraction contains mannan and protein in a ratio of 12:1 by weight. Partial purification of the enzyme by calcium phosphate gel and elution resulted in an enzyme fraction in which the specific activity on the basis of protein increased 12-fold, and the carbohydrate-protein ratio was reduced to 1:1.
Distribution and Characteristics of the Catalases of Lactobacillaceae
Authors: Johnston M. A. , Delwiche E. A.
Published: January 2020

Johnston
, M. A. (Cornell University, Ithaca, N.Y.),
and E. A. Delwiche
. Distribution and characteristics of the catalases of Lactobacillaceae. J. Bacteriol.
90:
347–351. 1965.—Certain strains of lactobacilli and pediococci incorporated hematin during growth, with the concomitant formation of cyanide- and azide-sensitive catalase. Three of five strains of lactobacilli and five of 25 strains of pediococci were capable of this biosynthesis. The pediococci required the heme component of blood, whereas the lactobacilli could incorporate the heme component in the form of purified and solubilized hemin or from blood. In all cases where inhibitor-sensitive enzyme was produced, it was accompanied by the production of inhibitor-insensitive enzyme. In the absence of hematin, only insensitive enzyme was obtained. Two catalase-positive strains of
Streptococcus faecalis
were found incapable of the synthesis of a heme-type enzyme, as was one member of the genus
Leuconostoc
. Iron and manganese in the growth medium stimulated the production of the insensitive catalase, but significant quantities of these metals could not be found in a purified enzyme preparation obtained from
Lactobacillus plantarum
. Aeration had little or no effect on growth, but it consistently doubled the amount of cyanide- and azide-resistant catalase. By means of conventional enzyme fractionation techniques, it was possible to separate the two different enzymes present in the cell-free extract of a strain of
Pediococcus homari
which had been grown in the presence of blood.
Kinetics of Mating of FP
+
and FP
−
Strains of
Pseudomonas aeruginosa
Authors: Loutit J. S. , Pearce L. E.
Published: January 2020

Loutit
, J. S. (University of Otago, Dunedin, N.Z.),
and L. E. Pearce
. Kinetics of mating of FP
+
and FP
−
strains of
Pseudomonas aeruginosa
. J. Bacteriol.
90:
425–430. 1965.—Recently, we reported the variability of the FP
+
× FP
−
mating in
Pseudomonas aeruginosa
, and the increase in efficiency when the cells were mated after dilution. The present work shows that when standardized cells were mated after a dilution of 10
−2
for FP
−
and 2 × 10
−3
for FP
+
, there was less variability in the system. Investigation of pairing between FP
+
and FP
−
cells, as measured by genetic transfer, revealed that none took place during 24 hr in liquid media in which growth of both parents was possible. Transfer in liquid minimal medium was not investigated, because the single marker in the male was insufficient to control back mutation in 24 hr. No transfer occurred on solid media which allowed full growth of both FP
+
and FP
−
cells. Transfer took place very slowly on minimal agar, requiring 19 to 20 hr. It is thought that this represents growth of microcolonies with eventual transfer when internal nutrients were exhausted.
Physiological Effects of a Constitutive Tryptophanase in
Bacillus alvei
Authors: Hoch J. A. , DeMoss R. D.
Published: January 2020

Hoch
, J. A. (University of Illinois, Urbana),
and
R. D.
DeMoss
. Physiological effects of a constitutive tryptophanase in
Bacillus alvei
. J. Bacteriol.
90:
604–610. 1965.—Tryptophanase synthesis in
B. alvei
is not under the control of tryptophan and is not subject to catabolite repression. Exogenously supplied tryptophan was converted to indole by tryptophanase, and was excreted into the culture medium. The amount of indole excreted was dependent upon the concentration of tryptophan supplied. At intermediate levels of tryptophan (5 to 15 μg/ml), the excreted indole was completely reutilized by the cell, in contrast to the result with higher levels. Indole reutil zation was shown to be dependent upon a functional tryptophan synthetase. In the absience of exogenous tryptophan, indole was excreted into the culture medium at an earlier physiological age. The early indole was shown not to be a consequence of tryptophanase action. The early indole accompanied uniformly the normal process of tryptophan biosynthesis, and the fission of indole-3-glycerol phosphate was suggested as the origin of the excreted indole.
Relative Contribution of the Cell Wall, Cytoplasmic Membrane, and Cytoplasm to the Gram-Positive Characteristic of
Bacillus megaterium
Authors: Bartholomew J. W. , Cromwell Thomas
Published: January 2020

Bartholomew
, J. W. (University of Southern California, Los Angeles),
and Thomas Cromwell
. Relative contribution of the cell wall, cytoplasmic membrane, and cytoplasm to the gram-positive characteristic of
Bacillus megaterium
. J. Bacteriol.
90:
643–647. 1965.—A comparison of the roles of the cell wall, cytoplasmic membrane, and cytoplasmic components revealed that the intact cell wall was the dominant contributor to the gram-positive state. Protoplasts of
Bacillus megaterium
were confirmed as being gram-negative, as reported by Gerhardt et al. The “gram-positive protoplast” report of Amano et al. was shown to be a laboratory-produced artifact, resulting from the comparison of smears made from saline suspensions of
Escherichia coli
cells with smears made from formalin-sucrose suspensions of
B. megaterium
protoplasts.
Repression of λ-Associated Enzyme Synthesis After λ
vir
Superinfection of Lysogenic Hosts
Authors: Lisio Arnold L. , Weissbach Arthur
Published: January 2020

Lisio, Arnold
L. (National Institutes of Health, Bethesda, Md.),
and Arthur Weissbach
. Repression of λ-associated enzyme synthesis after λ
vir
superinfection of lysogenic hosts. J. Bacteriol.
90:
661–666. 1965.—Phage λ
vir
is a multiple mutant of λ which is capable of overcoming the immunity of a host lysogenic for λ, and initiating normal vegetative replication of the superinfecting phage genome. Superinfection of
Escherichia coli
K-112 (λ
22
) with λ
vir
results in a normal phage yield, lysis time, and H
3
-thymine incorporation compared with infection of the sensitive host, K-112 (S). However, the production of the λ phage-specific early protein, λ-exonuclease, after superinfection of
E. coli
K-112 (λ
22
) with λ
vir
is only 25 to 50% of that obtained from corresponding infection of a nonlysogenic host,
E. coli
K-112 (S). This repression of λ-exonuclease synthesis is dependent on the C
1
cistron of the prophage and is overcome if the lysogenic host cells are induced prior to superinfection. The data are interpreted as evidence for partial repression of λ
vir
by the host immunity.
Inhibition of Growth of
Lactobacillus bulgaricus
by Purine Deoxyribonucleotides
Authors: Morris George K. , Williams William L.
Published: January 2020

Morris, George
K. (University of Georgia, Athens),
and William L. Williams
. Inhibition of growth of
Lactobacillus bulgaricus
by purine deoxyribonucleotides. J. Bacteriol.
90:
715–719. 1965.—An inhibition of growth of
Lactobacillus bulgaricus
GS was observed with deoxyadenylic acid and deoxyguanylic acid. Deoxynucleotides of cytosine, thymine, and uracil, and the deoxynucleosides of adenine, guanine, cytosine, and thymine were inactive as inhibitors. The inhibition was reversed by liver extract (a crude source of two unidentified growth factors for this organism). With suboptimal concentrations of liver extract, the inhibition was reversed by nucleotides of adenine, guanine, uracil, cytosine, and thymine. When the medium contained partially purified sources of the two growth factors rather than crude liver extract, fewer compounds reversed the inhibition. Adenylic acid and guanylic acid reversed the action of either inhibitor. Inosinic acid reversed inhibition caused by deoxyguanylic acid, but not that caused by deoxyadenylic acid. Thymidylic acid reversed inhibition caused by deoxyadenylic acid better than that caused by deoxyguanylic acid. Uridylic acid and cytidylic acid were no longer effective in reversing the inhibitions. This organism preferentially responded to monophosphorylated compounds as inhibitors and as reversers of inhibitions. Studies on the acid-soluble nucleotide pool revealed an accumulation of adenosine triphosphate, guanosine triphosphate, and an unidentified compound which resembled a nucleotide in its physical properties. These data cannot be explained by known metabolic pathways of nucleic acid biosynthesis. This organism responds differently from other related organisms to nucleic acid derivatives; therefore, it may be a new useful tool for studying nucleic acid metabolism and biosynthesis.
Effect of Aflatoxin B1on Cell Cultures
Authors: Gabliks J. , Schaeffer W. , Friedman L. , Wogan G.
Published: January 2020

Gabliks, J. (Massachusetts Institute of Technology, Cambridge), W.Schaeffer, L. Friedman, and G. Wogan. Effect of aflatoxin B1on cell cultures. J. Bacteriol.90:720–723. 1965.—Aflatoxin B1, a metabolite of the moldAspergillus flavus, is toxic to cell cultures. The toxic effect is evidenced by an inhibition of growth followed by progressive granulation, rounding, and finally sloughing of the cells from the glass. In studies with embryonated eggs, duck embryos were found to be four to five times more susceptible than chick embryos. In studies on Chang liver cultures, there were decreases in cell number, protein, ribonucleic acid (RNA), and deoxyribonucleic acid (DNA) per culture with increasing aflatoxin B1concentrations. Since the cell number decreased and the protein, RNA, and DNA content per cell increased with increasing concentrations of aflatoxin, enlarged cells were suggested. These data are consistent with in vivo data of other workers who have found hypertrophic cells with enlarged nuclei in histological studies on the tissues of rats and ducklings fed toxic peanut meal.
Electron Microscopy of Ultrathin Sections of
Sporosarcina ureae
Authors: Mazanec K. , Kocur M. , Martinec T.
Published: January 2020

Mazanec
, K. (J. E. Purkyně University, Brno, Czechoslovakia), M.
Kocur, and T. Martinec
. Electron microscopy of ultrathin sections of
Sporosarcina ureae
. J. Bacteriol.
90:
808–816. 1965.—Ultrathin sections of
Sporosarcina ureae
cells were studied by means of electron microscopy. The cell wall consists of several layers and is 340 A thick. The cytoplasm is of globular structure and includes ribosomelike structures, occasional mesosomes, and inclusions not precisely identifiable. The nuclear area has various shapes and is formed by filaments 10 to 20 A thick which proceed in various directions. Cell division occurs similarly to that of sarcinate. Both synchronic and asynchronic cell division was observed. The spores of
S. ureae
consist of an outer coat having several layers, a cortex, a spore wall, and cytoplasm. The results of the present investigation substantiate our previous suggestion that
S. ureae
should be transferred from the family Micrococcaceae to the family Bacillaceae.
Inhibition of Protein Synthesis by Polypeptide Antibiotics II. In Vitro Protein Synthesis
Authors: Ennis Herbert L.
Published: January 2020

Ennis, Herbert
L. (St. Jude Children's Research Hospital, Memphis, Tenn.). Inhibition of protein synthesis by polypeptide antibiotics. II. In vitro protein synthesis. J. Bacteriol.
90:
1109–1119. 1965.—This investigation has shown that the polypeptide antibiotics of the PA 114, vernamycin, and streptogramin complexes are potent inhibitors of the synthetic polynucleotide-stimulated incorporation of amino acids into hot trichloroacetic acid-insoluble peptide. The antibiotics inhibited the transfer of amino acid from aminoacyl-soluble ribonucleic acid (s-RNA) to peptide. The A component of the antibiotic complex was active alone in inhibiting in vitro protein synthesis, whereas the B fraction was totally inactive. However, the A component, when in combination with the B component, gave a greater degree of inhibition than that observed with the A fraction alone. On the other hand, the endogenous incorporation of amino acid was much less susceptible to inhibition than the incorporation of the corresponding amino acid in a system stimulated by synthetic polynucleotide. In addition, synthesis of polyphenylalanine stimulated by polyuridylic acid was inhibited to a greater extent when the antibiotics were added before the addition of polyuridylic acid to the reaction mixture than when the antibiotics were added after the polynucleotide had a chance to attach to the ribosomes. However, the antibiotics apparently did not inhibit the binding of C
14
-polyuridylic acid or C
14
-phenylalanyl-s-RNA to ribosomes. The antibiotics did not affect the normal release of nascent protein from ribosomes and did not disturb protein synthesis by causing misreading of the genetic code. The antibiotics bind irreversibly to the ribosome, or destroy the functional identity of the ribosome. The antibiotic action is apparently a result of the competition between antibiotic and messenger RNA for a functional site(s) on the ribosome.
Immunochemical Studies on α-Amylase III. Immunochemical Relationships Among Amylases from Various Microorganisms
Authors: Sirisinha Stitaya , Allen Peter Z.
Published: January 2020

Sirishinha, Stitaya
(University of Rochester School of Medicine and Dentistry, Rochester, N.Y.),
and Peter Z. Allen
. Immunochemical studies on α-amylase. III. Immunochemical relationships among amylases from various microorganisms. J. Bacteriol.
90:
1120–1128. 1965.—Immunochemical relationships among amylases obtained from a selected group of microorganisms were examined, and a cross-reaction was detected between the α-amylases of
Bacillus stearothermophilus
and
B. subtilis
. Immunodiffusion and quantitative precipitin studies, as well as cross-neutralization tests, indicate that
B. stearothermophilus
α-amylase reacts with a portion of antibody present in antisera to crystalline
B. subtilis
α-amylase. Amylases from these two species thus have some aspects of structure in common. Limited data obtained by immunodiffusion suggest that groupings which confer cross-reactivity to the
B. stearothermophilus
enzyme are lost after exposure to mercaptoethanol in the presence of ethylenediamine-tetraacetate, followed by treatment with iodoacetamide. With the antisera employed and within the concentration range examined, no immunochemical cross-reaction was observed among amylases from
Aspergillus oryzae, B. subtilis, B. polymyxa, B. macerans, Pseudomonas saccharophila
, and
Euglena sanguinis
. Immunoelectrophoresis of partially purified
B. stearothermophilus
α-amylase by use of antiserum to the crude enzyme, together with localization of amylase activity in immunoelectrophoretic plates, suggests that
B. stearothermophilus
α-amylase is antigenic in the rabbit.
Biochemical Changes in Lysogenic
Bacillus stearothermophilus
After Bacteriophage Induction
Authors: Welker N. E. , Campbell L. Leon
Published: January 2020

Welker
, N. E. (University of Illinois, Urbana),
and L. Leon Campbell
. Biochemical changes in lysogenic
Bacillus stearothermophilus
after bacteriophage induction. J. Bacteriol.
90:
1129–1137. 1965.—Cultures of
Bacillus stearothermophilus
1503-4R (TP-1) continued to grow at an unaltered rate after induction with mitomycin C (MC). MC-induced cultures exhibited a 2.5-fold increase in cell number before lysis occurred. Prior to lysis, cells were observed to elongate and to contain areas of lesser density. Protein synthesis was slightly inhibited in MC- or ultraviolet light (UV)-induced cultures for a period of 5 to 10 min, and then proceeded at a rate identical to that in the noninduced culture. Ribonucleic acid (RNA) synthesis was not affected by MC induction. UV induction caused RNA synthesis to occur in two stages: in the first stage, the rate of RNA synthesis was one-third that observed in the noninduced culture and lasted for a period of 15 min; the second stage of RNA synthesis then proceeded at a rate identical to that in the noninduced culture. The synthesis of deoxyribonucleic acid (DNA) in an MC- or UV-induced culture occurred in two stages. In the first stage, DNA synthesis in induced cultures occurred at a rate of one-half (MC) and one-third (UV) of that observed in the noninduced culture. The first stage of DNA synthesis in MC- or UV-induced cultures lasted for 25 to 30 min and 15 to 20 min, respectively. In the second stage, the rate of DNA synthesis in MC- or UV-induced cultures occurred at a rate three times that of the noninduced culture. UV induction appeared to have a greater inhibitory effect than MC induction on protein, RNA, and DNA synthesis as well as phage yield. The differential rate (
K
) of inducible and constitutive α-amylase synthesis was inhibited by 75 and 100%, respectively, for a period of 20 min after MC induction. After 20 min, the
K
values for α-amylase synthesis were identical to those obtained in the absence of MC induction. The synthesis of TP-1 phage DNA occurred rapidly and was complete 25 min after MC induction, whereas bacterial DNA was degraded or its rate of synthesis was decreased. During the second stage of DNA synthesis, only bacterial DNA was synthesized, but at a rate greater than that found in the noninduced culture.
Fructose-1,6-Diphosphatase and Acid Hexose Phosphatase of
Escherichia coli
Authors: Fraenkel D. G. , Horecker B. L.
Published: January 2020

Fraenkel
, D. G. (Albert Einstein College of Medicine, New York, N.Y.),
and B. L. Horecker
. Fructose-1,6-diphosphatase and acid hexose phosphatase of
Escherichia coli
. J. Bacteriol.
90:
837–842. 1965.—The conversion of fructose-1,6-diphosphate to fructose-6-phosphate (fructose-1,6-diphosphatase activity) is essential for growth of
Escherichia coli
on glycerol, acetate, or succinate, but is unnecessary for growth on hexoses or pentoses. It has sometimes been assumed that fructose-1,6-diphosphatase activity is due to a nonspecific acid hexose phosphatase. We have now obtained a number of one-step mutants which have lost the ability to grow on glycerol, succinate, or acetate, but which grow normally on hexoses; these mutants are deficient in a fructose-1,6-diphosphatase which can be assayed spectrophotometrically in the presence of Mg
++
and low concentrations of substrate. These mutants still possess the nonspecific acid hexose phosphatase, which does not require Mg
++
and is active only at much higher concentrations of fructose-1,6-diphosphate. Evidence is presented to support the hypothesis that the newly described activity is the physiological fructose-1,6-diphosphatase. The acid hexose phosphatase is a different enzyme whose function remains unknown.
Inhibitory Action of Selenite on
Escherichia coli, Proteus vulgaris
, and
Salmonella thompson
Authors: Weiss K. F. , Ayres J. C. , Kraft A. A.
Published: January 2020

Weiss
, K. F. (Iowa State University, Ames), J. C.
Ayres, and A. A. Kraft
. Inhibitory action of selenite on
Escherichia coli, Proteus vulgaris
, and
Salmonella thompson
. J. Bacteriol.
90:
857–862. 1965.—The resistance of three microorganisms,
Escherichia coli
(ISU-41),
Proteus vulgaris
(ISU-37c), and
Salmonella thompson
(ISU-86-2), to increasing concentrations of selenite was determined.
E. coli
was completely inhibited by 1.25% sodium hydrogen selenite, and 0.25% sodium hydrogen selenite caused a pronounced lag.
P. vulgaris
survived selenite concentrations of over 3%.
S. thompson
was inhibited completely by 3% selenite but not by 2.5%, although there was a considerable lag and a decrease in total growth. The relationship of growth, uptake, and reduction of selenite was determined. The susceptible
E. coli
incorporated up to twice as much selenium as did the other two organisms during the early stages of incubation. Radioautographs of seleno analogues of sulfur-containing amino acids revealed the presence of seleno-cystine in all three organisms, and seleno-methionine in
E. coli
. Compounds having

R
F

values corresponding to possible oxidation products of seleno-methionine were present in the hydrolysates of
P. vulgaris
and
S. thompson
. Kinetic aspects of selenite uptake, rather than the ultimate localization of selenite in the cell protein, appear to be the factors that determine the degree of resistance or of susceptibility to selenite.
Cell-Free Amino Acid-Incorporating System from
Pseudomonas indigofera
Authors: Shiio Tsuru , McFadden Bruce A.
Published: January 2020

Shiio, Tsuru
(Washington State University, Pullman),
and Bruce A. McFadden
. Cell-free amino acid-incorporating system from
Pseudomonas indigofera
. J. Bacteriol.
90:
978–983. 1965.—A cell-free preparation from
Pseudomonas indigofera
incorporated C
14
-phenylalanine and C
14
-leucine into a product which was insoluble in hot trichloroacetic acid. The phenylalanine incorporation process, which had a temperature optimum of 30 C and a
p
H optimum of 7.6, had many characteristics of protein synthesis. The process depended upon both “ribosomes” and supernatant fraction from centrifugation at 105,000 ×
g
. Incorporation required adenosine triphosphate, apparently depended upon guanosine triphosphate, and was inhibited by chloramphenicol, puromycin, actinomycin, ribonuclease, and deoxyribonuclease. Leucine incorporation was also studied and had many similar characteristics. C
14
-phenylalanine uptake was stimulated by sRNA or polyuridylic acid, and together these substances had a synergistic effect upon stimulation. The incorporation of C
14
-phenylalanine into a product which was precipitated by antiserum to crystalline isocitrate lyase was also observed.
Benzo[
a
]pyrene Uptake by Bacteria and Yeast
Authors: Moore B. G. , Harrison Arthur P.
Published: January 2020

Moore
, B. G. (Oak Ridge National Laboratory, Oak Ridge, Tenn.),
and Arthur P. Harrison, Jr
. Benzo[
a
]pyrene uptake by bacteria and yeast. J. Bacteriol.
90:
989–1000. 1965.—Various Enterobacteriaceae and yeast incubated in a medium containing 25 μg/ml of H
3
-benzo[
a
]pyrene (30% serum in the medium dissolves the hydrocarbon) retain radioactivity after washings with fresh 30% serum-medium. This radioactivity is defined as bound and represents intact benzo[
a
]pyrene. Factors relating to the binding of benzo[
a
]pyrene (benzo[
a
]pyrene uptake) have been studied in detail with
Escherichia coli
Ma, a triple auxotroph requiring
l
-leucine, uracil, and thymine. In defined medium, benzo[
a
]pyrene uptake by normally growing cells is 10
−10
to 2 × 10
−10
μg per cell. Uptake is the same in suspensions lacking leucine and containing chloramphenicol where there is neither measurable protein synthesis nor cell division. Uptake is diminished, but not eliminated, by autoclaving the cells; thus, some uptake occurs in the absence of enzymatic activity. Uptake is enhanced by heat shock, thymine deprivation, uracil deprivation, and exposure to penicillin. Thus, uptake is affected by the physiological state of the cells. Either the cells play a direct (enzymatic) role in uptake, or they affect uptake indirectly by increasing or altering the benzo[
a
]pyrene-binding structure. Physical fractionation of cells demonstrates that this structure is associated with the cell wall-membrane complex. All but 1% of the bound radioactivity is extracted with ethyl alcohol-ether. This residual radioactivity is defined as fixed, and may be associated with cell protein. The extracted radioactivity is identified as benzo[
a
]pyrene. Very little hydrocarbon is metabolized. Adverse photodynamic effects, increase in mutation, and dimunition in bacteriophage replication (in whole cells) have not been observed in the benzo[
a
]pyrene cultures.
Interference with Valine and Isoleucine Biosynthesis by Cyclic Hydroxamic Acids
Authors: Hogg Robert W. , Biswas Chitra S. , Broquist Harry P.
Published: January 2020

Hogg, Robert
W. (University of Illinois, Urbana),
Chitra S. Biswas, and Harry P. Broquist
. Interference with valine and isoleucine biosynthesis by cyclic hydroxamic acids. J. Bacteriol.
90:
1265–1270. 1965.—The introduction of a hydroxyl group in a number of common barbiturates, a substitution which converts these compounds to cyclic hydroxamic acids, gives rise to compounds which inhibit growth of
Escherichia coli
. The toxicity of these hydroxybarbiturates appears to be associated, at least in part, with interference with valine and isoleucine biosynthesis, as a combination of these amino acids counteracts their toxicity. A subinhibitory level of 1-hydroxy-5-ethyl-5-isopropylbarbituric acid (hydroxyipral) was counteracted either by valine or by its early precursor, α-acetolactate, and led to a study of the effect of these cyclic hydroxamic acids on acetolactate synthesis in a cell-free enzyme system of
E. coli
. In this system, the parent barbiturates and their respective hydroxy derivatives were only moderately active in blocking acetolactate synthesis. Detailed kinetic studies of the most active compound, hydroxyipral showed no obvious relationship to the substrate or cofactors of the system. The inhibitory effects of hydroxyipral, either on growth of
E. coli
or in the acetolactate-forming system, could not be counteracted by Fe
++
, but the toxic effect of aspergillic acid and
o
-phenanthroline in these instances was reversed by Fe
++
, which implies an iron involvement in the acetolactate-forming system of
E. coli
.
Decomposition of Poly-β-Hydroxybutyrate by Pseudomonads
Authors: Delafield F. P. , Doudoroff M. , Palleroni N. J. , Lusty C. J. , Contopoulos R.
Published: January 2020

Delafield
, F. P. (University of California, Berkeley), M.
Doudoroff, N. J. Palleroni, C. J. Lusty, and R. Contopoulos
. Decomposition of poly-β-hydroxybutyrate by pseudomonads. J. Bacteriol.
90:
1455–1466. 1965.—A number of aerobic pseudomonads capable of using poly-β-hydroxybutyrate as sole source of carbon have been partially characterized. One was selected for special study and described as a new species,
Pseudomonas lemoignei
Delafield. This bacterium constitutively produces extracellular digestive enzymes that hydrolyze the polymer to a mixture of
d
-β-hydroxybutyrate and the dimeric ester of this acid, as well as an intracellular “dimer hydrolase” which hydrolyzes the dimeric ester. The exoenzymes are excreted during growth, but mainly at its cessation. Metabolism of β-hydroxybutyrate largely suppresses enzyme excretion and causes a disappearance of excreted enzyme.
Use of Tetrazolium Salts for Electron Transport Studies in Meningopneumonitis I. Reduced Nicotinamide Adenine Dinucleotide System
Authors: Allen Emma G.
Published: January 2020

Allen, Emma
G. (Downstate Medical Center, Brooklyn, N.Y.). Use of tetrazolium salts for electron transport studies in meningopneumonitis. I. Reduced nicotinamide adenine dinucleotide system. J. Bacteriol.
90:
1505–1512. 1965.—Purified preparations of meningopneumonitis virus (MP) prepared from allantoic fluids of infected chick embryo reduce several tetrazolium salts in the presence of reduced nicotinamide adenine dinucleotide under both aerobic and anaerobic conditions. The pattern of reduction by MP differs from that seen in normal allantoic membrane homogenates, and is inhibited by several cations but not by KCN, atabrine, amytal, antimycin A, or 2,3-dimercaptopropanol (BAL). The reduction of cytochrome
c
by purified preparations of MP differs from its reduction of tetrazolium salts in that the cytochrome reaction is completely inhibited by BAL and partially inhibited by amytal, atabrine, and antimycin A. The cytochrome reductase of normal allantoic membrane preparations is completely inhibited by each of these compounds.