bluuebunny/crossref_metadata_2025 huggingface dataset:
The fine structure of "resting bodies" of Bdellovibrio sp. strain W developed in Rhodospirillum rubrum
Authors: Hoeniger Judith F. M. , Ladwig Rita , Moor Hans
Published: February 2010

Resting bodies of Bdellovibrio sp. strain W were produced following the infection of Rhodospirillum rubrum in liquid culture. Thin sections showed that young resting bodies possessed a narrow layer of amorphous material at their periphery, and storage granules in the region of the nucleoplasm. In mature resting bodies, the amorphous material (now called the outer layer) had thickened considerably to 30–40 nm, and the cell wall had differentiated into a folded, tripartite inner layer. Freeze-etched preparations of mature resting bodies showed a roughly particulate plasma membrane, a more finely particulate inner layer, and an outer layer having little structure.Bdellovibrio W did not produce resting bodies in a second host, Escherichia coli B. Also B. bacteriovorus strain 109 failed to form resting bodies in E. coli B, its usual host. It also failed to grow in cultures of R. rubrum. These restricted experiments suggest that the development of resting bodies may be specific for the Bdellovibrio W – R. rubrum parasite–host system.
Chromogenesis variations in strains of Pseudomonas aeruginosa growing in presence of chloramphenicol and oxytetracycline
Authors: Espinosa M. , Hidalgo A. , Portoles A.
Published: February 2010

The effects of subinhibitory doses of chloramphenicol and oxytetracycline on chromogen formation by normal and antibiotic-resistant Pseudomonas aeruginosa strains were studied. Partial or total inhibitions of the phenazine compounds were observed while the oxyphenoxazone synthesis appeared increased. In addition, several molecular modifications, presumably as a physiological response against the damaging drugs, were detected.
The replication of the Kilham rat virus (RV) in various host systems: immunofluorescent studies
Authors: Fields Howard A. , Nicholson Bruce L.
Published: February 2010

The replicative cycle of the Kilham rat virus (RV-13) in rat embryo (RE), hamster embryo (HE), and L-929 cell cultures was studied under conditions of high viral input multiplicity. The synthesis of RV antigen in infected cells was followed by the indirect fluorescent antibody (FA) technique and correlated with the appearance of extracellular hemagglutinin. The synthesis of specific antigen in RE and HE cell cultures appeared to follow a similar pattern. Cytoplasmic fluorescence was observed early in the replicative cycle of RV in both host systems. Nuclear fluorescence was detected 6–8 h later after a decline in the number of cells exhibiting cytoplasmic fluorescence. Nuclear fluorescence appeared more extensive and more intense in RE cells. In addition, a significantly higher hemagglutinin titer was obtained from the infection of RE cells. The replicative cycle of RV in L-929 cells appeared aborted. Although the synthesis of RV structural antigen was detected in the cytoplasm of these cells, subsequent nuclear fluorescence was totally absent and extracellular hemagglutinin was not detected.
The nature of epidermidins, new antibiotics from staphylococci
Authors: Hsu Chun-yang , Wiseman G. M.
Published: February 2010

New antibiotics have been isolated from Staphylococcus epidermidis strains 29297 and 36534. These agents are designated epidermidins A1, A2, B1, B2 and are peptides with an average molecular weight of 1200–1400 based on three independent methods of estimation. Each fraction contained 11 amino acid residues, eight of which were shared in common. The ratio of L- to D-amino acids was 7:4 for epidermidins A2 and B1, while that for epidermidins A1 and B2 was 5:6.The appearance of the same amino acids at the beginning and end of many of the peptide fragments obtained by partial hydrolysis of epidermidin A1 suggested that this antibiotic was a cyclic peptide. The absence of N- and C-terminal residues supported this finding. The amino acid sequence of epidermidin A1 was also tentatively deduced and may be written as follows: cyclo-lys-ala-asp-glu-ser-leu-thr-gly-val-gly-arg.
Isolation and characterization of Mycoplasma meleagridis
Authors: Ogra M. S.
Published: February 2010

The ability of Mycoplasma meleagridis to metabolize L-argininehydrochloride (HCl) and its inability to ferment dextrose can be used in identifying and differentiating this serotype from other Mycoplasma known to infect turkeys. Mycoplasma meleagridis may be the only species of turkey origin which lacks the ability to reduce tetrazolium chloride. A selective inhibitory effect of erythromycin and oleandomycin on M. gallisepticum can be used to differentiate it from M. meleagridis in in vitro tests. The metabolic inhibition test can be applied successfully to identification of M. meleagridis and its antibody. In birds carrying a chronic type of infection, Mycoplasma may be isolated from the vagina throughout much of their productive life. Since the infection is not readily transmitted, the maintenance of flocks free from M. meleagridis may not be difficult once the status is achieved.
Growth of mixed cultures of autotrophic and heterotrophic organisms
Authors: Pan P. , Umbreit W. W.
Published: February 2010

Growth of obligate autotrophic bacteria on their specific substrate and growth of an obligate phototrophic blue green alga was sometimes enhanced by the simultaneous presence of heterotrophic organisms, either directly mixed with the culture, or in parabiotic tubes separated by a membrane. The stimulating effect of such mixed cultures seems to be highly specific.
Analysis by gas chromatography of hydroxy acids produced by several species of Neisseria
Authors: Brooks J. B. , Kellogg D. S. , Thacker L. , Turner E. M.
Published: February 2010

A new technique, which uses formation of double derivatives for the detection of hydroxy acids in spent cultural media by gas–liquid chromatography (g.l.c), is described. The method is practical enough for use in routine analysis. Fourteen species of the genus Neisseria, including several serogroups of N. meningitidis, were tested. Four hydroxy acids and a keto acid which have not been previously reported in Neisseria were tentatively identified from acidified ether extracts of spent cultural media on both polar and nonpolar columns. Different g.l.c. profiles were obtained for several serogroups of N. meningitidis, N. gonorrhoeae, N. haemolysans, N. lactamicus, N. perflava, N. flava, N. mucosa, N. catarrhalis, N. ovis, and N. caviae. Strains of N. meningitidis, N. subflava, N. flavescens, N. caviae, and N. catarrhalis comprise a heterogeneous group. One strain previously identified as N. caviae gave a g.l.c. profile like that of N. ovis. The data indicate that g.l.c. analysis of metabolic products provides information necessary for differentiating many members of the genus.
A toxic substance from Aspergillus viridi-nutans
Authors: Lillehoj E. B. , Ciegler A.
Published: February 2010

A compound toxic to mice has been extracted from mycelia of Aspergillus viridi-nutans NRRL 4365, a member of the A. fumigatus group. After 2 weeks of growth on a Raulin-Thom medium in static culture at 28C, up to 2 g of toxin could be recovered from 300 g (wet weight) of mycelium. After the compound was isolated by chromatographic separation on activated magnesium silicate columns, the purified fraction was readily crystallized from cold benzene. A suspension of the substance in propylene glycol (administered intraperitoneally) had an LD50 of 2.8 mg/kg in 20-g mice. The toxin was highly fluorescent, exhibiting a 382-nm excitation band and an emission maximum at 450 nm. In thin-layer chromatographic analyses the crystalline compound appeared as a single fluorescent spot in two different solvent systems. The ultraviolet spectrum of the metabolite showed absorption maxima at 380 and 266 nm. Distinctive features of the infrared spectrum were the presence of chelated hydroxyl groups and a carbonyl ester function. Mass spectrometry demonstrated that the molecular weight of the toxin was 662 with a molecular formula of C34H30O14. Chemical microanalysis verified the formula and provided evidence of four methoxyl groups.
The influence of extracts from senescent corn leaves on sexual reproduction in Cochliobolus carbonum
Authors: Fries R. E. , Nelson R. R.
Published: February 2010

The biochemical requirements for the formation of perithecia, asci, and ascospores in Cochliobolus carbonum are present in senescent corn leaves. A chloroform–methanol extract from senescent corn leaves was found to support perithecial formation. Efforts were made to identify the compounds responsible for the observed activity.The qualitative and quantitative effects of several concentrations of the crude chloroform–methanol extract and of some fractions separated therefrom on the sexual process were studied. Sterol and watersoluble fractions stimulated perithecial formation. Each was active when applied alone, but stimulation was greater when the fractions were combined. Fatty acid fractions did not increase the number of perithecia formed. Neither the crude extract nor any of the components tested stimulated ascus and ascospore formation.It is suggested that the mode of action of perithecial stimulating chemicals extracted from senescent corn leaves is nutritional. The rationale for this belief is discussed.
Cytoplasmic polyhedrosis virus (CPV) of Malacosoma disstria: RNA polymerase activity in purified free viroin
Authors: Donaghue T. P. , Hayashi Y.
Published: February 2010

RNA polymerase activity is confirmed in virions of cytoplasmic polyhedrosis virus (CPV) of M. disstria obtained by the alkaline digestion of polyhedra as well as in virions isolated in a free form from the insect tissue.
The role of intracellular glucan in endogenous fermentation and spore maturation in Clostridium botulinum type E
Authors: Strasdine G. A.
Published: February 2010

The intracellular glucan of Clostridium botulinum type E (Minnesota) was rapidly accumulated then lost during growth and spore formation in glucose–trypticase media. In the absence of an exogenous supply of glucose, non-proliferating cell suspensions prepared from glucan-rich cells rapidly fermented their glucan reserves concurrent with the formation of mature spores. Exogenous glucose did not alter the rate of glucan fermentation although subsequent spore formation was either markedly reduced or inhibited. The data indicate that glucose was the sole precursor of glucan biosynthesis and that intracellular glucan in this organism functions in the capacity of an endogenous substrate supplying the cell with a readily available source of carbon and (or) energy for spore maturation.
Transport systems for organic acids induced in the marine pennate diatom, Cylindrotheca fusiformis
Authors: Hellebust Johan A. , Lewin Joyce
Published: February 2010

Cells of Cylindrotheca fusiformis, a marine littoral pennate diatom, can be induced to take up lactate by merely keeping them in the dark, and to take up succinate, fumarate, and malate as well as lactate by keeping them in the dark in the presence of any of these organic acids. Studies of uptake rates as a function of substrate concentration show a complex relationship indicating the presence of two or more uptake systems for any of these organic acids, each having different affinities and capacities for the substrates. Growth rate also shows a similar complex relationship to substrate concentration.Competition experiments indicate that lactate is taken up by different transport systems from those serving the 4-carbon dicarboxylic acids. Pyruvate is not taken up by C. fusiformis. Correlation of activities of enzymes involved in the immediate assimilation of the organic acids with the presence or absence of the ability to take up these substrates by cells incubated under different conditions show that the necessary assimilatory enzymes are already present and that it is rather the transport systems that are induced. The presence of glucokinase in dark-grown cells indicates that the inability of the cells to take up glucose is due to the lack of induction of a glucose transport system.The metabolic inhibitors dinitrophenol and iodoacetate inhibit the uptake of organic acids. However, since under normal conditions the organic acids are rapidly converted to other metabolites upon entry into the cells, and do not appear to accumulate, the observed inhibition may be at the level of assimilation rather than transport. The uptake of lactate and succinate is temperature dependent with a Q10 of 1.5–1.7, but is almost unaffected by changes in salinity from 10 to 150% of normal seawater. The relation between pH and rates of uptake of lactate and succinate suggests that the completely dissociated form of the organic acids is transported.
Thiosulfate oxidase from an Alcaligenes grown on mercaptosuccinate
Authors: Hall Mark R. , Berk Richard S.
Published: February 2010

The soil isolate Alcaligenes sp. (M1) was able to use mercaptosuccinate (MS) as a sole source of carbon, sulfur, and energy. Resting cells oxidized the sulfur moiety of MS completely to sulfate. Thiosulfate oxidase, rhodanese, sulfite oxidase, and adenosine-5-phosphosulfate reductase were all detected in crude extracts. However, only thiosulfate oxidase appeared to be induced by growth of the organism on mercaptosuccinate. The intracellular thiosulfate oxidase was purified 139 to 170-fold by a procedure which included MnCl2 precipitation, treatment with calcium phosphate gel, and successive column chromatography on diethylaminoethyl (DEAE) Sephadex and Sephadex G-150, respectively. The resultant enzyme had a pH optimum which appeared to be below 5.0 and an optimum temperature of 40 °C using ferricyanide as electron acceptor. However, with cytochrome c as electron acceptor the pH optimum was 7.2 to 7.6. No activity was observed with other electron acceptors such as methylene blue, nicotinamide-adenine dinucleotide, 2,6-dichlorophenol-indophenol, and flavine-adenine dinucleotide. Enzymatic activity was inhibited 100% by 10−3 M mercuric chloride and 90% by 10−3 M p-chloromercuribenzoate (p-CMB). The molecular weight of the enzyme was found to be about 90 000. Resting cells and thiosulfate oxidase converted thiosulfate labeled in the inner sulfur atom to tetrathionate as the only detectable product, thereby suggesting that thiosulfate oxidase does not play a direct role in sulfate formation from mercaptosuccinate.
Properties of Polyoma virus-transformed cells II. Characteristics of the virus-specific RNA
Authors: Hudson James B.
Published: February 2010

The Polyoma virus-specific RNA (PyRNA) synthesized in a line of Polyoma-transformed hamster cells, was analyzed and compared with the viral-specific RNA synthesized "late" in productively infected mouse cells. The PyRNA from the transformed cells sedimented heterogeneously on sucrose gradients, including appreciable amounts of PyRNA in the > 40-S region. The overall sedimentation profile resembled that of "late" PyRNA synthesized in mouse cells. Competition hybridization experiments, however, revealed that the bulk of the PyRNA sequences in the transformed cells were different from "late" PyRNA sequences. The use of DNA–DNA hybridization experiments (with Polyoma DNA of high specific radioactivity) enabled an estimate to be made of the average number of viral genomes per transformed cell. No more than two, and possibly less than one, complete genomes were found. These studies support the hypothesis that this line of Polyoma transformed cells contains an incomplete genome, possibly only comprising "early" genes (hence the inability to rescue infectious virus), and that the viral RNA transcribed is covalently linked to host cell RNA moieties.
Mutations that affect antibiotic synthesis by Cephalosporium acremonium
Authors: Lemke Paul A. , Nash Claude H.
Published: February 2010

The fungus Cephalosporium acremonium produces two β-lactam antibiotics, penicillin N and cephalosporin C. These antibiotics are modified tripeptides derived from α-aminoadipic acid, cysteine, and valine. Mutant strains of C. acremonium fall into four phenotypic classes based on potential to synthesize antibiotics: (A) strains with increased potential to synthesize cephalosporin C, (B) strains unable to synthesize either antibiotic, (C) strains able to synthesize only penicillin N, and (D) strains able to synthesize penicillin N and 6-aminopenicillanic acid. Mutants of the second class, β-lactam negative mutants, have been characterized further. One mutant is auxotrophic for lysine and will synthesize antibiotic only if grown in media supplemented with α-aminoadipic acid or pipecolic acid. Other mutants are prototrophic and consistently negative for antibiotic synthesis. These inactive mutants are further subdivided according to their ability to form peptides implicated as intermediates for the synthesis of β-lactam antibiotics.
Desdanine, an inhibitor of oxidative phosphorylation in mitochondria
Authors: Reusser Fritz
Published: February 2010

The antibiotic, desdanine, acts as an uncoupling agent of oxidative phosphorylation in rat liver mitochondria. In addition, mitochondrial respiration is also impaired but to a lesser degree. Studies of individual reaction sequences occurring within the respiratory chain indicate that desdanine interferes with electron transfer at the flavoprotein regions associated with the oxidation of NADH and succinate. The flavoprotein region associated with the oxidation of succinate is more susceptible to desdanine than the NADH-linked flavoprotein region.
Surface structures and unidentified organelles of Lycoperdon perlatum Pers. basidiospores
Authors: Hess W. M. , Bushnell J. L. , Weber D. J.
Published: February 2010

Lycoperdon perlatum basidiospores were studied by use of freeze-etched replicas. Surfaces of these basidiospores were found to have "rodlet" patterns similar to those reported for Aspergillus and Penicillium conidiospores. Cross-fractured basidiospores also contained unidentified organelles previously reported for Tilletia teliospores.
Autoclaving: a modification in the preparation of tissue culture medium 199
Authors: Kenny C. P. , Diena B. B. , Greenberg L.
Published: February 2010

HeLa cells and rhesus monkey kidney tissue cell lines can be propagated and maintained in medium 199 that has been sterilized by autoclaving. The choice of autoclaved M 199 is advantageous for some experimental procedures.
The effects of elevated temperatures on spore swelling and germination in Aspergillus niger
Authors: Anderson J. G. , Smith J. E.
Published: February 2010

Exogenous carbon and nitrogen sources were necessary for complete swelling (spherical growth) and germ-tube formation from Aspergillus niger spores. The rate of spherical growth was low at 30°, maximum at 38°, and decreased at higher temperatures until at 47° inhibition was complete. At temperatures from 35° to 44° the final spore size was similar and greater than at 30° although the time taken to reach this size varied. Germ-tube formation occurred in from 97 to 99% of the spores with a good degree of synchrony between 30° and 38°. At temperatures from 38° to 43° the proportion of spores which produced germ tubes gradually decreased with a concurrent loss of synchrony. At 44° germ-tube formation was completely inhibited although spherical growth could occur over a prolonged period to produce large spherical cells. This increase of cell volume was apparently accompanied by a system of wall extension which involved wall synthesis. Under conditions of spore crowding an inhibition became apparent which affected only the initiation of spherical growth and not the spherical-growth process itself. Other effects of spore crowding were observed and were attributed to alterations in the gaseous environment. Increased spherical growth was always accompanied by a greater degree of branching of the germ tube when produced and a hypothesis relating these effects is suggested.
Immunological relationships of Candida albicans and its transformants to Actinomycetales
Authors: Kwapinski J. B. G. , Dowler Judy
Published: February 2010

Immunochemical properties of a parental strain of C. albicans and of four transformants, obtained by exposing competent C. albicans cells to deoxyribonucleic acid (DNA) of Mycobacterium tuberculosis, were examined by selected methods. It was found that the cytoplasms of all the Candidas shared at least one antigen, but the transformants alone contained two additional antigenic factors. The cytoplasm preparations of all the Candidas were found immunologically related to M. microti, M. kansasii, M. abscessus, and to some strains of Runyon's Group IV, as well as to many Nocardias, Streptomycetes, Actinomycetes, Mycococci, and Dermatophili. The transformants were also related to the non-chromogenic mycobacteria.
Linear growth of a Torulopsis sp. on n-alkanes
Authors: McLee A. G. , Davies Stephanie L.
Published: February 2010

Slide cultures showed that growth of a hydrocarbon-utilizing Torulopsis sp. occurred only when the cells were in physical contact with the n-alkane droplets. Growth in batch culture was found to be linear and dependent on the surface area of substrate available to the cells. The hydrocarbon may enter the cell without first being converted to a more water-soluble intermediate.
Oxygen requirements of strains of Pseudomonas and Achromobacter
Authors: Clark D. S. , Burki T.
Published: February 2010

Studies on the oxygen requirements of aerobic psychrotolerant bacteria showed that the oxygen concentration of the atmosphere can be lowered to 2% without noticeably inhibiting growth rate. Tests were made with meat-spoilage strains of Achromobacter and Pseudomonas in nutrient media sparged with gases containing from 0.1 to 100% oxygen. Reduction of overall growth rate with reduction in oxygen concentration below 2% was mainly the result of an increase in the lag period. At an oxygen concentration of 0.5% or lower, however, cell generation time during the logarithmic phase was increased and cell yield at the stationary phase was reduced. The increased lag period could be eliminated by using an inoculum adapted to the oxygen concentration under test. Growth did not occur in the absence of oxygen. Oxygen concentrations greater than 21% (air) had a negligible effect on Pseudomonas, but inhibited the growth rate of Achromobacter. The results indicate that insufficient oxygen is not a major cause of the failure of these bacteria to grow rapidly in vacuum packaged meats.
Characteristics of nitrogenase activity in broken cell preparations of the blue-green alga Gloeocapsa sp. LB 795
Authors: Gallon J. R. , Larue T. A. , Kurz W. G. W.
Published: February 2010

Broken cell preparations of the blue-green alga Gloeocapsa sp. LB 795 reduce acetylene to ethylene and evolve hydrogen in the presence of sodium dithionite and adenosine triphosphate (ATP). The enzyme system is almost completely inhibited by adenosine diphosphate (ADP) (7.5 mM), O2 and CO (0.01 atm), and CO2 (0.05 atm). Its kinetic properties are very similar to those of nitrogenases from other sources, but, unlike the enzymes so far isolated from other blue-green algae, Gloeocapsa nitrogenase is sedimented by centrifugation at 10 000 g.
Development of herpes simplex virus in the isolated nuclei of HEp-2 cells. I. Viability of isolated HSV-infected nuclei
Authors: Fine Donald L. , Ludwig Ernest H.
Published: February 2010

A study was made to determine whether herpes simplex virus (HSV)-infected HEp-2 cell nuclei, when isolated post infection (p.i.) and incubated in the absence of cytoplasm, were capable of maintaining synthesis of protein and deoxyribonucleic acid (DNA). Demonstration of synthesis in nuclei isolated post infection was measured by the incorporation of 14C-glutamate into protein or 3H-thymidine into DNA. Both uninfected and HSV-infected nuclei synthesized nuclear protein and DNA for 2 h post isolation (p.e.). Similar rates of in vitro synthesis of nuclear protein were found in uninfected nuclei and nuclei isolated 2 h or 4 h post infection. In vitro synthesis of DNA occurs at about one-fourth the rate in virus-infected nuclei as compared to uninfected nuclei. These data serve as a determination of nucleus viability preceding further studies involving the maturation of HSV in isolated nuclei when incubated free from cytoplasmic control.
Development of herpes simplex virus in the isolated nuclei of HEp-2 cells. II. Intranuclear events in isolated HSV-infected nuclei
Authors: Fine D. L. , Ludwig E. H.
Published: February 2010

Specific immunofluorescence demonstrated a unique intranuclear fluorescent mass in incubated isolated herpes simplex virus (HSV)-infected HEp-2 nuclei. The intranuclear mass was observed to undergo a change in form, or maturation, during in vitro incubation when nuclei were isolated from HEp-2 cells 7 h post infection (p.i.). Both the accumulation and maturation of the intranuclear antigenic mass did not occur in HSV-infected nuclei isolated from HEp-2 cells grown in arginine-deficient medium. An accumulation of DNase-resistant acridine orange stainable aggregates occurred during in vitro incubation of nuclei isolated from 7- or 9-h HSV-infected cells. Enhanced nucleopathic effects did not occur under the same conditions of in vitro incubation. These data suggest that nuclei isolated from HSV-infected HEp-2 cells several hours p.i. are capable of allowing intranuclear virus development to continue under in vitro conditions in the absence of cytoplasmic contact. The findings may help to elucidate some of the roles of the cytoplasm and nucleus in herpes-virus development.
Regulation of cellulase from Ruminococcus
Authors: Fusee M. C. , Leatherwood J. M.
Published: February 2010

The regulation of cellulase was examined in Ruminococcus albus and R. flavefaciens. Hydrolysis of cellulose, as shown by the formation of clear zones around the colonies of bacteria grown in cellulose-agar roll tubes, was inhibited by moderate levels of cellobiose. An intermediate in the metabolism of cellobiose may be responsible for the inhibition since strains which can use either sucrose or lactose were similarly inhibited by these energy sources. The inhibition of cellulase was examined in relation to either repression of enzyme synthesis or product inhibition of the enzyme activity. There was no inhibition by cellobiose added either to the routine enzymatic assay or to assays using low concentrations of carboxymethylcellulose. A repression mechanism was indicated by the decrease in specific activity of cultures grown in higher concentrations of cellobiose. The specific activity was calculated as the enzymatic activity on carboxymethylcellulose with respect to cell growth. The mechanism of repression was not distinguished between the model proposed by Jacob and Monod and catabolite repression. The growth of R. albus cultured in cellobiose–cellulose liquid medium exhibited a diauxic pattern similar to that described by Monod.
Growth and nutrition of Saprospira grandis Gross (Flexibacterales)
Authors: Lewin Ralph A.
Published: February 2010

The obligately marine flexibacterium Saprospira grandis Gross requires a variety of nutrients for growth in defined media. They include the same 10 amino acids as are essential for higher animals, asparagine, and an unidentified factor or factors present in nucleic acid preparations.
Transduction of Salmonella typhimurium genetic material by coliphage P1 in S. typhimurium Hfr × Escherichia coli hybrids
Authors: Karunakaran V. , Middleton Richard B.
Published: February 2010

Coliphage P1 is shown to transmit Salmonella typhimurium genetic material from a S. typhimurium Hfr – Escherichia coli trp+ hybrid to trp mutants derived from it.
Virulent bacteriophage infection of Rhizobium leguminosarum
Authors: Ley A. N. , Warner H. R. , Kahn Phyllis L.
Published: February 2010

Bacteriophage 317, which virulently infects Rhizobium leguminosarum, has an eclipse period of 60–70 min and a latent period of 100 min at 30°. Electron micrographs of the phage indicated head, tail, and tail-fiber structural components.Base analysis of phage 317 deoxyribonucleic acid (DNA) indicated the presence of equimolar amounts of adenine and thymine and of guanine and cytosine, which suggests that the DNA is double stranded. The DNA has a molecular weight of 41 × 106 daltons as determined from electron micrographs.The results of 14C-uracil incorporation studies showed that net ribonucleic acid (RNA) synthesis was markedly inhibited after infection. There was a slight stimulation in DNA synthesis after infection as indicated by 14C-thymidine incorporation.The results of in vitro assays of enzymes involved in the biosynthesis of DNA showed that deoxyuridine 5′-triphosphate nucleotidohydrolase (dUTPase) and deoxythymidine 5′-monophosphate kinase (dTMP kinase) increased 50- and 30-fold respectively, after infection. The reason for the increased dUTPase activity is not readily apparent. Phage 317 DNA contains only the standard bases, unlike the DNA of other phages that induce an increase in this enzyme after infection. A high level of deoxythymidine 5′-monophosphatase (dTMPase) was observed in both uninfected and infected crude cell extracts. Further work is necessary to see if similar changes occur in Rhizobium during the establishment of symbiosis with legumes.
Cellular mediated immunity to the lymphogranuloma venereum agent
Authors: Sayed H. , Nicks R. , Wilt J. C.
Published: February 2010

A possible correlation between the skin test and the presence of a cellular mediated immunity has been investigated using a lymphogranuloma venereum (LGV) antigen. The macrophage inhibition (MI) and macrophage spreading inhibition (MSI) tests were used to detect evidence of a cellular mediated immunity. A positive correlation was obtained between the diameter of the skin reactions and the in vitro inhibition of macrophages. Further experimentation demonstrated that the in vitro inhibition of macrophages was not mediated by cytophilic antibodies but mediated partially or completely by a macrophage inhibition factor. Electrofocusing experiments were carried out on a sonicated LGV agent to isolate and identify the antigens which induced the cellular mediated immunity; four fractions with approximate pI (isoelectric point) values of 1.44, 1.38, 10.38, and 12.77 demonstrated a strong inhibition of macrophages in vitro. The antigen containing fractions had smaller amounts of nitrogen, higher ratios of non-reducing sugars per nitrogen content, and extremely high as well as low isoelectric point values as compared with fractions which exhibited no MSI reactions. The possibility of these antigens occurring as repeating units in the structure of the agent is discussed briefly.
Antiviral activity of aqueous clam (Mya arenaria) extract on amphibian virus (LT-1)
Authors: Li M. F. , Traxler G. S.
Published: February 2010

An aqueous extract of the soft-shell clam displayed antiviral activity which protected against infection of fathead minnow (FHM) cells by the amphibian virus (LT-1). The extract did not inactivate the virus particle extracellularly, nor could a combined action on virus and cell receptor sites account for the inhibitory effect of the extract. The observed inhibition appeared to be at the intracellular level.
Crystalline aggregates observed in the vicinity of freeze-etched poxvirus inclusions
Authors: Easterbrook K. B.
Published: February 2010

Freeze-etching has revealed the presence of crystalline aggregates closely associated with the developing viral inclusion of vaccinia virus. These have not been observed in frozen uninfected cells or, as yet, in infected cells processed by chemical fixation. Two types apparently exist, linear aggregates composed of cubically packed units, about 10 nm in size, and curved sheets or lamellae in which the subunits, each about 7.5 nm in size, are arranged hexagonally. The precise nature of these aggregates is undetermined, although the latter type is thought by analogy with other poxvirus systems to be related to the surface component of immature virions.
Modification of pigmentation and cell-wall structure of Rhodotorula aurantiaca by culture in the presence of sulfur amino acids
Authors: Killick K. A.
Published: February 2010

Growth of Rhodotorula aurantiaca in a medium supplemented with sulfur amino acids led to the synthesis and accumulation of S-adenosylmethionine, which was accompanied by a reduction in the total contents of carotenoid pigments and an increased sensitivity of the cell walls to snail gut enzymes (Helix pomatia) as judged by spheroplast formation. Walls isolated from supplemented cultures contained increased amounts of lipid and mannan but had a reduced content of protein and alkali-insoluble carbohydrate. The chemical modifications of the cell wall, which resulted as an indirect consequence of excessive S-adenosylmethionine synthesis, are interpreted to explain the ease with which sulfur amino acid-supplemented cultures of R. aurantiaca are converted to spheroplasts as well as their tendency to aggregate.
Genetic analysis of resistance to erythromycin and oleandomycin in Staphylococcus aureus
Authors: Bronson D. L. , Pattee P. A.
Published: February 2010

Strains U9(pase, tet, ery, nov) and U9(pase, tet, ol, nov) of Staphylococcus aureus were used as donors of the ery and ol markers, respectively, to strain 152. Thirty-three erythromycin-sensitive (ery-s) mutants of strain 152(ery) and 19 oleandomycin-sensitive (ol-s) mutants of strain 152(ol) were isolated following diethyl sulfate mutagenesis. The results of reciprocal transductions involving these mutants are as follows: (a) the frequency at which the ery and ol markers were transduced into each mutant varied greatly, and was especially low in those mutants which yielded recombinants in reciprocal transductions between the mutants; (b) 13 of the 19 ol-s mutants yielded recombinants in reciprocal transductions between the ol-s mutants; (c) no recombinants were detected in reciprocal transductions between ery-s mutants; (d) antibiotic-resistant recombinants were obtained in reciprocal transductions between three ery-s mutants and three ol-s mutants. The results of this study demonstrate that there is only one genetic locus which controls resistance to erythromycin and oleandomycin in these strains, and that it exists in an inducible state (the ery marker) and a constitutive state (the ol marker).
Mechanisms of prozone formation in agglutination reaction
Authors: Cho H. J. , Ingram D. G.
Published: February 2010

Natural and artificially induced inhibition of agglutination, in the presence of adequate agglutinating antibody, has been demonstrated using Brucella abortus as antigen and sheep serum as the source of antibodies.At least three types of inhibition have been demonstrated: (a) due to a heat-labile component, found in both normal and immune sera, which is probably complement, (b) due to a heat-stable component which sediments with 7S-globulins and migrates electrophoretically with the fast gamma-globulins, (c) induced by heating serum at 56 °C for prolonged periods or 60 °C for shorter periods. The latter inhibition appears to be due to complex formation of IgM with other serum proteins, which results in inhibition of the agglutinating, but not binding, capacity of this immunoglobulin.The extent to which any or all of these phenomena may be demonstrated varies with the time (and probably activity) of an infection, and may allow more precise assessment of the stage of infection, particularly in chronic diseases.
Lysosomes and the "toxicity" of Rickettsiales. I. Cytochemical studies of macrophages inoculated in vitro with C. psittaci 6BC
Authors: Kordová Nonna , Wilt John C.
Published: February 2010

Toxic doses of C. psittaci 6BC strain produced within 3–6 h after inoculation a rapidly progressive irreversible damage of mouse macrophages in vitro, an early leakage of a lysosomal enzyme, acid phosphatase, as well as a rapid disintegration of neutral red-stained cytoplasmic granules i.e. lysosomes. Pretreatment of the agent with immune serum neutralized the cytotoxic action of the agent and a reversible activation of lysosomes occurred. Pretreatment of the agent with undiluted control serum protected the macrophages from the early "toxic" injury; however, a cytopathic effect (CPE) occurred 48 h after inoculation and was accompanied by a release of lysosomal acid phosphatase. Heat-inactivated Chlamydiae produced an early agglutination of macrophages with leakage of lysosomal acid phosphatase, disintegration of neutral red-stained lysosomes, as well as a progressive irreversible damage of the macrophage. Concentrated, heat-inactivated agent-free, leuco-agglutinating material from 6BC infected L cells produced a similar injury of macrophages and their lysosomes. The findings are related to an earlier report of a rapid destruction of macrophages by C. psittaci in the intact animal (15). The possible mechanisms and factors of the "toxicity" of Rickettsiales are discussed.
Large-scale production of peripheral human lymphocytes for viral studies: the influence of viability and P.H.A. transformation on the growth of vesicular stomatitis virus
Authors: Rossier E. , Landry-Pigeon D.
Published: February 2010

Thirty-one normal blood donors were bled for purification and large-scale culture of lymphocytes in the presence of phytohemagglutinin (P.H.A.). Despite large fluctuations in the yield of lymphocytes, viability and transformation rates were high and reproducible.Infection of P.H.A.-stimulated lymphocyte cultures from different donors, with vesicular stomatitis virus, produced highly variable yields which at best were 10 × lower than from other tissue-culture systems. Production was probably limited by the low proportion of virus-susceptible cells and the influence of interferon.
Protein constituents of cell walls of the dimorphic phases of Blastomyces dermatitidis
Authors: Roy Ira , Landau J. W.
Published: February 2010

Some aspects of alkali-soluble proteins extracted from yeast- and mycelial-phase cell walls of Blastomyces dermatitidis were investigated. The mycelial phase was found to contain protein in ammonium sulfate fraction A whereas, the yeast phase had protein in both precipitable A and nonprecipitable B fractions. The different fractions were found to vary quantitatively and qualitatively in amino acid constituents. Proteins were also found to vary electrophoretically in both phases on SDS (sodium dodecyl sulfate) polyacrylamide gels. Cysteic acids and disulfide groups were found to be in highest amounts in the mycelial phase fraction A in comparison to other fractions. Disulfide reductase may have no role in the dimorphism of B. dermatitidis.
Biosynthesis of α-acetolactate and its conversion to diacetyl and acetoin in cell-free extracts of Lactobacillus casei
Authors: Branen A. L. , Keenan T. W.
Published: February 2010

Cell-free extracts of Lactobacillus casei 393 required two enzyme systems for production of acetoin and diacetyl from pyruvate. An enzyme closely associated with the particulate fraction obtained after sonic oscillation produced α-acetolactate, required thiamine pyrophosphate and magnesium for optimal activity, and was inhibited by citrate. Acetolactate was converted to diacetyl and acetoin by both enzymatic and nonenzymatic processes. The enzyme responsible for conversion of acetolactate to diacetyl and acetoin was readily solubilized by sonication of cells. This enzyme required thiamine pyrophosphate or pyridoxalamine for optimal activity and its activity was enhanced in cells cultured in media containing citrate. Results obtained suggested that under conditions which exist in cultures, α-acetolactate was decarboxylated to diacetyl primarily by a nonenzymatic process.
Some features of competent streptococci
Authors: Pakula R. , Spencer L. R.
Published: February 2010

The Wicky Streptococcus was rendered competent for deoxyribonucleic acid (DNA) uptake with the competence factor (CF) derived from a related strain. Initiation of competence resulted in an almost immediate decline of the rate of cell proliferation and of incorporation of 14C-uracil into acid-insoluble material. DNA synthesis was affected in the later stage of competence development. The competent cells were penicillin resistant.
Degradation of rutin by Aspergillus flavus. Studies on specificity, inhibition, and possible reaction mechanism of quercetinase
Authors: Oka T. , Simpson F. J. , Krishnamurty H. G.
Published: February 2010

The dioxygenase produced by Aspergillus flavus that oxidizes quercetin contains 2 moles of copper per mole of enzyme and binds at least 2 moles of substrate. The enzyme is not inhibited by sulfhydryl reagents or affected by H2O2, but is inhibited by copper-chelating agents and reducing agents. Nitrogen bases with chelating ability are more effective inhibitors than those that do not form metal chelates.The dioxygenase oxidizes flavones that possess a double bond between carbons-2 and -3 and a hydroxyl on carbon-3. Hydroxyls at other positions affect both the relative rates of enzymatic oxidation and the concentration of substrate required to attain half maximal rate (Km). The evidence indicates that the substrate binds to the copper of the enzyme via the 3-hydroxyl and 4-carbonyl groups of the substrate. A possible mechanism for the reaction is presented.
Cationic uptake and exchange in Salmonella enteritidis
Authors: Chipley J. R. , Edwards Jr. H. M.
Published: February 2010

The use of inorganic cations in cells and purified cell walls of Salmonella enteritidis was investigated. Both the uptake and exchange of radioactive cations were energy-dependent and influenced by pH, by dialysis time and temperature, and by the ionic content of the surrounding medium. Cell walls bound 47Ca2+ to the greatest extent, followed in order by 65Zn2+, 54Mn2+, and 59Fe3+. Another determining factor for cationic exchange was valency, with divalent cations exchanging to the greatest extent, followed by trivalent and monovalent cations, respectively. The greatest amount of exchange occurred between a radioisotope and a stable isotope of the same species. All losses of radioactivity were dialyzable indicating that this exchange involves very small moieties, perhaps the cation alone. Both 2,4-dinitrophenol (DNP) and N,N′-dicyclohexylcarbodiimide (DCCD) significantly decreased autologous exchange, cationic exchange, and cationic uptake in either cells or cell walls. It was postulated that these two compounds either inhibited ATP hydrolysis or reacted with membrane sites such that the membrane could no longer undergo configurational changes associated with cationic transport or exchange.
Sporulation of Bacillus popilliae in liquid medium as affected by kind of carbon and method of sterilization
Authors: Haynes William C. , Weih Lenora J. , Crowell Clarence
Published: February 2010

Of six activated carbons from two manufacturers, four made from nutshells evoked sporulation by Bacillus popilliae NRRL B-2309S in a tryptone–glucose–yeast extract – phosphate medium. Four to nine million refractile spores per milliliter were produced in cultures containing a selected carbon that was sterilized apart from the base medium. A reduction in yield of spores that resulted from sterilizing glucose in the medium was moderated when carbon was also present during sterilization.
Autoradiography of blood forms of Trypanosoma musculi
Authors: Viens P. , Targett G. A. T.
Published: February 2010

Blood forms of Trypanosoma musculi obtained from irradiated C3H mice were labeled with 3H-thymidine and were examined by autoradiography. Nucleus and kinetoplast were heavily labeled in about 5% of the parasites but most of the morphologically dividing forms did not take up the label. This technique is being used to clarify certain aspects of the theory that control of parasitaemia by the host is due, in part, to the production of ablastin, an antibody which specifically inhibits parasite reproduction.
Identification of staphylococcal epsilon hemolysin
Authors: Ali M. I. , Haque Riaz-ul
Published: February 2010

The culture filtrate of the M-3 strain of Staphylococcus epidermidis when electrophoresed at 5 mA/cm for [Formula: see text] in Ion agar No. 2 using barbitol buffer pH 8.4 revealed a hemolysin which migrated 14 mm towards the anode and lysed human and rabbit erythrocytes. This hemolysin is designated as the epsilon hemolysin of staphylococci.
Flotation of excised root and fungal cultures on liquid media
Authors: Zak B.
Published: February 2010

A method of floating excised roots and fungal cultures on liquid media using discs of nylon and dacron netting is described
A Rickettsia-like organism associated with the millipede, Ophyiulus pilosus (Newport) (Diplopoda: Julidae)
Authors: Wilson G. G. , Burke J. M.
Published: February 2010

A Rickettsia-like organism associated with the millipede, Ophyiulus pilosus is reported. Some of the general characteristics of the organism are indicated.
Characterization of arylsulfatase isoenzymes from Pseudomonas aeruginosa
Authors: Delisle G. J. , Milazzo F. H.
Published: February 2010

A method is described for the separation and isolation of two electrophoretically distinct arylsulfatases (arylsulfatase EC.3.1.6.1) from Pseudomonas aeruginosa.Characterization of the enzymes revealed that they were type I arylsulfatases, with similar kinetic properties. They differed, however, in respect to charge, pH optima for substrate hydrolysis, and activation by anions. In addition, the enzymes displayed dual pH optima curves with both substrates used and the curious property of a shift in pH optima with varied p-nitrophenyl sulfate concentrations.
Histidine biosynthetic pathway in Staphylococcus aureus
Authors: Burke Mary Ellen , Pattee P. A.
Published: February 2010

The enzymes involved in histidine biosynthesis and their metabolic control are similar in Staphylococcus aureus and other organisms which have been studied, although some of these enzymes in S. aureus appear to be more labile. As is true in Salmonella typhimurium, the imidazoleglycerol phosphate dehydratase of S. aureus is inhibited in vitro by 4-amino-1,2,4-triazole (amitrole). Unlike S. typhimurium, however, growth in the presence of amitrole does not result in derepression of the histidine biosynthetic enzymes, and as a consequence the inhibition of the growth of S. aureus by amitrole is not overcome. This observation provided the basis for isolating mutants of S. aureus which were resistant to amitrole. Most of these amitrole-resistant mutants possessed constitutively high levels of the histidine biosynthetic enzymes, and the levels of these enzymes were not repressed in most of these mutants when they were grown in excess L-histidine.
The effect of reserpine upon experimental coxsackievirus B-3 infection in mice
Authors: Grodums E. I.
Published: February 2010

Coxsackievirus (cox.) B-3 pathogenicity was markedly augmented in weanling and adult mice during a reserpine treatment. In both age groups the mortality rose to 100% after the 1st week of inoculation.In the olfactory bulb of the reserpine-treated weanling mice the score of viral lesions was 80% compared to 2% in the non-treated. In the heart of the reserpine-treated infected mice it was 62%, while it was 40% without reserpine. In the adult mice the viral tissue damage was aggravated in the interscapular brown adipose pad and the olfactory bulb. Moreover, the viral lesions in the reserpine-treated mice in both age groups showed some striking morphological differences when compared with mice injected with the virus only.The recovered virus yielded higher titers in the reserpine-treated mice in both age groups. In the adult reserpine-treated mice the LD50 of the cox. B-3 recovered from the brain and heart were as high as in the weanlings.
The occurrence of ascorbic acid among the yeasts
Authors: Heick H. M. C. , Graff G. L. A. , Humpers J. E. C.
Published: February 2010

Forty-two species of yeast were examined for their ability to produce enediols of the ascorbic acid class. A Roe and Kuether chromogen derived from such enediols could be isolated from 23 of the species. The chromogen from four yeasts was further identified by infrared (i.r.) spectrophotometry as being derived from ascorbic acid. At least one species from each family of yeasts was found to produce ascorbic acid.