bluuebunny/crossref_metadata_2025 huggingface dataset:
The microflora of peach bark and its possible relation to perennial canker (Leucostoma cincta (Fr.) v. Hohnel (Valsa cincta))
Authors: Wensley R. N.
Published: February 2010

Numerous microorganisms, antagonistic toward canker fungi, Cytospora cincta Sacc. (Leucostoma cincta (Fr.) v.H.) and C. leucostoma (L. persoonii (Nit) v.H.) were recovered from the outer bark of peach. In unsterilized outer bark, fungi predominated in a population of antagonists that included bacteria and actinomycetes. In surface-sterilized outer bark, antagonistic bacteria predominated. A predominance of antagonists in the spring- and fall-infection periods suggests that they contribute to the control of canker. The important but relatively low proportion of strong antagonists in the microflora of resistant Standard Elberta and Sunhaven varieties may explain in part the prevalence of canker on all varieties of peach. Their absence in favor of weak antagonists on Dixired at this time may contribute to its higher susceptibility (canker counts) than that of Standard Elberta, Sunhaven, and Redhaven varieties.
Changes in phosphorus composition of Candida utilis during the cell cycle and postcycle period
Authors: Glättli H. , Dawson P. S. S.
Published: February 2010

Cells of Candida utilis were grown under carbon limitation in phased culture at a doubling time of 4 h. The phosphorus contents of four (lipid, cold water extractable, RNA, and DNA) fractions, obtained empirically by serial extraction of the cells, were determined at [Formula: see text]-h intervals during the cell cycle and post-cycle periods. The results showed that the phosphorus composition of the cells was changing throughout both cell cycle and postcycle periods.Each phosphorus fraction doubled during the cell cycle; for the major fractions (cold water extractable P and RNA-P) this occurred as a gradual increase spread over the cell cycle period, but for the minor fractions (lipid-P and DNA-P) the increase was restricted to the latter half of the cell cycle period. Expressed as proportions of the total phosphorus content, the phosphorus contents of the major fractions remained constant, but the minor ones changed during the cell cycle. Other, different, changes were observed between the various fractions during the postcycle period.
The effect of carbon monoxide inhibition on the growth of an aquatic streptomycete
Authors: Francisco Donald E. , Silvey J. K. G.
Published: February 2010

A recent investigation has shown that the primary mycelium of aquatic streptomycetes is facultatively aerobic while the secondary mycelium is obligately aerobic. The nature of the differences in aerobic metabolism of various morphological phases in the life history was determined by carbon monoxide inhibition. A slide culture chamber technique which allowed continuous microscopic observation of the growing organism while in various gas environments was used. Two distinct patterns of inhibition were observed. The development of early stages of the life history was inhibited by carbon monoxide in the light and the dark. The site of this inhibition could not be determined. The later stages were inhibited only by carbon monoxide in the dark. This suggested a dependence of the secondary mycelium on the activity of cytochrome oxidase. Thus, the primary and secondary mycelial stages were found to be physiologically distinct.
Ultrastructural evidence of immunological reactions during experimental coxsackievirus B-3 infection in the hibernating squirrel
Authors: Grodums E. I. , Dempster G.
Published: February 2010

Ultrastructural studies upon the development of coxsackievirus B-3 lesion in the olfactory bulb of the hibernating, experimentally infected adult squirrel (Citellus lateralis) revealed two or possibly three types of pathological reactions. (1) Changes, which occurred before virus replication in the brain, resembled an acute allergic reaction with extensive hemorrhages and neutrophil infiltration, fibrinoid deposits, thrombus formation, and lytic tissue breakdown in the neuropil. (2) Pathological changes resulting primarily from virus replication which succeeded the allergic reaction. (3) A reaction which coincided with and followed the virus replication and was associated with an influx of antibody-producing cells into the olfactory bulb and might prove to be the result of a delayed hypersensitivity.
Persistence of captan and its effects on microflora, respiration, and nitrification of a forest nursery soil
Authors: Agnihotri V. P.
Published: February 2010

Addition of captan, n-(trichloromethylthio) 4-cyclohexene-1,2-dicarboximide (active ingredient, 62.5, 125, and 250 ppm/acre) to fresh soil in the laboratory affected the soil microflora and some of their activities. Captan showed extremely low persistence in a forest nursery soil. It was almost fully degraded in 1 week when applied at or below 250 ppm. Captan killed the population of two pathogenic fungi (Rhizoctonia and Pythium species) and encouraged the growth of three saprophytic fungi (Penicillium, Trichoderma, and Fusarium species). After an initial decrease, the population of actinomycetes gradually increased. Captan increased the population of bacteria by the 7th day; however, by the 35th day the population had dropped to that of the control soil.Captan also affected soil respiration. Initial depressions of CO2 production were directly proportional to the concentration of captan in the soil. After initial inhibition, the rate of soil respiration was stimulated because of the use of decomposition products of captan by microorganisms. Nitrification was impaired for 2 to 3 weeks, depending on the captan concentration.
Immunization of sheep against experimental Clostridium perfringens type A enteritis
Authors: Niilo L. , Hauschild A. H. W. , Dorward W. J.
Published: February 2010

Lambs were injected parenterally with formalized cell extract, or bacterin, prepared from sporulating cultures of an enteropathogenic strain of Clostridium perfringens type A. This procedure induced an antibody in the serum which neutralized the erythemal and enteropathogenic activities of the cell extract. Immunodiffusion of the serum against the toxic cell extract produced a single, specific band associated with enteropathogenic activity. Protective immunity was not evident when the immunized lambs were challenged by the intraduodenal and the ligated intestinal loop methods with toxic cell extract or with whole cells of C. perfringens. Non-immunized lambs, challenged nine times by the intraduodenal method over a period of 70 days, had no measurable antibody and remained susceptible to experimental enteritis.
Structural changes in cells of Clostridium perfringens infected with a short-tailed bacteriophage
Authors: Bradley David E. , Hoeniger Judith F. M.
Published: February 2010

A culture of Clostridium perfringens strain 80 in cooked meat broth contained three types of cell: normal, long, and small round cells. The process of phage maturation and cell lysis was studied in all three forms using the electron microscope. In normal cells, the nucleoplasm first enlarged, then small clear areas, slightly larger than intracellular phages, appeared mainly around the cell periphery. The nucleoplasm dispersed and mature phage particles were formed. Subsequent lysis was caused by the breaking off of portions of the cell envelope leaving holes for the release of the contents. Long cells were also able to support phage growth.
MICSYS, an information system using the digital computer for culture collections
Authors: Simpson F. J. , Okeren I. , Peardon G.
Published: February 2010

A system is outlined for the collection of alphanumeric information and data on organisms in culture collections, for storage on magnetic tape, and for selective retrieval by a computer. Information is recorded on standard forms and transferred to cards by key punch operators. The generic and specific names of the organisms are automatically compared with reference lists to check for authenticity, synonymy, type, and correct spelling before the entry is recorded on magnetic tape. Minor errors in spelling are corrected. Existing information can be changed, added to, or deleted. Programs have been written to produce lists or catalogs of species in individual collections and of a group of collections. Other programs for selective retrieval of information can be written. The system has sufficient flexibility to enable the user to establish the kinds of information stored and to design according to his requirements the formats of selective retrieval operations.
Caractéristiques d'un mutant homothallique de Saccharomyces cerevisiae Hansen
Authors: Arnaud A. , Vezinhet Françoise , Galzy P.
Published: February 2010

Through mutagenesis by nitrous acid a mutant was obtained which differed from the wild strain by two independent characters. The mutant gave smooth colonies on a solid medium containing lactic acid; the wild type yielded rough colonies on the same medium. The smooth colony character was unstable during vegetative growth. The mutant was homothallic. This character was stable during vegetative growth but it was not segregated through meïosis. This mutation inducing homothallism is not controlled by a gene.
Effect of dimethyl sulfoxide on the sclerotia of Sclerotium rolfsii
Authors: Melhuish Jr. J. H. , Bean G. A.
Published: February 2010

Sclerotium rolfsii was grown on a synthetic medium containing from 0 to 20 000 ppm dimethyl sulfoxide (DMSO). Growth rate and sclerotial production decreased with increased DMSO level. With 2000 ppm DMSO in the medium, sclerotial production decreased 45%. The sclerotial size and dry weight increased with DMSO level up to 8000 ppm and decreased at concentrations of 12 000 ppm, or more. Sclerotia, when produced on media containing DMSO and transferred to DMSO-free medium, produced normal mycelia and sclerotia. Sulfur-containing compounds similar to DMSO did not affect sclerotial production.
Reversible inactivation and dissociation of glutamine synthetase of Neurospora crassa by urea
Authors: Ward G. W. , Kapoor M.
Published: February 2010

The effect of urea on the stability and the state of aggregation of glutamine synthetase is reported. Substrates and modulators of this enzyme exert a protective effect against urea-induced loss of activity. On partial inactivation by urea, the enzyme appears to consist of a dimeric species and an intermediate, partially unfolded form. Subsequent to the removal of urea, the presence of substrates and effectors is necessary to bring about a reversal of inactivation and a return of the enzyme lo the native or near-native state.
Influence of sensitization with bacterial antigens on the replication of Friend spleen focus-forming virus
Authors: Flickinger John T. , Gentile John M.
Published: February 2010

The replication of the SFFV component of a polycythemia-inducing strain of Friend leukemia virus was shown to be enhanced by endotoxin either as purified fraction W of S. typhosa or present on heat-killed S. typhosa or P. mirabilis. Enhancement occurred to a significant level when the mice were sensitized with either form of endotoxin 5 or 3 days before virus administration. Administration of endotoxin simultaneously with virus resulted in a marked inhibition of SFFV replication. Endotoxin given at times subsequent to viral infection had no effect on SFFV replication. On the other hand the H or flagellar antigen from P. mirabilis given either before, simultaneously with, or after virus infection did not influence the replication of SFFV.
Demonstration of two types of DNA repair in X-irradiated Micrococcus radiodurans
Authors: Driedger A. A. , Grayston M. J.
Published: February 2010

The effect of chloramphenicol (CAP) on the initiation and continuation of DNA repair in X-irradiated Micrococcus radiodurans was studied. The repair of single strand breaks proceeds by two separate mechanisms, one of which is resistant to CAP, proceeds without thymidine incorporation, and is inhibited by EDTA. This direct repair might be due to the direct action of polynucleotide ligase on breaks with 3′OH and 5′PO4 end groups. The other type of repair is the classical repair replication: this requires postirradiation protein synthesis to be initiated but once under way is not halted by CAP.Postirradiation incubation with EDTA irreversibly prevented subsequent direct repair. The hypothesis is advanced that unrepaired breaks were converted to gaps by enzymatic activity during incubation with EDTA.
The effects of nalidixic acid on X-ray-induced DNA degradation and repair in Micrococcus radiodurans
Authors: Driedger A. A. , Grayston M. J.
Published: February 2010

In Micrococcus radiodurans normal DNA synthesis has two components of which one is highly sensitive to nalidixic acid (NA) and the other quite resistant. Irradiated cells repair the X-ray-induced breaks in DNA in the presence of NA except at high concentrations at which repair is inhibited through an abscopal effect of the drug on protein synthesis. Irradiated cells are stimulated to degrade a larger fraction of their DNA in the presence of moderate doses of NA even though the X-ray-induced breaks have been repaired. This effect is similar to that of phenethyl alcohol in that the normal response to the drug is not restored by DNA repair. There must, therefore, be critical X-ray-induced damage in a non-DNA target which is not repaired unless normal growth and division are resumed.
Fine structure of the fungus Metarrhizium anisopliae infecting three species of larval Elateridae (Coleoptera). IV. Development within the host
Authors: Zacharuk R. Y.
Published: February 2010

Metarrhizium anisopliae develops through three structural stages within the body cavity of elaterid larvae after penetration of the host integument. The fine structure of these stages is described. The penetrant hyphae give rise to hyphal bodies, which become distributed throughout the body cavity and give rise to secondary hyphae in all parts of the body. The third stage consists of discrete large, ovoid cells with abundant nutrient stores and few metabolically active inclusions. It is termed a chlamydospore stage to differentiate it from the hyphal body stage, the cells of which are also discrete and often ovoid. The suggestion is that the chlamydospores may maintain fungal viability within the body of the host for extended periods before surface sporulation.
Analysis by gas chromatography of fatty acids found in whole cultural extracts of Neisseria species
Authors: Brooks J. B. , Kellogg D. S. , Thacker L. , Turner E. M.
Published: February 2010

Sixty-five strains of Neisseria were tested. They included 12 species and several serogroups of N. meningitidis. A variety of acids, including keto acids, were detected by gas chromatography. Many of the acids detected have not been previously reported. Strains of N. meningitidis and N. catarrhalis were found to comprise a heterogeneous group. Cultures of N. flavescens, N. sicca, N. subflava, N. perflava, and N. cinerea produced acid patterns like N. meningitidis serogroup B. N. flava and N. mucosa were also like this group except that phenylpyruvic acid was detected in cultures of the former organisms. Strains of N. gonorrhoeae differed from strains of N. meningitidis in that acetic acid was produced, propionic acid was not used, and only a moderate amount of α-ketoisocaproic acid was detected. Strains of N. lactamicus, N. haemolysans, N. ovis, and N. catarrhalis also produced characteristic patterns that distinguished them from other species tested. The data indicate that criteria in addition to those now routinely used should be established to identify some members of the genus properly.
Leloir's pathway in Polyporus circinatus
Authors: Zancan Glaci T.
Published: February 2010

Polyporus circinatus grows in galactose as sole carbon source. The enzymes involved in galactose metabolism were investigated in the mold extracts. Evidences for the enzymes activities were obtained by the analysis of products through tracing techniques and paper chromatography. Galactokinase, Gal-1-P uridyl transferase, UDPGal-4-epimerase, and UDPGal pyrophosphorylase could be detected.
Aflatoxin biosynthesis in Aspergillus parasiticus: effect of methionine analogs
Authors: Detroy R. W. , Ciegler A.
Published: February 2010

The physiological effects of DL-ethionine and related methionine analogs upon cellular protein synthesis and methyl group transfer to aflatoxin B1 in Aspergillus parasiticus were examined in growing and resting cell systems. The addition of DL-ethionine (0.02 M) to growing mycelia inhibits cellular growth some 37% after 120 h of development. Addition of ethionine before 50 h prevents any aflatoxin synthesis; however, addition of ethionine after aflatoxin production begins has little effect upon continued synthesis. The enzymes responsible for aflatoxin production are made during the transitional phase of growth (50–70 h). During this period, ethionine administration blocks protein synthesis (measured by 14C-methionine incorporation) 85% and prevents aflatoxin synthesis. Since exogenous ethionine (3.2 mM) inhibits aflatoxin B1 synthesis about 50%, a competitive-type inhibition is indicated. Such inhibition is accompanied by the formation of a new aflatoxin B1 derivative. The incorporation of 14C-ethyl-ethionine into this derivative indicates a transethylation of the toxin ring system in the formation of ethoxy-aflatoxin B1. The addition of DL-ethionine and S-ethylcysteine to proliferating cells yields some of the aflatoxin B1 derivative.
Gamma-ray induced strand breakage of Bacillus subtilis DNA irradiated in vivo
Authors: Dugle David L. , Dugle Janet R.
Published: February 2010

Evidence is presented for the isolation of DNA having a molecular weight of 31 ± 5 × 108 from Bacillus subtilis strain 23 Thy− cells. This accounts for the total DNA content of the genome. Single-strand and double-strand breaks induced by 60Co gamma rays were measured by sucrose density centrifugation. The occurrence of repair of single-strand and possibly double-strand breaks at 0 °C is inferred from survival data and the effects of pre- or post-irradiation heating.
Chelating agents and the growth of Micrococcus lysodeikticus
Authors: Walsh B. L. , O'Dor Janet , Warren R. A. J.
Published: February 2010

Micrococcus lysodeikticus will grow in a defined medium, but only after an extended lag. The lag is lengthened by washing the inoculum, but this does not affect the final density of the culture. The lag for washed inocula is shortened by the addition of an iron-binding compound to the medium. The compounds effective in shortening the lag include both phenolic compounds and ferrichrome, a sideramine. Albomycin, a sideromycin, lengthens the lag for washed inocula but does not affect the final density of the culture. The iron-binding compounds which shorten the lag will antagonize the action of albomycin, as judged by the length of the lag, and will also stimulate the uptake of iron by M. lysodeikticus. Albomycin reduces the rate of uptake of iron. It is suggested that the initiation of growth in M. lysodeikticus is dependent upon the presence of an iron-binding compound, and that albomycin retards growth by decreasing the rate of uptake of iron.
Effect of growth substrate on enzymes of the citric and glyoxylic acid cycles in Thiobacillus novellus
Authors: Charles A. Michael
Published: February 2010

A quantitative study was conducted of enzymes involved in the citric acid cycle and associated systems of the facultative autotroph Thiobacillus novellus grown on five different substrates. Irrespective of the growth substrate the organism possessed complete citric and glyoxylic acid cycles and the specific activity of α-ketoglutarate dehydrogenase was always quite low. Also, the activities of the enzymes of both cycles were usually lowest in extracts from autotrophic cells, and highest in extracts from acetate-grown cells. The three remaining extracts had activities that were between the two extremes with those from glucose-grown cells generally lower than those from pyruvate and succinate. Several exceptions should be noted among these generalizations. For example, the activity of aconitate hydratase and malic dehydrogenase was lowest in extracts from glucose-grown cells while that of isocitric dehydrogenase was lowest in extracts from pyruvate-grown cells. Transhydrogenase activity was virtually absent from extracts of pyruvate- and succinate-grown cells while NADH oxidase, which was identical in these two extracts, was also relatively low. Of interest is the large amount of cytochrome c found in high-speed supernatants. In extracts from autotrophic cells this was about 2.3% of the soluble protein and is suggestive of a significant role being played by the electron-transport system during growth of the organism.
Deoxyribonucleic acid homology in the genus Lactobacillus
Authors: Miller III A. , Sandine W. E. , Elliker P. R.
Published: February 2010

Hybridization experiments were conducted to detect nucleic acid homology among recognized species of lactobacilli. Tritiated complementary ribonucleic acid (RNA) was synthesized and reacted with homologous and heterologous deoxyribonucleic acid (DNA) preparations. The amount of radioactivity retained by nitrocellulose membrane filters indicated the degree of DNA–RNA interaction. The results were discussed in relation to a previous study in which lactobacilli were placed in three groups on the basis of the guanine plus cytosine (GC) content of the DNA. Group I; a 42% or greater reaction was observed when Lactobacillus helveticus tritiated RNA was hybridized with DNA from L. helveticus, L. bulgaricus, L. jugurti, and L. (jugurti) bulgaricus. The latter two strains appeared to be closely related and were easily distinguished from L. helveticus. No appreciable cross reaction occurred with L. helveticus tritiated RNA and DNA from L. salivarius. Group II; no DNA–RNA hybrid formation was evident when L. casei tritiated RNA was reacted with DNA from L. plantarum, L. brevis, or L. buchneri; however, reactions of 50 to 100% were observed for nine strains of L. casei. Group III; L. lactis appeared to be more closely related to L. leichmannii than to L. delbrueckii. Also, L. fermenti and L. cellobiosus constituted a distinct subgroup within group III. The results presented substantiate and further define the grouping based on GC content previously proposed. Further subdivision of each group was suggested. The possibility of a phylogenetic relationship between selected lactobacilli and Bacillus coagulans was discussed also.
The metabolism of p-fluorophenylacetic acid by a Pseudomonas sp. I. Isolation and identification of intermediates in degradation
Authors: Harper D. B. , Blakley E. R.
Published: February 2010

A Pseudomonas sp. capable of growing on p-fluorophenylacetic acid as sole carbon source has been isolated using the enrichment culture technique. All the organic fluorine is released into the culture medium as fluoride ion during growth. A number of fluorinated intermediates have been isolated from the culture medium when resting cells were incubated with the substrate. Using infrared, nuclear magnetic resonance, and mass spectroscopic techniques together with chemical degradative procedures, these have been identified as D(+)-monofluorosuccinic acid, trans-3-fluoro-3-hexenedioic acid, (−)-4-carboxymethyl-4-fluorobutanolide, 4-fluoro-2-hydroxyphenylacetic acid, and 4-fluoro-3-hydroxyphenylacetic acid.
The metabolism of p-fluorophenylacetic acid by a Pseudomonas sp. II. The degradative pathway
Authors: Harper D. B. , Blakley E. R.
Published: February 2010

A Pseudomonas sp. grown on p-fluorophenylacetic acid is adapted to the metabolism of phenylacetic acid, 3-fluoro-3-hexenedioic acid, monofluorosuccinic acid, monofluorofumaric acid, β-ketoadipic acid, and β-hydroxyadipic acid. Cell suspensions catalyze the lactonization of 3-fluoro-3-hexenedioic acid to give 4-carboxymethyl-4-fluorobutanolide. The results suggest that 3-fluoro-3-hexenedioic acid is an intermediate in the degradation of p-fluorophenylacetic acid, and may be metabolized by two alternate pathways, depending on the lactone formed. 4-Carboxymethyl-4-fluorobutanolide may be hydrolyzed to give 3-hydroxy-3-fluoroadipic acid, which spontaneously eliminates hydrogen fluoride to give β-ketoadipic acid. Alternatively, 3-fluoro-3-hexenedioic acid may lactonize to form 4-carboxymethyl-3-fluorobutanolide, which is then hydrolyzed to 3-keto-4-fluoroadipic and cleaved to form acetate and monofluorosuccinic acid. The latter is converted to fluorofumaric acid by fumarase to give 2-fluoromalic acid. This unstable compound decomposes to oxaloacetate and hydrogen fluoride. The mechanism of ring cleavage and the mode of formation of 3-fluoro-3-hexenedioic acid are uncertain but may involve partial reduction of the aromatic ring before oxidative cleavage.
Substitution of 4-(2-hydroxyethyl)-1-piperazineethane sulfonic acid (HEPES) for bicarbonate in protein-free animal cell culture medium: application to vaccinia virus quantitation and fluorogenic acetylesterase assay in living LM cells
Authors: Medzon Edward L. , Gedies Adolph
Published: February 2010

The buffer 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) at 15 mM has been substituted for sodium bicarbonate in the protein-free medium used for the growth of LM mouse fibroblasts. Cells have been cultivated in spinner flasks for up to 6 months with continuous aeration from an air line. The generation time was similar to that of parallel bicarbonate-buffered cells. Cotton-plugged shaken Erlenmeyer flasks produced the same results. HEPES-buffered cells have been grown in cotton-plugged prescription bottles and in glass and plastic Petri dishes in an ordinary humidified incubator. Vaccinia virus plaque production was slightly reduced in cells grown and overlaid with HEPES medium compared to bicarbonate medium. There was little difference in plaque count on cells grown in bicarbonate and overlaid with HEPES medium. These results indicate that HEPES buffer could be used routinely for cell and virus growth in aerated systems where CO2 is not limiting. Acetylesterase (EC. 3.1.1.6), measured by the fluorometric breakdown of fluorescein diacetate by living cells, was lower in HEPES than in bicarbonate-buffered medium, indicating an effect of HEPES on the cell membrane. The ability of HEPES to withstand autoclaving also renders it useful as a buffer for currently available autoclavable Eagle's medium.
The growth and morphological changes of the genus Bordetella in rotated fluid glycine cultures
Authors: Mason M. Aileen
Published: February 2010

B. pertussis phase I (17 strains), atypical B. pertussis (4 strains), B. parapertussis (5 strains), and B. bronchiseptica (10 strains) were observed for morphological changes in rotated fluid cultures containing graded concentrations of glycine. Differences between the species were apparent in their tolerance to glycine and in their morphology. B. pertussis, the most fastidious species, was the least tolerant and showed fewest morphological changes when grown in glycine media. Strains of B. parapertussis and B. bronchiseptica, collectively, were the most tolerant to glycine and showed the greatest pleomorphism, and the atypical B. pertussis strains were divided between two extremes.
Isolation and properties of a bacteriophage lytic for a wide range of pseudomonads
Authors: Kelln R. A. , Warren R. A. J.
Published: February 2010

The lytic bacteriophage ø-S1 was isolated from sewage using a strain of Pseudomonas fluorescens as host. It had a hexagonal head 60 nm in diameter and a short tail 30 nm long. ø-S1 had a broad host range, lysing strains from 10 biotypes of Pseudomonads. Although the latent period was fairly constant for the bacterial strains tested, the burst size varied considerably. The rate of adsorption of the phage to different strains also varied considerably.
The biosynthesis of aspartic acid, glutamic acid, and alanine in Rhizobium japonicum
Authors: Lillich Thomas T. , Elkan Gerald H.
Published: February 2010

The biosynthesis of aspartic acid and the incorporation of its carbon skeleton into glutamic acid and alanine was investigated in Rhizobium japonicum. It was found that oxalacetic acid (OAA) occupies a key position in the metabolism of this amino acid and the dissemination of its carbon skeleton into other amino acids. Aspartic acid is formed by two pathways involving the amination of OAA. In one pathway, OAA is synthesized by the tricarboxylic acid (TCA) cycle and in the other by the carboxylation of either pyruvate or phosphoenolpyruvate. The carbon skeleton of aspartic acid can be incorporated into alanine either by deamination to OAA followed by decarboxylation to pyruvate and reamination or directly by decarboxylation of the number four carbon. There are at least two pathways by which aspartic acid carbon is incorporated into glutamic acid. One path involves the synthesis of α-ketoglutarate from OAA via the TCA cycle, the other is a condensation yielding either β-methylaspartate or α-ketoglutarate, which is then converted to glutamate.
Nutritional requirements of some marine luminous bacteria
Authors: Srivastava Vinod S. , MacLeod Robert A.
Published: February 2010

Photobacterium fischeri failed to grow in a salts glucose medium described previously as being suitable for the growth of photobacteria unless the buffer capacity of the medium was increased. This organism and a second strain of the same species grew and luminesced well if 0.1 M Tris buffer was added to the medium and the pH was adjusted to 7.5. Two other strains of Photobacterium failed to grow in this medium without the further addition of yeast extract. Complex mixtures of amino acids, vitamins, and other growth factors failed to replace yeast extract completely for the growth of either organism. The active component was not identified but some of its properties were determined. Passage of a solution of yeast extract through a cation exchange resin column failed to retain the active factor but succeeded in reducing contamination of the supplement by cations. This made it possible to prepare media for the growth of all four organisms sufficiently free of inorganic contaminants to permit the quantitative requirements of the organisms for Na+, K+, and Mg2+ to be determined. Three of the four Photobacteria required amounts of Na+ for optimum growth which were appreciably less than the requirements reported for other Gram-negative marine bacteria. The amounts of K+ and Mg2+ needed were similar to those required by other marine bacteria while Ca2+ showed no capacity to spare the Mg2+ requirement of P. fischeri.
Identification of staphylococcal delta-hemolysin
Authors: Murphy Richard A. , Haque Riaz-ul
Published: February 2010

Staphylococcal δ-hemoIysin is identified electrophoretically as a hemolytic entity which, when electrophoresed at 5 mA/cm for 2 h in Ionagar No. 2 using barbital buffer, pH 8.4, remained mainly at the origin with tailing towards the anode and completely lysed human, horse, and rabbit erythrocytes. Strain 146P is proposed as the prototype strain for its production.
Methionine biosynthesis in Candida albicans. I. S-Adenosyl-L-methionine (or S-methyl-L-methionine): homocysteine methyltransferase in cell-free extracts from yeast-like cells
Authors: Mardon D. N. , Balish E.
Published: February 2010

Six isolates of C. albicans were tested for their capacities to form methionine via S-adenosyl-L-methionine (or S-methyl-L-methionine): homocysteine methyltransferase (EC. 2.1.1.e). Cell-free extracts from all organisms were obtained from cultures containing predominantly (greater than 85%) yeast-like cells. Assay conditions with respect to pH, time of incubation, substrate, and protein concentrations for the methyltransferase reaction were determined.Extracts from all six strains formed methionine when either L-homocysteine, L-homocysteine thiolactone, or L-homocystine was used as the methyl acceptor, and more methionine was synthesized when S-methyl-L-methionine was the methyl donor than when S-adenosyl-L-methionine was used. The methyltransferase reaction was inhibited by methionine, L-methionine-ethyl-ester, and DL-N-hydroxy-methyl-methionine. Substantially less inhibition was observed with L-ethionine and S-methyl-L-cysteine, while no inhibition occurred when six other methionine analogs were tested.
Further studies of competition of antigens. I. Variation in immunosuppression induced by alterations of dosage, route of injection, nature of antigen, and immunological status of host
Authors: Eidinger D. , Pross H. F. , Kerbel R. S. , Baines M. G. , Ackerman A. , Khan S. A.
Published: February 2010

Several characteristics of antigenic competition were studied in mice using various pairs of antigens administered in sequence. Enhanced immunosuppression of the response to the second antigen was obtained by increasing the dose of the initial antigen relative to the dose of the test antigen. Diminished immunosuppression was elicited when the dose of the second antigen was increased to near maximum levels, corresponding to the plateau of immune responsiveness to this antigen when it was administered in equivalent dosage to normal control groups of animals. Induction of a primary immune response to the initial antigen was a more effective immunosuppressant than was induction of a secondary immune response to an equivalent dose of the same antigen. Antigenic competition was manifested when antigen was administered in differing sites in the animal such as in separate footpads. Administration of the antigens in the same site did not invariably result in antigenic competition, since a combination of two intraperitoneal injections of unrelated antigens in sequence was not associated with immunosuppression of response to the test antigen. Immunosuppression by antigenic competition did not alter the affinity of the antibody product to the test antigen.
Induction of phage-like particles in Agrobacterium by wounded host tissue
Authors: Manocha M. S.
Published: February 2010

Ultrathin sections of pea seedlings, previously inoculated with Agrobacterium tumefaciens, revealed the presence of bacteria in the intercellular spaces. Between 36 and 60 h after inoculation, bacterial cells were observed to contain phage-like particles 40–70 nm in diameter. These bacterial cells probably undergo lysis since no bacteria were observed 72 h after inoculation.
Comparison of herpes simplex antigens prepared from various tissues
Authors: Polley J. R. , Webb T. S.
Published: February 2010

Herpes simplex virus was propagated in various tissues, and the antigens prepared from each of them were compared for complement-fixing components. The amount of viral antigen component exceeded that of soluble antigen in the antigens prepared from tissue cultures but the reverse was true with chorioallantoic membrane antigen. The viral antigen component was more sensitive than the soluble antigen for the determination of herpes simplex antibodies.
A simple method for scanning electron microscopy of L-form colonies grown on agar
Authors: Bibel David J. , Lawson John W.
Published: February 2010

A simple procedure, using Millipore filters, for the observation of L-form colonies of streptococci by scanning electron microscopy is described.
Observations on acid-fastness and respiration of germinating yeast ascospores
Authors: Seigel J. L. , Miller J. J.
Published: February 2010

Germination of the ascospores of a strain of Saccharomyces cerevisiae Hansen was stimulated by fermentable carbon sources. Nitrogen sources alone had little or no stimulating effect on germination unless glucose was present, but peptone and casein hydrolysate were exceptions. Loss of acid-fastness proved to be a useful criterion of spore germination. Evidence was obtained that germination occurs anaerobically, but is not restricted by oxygen. It is concluded that the respiratory characteristics of the three main phases of the yeast life cycle differ in that growth can occur aerobically or anaerobically, sporulation is restricted to aerobic conditions, and spore germination is anaerobic.
Germ-tube production by Candida albicans in minimal liquid culture media
Authors: Mardon D. N. , Hurst I. S. K. , Balish E.
Published: February 2010

Candida albicans formed germ tubes within 3 h at 37C in a glucose–salts–biotin (GSB) medium containing L-alpha-amino-n-butyric acid as the nitrogen source. Optimal germ-tube production was obtained when the inoculum was grown on Sabouraud dextrose agar. The GSB medium containing L-alpha-amino-n-butyric acid promoted germ-tube formation more effectively than GSB medium plus gamma-amino-butyric acid or Sabouraud dextrose broth.Carbon-14 incorporation studies revealed that during germ-tube formation (0–4 h) the 3 carbon of alpha-amino-n-butyric acid was incorporated intracellularly to a greater extent than the 1 carbon. However, during blastospore formation (5–16 h), this difference was less pronounced.When six other Candida species were grown in GSB plus L-alpha-amino-n-butyric acid medium, few germ tubes were observed with the exception of one Candida stellatoidea strain. However, even this strain of C. stellatoidea produced far fewer germ tubes in this minimal culture medium than any strain of C. albicans tested.
Further studies on competition of antigens. II. Cellular deficit or inhibitory factor: an indirect evaluation of the problem
Authors: Eidinger David , Baines Malcolm
Published: February 2010

An indirect approach to the question of the role of a presumptive inhibitory factor or cell deficit to account for immunosuppression by antigenic competition was carried out in the present work.Several characteristics of antigenic competition were delineated. The response to PVP,* classed as a non-thymus dependent antigen, was capable of suppressing the response to a test antigen administered subsequently, and conversely, of being suppressed by unrelated antigens administered as initial antigens. Induction of immunological tolerance to RRBC* with cyclophosphamide did not prevent the capacity of the antigen to suppress the induction of humoral antibody formation to KLH* in a model of antigenic competition. Actinomycin-D in a dose of 0.60 mg/kg body weight abolished suppression by antigenic competition, although the drug suppressed the response to the suppressing antigen GRBC* and enhanced the response to RRBC, the test antigen, when administered to individual control groups of animals immunized with only the one antigen. Consequently, interpretation of the data in terms of antigenic competition was difficult.
Haemophilus vaginalis 594, a Gram-negative organism?
Authors: Criswell B. Sue , Marston Judith H. , Stenback Wayne A. , Black S. H. , Gardner Herman L.
Published: February 2010

The fine structure of Haemophilus vaginalis 594 (ATCC 14018) was examined by electron microscopy, and the biochemical composition of its cell wall was determined. For comparison, similar studies were done with a Gram-positive bacterium, Bacillus megaterium KM, and a Gram-negative bacterium, Escherichia coli B. Both Haemophilus vaginalis 594 and Escherichia coli B possessed a multiple-layered cell wall containing 11 to 14 amino acids, a low mucopeptide content, and no teichoic acid. In contrast, Bacillus megaterium KM had a thick, amorphous cell wall with five amino acids, high mucopeptide content, and detectable amounts of teichoic acid. Haemophilus vaginalis 594 resembled Escherichia coli, a member of the Gram-negative group of organisms. The structural and biochemical properties of Haemophilus vaginalis, which are described in detail, may prove useful in determining the ultimate taxonomic position of this species.
Dielectrophoretic separation of living cells
Authors: Mason B. D. , Townsley P. M.
Published: February 2010

Dielectrophoretic separation studies were undertaken to investigate the possibility of separating cells with varying physiological character. An attempt was made to define the importance of size in the determination of separability. Living cells of Saccharomyces cerevisiae var. ellipsoideus were separated from the same cells killed by heating, using a batch separation. Cells cultured in wort broth were separated from cells grown in yeast nitrogen base – 1% glucose using both batch and continuous separators. Size analyses of separated fractions were performed using a Coulter transducer/multichannel pulse height analyzer. A size differential in cell separability was demonstrated, although it is clear that a complex function of both size and polarizability is instrumental in determining the separation of cell types.
A ferredoxin-Iinked sulfite reductase from Clostridium pasteurianum
Authors: Laishley E. J. , Lin Po-Min , Peck Jr. H. D.
Published: February 2010

A soluble sulfite reductase (EC. 1.8.1.2) system is present in cell-free extracts of Clostridium pasteurianum that reduces sulfite to sulfide in the presence of molecular hydrogen. The natural electron donor for this reductase has been found to be ferredoxin, which can be completely replaced by methyl viologen or partially by benzyl viologen. The physiological electron donors NAD, NADP, FMN, and FAD were not active in the transfer of electrons from hydrogen for sulfite reduction. The pH optimum of the sulfite reductase was found to be 7.0 using phosphate buffer, and the extracts reduced nitrite and hydroxyl-amine in addition to sulfite. The stoichiometry of the reaction in terms of hydrogen uptake to sulfide formation was 2.7, which is very close to the theoretical ratio of 3. The above properties of the system indicate that it is an assimilatory rather than a dissimilatory sulfite reductase, as outlined in the Discussion.
The differentiation of Trichophyton rubrum and T. mentagrophytes by use of Christensen's urea broth
Authors: Kane Julius , Fischer J. B.
Published: February 2010

A comparison of the urease activity of 56 strains of T. rubrum and 64 strains of T. mentagrophytes on Christensen's urea medium with and without agar incubated 7 days at 28 °C showed that characteristic and consistent results are produced on this medium without agar. In the fluid medium T. mentagrophytes caused a rise in pH, resulting in a maximum change of the phenol red, and T. rubrum produced no change. The depressing effect of agar on the hydrolysis of urea was demonstrated. On the agar medium 9 (18.8%) of 48 strains of T. mentagrophytes and 3 (6.2%) of 48 strains of T. rubrum produced doubtful results. It is important that pure cultures be used for the test.
Immunodiffusion studies on the myxoviruses. III. Identification of the structural antigens of Myxovirus influenza A/PR8
Authors: Johnson C. Margaret , Westwood John C. N.
Published: February 2010

A comparison of the effect of several different virus disruption procedures on the biological activity and antigenic structure of the Myxovirus influenza A/PR8 virion has shown that sodium deoxycholate was the best disrupting agent. Six virus structural components were detected, of which one was classified as host specific, two were identified as virus specific, and three were found to possess dual specificity. These were classified as host-virus (HV) structural antigens.
Lysosomes in L cells infected with Chlamydia psittaci 6BC strain
Authors: Kordová Nonna , Wilt John C. , Sadiq Mohamed
Published: February 2010

Studies on lysosomal activation of Chlamydia psittaci infected L cells have been performed during the growth cycle of the agent and extended for 4 days after the initiation of infection. The present results indicate that lysosomes of infected L cells were not injured during phagocytosis, but that lysosomal enzyme release first occurred about 24 h after infection and apparently preceded the death and lysis of host cells. These observations attach a new significance to the study of injury and death of chlamydial infected cultured cells as well as to studies on the pathogenesis of psittacosis at the whole host level.
Growth and activity of Penicillium decumbens under different environmental conditions in glass microbead media
Authors: Taylor H. I. , Parkinson D.
Published: February 2010

Results of laboratory investigations on the application of glass microbead systems to studies on the activity of Penicillium decumbens are presented. The effects of microbead size, temperature, and aeration on CO2 evolution by P. decumbens are discussed. The results indicate that P. decumbens grows actively in nutrient-supplemented glass microbead systems and is tolerant of considerable changes in all the environmental conditions studied. Attempts are made to relate these observations to previously obtained ecological data for the test organism.
The influence of soil moisture tension on the fungal population of a pinewood soil
Authors: Shameemullah M. , Parkinson D. , Burges A.
Published: February 2010

In an attempt to make a critical evaluation of the effect of soil moisture content on soil mycofloras the concept of pF, as a means of expressing the availability of soil water, has been applied. In both laboratory and field experiments fungi have been isolated from H layer, A1 and C horizon soil samples taken from a pinewood soil, the soil samples having been held at known pF values. The results indicate that, for all soil samples, the pF range 1.9 to 2.3 (0.08 to 0.2 bar) is optimal for all fungal species, below pF 1.9 (0.08 bar) and above pF 3.8 (6.2 bar) there is a marked reduction in frequency of occurrence of many species.Trichoderma viride and Penicillium spp. appear capable of growing under a wide range of soil moisture conditions.
Rapid detection of Australia/SH antigen and antibody by a simple and sensitive technique of immunoelectronmicroscopy
Authors: Kelen A. E. , Hathaway A. E. , McLeod D. A.
Published: February 2010

A simple and practical method is presented for demonstrating the presence of the Australia/SH antigen and its corresponding antibody in serum specimens, both qualitatively and quantitatively. The method is based on the electronmicroscopic visualization of characteristic aggregates of antigen–antibody complexes formed in the mixture of a serum specimen and the appropriate Australia/SH detector reagent. It involves the use of a microtechnique requiring minute amounts of reagents and provides, as a result of diffusion and filtration through agar gel, partially purified and concentrated preparations, ready for electronmicroscopic examination in less than an hour. The method is highly specific and yields reproducible results. Its sensitivity was found to be greater than that of the crossover electrophoresis test and closely approximates that of the complement fixation test, with the added advantage of not being affected by the "prozone phenomenon." The method can be recommended for use in laboratories equipped with electronmicroscopic facilities to establish a differential diagnosis of viral hepatitis cases, perform rapid screening of blood samples (blood products) for the presence of Australia/SH antigen, and clarify equivocal results obtained by other methods. It is expected that the agar–diffusion–filtration technique will also prove useful, in general, for enhancing the chances of detecting virus particles in suspensions of relatively low virus concentrations.
Utilization of glyoxylate by acetate-grown Bacillus megaterium KM
Authors: Donawa A. , Inniss W. E.
Published: February 2010

Radioactively labeled glycine was produced from glyoxylate-14C by cell-free extracts of acetate-grown Bacillus megaterium KM. Alanine and aspartate were the best amino group donors for the transamination reaction. Glutamate or alpha-ketoglutarate had no effect on such activity. Glyoxylate reductase activity was also present but glyoxylate carboligase and tartronic semialdehyde reductase were absent.
Acid injury of Escherichia coli
Authors: Roth L. A. , Keenan D.
Published: February 2010

Two strains of Escherichia coli sublethally treated in acidic environments showed an increased sensitivity to violet red bile agar. The death of cells, treated in tryptic soy broth which had been acidified with two inorganic and five organic acids, was followed on both nutrient agar and the selective medium violet red bile agar. The death rates determined on violet red bile agar were much faster than those established on nutrient agar. Therefore, it appeared that unreliable results may occur if selective media are used for the detection and enumeration of Enterobacteriaceae in acid foods.