bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrastructure du bactériophage agissant dans certaines conditions comme une staphylococcine
Authors: Dobardzic R. , Payment P. , Sonea S.
Published: February 2010

The lysogenization of Staphylococcus aureus, strain BSS, by staphylophage [Formula: see text] of serological group A may be accompanied by the loss of its capacity to synthesize δ haemolysin. The high multiplicity of infection of [Formula: see text] phage changes the tinctorial affinity of BSS cell walls and lyses the same strain lysogenic for the homologous phage; this lysis is similar to that of the staphylococcin. In negative coloration by PTA, this bacteriophage shows one elongated head (750 Å × 420 Å) and a long tail (2650 Å). Electron microscopy demonstrated also the existence of structural subunits of the tail and the hexagonal end plate. By its morphology and dimensions, the [Formula: see text] phage is similar to 594n and b594n phages studied by Bradley and to staphylophages of serological group A: 3A, 3B, 3C, 6, 7, 42E, 47, 54 of the basic set of international lysotypy.
Yeasts isolated from soils of citrus orchards and citrus waste disposal areas in California and Florida: flavonoid utilization
Authors: Spencer J. F. T. , Gorin P. A. J.
Published: February 2010

Yeasts were isolated from soils from citrus orchards and citrus waste disposal areas in California and Florida. Species of Trichosporon, Cryptococcus, and Rhoclotorula were predominant. Strains of Hansenula saturnus, Hansenula californica, Hansenula mrakii, Pichia kluyveri, Saccharomyces rosei, Saccharomyces cerevisiae, and some species of Candida and Torulopsis were also found. The cultures isolated were tested for the ability to use a number of flavonoids. These compounds were used by strains of Trichosporon cutaneum, Cryptococcus albidus and its variety diffluens, Cryptococcus terreus, Cryptococcus lanrentii, Rhodotorula glutinis, Rhodotorula minuta, Rhodotorula rubra, and Candida humicola, but not by the ascosporogenous species or the other Candida species. Contrary to expectations, most of the cultures which used flavonoids were isolated from the orchard soils rather than from the soils of the waste disposal areas.
Filamentous forms of Streptococcus cremoris and Streptococcus lactis. Observations on structure and susceptibility to lysis
Authors: McDonald I. J.
Published: February 2010

Filamentous cultures of Streptococcus cremoris and Streptococcus lactis were isolated from growth which formed in orifices of medium inlet tubes of chemostats. Filamentous variants were maintained by biweekly transfer in agar stab cultures. Bacteria from parent and filamentous cultures grown in broth had the same DNA base content and the same bacteriophage susceptibility. Electron micrographs showed that filamentous streptococci had apparently normal cell walls and slightly enlarged cross walls. Filaments appeared to result from failure of daughter cells to separate after division. Filamentous cells were less readily autolyzed and were less susceptible to lysis by Iysozyme than normal cells. The results suggest that filament formation in lactic streptococci was associated with lower autolysin activity.
Marker frequency analysis mapping of the Staphylococcus aureus chromosome
Authors: Altenbern Robert A.
Published: February 2010

Marker frequency analysis by mutation induction of several strains of Staphylococcus aureus has yielded a genomic map supporting the map derived by another technique. Gene orders of exponential cells obtained by using reference cells with completed chromosomes effected by chloramphenicol or by phenethanol treatment were identical, suggesting that these two agents halted chromosomal replication at a common terminus. In several strains, the pantothenate or acriflavine resistance locus changed its apparent chromosomal position during exponential growth. The data indicate that more than one chromosomal growing point occurred during logarithmic growth in non-synthetic medium.
Les champignons et leur écologie dans un sol ensemencé en trèfle rouge
Authors: Aubé C. , Gagnon C.
Published: February 2010

The ecology of fungi in a soil seeded with red clover has been investigated. The dilution plate technique was used with a medium supplemented with streptomycin sulfate. A total of 67 species belonging to 43 genera were recovered. The most frequently isolated species were in decreasing order: Pénicillium spp., Coniothyrium spp., Trichoderma viride, Gliocladium roseum, Rhizopus nigricans, Fusarium oxysporum, and Fusarium culmorum. Ten species of fungi not previously reported in Canada were isolated from soils.The ecology of fungi is discussed in relation to soil moisture content, soil texture, depth of soil sampling, and period of the year.
A field trial with live attenuated mumps virus vaccine: a serological study
Authors: Rossier E. , Meunier J. , Baker F. , Marchessault V.
Published: February 2010

A controlled study with live attenuated mumps virus vaccine, B level Jeryl Lynn strain, was conducted on a group of mentally retarded patients, children and adults; 159 of them were studied, and 109 received the vaccine. The follow-up consisted of clinical observation, temperature recording in both vaccinees and controls for 1 week after vaccine administration, and serological assay by complement fixation and neutralization at the time of vaccination, at 1 month and at [Formula: see text] months.There was no statistical evidence of temperature rise in the vaccinees as compared with the controls nor any untoward clinical reactions. At [Formula: see text] months, the seroconversion rate was 48.8% when assayed by complement-fixation tests, and 90% when assayed by neutralization tests. It was concluded that the vaccine was safe and potent.
Properties of a Chlamydia psittaci isolated from muskrats and snowshoe hares in Canada
Authors: Spalatin J. , Iversen J. O. , Hanson R. P.
Published: February 2010

An etiologic agent of epizootic chlamydiosis of muskrats and snowshoe hares, designated as strain M56, was placed in C. psittaci species on the basis of insensitivity to sulfadiazine and d-cycloserine and the formation of diffuse, irregular, glycogen-free inclusions. Pathogenicity studies indicated a high virulence, a moderate toxicity, and a broad host range. Experimental infections tended to be pantropic. In addition to the muskrat and snowshoe hare, susceptible mammals were laboratory mice, guinea pigs, hamsters, and domestic rabbits. In adult domestic rabbits, infections were highly lethal, whereas mortality was rare in young rabbits. After 2 months, the agent persisted in the cerebrum, joints, and internal eye of several young rabbits in spite of relatively high titers of neutralizing antibodies. Strong immunity to strain M56 was established by intravenous inoculation of the living agent in young rabbits. In addition to ricebirds, susceptible birds were domestic chicks, parakeets, and mallard ducklings. The facility with which this organism infects both birds and mammals is a sufficient reason for epidemiologists to search marshes and lakes where water birds and muskrats intermingle for nidi of infection. The relatively high rate of subclinical chlamydial infections in man in northern Canada may be attributable, in part, to this agent.
Studies on the surface plate method of counting bacteria
Authors: Clark D. S.
Published: February 2010

A study of plate preparation, inoculum volume, and technique of spreading in the surface plate method showed that predrying plates to a weight loss of 3–4 g/15-ml plate allowed the use of inoculum volumes of up to 1 ml without affecting recovery of bacteria. Satisfactory drying was achieved at 24–50 °C with the plates positioned upside down separately or in stacks. Equally good recovery of bacteria was obtained either by spreading the inoculum until it had been completely absorbed, or by spreading it for only 15 s and waiting for absorption and evaporation of excess liquid before inverting the plate. The former technique was limited to about 0.5 ml of inoculum because of the length of the spreading time required for volumes greater than this, whereas the latter method was satisfactory for volumes up to at least 1 ml as shown in recovery tests with Escherichia coli and Pseudomonas fluorescens.
Self-assembly of bacteriophage lambda tails
Authors: Bleviss Morley , Easterbrook K. B.
Published: February 2010

The tail of bacteriophage λ was found to disassemble when treated in suspension with acid to a pH less than 2.8 or alkali to a pH greater than 11.8. Treatment of the tail of bacteriophage lambda results in the production of distinct subunit structures, discs when acid treated, and units unresolvable by electron microscopy when alkali treated. When returned to neutrality both subunits produce structures which resemble the original tail except that they can be up to several microns in length.The acid and alkali treatments produce structures that have high molecular weight. The acid-produced structure appears to be composed of six subunits arranged to form a disc with a central hole.The reactions were unaffected by temperature between 2 and 56 °C or by exposure to 8 M urea for 30 min. Ionic strengths greater than 0.7 M NaCl inhibited all the reactions as did prolonged exposure to urea at a concentration of 7 M or greater.The tail consists of at least two antigens as detected by the complement fixation test and serum-blocking test. While alkali treatment has no effect on either antigen, both acid and urea treatment at 7 M or greater were found to destroy the serum-blocking antigen.Results obtained suggested that the alkali dissociation reaction is initiated at the end which, in the complete phage, is attached to the head, and proceeds in a polar manner toward the bacteria-attaching tip. If the tail is treated with urea the reaction proceeds from either end. The acid reaction was unaffected by the tip barrier and therefore was not demonstrably polar.
A comparison of the electrophoretic properties of dehydrogenases from Arthrobacter, Agrobacterium, and Rhizobium
Authors: Skyring G. W. , Rouatt J. W. , Purkayastha Vesna
Published: February 2010

Eleven Arthrobacter, three Agrobacterium, and three Rhizobium cultures were characterized in terms of the electrophoretic properties of dehydrogenases active upon lactate, succinate, malate, glucose-6-phosphate, 6-phosphogluconate, isocitrate, glutamate, and dihydroorotate (K). Comparisons of the zymograms for each organism were made on the basis of selected data. Overall similarities so found corresponded in general with groupings of organisms found previously. A high degree of affinity between the arthrobacters and the rhizobia–agrobacteria seemed unlikely, but the results for glutamic dehydrogenase, dihydroorotate dehydrogenase, and to some extent those for lactic and malic dehydrogenases suggested that there may be some affinity not previously suspected.We have concluded that while dehydrogenase zymograms may be useful for the characterization of microorganisms, their application in bacterial taxonomy is not simple. Original or even edited data would not be appropriate for simple kinds of computer-assisted analysis without means of determining the extent of homology existing between enzymes from different sources.
The role of enterotoxin in Clostridium perfringens type A enteritis
Authors: Hauschild A. H. W. , Niilo L. , Dorward W. J.
Published: February 2010

Vegetative cells of three strains of Clostridium perfringens type A, free of erythemal activity, were suspended in fresh medium and injected into ligated intestinal loops of lambs. Examination of the loop contents after 6.5 h showed significant accumulation of fluid, multiplication and sporulation of C. perfringens, and erythemal activity in both the supernatant fluids and the sediments.The erythemal factor produced in vivo was identical with the erythemal factor of sporulated cells of C. perfringens grown in vitro, and again caused accumulation of fluid when transferred into ligated intestinal loops of recipient lambs. Immune rabbit serum prepared against extracts from sporulated cells of C. perfringens, and absorbed with extracts from vegetative cells of the same strain, completely neutralized the enterotoxic and erythemal activities of the in vivo-produced factor.It is concluded that the erythemal factor is the causative agent in C. perfringens type A enteritis. The term "Clostridium perfringens enterotoxin" is proposed to characterize the erythemal factor.
Catalase activity in Corynebacterium pyogenes
Authors: Cummins C. S.
Published: February 2010

Seven strains of Corynebacterium pyogenes have been investigated for evidence of catalase activity; six were negative, but one strain, ATCC 8104, showed weak catalase activity, inhibited by azide.
Localization of L-asparaginase in Pseudomonas aeruginosa
Authors: Day D. F. , Ingram J. M.
Published: February 2010

Whole cells of Pseudomonas aeruginosa possess L-asparaginase activity. The enzyme is released by suspension in 0.2 M MgCl2 and resuspension in 0.1 M Tris buffer, pH 8.4. Under these conditions neither the plasma membrane enzyme, NADH oxidase, nor the scluble enzyme, lactic acid dehydrogenase, are released. The L-asparaginase and the periplasmic alkaline phosphatase are completely inactivated by treatment of whole cells with diazonaphthalene–disulfonic acid, a reagent which does not penetrate the cytoplasmic membrane. Under the conditions used no inactivation of NADH oxidase or lactic acid dehydrogenase was observed. L-Asparaginase is also released by converting whole cells to spheroplasts. The results suggest that L-asparaginase of P. aeruginosa is located exterior to the cytoplasmic membrane, possibly in the periplasmic space.
An extracellular proteolytic enzyme from Scopulariopsis brevicaulis. 1. Purification and properties
Authors: Singh Kartar , Vézina Claude
Published: February 2010

A proteolytic enzyme present in culture filtrates of Scopulariopsis brevicaulis was purified about 200-fold by (NH4)2SO4 and ethanol fractionations followed by chromatography on DEAE-cellulose, DEAE-Sephadex, and hydroxylapatite. Ultracentrifugation of the purified enzymes showed only one sedimenting component and its molecular weight was estimated to be about 24 000. The protease hydrolyzed casein, urea-denatured hemoglobin, gelatin, fibrinogen, fibrin, insulin chains A and B, but not human serum albumin or ovalbumin. It also coagulated milk. The enzyme had no action on the various peptides tested and showed low esterase activity. Optimum pH for casein hydrolysis was 10.5 to 11; for hemoglobin hydrolysis 7.0–9.5, and for gelatin hydrolysis, 6.0–8.0. The enzyme activity was unaffected by most metal ions, SH-reagents, and some natural trypsin inhibitors. The protease was strongly inhibited by diisopropylfluorophosphate and phenylmethanesulfonyl fluoride. Although similar in some respects to CA-7, the enzyme isolated from Aspergillus oryzae, and other alkaline proteases, the S. brevicaulis protease does not appear to be identical with any one of them.
Initiation of spore germination in Bacillus cereus: a proposed allosteric receptor
Authors: Wolgamott Gary D. , Durham Norman N.
Published: February 2010

The initiation of germination of spores of Bacillus cereus was induced by L-alanine or L-phenylalanine and a combination of the amino acids showed an additive effect. Several compounds such as β-phenethylamine, phenylacetonitrile, benzyl alcohol, and phenethyl alcohol inhibited the initiation mechanism. The initiation of germination by L-alanine was more sensitive to β-phenethylamine while the L-phenylalanine induction was more sensitive to phenethyl alcohol. Selected antibiotics, known to block macro-molecular syntheses, were not effective as inhibitors of initiation. The results suggest that the receptor site may be compatible with an allosteric enzyme model and β-phenethylamine and phenethyl alcohol act as allosteric effectors.
The acetylene reduction assay for measuring nitrogen fixation in waterlogged soil
Authors: Rice W. A. , Paul E. A.
Published: February 2010

Nitrogen fixation in waterlogged, soil–straw, and sand–clay–straw mixtures was measured with the C2H2 reduction assay, the 15N-tracer technique, and the Kjeldahl method. The reduction of 6 to 15 moles C2H2 corresponded to the fixation of 1 mole N2. The theoretical ratio is 3 moles C2H2 to 1 mole N2. A ratio of 3 moles C2H2 reduced for each mole of N2 fixed was obtained when samples of sand–clay–straw were incubated under conditions that minimized effects that were due to gas diffusion through the aqueous phase. Calculations indicated that N2 at a partial pressure of 0.2 atm above the samples was not sufficient to saturate the nitrogenase enzyme of the organisms in lower layers of soil–straw samples. Thus the concentration of N2 dissolved in the aqueous phase limited nitrogen fixation. C2H2 is more soluble in water than N2; the C2H2 reduction was not as limited by the C2H2 concentration in the aqueous phase.N2 was experimentally shown to be limited at depth in a sand–clay–glucose system in that fixation decreased from 128 to 36 μg N/g of sand–clay incubated so that the total sample depth ranged from 0.2 to 3 cm.The C2H2 reduction assay provides a method for measuring the potential nitrogenase activity in the waterlogged soil amended with straw; however, this assay must be calibrated for specific conditions. The data also indicate that where N2 diffusion rates may limit N fixation, a normal atmosphere (80%) of N2 should be used in the experiment.
The amino acid source of HCN in cultures of a psychrophilic basidiomycete
Authors: Ward E. W. B. , Thorn G. D. , Starratt A. N.
Published: February 2010

This investigation was prompted by the reported formation of HCN from isoleucine by way of the cyanogenic glycoside lotaustralin in a psychrophilic basidiomycete. In comparable experiments we found steam distillates from cultures incubated with L-isoleucine-U-14C were radioactive but this was shown not to be due to H14CN, by removal of the HCN as AgCN. This was confirmed using isoleucine-2-14C from which H14CN recovery was negligible. Evidence was obtained that the steam volatile radioactive material regarded by other workers as H14CN consisted largely of organic acids. Hence isoleucine cannot be considered to be a precursor of HCN in this fungus and the occurrence of lotaustralin as an intermediate is therefore doubtful. Under the same conditions HCN was shown to arise from carbon-2 of glycine, confirming previous reports from this laboratory.
Regenerative functions and microbial ecology of coral reefs. II. Oxygen metabolism in the regenerative system
Authors: DiSalvo Louis H.
Published: February 2010

Measurements were made relevant to the oxygen metabolism of the internal zone of coral reefs. Oxygen demands of internal sediments by a dark bottle method yielded rates of 0.06 to 0.50 mg O2 per gram sediment per hour. Antibiotics significantly lowered oxygen demands and bacterial counts, suggesting an important respiratory role of aerobic bacteria. Measurements of total oxygen consumption by two intact coral "deadheads" were compared to oxygen demands by their internal sediments. Oxygen consumption of these sediments in suspension was about 10% of the total O2 consumption of intact heads.Water samples collected from within regenerative spaces in situ generally showed oxygen debts when compared to ambient reef waters. Oxygen debts of internal waters of (stressed) inshore reefs were higher than those of an offshore reef. A diurnal set of oxygen measurements on waters from within reef mass brought to the laboratory showed constant internal oxygen deficit relative to the oxygen concentration in ambient waters.Coral skeleton microcosms were apparently adapted to local conditions of aeration at different collecting stations. Oxygen stress of skeletal mass resulted in internal oxygen depletion and related changes in microbial metabolism destructive to the aerobic infaunal (metazoan) community.
Mitochondriogenesis: a comparative study of some commonly used strains of Saccharomyces cerevisiae
Authors: Ball A. J. S. , Janki R. M. , Tustanoff E. Reno
Published: February 2010

In view of the numerous different yeast strains which are used in studies of mitochondriogenesis, we considered that a comparative study of some of these strains would provide useful information for workers in this field. To this end, we have compared the growth characteristics of several widely used strains and of some randomly selected strains from our culture collection. The yeast were grown on glucose, both aerobically and anaerobically; parameters studied included ethanol metabolism, respiratory quotients, growth rates, and carbon source utilization.The nine strains can be divided into three classes : class 1, Brewers yeast showing very fast fermentation and high ethanol yields together with a pronounced diauxic, aerobic growth curve; class 2, wine yeasts with a slower fermentation rate, lower ethanol yields, and poorer growth under anaerobic conditions; class 3, a miscellaneous collection including auxotrophs, petites, and an obligate aerobic yeast.It is concluded that a large proportion of the work done on mitochondriogenesis has been performed on similar yeast strains but that some caution must be exercised when comparing yeasts from different classes.
An adaptation of a moist-chamber method for isolating and identifying Verticillium spp.
Authors: McKeen C. D. , Thorpe H. J.
Published: February 2010

An adaptation of a moist-chamber method is described whereby Verticillium albo-atrum, V. dahliae, and V. nigrescens can readily be isolated from herbaceous and woody hosts and easily identified. Segments of infected stems, petioles, and roots cut transversely can be observed microscopically at daily or frequent intervals to determine the origin of outgrowing fungal hyphae in the absence of troublesome contaminants.
Enhancement of vesicular stomatitis virus production by serum
Authors: Kouroupis G. M. , Sabina L. R.
Published: February 2010

The production of vesicular stomatitis virus in MDBK cells has been shown to be markedly enhanced by the addition of whole serum to maintenance media. Maximum virus production occurred in the presence of human and fetal calf sera. When different serum protein fractions were tested, cultures nourished with medium containing bovine fraction IV-1 gave the highest infectivity, but fraction IV-1 did not completely substitute for whole serum. In contrast, fetuin was strongly inhibitory for the production of infectious virus. No loss of infectivity was observed if serum was added to cultures as late as 8 h postinfection. The incorporation of 3H-uridine into viral RNA of actinomycin D treated cultures nourished with serum or serum-free media proceeded at nearly similar rates from the time of infection up to 7 h postinfection. This result indicates that viral RNA synthesis was initiated with equal amounts of template. Late in the virus replicative cycle the incorporation rates of radioactive label were higher in serum-containing cultures than in serum-free cultures. The results of this investigation suggest that serum does not have a direct specific viral function but rather acts indirectly through the host cell to promote maximum virus production.
Etude de la respiration de la levure au cours de la sporulation
Authors: Vezinhet Françoise , Arnaud A. , Galzy P.
Published: February 2010

During the process of sporulation, the oxidation rate of exogenous carbon source, acetic acid, is high during a period lasting from 1 to 4 h. Then it falls rapidly and the metabolism of acetic acid seems to be deflected. Endogenous oxidation rate rises rapidly at the beginning of the process and reaches its maximum after a 12- to 16-h contact with the sporulation medium. Then it falls regularly.
Chemical studies on the exudate and developing sclerotia of Sclerotinia sclerotiorum (Lib.) DeBary
Authors: Colotelo N. , Sumner J. L. , Voegelin W. S.
Published: February 2010

The exudate from sclerotia of 6-day-old cultures of Sclerotinia sclerotiorum (Lib.) DeBary was found to contain cations, lipids, ammonia, amino acids, proteins, and various enzymes. Disc-gel electrophoretic patterns of proteins, peroxidase, and polyphenoloxidase isoenzymes of the exudate differed from those of sclerotial extracts. Specific activities for catalase, peroxidase, polyphenoloxidase, and β-glucosidase enzymes of the exudate and sclerotial extracts were very similar. Cellulolytic and polygalacturonase activities for the exudate and sclerotial extracts were demonstrated. The nature and origin of the exudate are briefly discussed.
Disruption of Bordetella pertussis in the Ribi Cell Fractionator. 2. Effect of different suspending media
Authors: Hollinger E. , Wardlaw A. C.
Published: February 2010

Using the RCF at various pressures and centrifuging the resulting lysates at 20 000 g, cell envelope and soluble fractions of B. pertussis were obtained. At each pressure the extent of solubilization of several biologically important factors was greatly influenced by the medium in which the cells were suspended during disruption. Disruption at 20 000 – 30 000 psi in tris or tris-EDTA buffers, pH 8.0, gave cell envelopes containing very little of the original DNA, lipopolysaccharide, histamine-sensitizing factor, or protective antigen, whereas disruption in phosphate buffer, pH 7.0, gave cell envelopes rich in these factors. The solubilizing effect of tris on DNA and on cell envelope components could be counteracted by Mg2+ and less efficiently by NaCl or sucrose.
The effect of hypotonic solutions on the morphology of cells of Mycoplasma gallisepticum
Authors: Bernstein-Ziv Ruth
Published: February 2010

Cells of Mycoplasma gallisepticum strains A5969 and S6 were studied by electron microscopy after being treated with hypotonic solutions such as 0.01 M and 0.001 M sucrose and deionized water. It was found that hypotonic solutions induced cells to produce filaments. In addition the outer layer of the membrane increased twofold in width and tended to become amorphous. Hypotonic solutions had no effect on the viability of the cells.
Isolation and preliminary characterization of an extracellular protease of Cytophaga sp.
Authors: Christison J. , Martin S. M.
Published: February 2010

The extracellular protease(s) of Cytophaga sp. is present naturally as a complex with acidic polysaccharides of the slime layer. The protein was separated from the slime by selective precipitation of the polysaccharide with a cationic detergent and the enzyme was purified about 100-fold by precipitation with alcohol and by chromatography on DEAE-cellulose. Inhibitor studies indicated that this alkaline protease was not of the trypsin/chymotrypsin type. Ca2+ had a strong stabilizing effect on the enzyme. The complex of basic protein (enzyme) and acidic slime polysaccharides has led to the conclusion that the enzyme is perhaps not truly extracellular but rather is surface bound. The slime layer would appear to have a role in attaching the bacterial cells to insoluble substrates as well as ensuring that degradative enzymes are kept in close contact with the substrate.
Immunological relationships between capsid components of adenoviruses of different host cell species origin
Authors: Norrby E. , Marusyk R. G. , Wadell G.
Published: February 2010

A comparative immunological analysis between human (types 2 to 6, 9, 11, 12, 15) and simian-monkey adenoviruses (types SA-7, SV15, SV20), selected to represent different hemagglutinating subgroups, and two canine (infectious canine hepatitis, ICH, and infectious canine laryngotracheitis, ICL) and one avian adenovirus (CELO) was undertaken using purified components and sera against these. Cross-reactions between hexons of all mammalian adenoviruses, but not the avian serotype studied, were found in complement fixation tests. Cross-absorption experiments did not indicate the presence of any antigenic specificities of hexons, unique for groups of adenoviruses of different host cell species origin. Vertex capsomers in penton hemagglutination enhancement (HE) tests, like hexons, were found to contain antigenic specificities common to adenoviruses of different mammalian host cell origin. Furthermore, using the fiber-HE test one-way or two-way cross-reactions were demonstrated in certain combinations between all fibers of mammalian adenoviruses studied. The degree of cross-reaction was more pronounced between hexons than between vertex capsomers, which in turn was more extensive than that between fibers. However, fibers of SV20 displayed a close relationship to fibers of certain members of subgroup 111 of human adenoviruses.Fractionation of soluble components of type SV20 revealed the presence of a soluble complete HA of a kind not previously encountered. It sedimented at a rate slightly lower than that of hexons and was trypsin sensitive. It is suggested to possibly represent a penton–fiber complex.
An expanded genomic map of Staphylococcus aureus
Authors: Altenbern Robert A.
Published: February 2010

A genomic map of 26 separate loci of Staphylococcus aureus has been derived by a combination of two methods of chromosomal mapping, by synchronous chromosomal replication and by marker frequency analysis.
Streptococci deficient in genetic transformation
Authors: Pakula R. , Spencer L. R. , Goldstein P. A.
Published: February 2010

Three strains of group H streptococci have been found to produce competence factors (CF's) similar to that synthesized by the highly transformable strain Challis. All these factors efficiently converted to competency for DNA uptake the spontaneously nontransformable strain Wicky. Two of the three strains could be transformed to drug resistance with an extremely low efficiency and one strain was nontransformable. When the bacteria were exposed to tritium-labeled DNA, it was found that a viable unit of the three strains contained about 10 times less radioactivity than a viable unit of Challis and Wicky in the competent state. The probability that CF may not be the only factor required for DNA uptake is discussed.
Therapeutic effects of a series of non-viral interferon inducers on a viral-induced leukemia
Authors: Rheins M. S. , Barker A. D. , Wilson H. E.
Published: February 2010

A large group of DBA/2 mice with established Friend virus leukemia was treated with a regimen of non-viral inducers of interferon. Treatment was begun 7 days postinoculation of Friend virus and continued at 7-day intervals through 28 days. Treated mice exhibited an increased mean survival of 19 days, decreased splenomegaly, and lower Friend virus titers in the spleen. Fewer viral particles and reticulum type cells were demonstrated in the spleens of the treated animals, as revealed by electron microscopy. Leukemic and normal mice produced comparable levels of interferon in response to the inducers used.
Genetic determinant(s) for D-cycloserine resistance in Staphylococcus aureus
Authors: Miller Marcia A. , Rheins Melvin S.
Published: February 2010

The characterization of the genetic determinant(s) governing resistance to the antibiotic D-cycloserine in Staphylococcus aureus U9W was described. Only single-step low-grade resistant mutants developed from the parent strain, which was originally sensitive to the antibiotic. After exposure of resistant mutants to acridine orange and (or) elevated temperature, D-cycloserine-sensitive segregants were recovered. No resistant recombinants were obtained from transduction experiments using various D-cycloserine-sensitive "cured" mutants as donors. Buoyant density studies, however, did not reveal satellite DNA.
A method for recovering enterovirus from infected samples by adsorption onto shaken suspended cells
Authors: Konowalchuk Jack , Speirs Joan I.
Published: February 2010

A method is described whereby enterovirus present in a 5-ml liquid sample may be efficiently recovered for plaque enumeration on a single 60 × 15 mm culture dish. Adsorption is accomplished by constant agitation of the sample with suspended cells followed by a stationary period to allow monolayer formation for plaque development. Comparative studies with the use of coxsackievirus B5 and poliovirus 1, on HEp-2 and Vero cells respectively, indicated that the conventional method of adsorption onto stationary monolayers would require 50 times as many dishes and cells for an equal efficiency. The new method might be useful for the recovery of small numbers of viruses from food or water samples providing they are nontoxic to cells and contain no bacteria.
Cation content and cation-exchange capacity of intact cells and cell envelopes of viomycin-sensitive and -resistant strains of Rhizobium meliloti
Authors: Yu K. K.-Y. , Jordan D. C.
Published: February 2010

The envelope (wall plus plasma membrane) of a viomycin-resistant mutant of Rhizobium meliloti exhibited a higher calcium concentration than that of the viomycin-sensitive parent strain. However, the cation exchange capacity of the sensitive cells was almost twice that of the resistant cells, indicating that the excess calcium in the resistant cells is not available for exchange with external cations. Since externally supplied cations can block viomycin uptake by sensitive cells it is suggested that viomycin penetration in such cells involves an initial attraction of the basic antibiotic molecules to negatively charged sites in the envelope. Viomycin resistance in the mutant strain appears to be the result of (a) a decrease in the number of negatively charged sites and (b) the association with these sites, via calcium-bridging, of previously discovered envelope phospholipids capable of complexing with the drug.Chelators decreased viomycin resistance in the mutant strain, presumably by removal or destruction of the barrier in the cell envelope involved in decreased drug penetration. The decrease in viomycin resistance caused by cold shock was accompanied by a release of envelope phospholipid without a concurrent release of Ca2+.
Soil bacteria: principal component analysis of physiological descriptions of some named cultures of Agrobacterium, Arthrobacter, and Rhizobium
Authors: Skyring G. W. , Quadling C. , Rouatt J. W.
Published: February 2010

A principal component (PC) analysis was used to examine binary descriptive data for 38 cultures of Arthrobacter, 16 of Agrobacterium, and 27 of Rhizobium. The descriptions were based on the responses of the cultures to 65 tests concerned with the following: nutritional requirements; use of acetate, succinate, citrate, aldoses, adonitols, ketoses, disaccharides, trisaccharides, aromatic compounds, and amino acids; hydrolysis of starch and protein; and reduction of nitrate. No data for morphological, for symbiotic characteristics, or for pathogenicity were included. The PC analysis showed that the rhizobia, the agrobacteria, and the arthrobacters were separable in terms of the tests used, and that the rhizobia and agrobacteria groups were most alike. The PC analysis indicated important characteristics which distinguished these three groups from each other. Such characteristics included the following: use of arabinose, dulcitol, adonitol, sorbose, inulin, aromatic compounds, glycine, and phenylalanine as carbon and energy sources; use of glucose as carbon and energy source under anaerobic conditions; growth in the presence of 10% NaCl; growth in medium at pH 4.5 or 9.0; growth at 4C; and hydrolysis of starch. Bacteriological characteristics, DNA guanine–cytosine contents, and clustering of the arthrobacter cultures are discussed.
The production and assay of Myxovirus influenza A/PR8 in suspension cultures of a continuous cell line of human origin (G2)
Authors: Johnson C. Margaret , Westwood John C. N.
Published: February 2010

High yields of influenza A/PR8, comparable to those obtained in the 10-day chick embryo, were obtained using a low input multiplicity of infection in suspension cultures of a continuous line of mammalian cells (G2). By using the hemadsorption differential (HAD) count, a technique combining hemadsorption with viable cell counting, the progress of virus production can be assayed and correlated with the metabolic condition of the cells.
Lipids of antibiotic-sensitive and -resistant strains of Pseudomonas aeruginosa
Authors: Anderes E. A. , Sandine W. E. , Elliker P. R.
Published: February 2010

From a population of cells of Pseudomonas aeruginosa sensitive to 33 parts per million (ppm) of quaternary ammonium compound (QAC) and to 0.1 mg/ml of chloramphenicol (CAP), pure strains resistant to 750 ppm and 2.5 mg/ml of these antibacterial substances were isolated. Lipids from the sensitive and resistant cells grown under various conditions were extracted and characterized. Increased lipid biosynthesis was investigated as a possible factor in the resistance of this bacterium to CAP and QAC.Resistant cells grown in medium containing 207 ppm QAC at 25C averaged 77% more total lipid than sensitive cells. Resistant cells grown in the absence of QAC at 25C retained their resistance and averaged 27% more total lipid than sensitive cells. Cells grown at 32C in the presence of QAC contained 8% more total lipid than sensitive cells but less than cells grown at 25C under the same conditions. There was no increased lipid production by QAC-resistant cells grown at 37C in a Fermacell fermentor. Cells grown in CAP-containing medium (2.5 mg/ml) at 25C developed 28% more total lipid than sensitive cells grown in antibiotic-free medium.Gas–liquid chromatograms of the phospholipid, free fatty acid, and triglyceride fractions of the various cell types indicated that the same fatty acids were present. There was a 10% increase of the C18:1 fatty acid in both the phospholipid and free fatty acid fractions of the free lipids of cells grown in a Fermacell fermentor in the presence of CAP or QAC. However, there was no compensatory decrease in any single fatty acid, but rather a general decrease.Sensitive P. aeruginosa contained 14% free lipid and 3% to 6% bound lipid. The major phospholipid was phosphatidyl ethanolamine, which constituted 59% of the total phospholipid fraction of the sensitive cells. Analysis of fatty acids revealed that C16 amounted to 34%, C18:1 19%, and C16:1 and C18 each about 5% of the total present. These four fatty acids accounted for 63% of the free lipid present in the sensitive cells.
Fractionation of staphylococcal enterotoxin C2 by isoelectric focusing
Authors: Chang P.-C. , Yano Y. , Dighton M. , Dickie N.
Published: February 2010

Purified enterotoxin C2 was fractionated by isoelectric focusing into three toxic and immunologically identical components having isoelectric points of 6.65, 5.90, and 5.50.
Observations on the conversion of an inactive precursor protein to the antibiotic nisin
Authors: Hurst A. , Paterson G. M.
Published: February 2010

Stationary-phase cultures of Streptococcus lactis (strain 1) ere used to produce basic peptides which had no antibiotic activity but which contained material electrophoretically similar to nisin. Cells of S. lactis (strain 354/07) which produce nisin in late log phase and stationary phase were harvested in early log phase and used for preparing cell extracts (C.E.). Incubation of C.E. with basic peptide preparations from strain 1 generated an antibiotic believed to be nisin. The amount generated was directly related to one of the peak areas in the electrophoretograms of the basic peptide preparations. It is suggested that material in this peak is similar to or is a precursor of nisin. The specific activity of the C.E. was highest when a mild disruption method was used which affected neither the phase-contrast appearance nor the Gram reaction of the organism.
Studies on lipopolysaccharides of Proteus
Authors: Dmitriev B. A. , Hinton N. A. , Lowe R. W. , Jones J. K. N.
Published: February 2010

The polysaccharide moieties of the lipopolysaccharides of serotyped strains of Proteus have been examined. The strains were selected to provide a wide range of serotypes. The primary acetic acid extracts of different strains of Proteus were fractionated on Sephadex G-50 and yielded three main components: a peak (I), which was composed mainly of polysaccharide; a second peak (II), the core polysaccharide, which contained heptose and phosphate; and a third component (III), which corresponded to a low molecular weight fraction and contained KDO and phosphate as well as other components. Peak I was not encountered in rough strains of Proteus. The chemical composition of the peaks obtained for S, SR, and R strains is discussed in relation to their agglutinating ability to homologous antiserum.
Sur l'activité antibiotique de l'Armillaria mellea
Authors: Richard Claude
Published: February 2010

Antibiotic activity of Armillaria mellea (Vahl ex Fr.) Kummer towards many fungi and bacteria, including some very important plant pathogens, was clearly established. Preliminary extraction trials have been negative. No direct relationship was found between the bioluminescence of A. mellea and its antibiotic activity. Clitocybe tabescens (Scop, ex Fr.) Bres. also possesses antibiotic capability, but to a much lower degree.
Cyathin, a new antibiotic complex produced by Cyathus helenae
Authors: Allbutt A. D. , Ayer W. A. , Brodie H. J. , Johri B. N. , Taube H.
Published: February 2010

The fungus Cyathus helenae Brodie (Gasteromycetes) produces a complex of antibiotic substances collectively called cyathin. Highest yields were obtained when the fungus was grown at room temperature for 25 days on a chemically defined liquid medium in static culture. The action spectrum of cyathin (and its components) was determined by placing cyathin-bearing paper discs on agar plates seeded with the microorganisms being tested. The cyathin complex is active against actinomycetes, bacteria (gram-positive as well as gram-negative), and some fungi, including dermatophytes. Weaker antimicrobial activity is also shown by C. striatus (Huds.) Willd. ex Pers., C. poeppigii L., and C. limbatus L. Seven different compounds have been isolated from the cyathin complex: 2,4,5-trihydroxybenzaldehyde (C7H6O4),cyathin A3(C20H30O3), cyathin A4(C20H30O4),allocyathinA4(C20H30O4),cyathin B3(C20H28O3), cyathin B4(C20H28O4), and cyathin C5(C20H26O5). Aside from 2,4,5-trihydroxybenzaldehyde, these compounds appear not to have been previously described. A discussion of some of the structural features of cyathin A4 and cyathin A3 is presented
Ultraviolet radiation studies on the colonial alga, Eudorina elegans
Authors: Kemp C. L. , Wentworth J. W.
Published: February 2010

Eudorina elegans was used to examine the response of an easily manipulated, multicellular organism to ultraviolet irradiation. The results indicate that E. elegans possesses an efficient photoreversal process. It is capable of complete reversal of ultraviolet induced damage sufficient to inactivate 99.99% of the colony-forming ability of the organism. Eudorina loses the ability to respond to visible light reversal of ultraviolet-induced damage exponentially with time. The half-life of this loss is about 10 h at 32° and about 20 h at 22°. Postultraviolet temperature of incubation influences the surviving fraction with fewer survivors at 22° than at 32°. The survival patterns of E. elegans suggest that a specific dark repair of ultraviolet-induced lesions may not occur, but that some repair processes take place during cellular deoxyribonucleic acid (DNA) synthesis.
Purification and characteristics of the enterotoxin of Clostridium perfringens type A
Authors: Hauschild A. H. W. , Hilsheimer R.
Published: February 2010

Enterotoxin was extracted from sporulated cells of Clostridium perfringens type A and purified by gel and ion exchange chromatography. A single protein band was obtained after electrophoresis of the toxin on cellulose polyacetate, and a single precipitin line after immunodiffusion against crude antiserum. Disc gel electrophoresis resulted in the resolution of the toxin into one major and two accessory bands, all biologically active, and into a few faint bands which had no measurable biological activity and constituted less than 3% of the total protein. The two accessory enterotoxin bands appeared to be derived from the major band as a result of ion exchange chromatography.The ultraviolet absorption spectrum of the purified enterotoxin was characteristic for proteins. The toxin was essentially free of nucleic acids, fatty acids, lipid phosphorus, and reducing carbohydrates. Its apparent molecular weight was 36 000 ± 4000, the Stokes radius was 2.6 mμ, and the isoelectric point was at pH 4.3. The purified toxin was enterotoxic in ligated intestinal loops of rabbits and had a specific toxicity of about 2000 mouse MLD/mg N.
The action of hydrolytic enzymes and vapor rehydration on semidried cells of Klebsiella pneumoniae
Authors: Maltman J. R. , Webb S. J.
Published: February 2010

Airborne cells of Klebsiella pneumoniae have been found to develop a sensitivity to lethal actions of hydrolytic enzymes. The degree to which the cells become sensitive to enzymic damage is shown to depend on (a) the medium from which they are aerosolized, (b) the relative humidity (RH) at which they are stored, (c) the duration of their storage in aerosols, (d) the method by which they are rehydrated, and (e) the particular enzyme. When cells are aerosolized from suspensions in distilled water they develop their maximum sensitivity to lysozyme and DNase after storage at 55% and 80% relative humidity (RH) respectively. Sensitivity to RNase is small and independent of the storage RH. The addition of glycerol to the cells before their aerosolization results in the development of maximal sensitivities to lysozyme and RNase occurring after storage at 55% RH, while sensitivity to DNase remains at a maximal level after holding at 80% RH. If the cells are atomized from suspensions containing raffinose or myo-inositol their sensitivity to lysozyme, RNase, and DNase is greatest after storage at 30%, 55%, and 80% respectively. When the airborne cells either are rehydrated with water vapor before their collection, or held in buffer after collection, before being exposed to these enzymes, their susceptibility to enzymic damage is reduced. The possible bearing these findings have on the mechanisms of cell viability and loss of ability to infect a host, because of their semidehydration, is discussed.
Purification and properties of a phenol carboxylic acid acyl esterase from Aspergillus flavus
Authors: Child J. J. , Oka T. , Simpson F. J. , Krishnamurty H. G.
Published: February 2010

Aspergillus flavus produces an extracellular esterase that hydrolyses phenolic carboxylic acid acyl esters. An assay based upon the measurement of the rate of release of phloroglucinol on hydrolysis of the ester of phloroglucinol and protocatechuic acid is described. The most active preparation hydrolyzed 30.8 μmoles of substrate per minute per milligram of protein and was active against a wide range of esters of meta and para hydroxybenzoic acid derivatives.The enzyme was isolated as a homogeneous protein, as judged by ultracentrifugation and by electrophoresis and had an isoelectric point of pH 4.45. The molecular weight was determined as 166 000. The enzyme is a glycoprotein containing 42.8% carbohydrate and the amino acid composition is described.
Mode of action of oxathiin systemic fungicides. IV. Effect of carboxin on solute leakage from hyphae of Rhizoctonia solani
Authors: Shively O. D. , Mathre D. E.
Published: February 2010

Mycelial discs of Rhizoctonia solani were treated with the oxathiin systemic fungicide carboxin (5,6-dihydro-2-methyl-1,4-oxathiin-3-carboxanilide) at 10−4 M to determine the effect upon fungal plasma membranes. Electrical conductance was used as a preliminary monitor for cell leakage. Carboxin treatment consistently resulted in the release of ionic materials. Potassium ions, organic acids, and phosphate-containing materials were exuded from cells treated with carboxin. Phosphate losses were sufficient to retard, but not to stop, further growth of the organism after removal of the fungicide and placement of the mycelium on a growth medium lacking phosphate. Starvation of mycelial discs in deionized water markedly reduced respiratory metabolism and carboxin treatment after starvation did not result in cell leakage, thus indicating that membrane damage did not occur. Nystatin, a known disrupter of membranes, did cause leakage from starved cells. Inasmuch as carboxin is known to inhibit respiratory metabolism, organic acids and phosphate-containing materials may accumulate in treated cells and then be exuded as a secondary effect.