bluuebunny/crossref_metadata_2025 huggingface dataset:
Observations microbiologiques dans quelques sols forestiers du Québec
Authors: Fortin J. André
Published: February 2010

Numerations of total microflora, bacteria, and fungi were realized in seven ecologically defined soils of Quebec. The results show several relations between the quantity of microorganisms found and the nature of the soil as well as the composition of the vegetation.Spores of the Endogonaceae were found in abundance only in the brunisols under maple forest whereas the sclerotia of Cenococcum graniforme were observed mainly in the podzols with fir and spruce forests.
Fate and behavior of five chlorinated hydrocarbons in three natural waters
Authors: Oloffs P. C. , Albright L. J. , Szeto S. Y.
Published: February 2010

Water samples removed from two rivers and from the subtidal zone of Georgia Strait in British Columbia were treated with either 0.025 ppm of DDT, lindane, α-chlordane, or γ-chlordane, or 0.1 ppm Aroclor 1260 (PCB). The samples were incubated in the laboratory for up to 12 weeks at the temperatures of these natural waters at the time of sampling. Lindane persisted in all water samples throughout the experiment, but large proportions of the other compounds were transported into the atmosphere during incubation except when the containers were sealed. No metabolic breakdown could be demonstrated. As demonstrated with 14C-γ-chlordane, uneven distribution of the pesticides occurred rapidly, but was prevented, or reversed, by addition of a surfactant to the water. Total bacterial counts were generally higher in treated than in untreated water samples.
An automatic, multichamber soil-washing apparatus for removing fungal spores from soil
Authors: Bissett J. , Widden P.
Published: February 2010

An automatic soil-washing apparatus is described which enabled the washing of fungus spores out of large numbers of soil samples simultaneously. Tests of the apparatus indicated that superficial spores were removed from most of the soil particles. This allowed organisms growing in soil as vegetative mycelium to be isolated more readily without the serious competition commonly encountered from organisms sporulating heavily in the soil. Virtually no cross-contamination of soil samples occurred in the multichambered apparatus.
Changes in nutritional types in bacterial successions
Authors: Ayanaba A. , Alexander M.
Published: February 2010

In a succession in which three bacteria having different nutritional needs were inoculated simultaneously into a medium with no added growth factors, the fastidious population developed only after an initial period of growth by bacteria with simple nutritional demands. In a model succession of soil bacteria inoculated into a glucose–salts medium, the relative abundance of cells requiring no growth factors declined with time, while bacteria needing growth factors made up an increasing percentage of the community in late stages of the succession.
Lactose-utilizing mutants of lac deletion strains of Escherichia coli
Authors: Warren R. A. J.
Published: February 2010

Strains of Escherichia coli having deletions within the gene for β-galactosidase can give rise to mutants which grow on lactose as sole carbon source at rates 60 to 70% of that of a lac+ strain, yet appear lactose-negative on some standard indicator media. The mutations result in the constitutive synthesis of low levels of β-galactosidase activity. Although the mutations are not linked to the lactose operon, they apparently result in constitutive expression of this operon.
Recherches préliminaires sur les bactéries lipolytiques psychrophiles des sols et des eaux
Authors: Breuil C. , Gounot A. M.
Published: February 2010

Different soil extract media and other media were assayed for a comparative evaluation of both total and lipolytic populations of bacteria taken from soil and water samples during winter. By incubating at a low temperature, psychrophilic microorganisms were counted and isolated. Gram-negative bacteria, especially Pseudomonas species, were the most numerous.
Exogenous carbon and nitrogen requirements for conidial germination by Aspergillus flavus
Authors: Pass T. , Griffin G. J.
Published: February 2010

In a phosphate-buffered (pH 5.7) inorganic salts solution (B), nearly full dependence on exogenous carbon was found for germination of washed, Tween 20-treated conidia of Aspergillus flavus over a range of conidial densities. No exogenous carbon-independent germination was observed for settling tower-deposited dry conidia. At equivalent carbon, an amino acid mixture supported highest germination of washed conidia; proline, alanine, or glucose plus NH4Cl supported higher germination than several other single amino acids or single sugars plus NH4Cl tested. When exogenous carbon was supplied as glucose, total and percentage germination of washed conidia were influenced more by exogenous nitrogen, supplied as NH4Cl, as the conidial density increased and as the glucose and NH4Cl concentrations increased. At equivalent nitrogen, proline alone, or certain amino acid mixtures supported highest germination of several nitrogen sources in B solution plus glucose. Germination decreased as the conidial density decreased when exogenous carbon and nitrogen were supplied at each density at constant amounts per conidium. Removal of CO2 from the germination medium inhibited germination. Tween 20 and Tergitol NPX stimulated germination of settling tower-deposited conidia. "Amino acid carry-over" for conidial germination was not demonstrated. The possible relation of these findings to the ecology of conidial germination in soil is discussed.
The antiviral activity of Isoprinosine
Authors: Gordon Paul , Brown Eric R.
Published: February 2010

A hypothesis predicting that increase in the rate of synthesis of host messenger RNA would be associated with antiviral activity was examined. Biochemically, Isoprinosine or NPT-10381 (methisoprinol) increased the rate of rapid labeling of polyribosomal RNA and protein in uninfected monkey kidney cells in tissue culture. In tissue-culture systems, Isoprinosine exerted antiviral effects against influenza virus, PR-8 and A2 strains; herpes virus, LU strain; polio virus 3; and adenovirus 10. In in vivo mortality studies, Isoprinosine was observed to exert therapeutic antiviral effects against the A2 strain of influenza and, as well, against a herpes infection of newborn mice. Experiments were carried out which demonstrated a correlation between the in vivo anti-influenza (PR-8) effects of Isoprinosine and reduction in the virus titer in lungs of infected mice.
Effects of Gaffkya homari on glucose, total carbohydrates, and lactic acid of the hemolymph of the lobster (Homarus americanus)
Authors: Stewart James E. , Cornick John W.
Published: February 2010

The lobster pathogen, Gaffkya homari, in vitro and in vivo caused the virtual disappearance of glucose and lactic acid from the hemolymph of the lobster, Homarus americanus. In vitro results suggested that almost half of the non-glucose components of the hemolymph could be used by G. homari.
Respiration, peroxidase, and diphenol oxidase isozymes in reproductive and nonreproductive growth of Glomerella magna
Authors: Wilson D. M. , Huisingh D.
Published: February 2010

Respiration rates were measured and respiratory quotients (RQ) were calculated for sexually reproducing and nonreproducing cultures of Glomerella magna. Oxygen uptake per unit of extractable protein by reproducing cultures was fairly constant until day 7 when it increased markedly as the sexual structures were being differentiated. Oxygen uptake by nonreproducing cultures was highest on days 2, 3, and 4 while initiation of sexual reproduction by exposure to light was still possible. RQ values of reproducing cultures were constant at about 0.85, while the nonreproductive cultures reached a maximum of 1 by day 4 and then declined with culture age to 0.47. The isozymes of peroxidase and o-diphenol oxidase were similar in reproducing and nonreproducing cultures. One "tyrosinase" band and one "laccase" (p-diphenol oxidase) band were observed with tyrosine and p-phenylenediamine as the substrates. Isozymes of peroxidase or diphenol oxidase exhibited different substrate specificities.
Myxobacteria exert partial control of damping-off and root disease in container-grown tree seedlings
Authors: Hocking Drake , Cook Fred D.
Published: February 2010

Many tree seedlings for reforestation are now being produced in small discreet containers. On these seedlings, losses and stunting from root pathogens occur widely and unpredictably. Some myxobacteria of the group Cytophaga which produce powerful extracellular proteolytic and chitinolytic enzymes were introduced into fumigated or non-fumigated peat before or after sowing seeds of four species of conifer. They actively colonized the rhizosphere of the developing seedlings without affecting seedling development. In subsequent inoculation tests with pathogenic fungi, there was significantly less mortality, chlorosis, and stunting, than in checks without myxobacteria.
Bacteriophages of Agrobacterium tumefaciens, III. Effect of attenuation of virulence on lysogeny and phage production
Authors: Beaud R. , Beardsley R. E. , Kurkdjian A.
Published: February 2010

Two avirulent clones of Agrobacterium tumefaciens which appeared spontaneously during culture are indistinguishable from the parental strains from which they were derived with respect to either sensitivity to the bacteriophages tested or the production of phages during growth. One attenuated clone, isolated after treatment of the virulent B6 strain with proflavin is able to induce limited proliferations in infected tissues that do not progress into visible tumors. These proliferations do not respond to exogenous auxin. Tumors appearing in decapitated pea seedlings inoculated with the attenuated clone after infection by virulent bacteria are larger than those of seedlings inoculated only with virulent bacteria. When introduced into tissues before virulent bacteria, attenuated bacteria inhibit tumor formation. Like the parental strain, the attenuated clone is lysogenic for phages inducible by ultraviolet irradiation and also by conditions within host tissues.
Some qualitative and quantitative aspects of the intestinal microflora of the glaucous-winged gull (Larus glaucescens)
Authors: Wood A. J. , Trust T. J.
Published: February 2010

The intestinal microflora of two distinct populations of glaucous-winged gulls (Larus glaucescens) was examined both qualitatively and quantitatively. The constant presence of Escherichia coli type I, Clostridium perfringens, and Streptococcus faecalis was demonstrated. The number of microorganisms of these normal indicators of fecal pollution of water was sufficiently great to suggest that more attention must be given to the contamination of water supplies by this bird.
Comparative studies on the protective potential of antisera directed against four antigenic preparations from Pseudomonas aeruginosa
Authors: Johnston Linda J. , Syeklocha Delfa
Published: February 2010

Three subcellular fractions and a formalin-killed whole-cell vaccine were prepared from a virulent strain of Pseudomonas aeruginosa (PA-7) and tested for their ability to induce protective antisera in rabbits, as measured by passive protection afforded mice challenged with a lethal dose of viable cells 4 h after receiving an intraperitoneal injection of 0.2 ml of whole or diluted immune rabbit serum.All preparations were found to elicit antiserum capable of providing protection for mice given a challenge dose of 20 LD50. The passive hemagglutinating antibody titer of a given serum appeared to be more reliable than the bacterial agglutinin level as a criterion for estimating the protective potential of the serum.
Salt response of amylase produced in media of different NaCl or KCl concentrations by a moderately halophilic Micrococcus
Authors: Onishi Hiroshi
Published: February 2010

Amylase production by a moderately halophilic Micrococcus sp. was influenced by the salt concentration of the medium, whereas salt-response patterns of amylase produced in media of 0.75 to 3.0 M NaCl or KCl were found to be almost identical.
The nomenclature of Salmonella, its usage, and definitions for the three species
Authors: Ewing William H.
Published: February 2010

The nomenclature of the genus Salmonella and the biochemical reactions given by members of this genus are reviewed. It was concluded that the three-species system is the best solution to the problem of nomenclature within the genus Salmonella. Methods are outlined by which members of the three species of Salmonella (Salmonella cholerae-suis, Salmonella typhi, and Salmonella enteritidis) can be differentiated from each other, définitions are given for each of the species, and recommendations are made as regards usage of the system of nomenclature.
Recombination in Ustilago violacea after liquid nitrogen refrigeration
Authors: Day A. W. , Wellman A. M. , Martin J.
Published: February 2010

The effect of liquid nitrogen storage on intragenic recombination in strains of the anther smut Ustilago violacea mutant at the uvs-1 locus was analyzed. Such low temperature storage did not affect significantly recombination at this locus, and it appears to be a useful method of preserving genetic strains.
The effect of ethylenediaminetetraacetate and its calcium chelate on the rate of swelling of a strain of Pseudomonas aeruginosa in salt solutions
Authors: Bernheim Frederick
Published: February 2010

When washed suspensions of Pseudomonas aeruginosa are placed in salt solutions, the cells shrink rapidly and then swell more slowly as salt and water enter them. The rate of swelling is increased by EDTA and its calcium chelate. The effect of EDTA is antagonized by diamines; the effect of the calcium chelate by carboxylic acids. The relative effects of EDTA and the calcium chelate differ in different salts which suggests different sites of action. The evidence indicates that EDTA does not act by chelating calcium or magnesium in the membrane of these cells but that its two nitrogen atoms combine by electrostatic forces with anionic sites, and the chelate, in which the nitrogen atoms are bound to calcium, combines by the same forces to cationic sites. Barium, strontium, and magnesium chelates are inactive.
Fluorometric determination of glycolytic intermediates and adenylates during sequential changes in replacement culture of Aspergillus niger
Authors: Smith John E. , Ng Wai Shing
Published: February 2010

Fluorometric methods have been used for the determination of the momentary levels of some glycolytic intermediates and adenylates during the development of Aspergillus niger in fermenter culture and also in a medium which allows vegetative growth but not conidiation. During periods of active glycolysis the levels of the hexose monophosphates were low while the other intermediates were high; during periods of low glycolysis this pattern was reversed. The interrelations of the momentary concentrations of the intermediates indicated that the phosphofructokinase step may be a control site in glycolysis in Aspergillus niger.
The effect of glycerol and a rat liver extract (ICS) on sterol synthesis in Fusarium oxysporum
Authors: Madhosingh C. , Lepage M. , Migicovsky B. B.
Published: February 2010

The net yields of sterols in cultures of Fusarium oxysporum Schl. em Sny. et Hans, were reduced 44% by an inhibitor of cholesterol synthesis (ICS) obtained from mitochondria of starved rats' livers and 63% by glycerol. The yields of sterols were determined by weighing and the incorporation of radioactive carbon from sodium acetate-2-14C into digitonide precipitates was assayed by liquid scintillation. The major sterol was identified as ergosterol.
An S-adenosylmethionine requirement for chemotaxis in Escherichia coli
Authors: Armstrong John B.
Published: February 2010

A spontaneous ethionine-resistant mutant of Escherichia coli was found to be nonchemotactic. The mutant had low S-adenosylmethionine (SAM) synthetase activity and a greatly reduced SAM pool. Transductants regained both chemotaxis and ethionine sensitivity. A partial revertant was chemotactic and its SAM pool was substantially higher than in the mutant, though the revertant still had low SAM synthetase activity and was only slightly ethionine sensitive. The results support the hypothesis that SAM is required for a normal tactic response to a chemical stimulus.
Variability in ultrastructure of Clostridium botulinum spores
Authors: Stevenson Kenneth E. , Vaughn Reese H.
Published: February 2010

The ultrastructure of spores of Clostridium botulinum strains 78A, 17B (nonproteolytic), and C51C3 was investigated. Electron photomicrographs revealed the following: strain 78A: the oval spores, enveloped by multilayered exosporia, were normally found within swollen sporangia. The spore coat contained a distinct outer layer and a thicker inner coat. Strain 17B: the oval spores were covered by open-ended, sheath-like exosporia. Some spores were enclosed within slightly swollen sporangia, while most were present as free spores. A layered, electron-translucent outer coat and an electron-dense inner coat comprised the spore coat. Strain C51C3: the oval to cylindrical spores were seldom found within intact sporangia. The spore coat was a single, thin, electron-dense layer. Exosporial layers were in apposition to the spore coat.
Photosynthetic properties of extracts of Anacystis nidulans prepared by lysozyme digestion
Authors: Jansz E. R. , Maclean F. I.
Published: February 2010

Cell-free extracts of A. nidulans show high rates of cyclic and noncyclic photophosphorylation and P/2e ratios of about 0.8. These extracts also reduced ferricyanide at rates as high as 700 μmol/mg chlorophyll per hour. Rates of dichlorophenol indophenol (DCPIP) reduction and reduced cytochrome c oxidation similar to those previously reported in the literature have also been observed. The extracts, however, showed no NADP-reducing capacity. Subjecting cell-free extracts to cold shock caused no decline in electron flow but a marked decline in photophosphorylation. The sensitivity of photosynthesis of this organism to cold shock (1, 2) might be explained, at least to some extent, by this decline in photophosphorylation.
Studies in intermicrobial symbiosis. Saccharomyces cerevisiae and Lactobacillus casei
Authors: Megee III R. D. , Drake J. F. , Fredrickson A. G. , Tsuchiya H. M.
Published: February 2010

Saccharomyces cerevisiae and a riboflavin assay strain of Lactobacillus casei have been propagated anaerobically in mixed culture. Both batch and continuous culture techniques were used. By varying the concentrations of glucose and riboflavin in the growth medium, it was possible to produce symbioses of commensalism + competition, competition, and mutualism + competition. In short, the interaction prevailing is determined by the medium as well as by the genetic characteristics of the organisms. The behavior of the mixed cultures in these situations was predicted from data taken on pure cultures of the organisms.
Studies on the bacterial flora of vacuum-packaged fresh beef
Authors: Roth L. A. , Clark D. S.
Published: February 2010

Vacuum-packaging of fresh beef in a gas-impermeable film (vinyldene chloride – vinyl chloride copolymer), as compared to packaging in a gas-permeable film (polyvinyl chloride), reduced the growth rates of most incident bacteria (lower total aerobic and anaerobic counts), favored the development of lactobacilli, and markedly increased the odor and color shelf life during storage at 5 °C. The growth rate of both aerobes and anaerobes on meat packaged in vinyldene chloride (VC) film was about 1/8 of that of meat packaged in the polyvinyl chloride (PVC) film. The flora of VC-packaged samples consisted largely of lactobacilli (50–70%) while that of PVC-packaged samples consisted mostly of pigmented pseudomonads and M. thermosphactum (collectively 60%). Exposure of VC-packaged samples to air changed the microflora to one resembling that of samples initially packaged in PVC film. VC-packaged meat did not undergo noticeable changes in odor or color even after 32 days of storage while meat stored in PVC developed off-color (brown) and off-odor (putrid) in 5 days. The color shelf life in PVC film of beef previously stored in VC film was 3 days regardless of how long the meat was stored in the latter film before repackaging.
Regeneration of protoplasts in Saccharomyces
Authors: Shahin M. M.
Published: February 2010

Protoplasts prepared from cells of different stages within the logarithmic growth phase and from transition phase showed different degrees of colony-forming ability. The cells yielding higher frequency of protoplast formation also gave protoplast with a high degree of colony-forming ability.
Candida iberica sp. n. A new species isolated from Spanish sausages
Authors: Ramírez Carlos , González Carmen
Published: February 2010

In the course of a taxonomic study on the mycoflora of processed meat products, five strains of a yeast of the genus Candida were isolated from different brands of Spanish sausages, "Salchichón." They could not be identified with any known species.The five strains represent a new species for which we propose the name of Candida iberica.The identification techniques used were based mainly on those described in The yeasts. A taxonomic study J. Lodder. (Editor) Amsterdam. 1970.
A reexamination of phase IV Bordetella pertussis
Authors: Aprile Marie A.
Published: February 2010

Eight strains of Bordetella pertussis labeled as "phase IV" and received from different laboratories were examined for their cultural, biochemical, and immunological characteristics in comparison with four phase I strains. Five of the strains possessed cultural and biochemical characteristics agreeing with published information on phase IV B. pertussis. Two of the strains had properties more closely resembling those of Brucella melitensis and one resembled Lophomonas sp.None of the phase IV strains possessed the protective antigen (PA) or the histamine-sensitizing factor (HSF) and they showed little immunological relationship with one another when tested for agglutination by antisera to phase IV except for L-46, L-51, and L-84, which formed a homogeneous serological group. Certain phase I antisera showed some degree of cross-reactivity with phase IV strains but there was much variation between the individual phase IV strains. Conversely the phase IV antisera cross-reacted with phase I organisms.
Permeability increases in cells of Salmonella enteritidis induced by ethylenediaminetetraacetate and temperature treatments
Authors: Chipley J. R. , Edwards Jr H. M.
Published: February 2010

Treatment of cells of Salmonella enteritidis with ethylenediaminetetraacetate (EDTA) resulted in losses of less than 4% of the total cellular deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and protein. No lethal effects could be observed when treated cells were plated and counted. The uptake of 14C-actinomycin-D, 22Na+, and 65Zn2+ into EDTA-treated cells and the release of 65Zn2+ from EDTA-treated cell walls were strictly temperature-dependent. The uptake of 22Na+ and 65Zn2+ in control and EDTA-treated cells appeared to be enzymatically controlled and could be inhibited by p-chloromercuribenzoate. The uptake and release of these radioisotopes in treated cells was two to five times that of untreated, control cells. The release of lipopolysaccharide could be correlated with a change in permeability of cells when they were treated with EDTA.
Quinate metabolism in Pseudomonas aeruginosa
Authors: Ingledew W. M. , Tai C. C.
Published: February 2010

Data obtained with the Warburg constant-volume respirometer and from enzyme analysis have demonstrated that the method of regulation of the "hydroaromatic" degradation pathway found in Pseudomonas aeruginosa is vastly different from that previously discovered in Acinetobacter calcoaceticus and perhaps also significantly different from P. putida. Two mutants have been analyzed: the first with multiple impairment of degradative abilities; the second with a single defect, i.e. a lack of quinic dehydrogenase activity. Quinic dehydrogenase has also been shown to function for shikimate utilization in P. aeruginosa, even though 5-dehydroshikimate reductase in vitro catalyzes the same reaction. The possible relationship of these findings to pyocyanine formation is discussed.
Photosynthetic characteristics of a purple sulfur bacterium grown under different light intensities
Authors: Takahashi M. , Shiokawa K. , Ichimura S.
Published: February 2010

Photosynthetic characteristics of a purple sulfur bacterium, Chromatium, strain D, cultured under various light intensities were examined. With a decrease in the light intensity used for culture, the bacteriochlorophyll a content per unit cell nitrogen increased. Also, at low light intensities, the rate of photosynthesis (per unit bacteriochlorophyll a) was higher in samples grown under low light than in those grown under high light. These two responses to low light intensity are adaptations that ensure a high photosynthetic rate for the purple sulfur bacterium that usually occurs in a dimly lit environment. Possible chemical and structural mechanisms involved are discussed.
Lysozymes in yellow fever infection
Authors: David-West Tam. S. , Desalu A. B. O. , Smith J. A.
Published: February 2010

The activities of acid phosphatase and leucine aminopeptidase in brain and liver of yellow fever infected mice were assayed sequentially. It was shown that there was a highly significant activation of both enzymes in the two organs in the course of infection. The activation of enzymes coincided with histopathological expression of the infection. Tissue destruction was more dramatic in the brain than in the liver; although the level of enzyme for each day was higher in the liver than in the brain. In the former there was extensive encephalitis with intensive lytic necrosis of the cortex, while in the latter there was some ballooning of the hepatocytes, but no hepatitis. There was no direct correlation between enzyme activation and the titer of infective virus in the organs.It is suggested that the liver pathology of yellow fever infected mice hitherto regarded as insignificant should be reexamined, since the physiologic injury triggered off by the infection might make itself manifest in the two organs to varying degrees histopathologically.
Biodegradation of petroleum in seawater at low temperatures
Authors: Atlas R. M. , Bartha R.
Published: February 2010

To evaluate the significance of biodegradation in the removal of polluting oil from cold oceans, freshly collected seawater samples were treated with petroleum and were incubated at controlled temperatures between 5 and 20 °C. Biodegradation was monitored by the measurement of CO2 evolution and by quantitative gas chromatographic analysis. Low water temperatures not only resulted in slower degradation rates, but caused increasing lag periods that preceded the onset of measurable biodegradation. A substantial portion of these lag periods was eliminated when, instead of fresh petroleum, a "weathered" sample was used. The results suggest that some volatile components of petroleum that are inhibitory to oil-degrading microorganisms evaporate only very slowly at low temperatures, and thus retard biodegradation.
Biochemical transformations of herbicide-derived anilines in culture medium and in soil
Authors: Bordeleau L. M. , Bartha R.
Published: February 2010

A correlation was established between peroxidase activity of soil and its capacity to transform 3,4-dichloroaniline, a breakdown product of several herbicides, to 3,3′,4,4′-tetrachloroazobenzene. Supplementation of soil by carbon and nitrogen sources for microbial growth stimulated both activities, and pointed to the microbial origin of soil peroxidases. Several peroxidase-producing bacteria, actinomycetes, and fungi were isolated from soil and were characterized. On the basis of its rapid growth and high peroxidase activity, a Geotrichum candidum strain was selected for further study. The culture filtrate of this organism exhibited both peroxidase and aniline oxidase activity. The highest per milligram dry weight activity of these enzymes was observed after cultivation on a mineral salts medium supplemented with soil extract and yeast extract.
Biochemical transformations of herbicide-derived anilines: purification and characterization of causative enzymes
Authors: Bordeleau L. M. , Bartha R.
Published: February 2010

From culture filtrate of the soil fungus Geotrichum candidum two extracellular enzymes were separated that were active in transformation of aniline. Using a concentration, salt precipitation, dialysis, and gel filtration sequence, the two enzymes, a peroxidase and an aniline oxidase, were purified 54- and 68-fold, respectively. The characteristics of the partially purified enzymes were compared and were found to be for peroxidase and for aniline oxidase, respectively, as follows: optimal pH = 4.4–5.0 and 4.8–5.4, energy of activation (Q10) = 3.0 and 1.6, apparent Km (aniline) 3.1 × 10−4 and 4.4 × 10−4 M. Km (H2O2) for peroxidase was 2.4 × 10−6, Km (O2) for aniline oxidase was 9.1 × 10−4 M. In the natural soil environment, peroxidase seems to have a greater role in pesticide residue transformation than aniline oxidas
Biochemical transformations of herbicide-derived anilines: requirements of molecular configuration
Authors: Bordeleau L. M. , Bartha R.
Published: February 2010

4-Chloroaniline transformation products, generated in soil and by partially purified enzymes of the soil fungus Geotrichum candidum were compared using autoradiochromatography. The results of this comparison indicated that these enzymes constitute a useful model system for investigation of aniline susceptibility to polymerizing transformations. Forty-three variously substituted anilines were exposed to the fungal enzymes and the reaction products were analyzed by spectrometric and gas chromatographic methods. Susceptibility to enzymic transformation increased with increasing electron density at the amino group. Electron-releasing substituents increased yields of higher polymers, but decreased the yields of azobenzenes. Anilines substituted by electron-attraction groups in both ortho positions resisted enzymic transformations. The results allow predictions about the environmental fate of pesticide-derived aniline residues.
Characterization of the aminopeptidase from Bacillus subtilis as an extracellular enzyme
Authors: Wagner Fred W. , Chung A. , Ray Lee E.
Published: February 2010

A strain of Bacillus subtilis produced an aminopeptidase detectable in the cultural fluid and in cell-free extracts. Both extracellular and intracellular aminopeptidases hydrolyzed L-leucyl-β-naphthylamide substrate after activation with cobalt ions. In the cultural fluid, trace amounts of activity were present as early as 12 h, but the highest activity was attained between 36 and 96 h. The addition of lysozyme to cultures less than 36 h old inhibited the production of the aminopeptidase of the cultural fluid, but was less effective in older cultures. This trend was correlated to the Gram-variability of the organisms in the culture. Chloramphenicol and oxytetracycline also inhibited enzyme production without affecting normal cell lysis. These data were interpreted to imply that the aminopeptidase of the cultural fluid did not result from the release of the intracellular aminopeptidase by cell lysis, but that it was produced by viable, metabolizing cells, most probably Gram-negative. Chromatography of the cultural fluid on CM-Sephadex C-50 showed an aminopeptidase characteristic of the extracellular medium. The possible implication of this enzyme as a regulatory mechanism for nitrogen utilization by Bacillus subtilis is discussed.
Somatic mitosis in Erysiphe graminis hordei
Authors: McKeen W. E.
Published: February 2010

Somatic nuclear division in Erysiphe graminis hordei was studied by light and electron microscopy after various fixation and staining procedures. Electron microscopy studies of alcohol – acetic acid fixed material aided in providing an understanding of nuclear division and showing the gross alterations which occurred. Light microscopy indicated that a central body was always present at a specific site on the nuclear membrane in the interphase nucleus and was connected to chromatic spherical bodies. Microtubules were preserved when a short glutaraldehyde – osmium tetroxide fixation was used. Some microtubules extend from plaque to plaque while others terminate in kinetochores. A microtubular spindle, oblique to the nuclear and mildew-cells axes formed within the nuclear membrane. Typical prophases, metaphases, anaphases, and telophases were observed. Then one set of daughter chromatids bypassed the nucleolus which persisted intranuclearly until the daughter nuclei reached their destination, and the other set of daughter chromatids moved to midpoint in the other daughter cell. A narrow corridor, which connected daughter nuclei for some time, was filled mainly with microtubules and probably was the filament which was observed in the nucleus by light microscopy during nuclear division. At least six chromosomes were present in each nucleus.
The isolation and enumeration of cytophagas
Authors: Christensen Penelope J. , Cook F. D.
Published: February 2010

A comparison of 20 media based on degraded milk protein or tryptone, yeast extract, and sodium acetate snowed that various new formulae were superior to standard media for enumeration of cytophagas from aquatic habitats, for their isolation, and for maximum expression of the spreading characteristic. The use of 0.1 μliter/liter Tween 20 in dilution blanks increased counts of cytophagas up to threefold, but incorporation of Tween 20 into the plating agar had no significant effect on the numbers recovered. Sodium lauryl sulfate (S.L.S.) was examined as a possible screening agent for identification of cytophagas. A concentration of 0.1% S.L.S. inhibited the growth of 97% of the 66 cytophagas tested, but more than 80% of the other 41 organisms tested were also affected. However, 91% of the cytophagas were sensitive to S.L.S. and showed proteolysis on skim acetate medium compared to 53% of the Flavo-bacteria and 50% of the other organisms tested. None of the third group of organisms could be confused morphologically with the cytophaga group; thus it is suggested that S.L.S. susceptibility performed on skim acetate medium could be a useful screening test for cytophagas.
Relationship between Bdellovibrio bacteriovorus 6-5-S and autoclaved host bacteria
Authors: Crothers S. F. , Fackrell H. B. , Huang J. C. C. , Robinson J.
Published: February 2010

Bdellovibrio bacteriovorus, strain 6-5-S, multiplied in the presence of washed suspensions of Escherichia coli, Spirillum serpens VHL, and Bacillus megaterium which had been autoclaved for 5 min at 121C. No intracellular life cycle was observed. Bdellovibrio bacteriovorus was also able to multiply in an extract from autoclaved E. coli cells after the cells had been removed by centrifugation. Growth of the parasite was dependent upon the addition of Ca2+ and Mg2+ to the buffer solution. The growth rate and yield of B. bacteriovorus on autoclaved cells were not affected by the initial concentration of the parasite. During multiplication of B. bacteriovorus, amino acids, amino sugars, and reducing sugars were released into the culture fluid.
Photosensitization of Paramecia by aflatoxin
Authors: Smith Robert C. , Neely William C.
Published: February 2010

Cultures of Paramecium caudatum or P. multimicronucleatum incubated with aflatoxin were killed when irradiated with light of wavelength 366 nm. Cultures incubated either with aflatoxin in the dark or in the light with no aflatoxin were not affected.
Etudes sur l'action anti-interféron des extraits de cellules transformées par le virus SV40
Authors: Brodeur B. , Légaré C. , Brailovsky C. A.
Published: February 2010

From extracts of a hamster cell line transformed by the Simian virus 40, we have shown the presence of a factor that stimulates the replication of K virus and also counteracts the mechanism of action of interferon. The sensitivity of this factor to a proteolytic enzyme is a possible indication that we are dealing with a protein. This "stimulon" is unrelated to the T antigen as shown by chromatography on Sephadex G-100 and by complement fixation test. Furthermore, at 56 °C, all direct effects on virus K replication are lost but the anti-interferon activity is preserved.
Metabolism of nitrate in Achromobacter fischeri
Authors: Prakash Om , Sadana J. C.
Published: February 2010

The relationships between the nitrate, nitrite, and oxygen respiratory pathways in Achromobacter fischeri have been studied. The formation of both nitrate and nitrite reductases is inhibited by oxygen. Nitrate and nitrite reductions by the growing cells occur only when the respiratory enzymes are not saturated with oxygen. Nitrite reduction also does not occur so long as there is nitrate in the growth medium. Nitrate is reduced to nitrite which is then reduced to ammonia. The reduction of nitrite with NADH or NADPH requires two enzymes: (a) NAD(P)H – flavin reductase, (b) nitrite reductase, plus the necessary participation of flavin as electron carrier. NAD(P)H – flavin reductase is required only to transfer electrons from NADH or NADPH to flavin, which then transfers electrons to nitrite reductase. The nitrite reductase from A. fischeri is nonspecific with respect to electron donor since it can use either FMNH2 or FADH2. The flavin reductase is also nonspecific with respect to electron donor as it can use both NADH and NADPH.Nitrate metabolism in A. fischeri is unique in that the product of nitrate metabolism is ammonia, but it resembles the respiratory type in other respects.
Effect of acetohydroxamic acid on growth and volatile fatty acid production by rumen bacteria
Authors: Chan Catherine C.-L. , Jones G. A.
Published: February 2010

Six strains of anaerobic rumen bacteria were grown in a rumen fluid medium containing different concentrations of the urease inhibitor, acetohydroxamic acid. Bacteroides succinogenes S85 failed to grow in the presence of 1 × 10−2 M acetohydroxamic acid whereas growth by Selenomonas ruminantium GA192 was not affected when the initial concentration was 5 × 10−2 M. In cultures of the remaining strains, acetohydroxamic acid extended the lag phase without changing the growth rate in the log phase. The order of decreasing overall sensitivity to acetohydroxamic acid by the strains in terms of growth was Bacteroides succinogenes S85 [Formula: see text]Bacteroides ruminicola 23 > Butyrivibrio fibrisolvens D1 ≥ Butyrivibrio sp. C3 > Megasphaera (Peptostreptococcus) elsdenii B159 > Selenomonas ruminantium GA192. Washed cell suspensions of Butyrivibrio fibrisolvens D1, Megasphaera elsdenii B159, and Selenomonas ruminantium GA192, but of none of the other strains were capable of degrading acetohydroxamic acid. In the presence of 5 × 10−3 M acetohydroxamic acid, the extent of glucose, starch, and xylan fermentation by the strains was modified. The amounts and molar proportions of volatile fatty acids produced from these substrates were also changed. In Bacteroides ruminicola 23, the presence of acetohydroxamic acid resulted in an 89% reduction in glucose fermentation and a shift in volatile fatty acid production from propionate to acetate. Butyrivibrio fibrisolvens D1 and Butyrivibrio sp. C3 fermented more glucose, but less xylan, when acetohydroxamic acid was present; with glucose as substrate, volatile fatty acid production shifted markedly from n-butyrate to propionate. The results support the conclusion drawn from previous studies with the mixed rumen microbiota, that the potential effect of the compound upon rumen microbial activities in vivo is not limited to inhibition of urease activity.
Degradation of polychlorinated biphenyls by two species of Achromobacter
Authors: Ahmed M. , Focht D. D.
Published: February 2010

Two species of Achromobacter were isolated from sewage effluent using biphenyl (BP) and p-chlorobiphenyl (pCB) respectively as sole carbon sources. Achromobacter BP grown on biphenyl accumulated a product with an ultraviolet absorption maximum at 257 nm which could not be identified. Washed cell suspensions of both isolates oxidized biphenyl, o-phenylphenol, phenylpyruvate, catechol, p-chlorobiphenyl, m-chlorobiphenyl, o-chlorobiphenyl, o,o′-dichlorobiphenyl, and p,p′-dichlorobiphenyl. Both isolates produced meta cleavage products by fission of the benzene ring. However, spectral characteristics of degradation products from respective substrates were different between the two isolates, indicating divergent degradation pathways. Benzoic and p-chlorobenzoic acids were produced from the degradation of BP and pCB, respectively, by Achromobacter pCB. Chloride was not produced by either isolate during the degradation of all chlorobiphenyls tested including the growth of Achromobacter pCB on p-chlorobiphenyl.
Studies on the immunogenicity of virus-infected lymphocytes for the production of antilymphocyte serum
Authors: Rossier E.
Published: February 2010

The possibility of enhancing the immunogenicity of human lymphoid cells by infection with vesicular stomatitis virus (V.S.V.) was investigated. V.S.V. infected, purified peripheral human lymphocytes, as well as lymphoblastic cells from the R.P.M.I. series 1788 and 7249, were used to raise antilymphocyte sera in rabbits. The sera were then tested for cytotoxicity and viral neutralization.As compared with uninfected, control lymphoid cells, V.S.V. infection did not enhance the immunogenicity of either type of lymphoid cells. Furthermore, there was no correlation between cytotoxicity and neutralization titers.
Physiological and biochemical properties of the exudate associated with developing sclerotia of Sclerotinia sclerotiorum (Lib.) DeBary
Authors: Colotelo Nicholas
Published: February 2010

Physiological and biochemical properties of the liquid exuded from developing sclerotia of Sclerotinia sclerotiorum were studied. In aging cultures the weight of dry matter, total proteins, free ammonia, crude lipid, potassium, and magnesium decreased, whereas sodium and the pH of the liquid increased. In general, the free amino acids decreased. Specific activities of catalase, peroxidase, polyphenoloxidase, and β-glucosidase did not follow similar trends. Catalase and β-glucosidase activities were high during the pigmentation phase of sclerotia development. Trehalase activity was not detected. Disc-gel electrophoretic patterns for proteins, peroxidases, and polyphenoloxidases are shown. Alpha-ketoglutaric, glyoxylic, malic, and succinic acids were detected. An hypothesis to account for the presence of large drops of liquid on the surface of developing sclerotia is proposed.
Biosynthesis of branched long-chain fatty acids from the related short-chain α-keto acid substrates by a cell-free system of Bacillus subtilis
Authors: Kaneda Toshi
Published: February 2010

The biosynthesis of branched-chain fatty acids by cell-free extracts of Bacillus subtilis has been studied.The extract of B. subtilis requires α-ketoisovalerate, DPNH, malonyl CoA, TPNH, and dithiothreitol for the synthesis of 14-methylpentadecanoic acid (major acid). Concentrations of α-ketoisovalerate, malonyl CoA, and TPNH giving half maximum activity are 2 μM, 6 μM, and 250 μM, respectively. Relative activity of three α-keto acids, α-ketoisovalerate, α-ketoisocaproate, and L-α-keto-β-methylvalerate for the fatty acid synthesis is in the ratio of 1/2.4/5.3.The B. subtilis extract can be divided into a heat-labile enzyme fraction and a heat-stable fraction, both of which are essential for the synthesis. The enzyme is soluble; all the activity remains in the supernatant when this fraction is treated by ultracentrifugation. The heat-stable factor can be replaced by a similar fraction from an extract of Escherichia coli. The amount in a crude extract of B. subtilis is, however, insufficient to give the full activity to the enzyme fraction.The B. subtilis system incorporates isobutyryl CoA into fatty acids, but not acetyl CoA. The reverse is true of E. coli. Hence the absence of branched-chain acids in E. coli is due both to the lack of α-ketoisovalerate dehydrogenase and to the substrate specificity of the enzyme toward CoA esters.
On the mycophage of Penicillium chrysogenum
Authors: Nash C. H. , Douthart R. J. , Ellis L. F. , Frank R. M. Van , Burnett J. P. , Lemke P. A.
Published: February 2010

A mycovirus has been purified from mycelia of Penicillium chrysogenum by isopycnic centrifugation in sucrose and in CsCl. Viral particles band with a buoyant density of 1.20 in sucrose and 1.38 in CsCl. Particles have icosohedral symmetry, are 35 nm in diameter, and have an absorption profile characteristic of nucleoprotein. One enzymatic activity, RNA polymerase, is associated with the purified mycophage. Nucleic acid extracted from purified virus has a buoyant density in CS2SO4 of 1.61, a molar extinction coefficient of εp (258 nm) of 7200, a s20, w of 13.0, and a pattern of circular dichroism characteristic of double-helical ribonucleic acid. Molecules of this double-stranded ribonucleic acid (dsRNA), examined by electron microscopy, have a mean contour length of 0.86 μm which corresponds to a molecular weight of about 2.0 × 106 daltons. This dsRNA is resolved further by acrylamide gel electrophoresis into three closely spaced bands. Thermal denaturation of the viral dsRNA is dependent on ionic strength and gives a linear relationship with the negative logarithm of the sodium ion concentration.
Gene order in species of Staphylococcus
Authors: Altenbern Robert A.
Published: February 2010

The map order of several genes on the chromosome of Staphylococcus aureus, S. epidermidis, S. muscae, and S. lactis has been determined, revealing few significant differences. In contrast, ratios of the total number of mutants induced in various genes have demonstrated appreciable differences among these four organisms. Such ratios may be a useful taxonomic tool for comparing deoxynucleotide structure of a functionally similar gene in various strains and species.
Protease production by thermophilic fungi
Authors: Ong Poh Seng , Gaucher G. Maurice
Published: February 2010

Submerged cultures of 10 thermophilic fungi, grown at 45° in a medium containing 4% casein, 0.4% glucose, 0.3% yeast extract and salts, were surveyed for extra- and intra-cellular protease production. The yield, thermostability, pH optimum, and inhibitor sensitivity of the crude proteases were determined in each case. The inhibitors used were diisopropylfluorophosphate (DFP), ethylenediaminetetraacetic acid (EDTA), and p-chloromercuribenzoate (pCMB).Seven of the thermophiles produced a substantial quantity of protease, particularly extracellular protease. In comparison to mesophilic fungi most proteases appeared to be unusually thermostable. Neutral and alkaline proteases were most common, as were proteases inhibited by DFP and pCMB. Finally in most of the cases a sensitivity to more than one inhibitor indicated the existence of more than one type of protease.