ISSN:0008-4166    

DOI:10.1139/m82-084

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

A new species ofSporopachydermiaRodrigues de Miranda has been isolated from exudates of red oaks (Quercus rubra). Morphologically, it resemblesS.cereanaby producing curved cells. Physiologically, it is closer toS.lactativora. It differs from both species by its lower maximum temperature of growth. The epithetquercuumis proposed to indicate its origin.

ISSN:0008-4166    

DOI:10.1139/m82-085

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

During the summer of 1979, indicator rabbits were placed in three sites in Entrelacs (Laurentian area, province of Quebec) and mosquitoes were collected in order to monitor arbovirus activity in the area. Eight seroconversions to California encephalitis (CE) group viruses were detected in rabbits during June, July, and August. Twenty-five strains identified as members of the CE group were isolated: 3 were obtained from viremic rabbit sera, 1 from adultAedes communisreared in the laboratory from field-collected larvae, and 21 from mosquito pools. Twenty-two of these were typed as snowshoe hare (SSH) virus. No evidence of La Crosse (LAC) virus was detected but three strains belonging to the CE group showed antigenic properties different from reference SSH, LAC, or Jamestown Canyon (JC) viruses. One isolate identified as Flanders virus was obtained fromCulex pipiens. Three mosquito species (A.communis,A.punctor, andA.excrucians) were involved in the transmission cycle of SSH virus in Entrelacs. This is the first report, in the province of Quebec, of SSH isolation from animal sera and the first demonstration of its transovarial transmission.

ISSN:0008-4166    

DOI:10.1139/m82-086

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

Fluctuation of bacterial population occurring in the three growth stages (young, old, and decaying) of the leaves ofPinus densifloraand in the air of the same pine forest was examined using the dilution plate method. The total count of bacteria isolates from the phylloplanes of pine was not high but seasonal fluctuations, particularly with respect to composition, were marked bacterial populations. Approximately 70% of the total isolates collected in 5 years was found to belong to the following four groups: pink chromogens,Bacillus,Flavobacterium, and coryneform bacteria. Among them, pink chromogens occurred abundantly on the living phylloplanes ofP.densifloraduring summer.Bacilluswas isolated from the various sources all year round. Coryneform bacteria occurred in the air of the pine forest throughout the year.Flavobacteriumwas observed in all sources, but not in high number.StaphylococcusandMicrococcuswere not detected on the phylloplanes in spite of their abundance in the air.

ISSN:0008-4166    

DOI:10.1139/m82-087

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

β-Glucosidase activity was induced inStreptomyces venezuelaeduring growth on cellobiose, gentiobiose, salicin, methyl β-glucoside, andp-nitrophenyl β-D-glucopyranoside. Activity in cell extracts was separated by DEAE-cellulose chromatography into two fractions differing in substrate preference. One component showed higher activity with, and was more strongly induced by, cellobiose; the other showed greater activity and inducibility with salicin. Addition of glucose to cultures severely depressed induction of β-glucosidase activity by cellobiose but not by salicin. Acetate and several amino acids inhibited induction by either substrate. The action of glucose was not reversed by cyclic AMP. Cultures ofS.venezuelaeusing glucose, cellobiose, or a mixture of the two saccharides as their carbon source produced chloramphenicol during growth. In contrast with its effect on the induction of cellobiase activity, glucose did not suppress chloramphenicol production, indicating that the control mechanisms that establish carbon source preferences are not linked to those that regulate antibiotic biosynthesis in this organism.

ISSN:0008-4166    

DOI:10.1139/m82-088

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

The production and activity of syringacin W-1, a particulate bacteriocin made byPseudomonas syringaePsW-1, was studied in plant tissue. The bacteriocin is rod shaped, approximately 20 nm wide and 75 nm long, and composed of an outer sheath and inner core. Both the producing strain, PsW-1, and a sensitive strain, 16, grew within red kidney bean stems. Strains PsW-1 and 16, or mutants derived from them, were injected into bean stems singly or in mixtures. All singly inoculated strains grew well. However, when the bacteriocin-producing strain was co-inoculated with the sensitive strain, the latter grew poorly, if at all. This was not due to competition for available nutrients, since the sensitive strain grew as well in the presence of a bacteriocin-nonproducing mutant as it did alone. Also, a bacteriocin-resistant mutant grew as well in the presence of the producing strain as it did alone. Bacteriocin activity and particles were recovered from infected plant tissue.

ISSN:0008-4166    

DOI:10.1139/m82-089

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

Actively growingZostera marinaplants had a greater rhizosphere inorganic phosphate solubilizing potential than dormant plants. Rhizosphere bacteria that were capable of calcium phosphate solubilization were obligate aerobes and numbered approximately 4 × 108colony-forming units/g dry weight root. Bacterial isolates solubilized calcium phosphate when cultured with glucose as the sole carbon and energy source but not when cultured with amino acids. Both calcium phosphate (hydroxyapatite) and glucose were found in sea grass bed sediment. Acetic acid was also detected from roots plus clinging sediment, from sediment, and from cultured bacterial isolates in a glucose-supplemented medium. The minimum concentration of acetic acid that showed detectable solubilization of calcium phosphate was 10−5 M. It is suggested that acetic acid, a product of glucose metabolism in the rhizosphere flora, is responsible for phosphate solubilization in the environment.

ISSN:0008-4166    

DOI:10.1139/m82-090

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

The mechanisms by which a number of alkylamines and ethylenediamine derivatives protect Vero cells from diphtheria toxin were studied. The protective alkylamines and ethylenediamine compounds blocked the cellular degradation of diphtheria toxin, but did not prevent bulk toxin uptake. Specific antibody neutralized the inhibitory effects of toxin on protein synthesis in amine-treated cells when added at 37 °C, but was ineffective when added at 4 °C. Analogous results were obtained when inositol hexaphosphate was used in the place of specific antibody. Both experiments suggested that, in the presence of the amine compounds studied, diphtheria toxin is sequestered intracellularly and is recycled to the surface for antibody or inositol hexaphosphate neutralization. Finally, it was shown that the protective amines markedly increased the intralysosomal pH of Vero cells and that when the pH of the culture medium was lowered to 4.5, the amine-mediated protective effect was bypassed. In general, the results suggest that the amines exert their protective effect at the level of some acidic intracellular vesicle population, possibly the lysosomes, and thus may indicate a crucial role for the lysosomes in the generation of cytotoxicity.

ISSN:0008-4166    

DOI:10.1139/m82-091

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

Production of lipids and lipase activity by a strain ofMucor hiemalisknown to have potential for high lipase activity was studied in a medium containing glucose as the carbon source. Most of the glucose was utilized by the end of the growth phase when the mycelium showed maximal lipase activity (17 U/g dry mycelium) as well as maximal lipid content (13 mg/g dr*** mycelium). Maximal broth lipase activity (76 U/100mL) was observed after cell lysis had begun. The fractions identified in the mycelial lipid extracts were sterol esters, triglycerides, fatty acids, diglycerides, sterols, monoglycerides, phosphatidylethanoamine, phosphatidylcholine, phosphatidylserine, and an unknown polar lipid. The proportion between the neutral and the polar lipids was only 0.06 at 44 h, increasing gradually to 1.51 at 164 h of fermentation. A relationship between the production of lipase and the neutral lipids appears to exist.

ISSN:0008-4166    

DOI:10.1139/m82-092

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

A comparison of the kinetics of [1−14C]leucine and [2-14C]uracil incorporation into germinating spores ofGlomus caledoniusshowed that RNA and protein synthesis had begun by 35 min after imbibition of water. Protein synthesis was essential for spore germination, and cycloheximide-sensitive protein synthesis occurred after the onset of germination. Early RNA synthesis was not affected by cycloheximide. Within 35 min of imbibition the tricarboxylic acid cycle, gluconeogenesis, and most amino acid biosynthetic pathways were operating.

ISSN:0008-4166    

DOI:10.1139/m82-093

出版商:NRC Research Press    

年代:1982

数据来源: NRC