ISSN:0008-4166    

DOI:10.1139/m81-071

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Bacteroids were isolated from the nodules of soybean plants by means of self-generating Percoll density gradients. The entire procedure can be performed in less than 1 h using an ordinary refrigerated centrifuge and angle head rotor. All of the markers for cytosol and bacteroid fractions behaved in accord with other reports in the literature. Asparaginase, β-hydroxybutyrate dehydrogenase, and alanine dehydrogenase were all localized in the bacteroid fraction. Invertase, phosphoenolpyruvate carboxylase, and leghaemoglobin were all found in the cytosol fraction. Very little (< 7%) cross contamination between the fractions was observed. The isolated bacteroids were viable, and based on electron micrographs, were free from contaminating plant material. Since the entire procedure is performed isosmotically, very little damage to the bacteroids is likely to occur. No organic compounds, except Percoll, were added to the isolating media, thus aiding in the analysis of bacteroid and cytosol metabolites.

ISSN:0008-4166    

DOI:10.1139/m81-072

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

A new, narrow host range temperate phage, SV2, was isolated from soil. It lysogenized and lysed strains ofStreptomyces venezuelaeand seemed to be specific for this species. In general morphology, the virions were typically lambdoid, but had unusually ringed tails similar to those of some rare phages isolated from hosts belonging to different bacterial genera. The molecular weight of double-stranded linear SV2 DNA, estimated at about 24 × 106, was lower than the published values for otherStreptomycesphages.

ISSN:0008-4166    

DOI:10.1139/m81-073

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

An examination of shipments of aquarium species arriving in Canada over a 2-year period revealed that one-third of the shipments of aquarium snails and aquarium frogs were contaminated, withSalmonella.Salmonellawere also isolated from a shipment of aquarium newts but were not recovered from goldfish. Included among these salmonellae were four of the serovars most commonly associated with human salmonellosis in Canada. Several unusual salmonellae were also isolated including aSalmonella floridathat produced a delayed, weakly positiveo-nitrophenyl-β-D-galactosidase reaction, and a bacteriophage 14 lysogenizedSalmonella mbandaka. The association of salmonellae with aquarium species is clearly adding to the pool of this human pathogen in Canada, and may contribute to human infections.

ISSN:0008-4166    

DOI:10.1139/m81-074

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Halophilic protease in culture fluids of a moderately halophilic marinePseudomonassp. (A-14) was purified by ammonium sulfate precipitation, DEAE-cellulose chromatography, and gel filtration through Sephadex G-200. The enzyme was purified to homogeneity, as judged by polyacrylamide gel electrophoresis. The molecular weight of the enzyme was estimated to be 120 000. The optimum pH for activity was 8.0. The enzyme had maximal activity at 18% NaCl concentration. The enzyme was activated by Mg2+, Co2+, and Ca2+. Ca2+increased the heat stability, and heavy metal ions such as Fe2+, Cu2+, and Hg2+inactivated the enzyme. Thiol reagents and diisopropyl fluorophosphate did not affect the enzymatic activity of the protease. Metal-complexing reagents, such as ethylenediaminetetraacetic acid ando-phenanthroline, inhibited enzymatic activity, although citrate and oxalate did not affect it.

ISSN:0008-4166    

DOI:10.1139/m81-075

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

The reduction of acetylene and the production and oxidation of methane in a stream sediment–water system amended with either fresh leaves or autumn-shed leaves in the presence and absence of air were studied. Net methane production by the sediment–water system occurred only when leaf material was added, with fresh leaves giving 2.2 times the methane accumulation as autumn-shed leaves. Static incubation in the presence of air had little effect on net methane production, with such production being about the same as (with fresh leaves) or 79% of (with autumn-shed leaves) the anaerobic rates. Acetylene reduction was more affected by the presence of air, with anaerobic rates being at very low levels. The presence of fresh leaves was again stimulatory, with the acetylene reduction rate being 5.5-fold greater than that occurring with autumn-shed leaves.

ISSN:0008-4166    

DOI:10.1139/m81-076

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Bacteroides succinogenesS-85 grows readily in media containing 0.2% (w/v) filter paper cellulose or microcrystalline ellulose as the carbohydrate source. During growth, the cells appear to adhere to the cellulose. Cell-free culture supermates and ell extracts from cellulose-grown cultures had very low hydrolytic activity against either filter paper or crystalline cellulose Avicel) as substrate, although H3PO4-swollen cellulose, carboxymethylcellulose, and cellobiose were readily hydrolyzed. Cells rown on either cellobiose or glucose exhibited cell-bound carboxymethylcellulase (CMCase) and cellobiase activities. Cultures rown on cellulose had seven to eight times more CMCase activity than either cellobiose- or glucose-grown cultures. Seventy ercent of the CMCase activity was present in the supernate, of which 50–60% was associated with sedimentable membranous ragments. The cellobiase, which was largely cell associated, appeared to be constitutive, and the only product detected on nzymic hydrolysis of cellobiose was glucose. The cellobiase activity was strongly inhibited by 0.02 Mtris(hydroxymethyl)-minomethane (Tris), pH 7.1, but this was partially relieved by phosphate ions. These data indicate thatB.succinogenes-85 contains high endo-β-1,4-glucanase and β-1,4-glucosidase-like activities.

ISSN:0008-4166    

DOI:10.1139/m81-077

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Glutaraldehyde, the biological fixative of choice in the cytochemical localization of the phosphatases, was investigated for its effects onPseudomonas aeruginosaalkaline phosphatase. Comparative studies on the inactivation of alkaline phosphatase by glutaraldehyde showed significant differences when the purified protein was compared with whole, cell-bound enzyme.The effects of the reagent on the kinetics of the purified enzyme were studied and some conclusions drawn as to the mode of inactivation. The reaction of glutaraldehyde with the cell envelope ofP.aeruginosawas also investigated, and it was found not to modify the extraction of lipopolysaccharides from the outer membrane. This study emphasizes the care that must be taken to interpret data, cytochemical or otherwise, obtained when glutaraldehyde is used as a fixative or cross-linking reagent.

ISSN:0008-4166    

DOI:10.1139/m81-078

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

The developmental mode by which oospores ofPythium aphanidermatumgerminate may be controlled by the concentration of glucose present in the germination medium. When incubated in a liquid medium containing emulsified lecithin without added glucose (S + L), oospores germinated indirectly, with zoospore release occurring during the 10th to 13th h. A decrease in dry weight of the fungus took place by the 13th h of indirect germination. When 0.2 mMglucose was added to S + L, the dry weigh of germlings increased and direct germination occurred without zoospore formation. Polar lipid comprised the bulk of total acylglycerides of dormant oospores. A greater decrease in total fatty acid content took place during direct germination that during indirect germination. During both developmental modes of germination, polar lipid content decreased considerably neutral lipids, however, increased during indirect germination and decreased during direct germination. Protein content of the fungus increased in both developmental modes of germination, being initally 9.7% of the dry weight of dormant oospores. After 13 h of incubation, KOH-soluble polysaccharide decreased by 35% during direct germination and by 48% during indirect germination.

ISSN:0008-4166    

DOI:10.1139/m81-079

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Membrane-associated cytidine 5′-diphospho-1,2-diacyl-sn-glycerol:L-serineO-phosphatidyltransferase (EC 2.7.8.8) wa solubilized from the cell envelope fraction of the gram-positive anaerobeClostridium perfringenswith Triton X-100 Successful solubilization of the enzyme was dependent on the addition of manganese ions.

ISSN:0008-4166    

DOI:10.1139/m81-080

出版商:NRC Research Press    

年代:1981

数据来源: NRC