摘要:

The thermogenesis of 17 strains belonging to 12 species of the Enterobacteriaceae family was measured at 30 °C with an ampoule microcalorimeter. It was analyzed qualitatively (aspect of profiles) and quantitatively (total heat evolved, thermogenesis duration, maximum thermal power). The value of these criteria is discussed with respect to their discriminating value in the classification of bacteria. The information obtained may concur with the identification of species; it gives ground to reconsider actual phenotypes and genotypes and taxonomy generally. [Journal translation]

ISSN:0008-4166    

DOI:10.1139/m80-069

出版商:NRC Research Press    

年代:1980

数据来源: NRC

摘要:

An electron microscopic analysis ofBacillus subtiliscells revealed that netropsin blocked sporulation ultrastructurally at stages 0–I. These observations are consistent with previous results which indicated that cells were not committed to sporulation in the presence of the drug. Further, the addition of netropsin up to stage III of sporulation prevented the normal sharp increase in dihydrodipicolinate synthase activity which results in dipicolinic acid accumulation at stage IV. The addition of netropsin after stage III had much less effect on the synthesis of dihydrodipicolinate synthase and on sporulation. Thus, morphological events in sporulation are blocked early whereas a sporulation-associated enzyme may be affected at later stages. These data indicate that netropsin affects the expression of sporulation-associated genes in a differential manner.

ISSN:0008-4166    

DOI:10.1139/m80-070

出版商:NRC Research Press    

年代:1980

数据来源: NRC

摘要:

Bovine polymorphonuclear neutrophils (PMN) can mediate antibody-dependent cell cytotoxicity (ADCC) of herpes virus-infected cells. Since cytotoxicity occurs only in the presence of PMN and specific antiviral antibody, but not until viral membrane antigens are expressed on the target cell, it is concluded that antibody must recognize viral membrane antigens before cytotoxicity can occur. Cytotoxicity also requires very close contact between the target cell and the PMN cell. These interactions occur as early as 1 h after incubating antibody, infected cells, and PMN, but the actual lysis and release of intracellular components occur over an extended period. It was assumed that degranulation was not involved in the initiation of cytotoxicity, but was involved in the final stage of destruction. The mechanism of lysis is proposed to involve the interaction of PMN membranes with target cell membranes with subsequent reorganization and activation of the PMN plasma membrane at points of contact with the target cell. This results in possible production of transmembrane channels which allows for the release of target cell contents.

ISSN:0008-4166    

DOI:10.1139/m80-071

出版商:NRC Research Press    

年代:1980

数据来源: NRC

摘要:

Following the 1975 epidemic of St. Louis encephalitis (SLE) in Ontario, programs were instituted to monitor virus activity in mosquito populations during 1976 and 1977. Mosquitoes were trapped with CDC light traps and CO2cone traps, pooled by species, and tested for virus by intracerebral inoculation of suckling mice. In 1976, 51 175 mosquitoes were tested. SLE virus was isolated from two mixed pools ofCulex pipiens–C.restuansmosquitoes. Five isolations of California serogroup viruses were made. Three of these were trivittatus virus, which has not been demonstrated previously in Canada, and the other two were snowshoe hare virus. Other viruses isolated in 1976 were a virus antigenically identical to the virus of infectious bursal disease of chickens and 34 Flanders viruses. In 1977, 34 428 mosquitoes were tested. Flanders virus was isolated most frequently, from pools of mixedC.pipiens–C.restuansmosquitoes. The only other isolate was a Bunyamwera group virus, Cache Valley virus. This virus has not been reported previously in Ontario.

ISSN:0008-4166    

DOI:10.1139/m80-072

出版商:NRC Research Press    

年代:1980

数据来源: NRC

摘要:

Superoxide dismutase (SOD, EC 1.15.1.1) from nitrogen-fixingAzotobacter chroococcumwas purified and identified as being similar to the manganese SOD of other procaryotes. The enzyme was relatively thermostable and insensitive to cyanide. A molecular weight of approximately 33 000 was estimated. Superoxide dismutase was found to be cytoplasmic (not bound to cell membranes) inA.chroococcum, but some enzyme was released by sonication of membrane vesicles.

ISSN:0008-4166    

DOI:10.1139/m80-073

出版商:NRC Research Press    

年代:1980

数据来源: NRC

摘要:

Indole-3-propanoic acid (IPA), 3-(p-hydroxyphenyl)propanoic acid (HPPA), and 3-phenylpropanoic acid (PPA) were present in the spent bacterial media ofClostridium sporogenes(20/20 strains) andC.cylindrosporum(1/1 strains), but absent in 32 other clostridial species (74 strains) tested. Both IPA and HPPA (but not PPA) could be readily detected by thin-layer chromatography andp-hydroxybenzaldehyde spray reagent. IPA forms a scarlet complex withp-hydroxybenzaldehyde which shifts to purple and remains stable for up to 6 weeks. IPA can be detected in acidified extracts ofC.sporogenesby a simple spot test. The structures of IPA and HPPA were confirmed by nuclear magnetic resonance (nmr) and mass spectroscopy and their formation was detected by the absorbance at 280 nm. Addition of one of the precursor amino acids (L-tryptophan,L-tyrosine, orL-phenylalanine) to the medium greatly enhanced formation of the corresponding deaminated acid and depressed the formation of the other two acids. The products IPA, HPPA, and PPA, at 10−3M, and spent bacterial media were negative in the direct Ames's assay for mutagenicity and noncytotoxic towards MRC-S cells.

ISSN:0008-4166    

DOI:10.1139/m80-074

出版商:NRC Research Press    

年代:1980

数据来源: NRC

摘要:

The transport systems of the oligotrophic bacterium 486 forD-glucose andL-proline have been compared with those of the heterotrophic bacterium RP-303. Kinetic studies demonstrated that the rates ofD-glucose andL-proline uptake by the two organisms were saturable processes. The apparentKmvalues of strain 486 forD-glucose andL-proline were 13.0 μMand 0.2 μM, respectively, whereas those of strain RP-303 were 3.2 μMforD-glucose and 1.8 μMforL-proline. Competition studies indicated that theD-glucose transport system of each bacterium was highly specific forD-glucose. TheL-proline transport system of the oligotrophic bacterium 486 had a broad specificity, whereas that of the heterotrophic bacterium RP-303 had a narrow one.

ISSN:0008-4166    

DOI:10.1139/m80-075

出版商:NRC Research Press    

年代:1980

数据来源: NRC

摘要:

Pseudomonas maltophiliahas been identified in the rhizosphere of several cultured plants: cabbage, rape, mustard, corn, beet. In comparison with nonrhizospheric soil, all the rhizospheric samples analysed contain more of thisPseudomonasand the most important stimulation is supplied by cruciferous plants. The possible relation with greater amounts of sulphur-containing amino acids in root secretion is suggested.

ISSN:0008-4166    

DOI:10.1139/m80-076

出版商:NRC Research Press    

年代:1980

数据来源: NRC

摘要:

Eight strains of Chromatiaceae isolated from marine sediments are cultivated under light intensities of 50–5000 lx. A decrease in the light intensity brings about an increase in the specific bacteriochlorophyll content and also in the length of development. In certain strains, the increase in pigment contents partly compensates for the loss in light intensity, up to the maximum concentration of bacteriochlorophyll. This mechanism is only a physiological compatibility which ensures the survival of these organisms under feeble light intensities.

ISSN:0008-4166    

DOI:10.1139/m80-077

出版商:NRC Research Press    

年代:1980

数据来源: NRC

摘要:

Fifty-four strains ofNeisseria gonorrhoeaewere examined for their ability to be agglutinated by various lectins. Wheat germ agglutinin, ricin, soybean lectin, and peanut agglutinin agglutinated all strains tested.Dolichos biflorus,Sophora japonica,Maclura pomifera,Ulex europaeus,Lens culinaris,Canavalia ensiformis,Phaseolus lunatus, andBandeiraea simplicifoliaBS I and BS II lectins either failed to agglutinate or agglutinated some strains but not others. Agglutination of gonococci by wheat germ agglutinin, ricin, and soybean lectin is sugar specific and most effectively inhibited by ligands known to interact with lectin combining sites. Lectin reactive groupings appear to be independent of antigenic determinants conferring Gc serogroup specificity. Interactions with wheat germ agglutinin and ricin suggest the occurrence of multiple β-linkedN-acetyl-D-glucosamine (D-GlcNAc) and β-D-galactosyl (β-D-Gal) units as common structural features of gonococcal cell envelope polysaccharide. Interactions with soybean agglutinin, peanut agglutinin, andDolichos bifloruslectins suggest that α-N-acetyl-D-galactosamine (α-D-GalNAc) units and β-D-Gal linked to GalNAc and (or) GlcNAc may also occur as structural features of the polysaccharide components of the cell envelope of some gonococci.

ISSN:0008-4166    

DOI:10.1139/m80-078

出版商:NRC Research Press    

年代:1980

数据来源: NRC