摘要:

The degree of competence for uptake of deoxyribonucleic acid (DNA uptake) of the Challis streptococcus was found to be strictly related to the concentration of cell-bound competence-provoking factor (CPF). Antibodies against competent cells and antibodies against crude concentrates of CPF inhibited DNA uptake by competent cells. Both types of antibodies interacted also with soluble CPF and reduced its capacity to induce competence. Two characteristic features of competent streptococci were revealed: high precipitability at low pH's and a reduced capacity to absorb methylene blue.

ISSN:0008-4166    

DOI:10.1139/m70-061

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Features of 378 clinical isolates of saccharolytic, nonfermentative Gram-negative rods and 20 reference strains were examined. All but four of the clinical strains were assigned to recognized taxa, namelyAcinetobacter,Chromobacterium,Flavobacterium,Pseudomonas aeruginosa,Pseudomonas fluorescens,Pseudomonas maltophilia,Pseudomonas multivorans,Pseudomonas putida,Pseudomonas stutzeri, andXanthomonas.

ISSN:0008-4166    

DOI:10.1139/m70-062

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Aspergillusspecies (UC4177) accumulated mannitol from glucose substrate and it also used mannitol as the sole carbon source. Experiment with radioactive mannitol showed that the accumulation of mannitol and the oxidation of mannitol to CO2proceeded simultaneously. The presence of glucose in the medium did not inhibit mannitol oxidation. Mannitol was oxidized at about 25% of the metabolic rate of glucose. The rate of mannitol oxidation and several of the enzymes directly involved in mannitol metabolism were unaffected by using glucose or mannitol as the sole source of carbon. Nine enzymes of glucose metabolism were tested and none appeared to limit the rate of glucose oxidation.Aspergillusphosphofructokinase was not inhibited by 2.4 mMATP or 10 mMcitrate. Possible enzymatic defects favoring mannitol accumulation were not found.

ISSN:0008-4166    

DOI:10.1139/m70-063

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

3′,4′-Dichloropropionanilide; its biodegradation products 3,4-dichloroaniline and 3,3′,4,4′-tetrachloroazobenzene; and related chloroaniline and chlorobenzenes were tested for effects on the back mutation frequency of themeth3locus inAspergillus nidulans. 3,4-Dichloroaniline was more mutagenic than 3,3′,4,4′-tetrachloroazobenzene and 3′,4′-dichloropropionanilide. Chlorine in the para position on benzene ring increased mutagenicity more than chlorine in the meta or ortho position. Chloroaniline was more mutagenic than the corresponding dichlorobenzene.

ISSN:0008-4166    

DOI:10.1139/m70-064

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The number of bacteria in sediment from an estuarine environment, salinity 20–25‰, in Cape Breton Island, Nova Scotia, was determined by membrane filter counts from 73 fresh (on board ship) and 67 frozen (in laboratory) samples from 20 stations and the results compared. Taylor's model (log variance = a + blog mean) was used to determine dispersion on filters and normalizing transformations in preference to aligning data with Poisson expectation via Fisher's χ2test. Mean with 95%colonies per gram dry sedimentfrom fresh samples. Variance between replicate filters was negligible. Most remaining variance was between samples. Conversion of counts to weight basis introduced negligible variance. Counts from frozen samples were less variable than those from fresh samples. Fresh and frozen counts correlated well after transformation. Freezing confirmed as a method of preserving sediment for bacterial counts. Distribution in sediment of bacteria detected by these counts was slightly overdispersed (aggregated). Chromogenic colonies were prominent in the counted flora and their significance is discussed.

ISSN:0008-4166    

DOI:10.1139/m70-065

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Sarcomas were induced in the subcutis of hamsters by a respiratory-associated (RA) canine adenovirus, A26/61. The tumors were transplantable in vivo and retained their oncogenic properties after in vitro cultivation. Hamsters bearing RA-induced tumors developed complement-fixing antibodies against T antigens prepared in cell culture. The sera reacted to a lesser degree with T antigens induced by infectious canine hepatitis (ICH) virus, but not with those induced by an unrelated simian adenovirus.

ISSN:0008-4166    

DOI:10.1139/m70-066

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Six apyocyanogenic strains ofPseudomonas aeruginosawere shown to be capable of degrading pyocyanine under conditions normally conducive to pigment formation.P.aeruginosaB-275 was shown to metabolize pyocyanine to the extent that it was no longer chloroform extractable by following the fate of14C-labeled pyocyanine. Also,P.aeruginosaB-275, an apyocyanogenic strain, was found capable of producing pyocyanine by the dilution of radioactivity in undegraded14C-labeled pigment.

ISSN:0008-4166    

DOI:10.1139/m70-067

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Enterobacter aerogeneswas examined for its ability to utilize a known lathyrogen or chemically related compounds for use in developing an in vitro model system to study experimental lathyrism.Enterobacter aerogenesgrew in a minimal medium containing the lathyrogen, beta-aminopropionitrile fumarate. Related compounds or combinations of related compounds which together contained all the constituents of the lathyrogen failed to support growth. The specificity of this compound in supporting growth of this polysaccharide-producing microorganism suggests that this microorganism may be useful in developing an in vitro model system to study polysaccharide metabolism in experimental lathyrism.

ISSN:0008-4166    

DOI:10.1139/m70-068

出版商:NRC Research Press    

年代:1970

数据来源: NRC