摘要:

A method is described for the rapid isolation of chromosomal deoxyribonucleic acid from species of the genusMycoplasma. The method involves incubation of washed cells at elevated temperature in the presence of an ionic detergent, chelating agents, and proteinase K prior to the removal of residual protein and ribonucleic acid with ribonuclease and chloroform. It results in a good yield of high molecular weight material that is shown to be free of endogenous nuclease and substantially free of protein or ribonucleic acid contamination without the use of phenol. The isolated DNA is shown to be an excellent substrate for restriction endonuclease digestion and ligation with T4 DNA ligase.Key words:Mycoplasma, DNA isolation, micromethod.

ISSN:0008-4166    

DOI:10.1139/m90-011

出版商:NRC Research Press    

年代:1990

数据来源: NRC

摘要:

A hundred strains ofSaccharomyces cerevisiaewere examined for the ability to produce higher alcohols. In the strains tested the production of higher alcohols was found to be an individual strain characteristic and, as such, was statistically significant. The characteristics of the strains used (flocculation ability, foaming ability, killer character, and non-H2S production) were found to be uncorrelated to isobutanol and isoamyl alcohol production, whereas the production of high levels ofn-propanol was found to be related to inability to produce H2S. This, in turn, suggests a link to methionine biosynthesis.Key words:Saccharomyces cerevisiae, higher alcohols, biometry, H2S production.

ISSN:0008-4166    

DOI:10.1139/m90-012

出版商:NRC Research Press    

年代:1990

数据来源: NRC

摘要:

Between October 1987 and June 1989, 84 isolates ofNeisseria gonorrhoeaecarrying theTetMresistance determinant (TRNG) were received at the Laboratory Centre for Disease Control, Ottawa, from six Canadian provinces and were characterized into classes based on auxotype, serovar and plasmid content. One-fifth (17/84) of the TRNG were also penicillinase producing (PPNG). The PPNG–TRNG isolates comprised six classes based on auxotype, serovar, and plasmid content. Most (16/17) PPNG–TRNG carried 3.2-MDa β-lactamase plasmids and the 25.2-MDaTetM-containing plasmid. We report, for the first time, the association of a 4.5-MDa β-lactamase plasmid with the 25.2-MDa plasmid in a clinical TRNG isolate. Non-PPNG TRNG isolates comprised 11 classes based on auxotype, serovar, and plasmid content, including two previously unreported auxotype–serovar classes, P/IB-26 and P/IB-20.Key words:Neisseria gonorrhoeae, tetracycline resistance, plasmid, epidemiology.

ISSN:0008-4166    

DOI:10.1139/m90-013

出版商:NRC Research Press    

年代:1990

数据来源: NRC