RESUMO
The composition of intracellular soluble proteins in a parental strain of Mycobacterium "rubrum" and its mutants was studied by polyacrylamide gel gradient electrophoresis. The composition of the protein fractions of the parental and the mutant strains was similar, they differed in one protein only. The presence of a 60 kDa protein should be stressed since its increased amount may be connected with a different intensity of the production of pigments in the strains studied.
Assuntos
Proteínas de Bactérias/química , Mutação , Mycobacterium/química , Proteínas de Bactérias/genética , Extratos Celulares/análise , Mycobacterium/genéticaRESUMO
Mutant strains of Mycobacterium sp. V-649 producing highly mucous colonies on a solid cultivation medium were prepared after treatment with N-methyl-N'-nitro-N-nitrosoguanidine and production of the exocellular polysaccharide was tested. The strains were cultivated in media with suitable sugar sources under submerged conditions. It was found that Mycobacterium sp. V-649/15 produces a maximum of 15-19% polymer after a 5-6-d cultivation. Gas chromatography indicated that the exocellular polysaccharide produced by this strain is of glucan type.
Assuntos
Mycobacterium/metabolismo , Polissacarídeos Bacterianos/biossíntese , Cromatografia Gasosa , Meios de Cultura , Mutação , Mycobacterium/genética , Mycobacterium/crescimento & desenvolvimento , Polissacarídeos Bacterianos/químicaRESUMO
It is generally assumed that genetic research of mycobacteria is delayed as compared with other, more commonly used, bacterial models, particularly in the field of genetic transfers. In the field of mutagenesis the problems have been studied to such an extent that replication maps of the chromosome of M. phlei and M. tuberculosis H37 Rv have already been constructed and a new model of the cell cycle of bacteria exhibiting a slow growth rate has been worked out. When the problems of mycobacterial genetics are looked upon in the light of gene manipulations it may be concluded that mycobacteria belong to a few models whose genes are used for cloning and that problems of practical significance will be studied by means of the most modern approaches.
Assuntos
Genética Microbiana , Mycobacterium/genéticaRESUMO
N-Methyl-N-nitrosourea was used to induce auxotrophic, scotochromogenic and isonicotinic acid hydrazide resistant mutants in Mycobacterium phlei and its effect was compared with that of nitrosoguanidine. Seventeen auxotrophic mutants requiring amino acids or vitamins and 52 scotochromogenic mutants with orange colonies were induced. The frequency of isonicotinic acid hydrazide-resistant mutants increased by two orders of magnitude.
