This review summarizes the main results obtained in the fields of general and molecular microbiology and microbial genetics at the Institute of Microbiology of the Academy of Sciences of the Czech Republic (AS CR) [formerly Czechoslovak Academy of Sciences (CAS)] over more than 50 years. Contribution of the founder of the Institute, academician Ivan Málek, to the introduction of these topics into the scientific program of the Institute of Microbiology and to further development of these studies is also included.

• MeSH
• Academies and Institutes history   MeSH
• History, 20th Century MeSH
• Genetics, Microbial history   MeSH
• Molecular Biology history   MeSH
• Check Tag
• History, 20th Century MeSH
• Publication type
• Journal Article MeSH
• Historical Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Geographicals
• Czech Republic MeSH

By second-step mutagenesis and treatment with N-methyl-N'-nitro-N-nitrosoguanidine a mutant strain of Mycobacterium sp. V-649 producing a glucan extracellular polymer and another new streptomycin-resistant mutant were prepared. This mutant strain formed more than 100% first-rate (1.0-1.2%) exocellular polysaccharide. Treatment with 1% dimethyl sulfoxide during submerged cultivation of the mutant strain did not increase the production of the extracellular polysaccharide.

• MeSH
• Drug Resistance, Microbial genetics   MeSH
• Polysaccharides, Bacterial biosynthesis   drug effects   MeSH
• Culture Media MeSH
• Methylnitronitrosoguanidine pharmacology   MeSH
• Mutation MeSH
• Mycobacterium genetics   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Polysaccharides, Bacterial MeSH
• Culture Media MeSH
• Methylnitronitrosoguanidine MeSH

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.

• MeSH
• Polysaccharides, Bacterial biosynthesis   chemistry   MeSH
• Chromatography, Gas MeSH
• Culture Media MeSH
• Mutation MeSH
• Mycobacterium genetics   growth & development   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Polysaccharides, Bacterial MeSH
• Culture Media MeSH

Inducible pigmentation changes were observed in pigmented strains of Brevibacterium sp. M27 and B. flavum treated with N-methyl-N'-nitro-N-nitrosoguanidine. The highest frequency of induction was reached already at a survival of 30-40% with the maximal yield of 6-10%. As compared with the initial yellow colour, three new pigmentation types, viz. white, pink and orange, were observed. The yellow pigmented parent strains are most resistant to the lethal effects of UV radiation. By selecting pigmented mutants of all types on media containing antibiotics it was possible to obtain strains that were resistant either to tetracycline or to streptomycin. Auxotrophic pigmented mutants were also isolated. In multiple mutant strains of Brevibacterium sp. M27 a number of strainsexhibited a changed L-lysine production. In some strains the production was variable, whereasother strains did not produce L-lysine at all and stains with a limited production of other amino acids were also detected.

• MeSH
• Pigments, Biological metabolism   MeSH
• Brevibacterium drug effects   metabolism   radiation effects   MeSH
• Species Specificity MeSH
• Kinetics MeSH
• Methylnitronitrosoguanidine pharmacology   MeSH
• Mutation * MeSH
• Ultraviolet Rays MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Pigments, Biological MeSH
• Methylnitronitrosoguanidine MeSH

• MeSH
• Histidine metabolism   MeSH
• Culture Media MeSH
• Methylnitronitrosoguanidine pharmacology   MeSH
• Mutation * MeSH
• Mycobacterium drug effects   genetics   metabolism   MeSH
• Vancomycin * pharmacology   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Histidine MeSH
• Culture Media MeSH
• Methylnitronitrosoguanidine MeSH
• Vancomycin * MeSH

New facts about the replication map of Mycobacterium phlei chromosome are summarized. Replication positions of two genes located in marginal regions of the replication map, ile close to the origin and ser near the terminus, were determined. Known positions of replication of some genes were defined with more precision within 2.5--5-min intervals using the method of sequential mutagenesis in synchronized cultures (leu, met, bac, pyr, stm, tet, cyc, his). Replication positions of genes responsible for the biosynthesis of thiamine and resistance to tetracycline and vancomycin were further identified. The contemporary replication map contains replication positions of 24 genes.

• MeSH
• Chromosomes, Bacterial * MeSH
• Genes * MeSH
• Chromosome Mapping MeSH
• Mycobacterium phlei genetics   ultrastructure   MeSH
• Mycobacterium genetics   MeSH
• DNA Replication MeSH
• Publication type
• Journal Article MeSH

• MeSH
• Hydrolysis MeSH
• Lacticaseibacillus casei drug effects   metabolism   MeSH
• Lactates biosynthesis   MeSH
• Methylnitronitrosoguanidine pharmacology   MeSH
• Mutagens * MeSH
• Proteins metabolism   MeSH
• Tyrosine metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Lactates MeSH
• Methylnitronitrosoguanidine MeSH
• Mutagens * MeSH
• Proteins MeSH
• Tyrosine MeSH

The aim of the present work was to construct a replication map of the chromosome of Mycobacterium phlei. The method of mutagenesis of the replication point by means of nitrosoguanidine was applied to synchronously multiplying populations. Back mutations and forward mutations were induced in auxotrophic mutants PA met and PA leu as well as in double auxotrophic mutants with methionine as the reference marker and the following order of replication of eleven genes on the chromosome was thus established: leu-Eth, Res-Stm, Cyk-pur-met, arg, Cyk-Bac-inl.

• MeSH
• Drug Resistance, Microbial MeSH
• Cell Division MeSH
• DNA, Bacterial biosynthesis   MeSH
• Genes MeSH
• Leucine biosynthesis   MeSH
• Chromosome Mapping * methods   MeSH
• Methionine biosynthesis   MeSH
• Methylnitronitrosoguanidine MeSH
• Mutation MeSH
• Mutagens MeSH
• Mycobacterium phlei * drug effects   growth & development   metabolism   MeSH
• Mycobacterium * MeSH
• DNA Replication MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• DNA, Bacterial MeSH
• Leucine MeSH
• Methionine MeSH
• Methylnitronitrosoguanidine MeSH
• Mutagens MeSH

• MeSH
• Time Factors MeSH
• Hydrogen-Ion Concentration MeSH
• Leucine metabolism   MeSH
• Methionine metabolism   MeSH
• Mutation * MeSH
• Mutagens * MeSH
• Mycobacterium drug effects   growth & development   metabolism   MeSH
• Nitrosoguanidines pharmacology   MeSH
• Cold Temperature MeSH
• Buffers MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Leucine MeSH
• Methionine MeSH
• Mutagens * MeSH
• Nitrosoguanidines MeSH
• Buffers MeSH

• MeSH
• Acridines pharmacology   MeSH
• Drug Resistance, Microbial MeSH
• Models, Biological MeSH
• Nitrites pharmacology   MeSH
• Guanidines pharmacology   MeSH
• Hydroxylamines pharmacology   MeSH
• Isoniazid pharmacology   MeSH
• Culture Media MeSH
• Sulfonic Acids pharmacology   MeSH
• Genetics, Microbial * MeSH
• Mutation * MeSH
• Mutagens MeSH
• Mycobacterium drug effects   growth & development   metabolism   radiation effects   MeSH
• Nitroso Compounds pharmacology   MeSH
• Pigmentation MeSH
• Selection, Genetic MeSH
• Streptomycin pharmacology   MeSH
• Ultraviolet Rays MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Acridines MeSH
• Nitrites MeSH
• Guanidines MeSH
• Hydroxylamines MeSH
• Isoniazid MeSH
• Culture Media MeSH
• Sulfonic Acids MeSH
• Mutagens MeSH
• Nitroso Compounds MeSH
• Streptomycin MeSH