[Pleiotropic effect of the rpoC mutation in Escherichia coli K-12 reducing the frequency of lysogenization by phage lambda].

We described earlier the isolation of lfl25 mutation reducing the frequency of lysogenization of mutant cells by phage lambda (LycA phenotype). The mutation is mapped at present in the rpoC gene coding for the beta' subunit of bacterial RNA polymerase and named rpoC90. It is dominant and causes decrease in pools of some branched amino acids, pyrimidines and thiamine (vitamin B1) in mutant cells.

[cAMP acceptor protein of Escherichia coli K-12 may be the repressor of the late promoter of bacteriophage lambda].

By computer analysis of the lambda phage DNA putative cAMP-CAP binding site has been found. This site (44506-AcgTGTGAccgcatTCAAAaT-44486) is located 40 bp upstream to the late PR' promoter. The sequence denoted is located on the coding DNA strand, similar to the cAMP-CAP binding sites in all four genes known to be subject to cAMP-CAP repression.

[Direct method of selecting LycA mutants of Escherichia coli K-12].

Lambdoid phage form clear plaques and show reduced ability to establish immunity in LycA mutants of Escherichia coli. This study was undertaken to isolate new LycA mutants. For this purpose, a selective method for isolation of LycA mutants was developed.

[An information-search system for micro-organism collection].

A search-information system has been developed which allows to keep and provide the needed information concerning collections of any microorganisms. The system contains up to 20 000 strains which can be characterized by 4000 properties. The system allows to find all strains corresponding to the given set of characters and also provides the information available for the strain required.