[Genetic control of the destruction of surface-active agents].

Degradation of anionic, cationic, and zwitterionic surfactants, such as alkylbenzene sulfonate, ethonium, amidobetaine, and alkylaminobispropionate, by pseudomonads can be controlled by plasmid genes. The majority of plasmids of surfactant-degrading strains are capable of conjugal transfer.

[Plasmid determined degradation of sulfo-aromatic compounds by Pseudomonas sp. BS1304].

Utilized sulfo-aromatic compounds of Pseudomonas sp. BS1304 were isolated. It was shown that the first step of conversion is desulfonation with following meta-cleavage of the substituted aromatic ring.

[Preparation and analysis of mutants of rhizospheric pseudomonads, resistant to toxic analogs of tryptophan and phenylalanine].

The absence of plasmids in strains of fluorescent pseudomonads characterized by high level of synthesis of phytohormone indole-3-acetic acid (IAA) as well as invariability of this feature in plasmid and non-plasmid variants of strain BSP8 suggests chromosomal control of IAA synthesis by the rhizosphere bacteria tested. Using toxic analogues of aromatic amino acids -5-fluorine-tryptophan and 5-methyl-tryptophan variants were obtained which synthesized and secreted only anthranilic acid. Mutants with resistance to p-fluorine-phenylalanine and capable of secreting tryptophan and/or phenylalanine were found.

[Analysis of the conjugation system of plasmid pBS1001 with a broad range of hosts].

Tn5-induced tra mutations were localized on the physical map of a broad host range plasmid pBS1001. Mutations were united into three clusters covering 25% of plasmid DNA. They were distributed in 7 groups by complementation analysis.

[Localization in Escherichia coli of transcribed regions of the broad host range plasmid pBS222].

The set of insertions of the CmR-gene region devoid of the promoter into the broad host-range plasmid pBS222 regions transcribed in Escherichia coli cells has been obtained and characterized. Three transcribed regions of the plasmid that are dispensable for life functions of the plasmid have been identified by the insertions technique. The deleted plasmid derivatives have been isolated suitable for using as the broad host-range vectors.