[Selection and properties of totally phage-resistant mutant Pseudomonas putida PpG1].

The efficiency of using bacteria in open systems to degrade different anthropogenic toxic pollutants can depend strongly on the interaction between these bacteria and natural bacteriophages. The possibility of selecting bacterial Pseudomonas putida mutants resistant to all bacteriophages of this species known so far was tested (in our work, these mutants were designated totally phage-resistant mutants). In a model experiment, changes in the composition of a population upon prolonged growth of bacteria in the presence of one of the virulent phages were examined.

[Phage-stable mutants of Pseudomonas putida: new types of stability].

More than 170 phage-resistant mutants (PRM) of the first order of Pseudomonas putida strain PpG1 were obtained using newly isolated and previously described bacteriophages specific for this strain. According to the results of analysis of resistance of the mutants to each of 31 phages of PpG1 strain and 8 phages of the PpN strain, the PRM strains were distributed into 20 groups. In most cases, the reason for resistance is loss of absorption capacity of bacteria.

[Study of morphology and genome structure of Pseudomonas putida bacteriophages for their classification].

A group of 27 bacteriophages specific for Pseudomonas putida strains PpG1 and PpN has been isolated. The phages were characterized and compared with the previously described virulent (pf 16, af, tf and PMW) and temperate (PP56 and PP71) phages. The new phages belong to B1 and C1 morphotypes, according to Ackerman's classification.

[Isolation and comparative characteristics of 2 unrelated temperate phages of Pseudomonas putida PpG1].

Two temperate bacteriophages, PP56 and PP71, specific for bacteria of Pseudomonas putida strain PpG1 have been isolated for the first time. Characterization of the phages was performed. Both of them accomplish stable lysogenization of P.