[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. putida PpG1 cells. The phages are inducible. Several groups of clear plaque (c) mutants of PP56 and PP71 with altered processes of establishment and maintenance of lysogenic state have been isolated, according to complementation test. The phages differ in following characters: 1) in morphology of mature phage particles (C and B types, according to Bradley classification); 2) in sizes and genome organizations: DNA of PP56 is permuted (up to 30%), its size is 45 kb, the size of terminal redundancy being 2.5 kb; there is no permutation in PP71 DNA of 48 kb and it has "cohesive" ends; 3) no DNA/DNA homology is shown in tests between PP56 and PP71 DNAs. All the data obtained permitted to consider the phages PP56 and PP71 to belong to different unrelated species (families).