Вurova L. Peculiarities of interaction of the temperate bacteriophage P1 of Escherichia coli with phytopathogenic bacteria of Erwinia genus

Peculiarities of interaction of phage P1 of Escherichia coli with phytopathogenic bacteria on the level of its lytic, transduction, lysogenic and recombination development were studied in this work. It was shown, that phage P1 was able to kill bacteria of genus Erwinia of groups "carotovora", "amylovora" and "herbicola", by provoking phage-by-phage induction. Phage-by-phage induction is tightly connected with pseudolysogenic state and is spreading not only on erwinias, but also on the laboratory strains of E. coli. In lysogenic cells of E. horticola P1-prophage expresses chloramphenicolacetyltransferase and restriction-modification genes EcoP1I. For the first time comparison of two heterologeous systems coliphage P1-Erwinia and carotovoricins of phage tail-like type-E. coli was held and physiological relation between them was shown. It was established, that phage P1 effectively transdused marker of chloramphenicol resistance to E. carotovora subsp. atroseptica cells. In the cells of transductants plasmid circular DNA is presented by the authentic prophage P1. Lysogen conversion, carried out by P1 prophage, is related with the survival of bacteria through the high temperatures of the environment. In this work for the first time the method of incorporation of Tn9 transposon into the endogenous plasmids of E. carotovora was proposed. The inheritance stability and the transposition specifity of Tn9 while its recombination with the phage P1 of E. coli are the peculiarities of the plasmid pCA25 of E. carotovora subsp. carotovora 48A. The results of the heterologeous system with participation of coliphage P1 research create the background for the direct transposon mutagenesis and detection of the pathogenic potential of the bacteria of Erwinia genus.