Kushkina A. Lysogenic pathway of temperate bacteriophage ZF40 of Erwinia carotovora

For the first time the structure of genomic c-region of temperate bacteriophage ZF40 Е. сarotovora (Ecc) was characterized. That phage genomic c-module has 4 cistrons. The system of sensible indicator strains for study of phage ZF40 lysogenic development was elaborated. The prophage ZF40 functional organization which included its immunity and inducibility was described. Lysogens of E. carotovora, which take in boarders the phage and its clear-mutants, have a superimmunity. Such status is manifesting in steadiness to the infection not only to homoimmunity phages, but to virulent mutants also. The obtaining of the virulent mutants of the phage ZF40 is possible when special lysogenic variants are used. The phage ZF40 generates two types of lysogens, which differed by the level of spontaneous and lysogenic induction. Availability of carbon sources influences on the phage burst. The prophage ZF40 results in destabilization of the defective lysogeny of Ecc . For the first time the pathogenicity lysogenic conversion of Ecc by the temperate bacteriophage ZF40 was discovered. The prophage ZF40 results in recovering of pathogenicity and in increasing of pectolitic activity in low-virulent strains-derivate Есс 62A-d1 cells.