Balko O. Structural and functional organization of carotovoricins and their role in bacterial antagonism

The thesis is dedicated to investigation of biological, physical-chemical, lytic and nuclease properties of different types of Erwinia carotovora bacteriocins, features of their lysogenic induction, isolation and killer action as well as polypeptide composition studying, structural organization and the role of the presented killer factors in antagonism processes between bacteria. In the model experiments it was shown that in the process of interbacterial antagonism bacteriocins play an important role. Lysogenic induction of E. carotovora is resulting to formation of three types of carotovoricins: macromolecular killers of types В and К and colicin-like killers of type С. The process of carotovoricins excretion possesses the wavelike nature. Colicin-like carotovoricins influence especially on closely related strains of E. carotovora, associated with non-specific endonuclease activity, which increases their killer action by the help of bacteriophage lysogenic induction. Macromolecular carotovoricins arecharacterized by a broad spectrum of killing action and lyse E. carotovora and Escherichia coli strains. High-molecular-weight carotovoricins contain of 7 polypeptides - three major (23, 25, 46 kDa) and four minor (31, 54, 58, 91 kDa). Colicin-like carotovoricins consist of the only one major polypeptide (54 kDa).