PECTOBACTERIUM CAROTOVORUM SUBSP.CAROTOVORUM LOW-MOLECULAR-WEIGHT CAROTOVORICINS

Abstract

The aim was studying of properties of low-molecular-weight bacteriocins of Pectobacterium carotovorum subsp. carotovorum B4. Methods. Low-molecularweight bacteriocins were obtained from 13 Pectobacterium carotovorum strains by nalidixic acid induction, concentrated by salting-out with ammonium sulphate, separated by ultracentrifugation, additional purification was carried out at DEAE-sepharose. The activity of obtained bacteriocins was tested against Pectobacterium carotovorum 66А, as well as Escherichia coli BЕ, K12 and C600. Molecular mass was determined and serologic relationships with pyocins of S1-S5-type were checked for the researched substances. Results. The obtained lowmolecular-weight carotovoricins differed in level and spectrum of killer activity against indicator strains, but the highest activity was against Escherichia coli BЕ. It was shown that proteins of 30, 38, 42 and 54 kDa were the parts of summary fraction of Pectobacterium carotovorum subsp. carotovorum B4 carotovoricins. After further purification a single active component with molecular mass of 54 kDa was isolated. This protein was characterized by narrow pectrum of killer activity and influenced only on Escherichia coli BЕ. Checking of homology of the researched carotovoricin and pyocins of S1-S5-type indicated the absence of serologic relationships. Conclusions. According to revealed properties, Pectobacterium carotovorum subsp. carotovorum B4 carotovoricin with molecular mass of 54 kDa doesn’t conform to the characteristics of any described bacteriocins and can be a member of new low-molecular-weight carotovoricins. The absence of serologic relationships with low-molecular-weight pyocins of S-type and activity against only Escherichia coli BЕ can indicate the homology of this protein and colicins.

Keywords

• pectobacterium carotovorum
• низькомолекулярні каротоворицини
• серологічна спорідненість
• піоцини
• коліцини