[Mechanisms of protective action of bacterial intracellular metabolites for lowering of bactericidal effect of hydroxyl radicals].

ABSTRACT

AIM: To study mechanisms of attenuation of bactericidal effect of hydroxyl radicals by bacterial intracellular metabolites. MATERIALS AND METHODS: Culture liquids of 16 strains of Lactobacillus spp., 21 strains of Corynebacterium spp., 8 strains of Micrococcus spp. and 17 strains of Staphylococcus spp. and fractions obtained from them were used. Bactericidal effect of hydroxyl radicals on Escherichia coli was measured by survival of the bacteria. RESULTS: High prevalence of ability of bacteria to prevent other microorganisms from bactericidal action of hydroxyl radicals produced in Fenton's reaction was revealed. This effect was accompanied by other two ability to oxidize Fe2+ in Fe3+ and production of substances with antioxidant properties - extracellular polysaccharides, pigments and lipid-containing compounds. CONCLUSION: It was assumed that defense of microorganisms composing microbiocenosis from toxic effect of hydroxyl radicals realizes through production of bacterial metabolites which inactivate hydroxyl radicals or prevent their formation.