[Effect of corrosion inhibitor on adhesion of sulfate-reducing bacteria to steel and their production of exopolymer complex].

It was shown in the laboratory investigations that the cells of sulphate-reducing bacteria of both aggressive Desulfovibrio sp. strain Kiev-10 and nonaggressive Desulfovibrio desulfuricans strain Kiev-45 strains can produce exopolysaccharides (EPS). Plankton (freely floating) cells of sulphate-reducing bacteria produce greater quantity of EPS than the cells of the biofilm formed on steel. The inducing effect of metal on EPS synthesis by sulphate-reducing bacteria has been established. The content of carbohydrates in EPS is higher in the biofilm of aggressive strain Desulfovibrio sp. Kiev-10 than in plankton bacteria as well as compared with the biofilm of less aggressive strain Desulfovibrio desulfuricans Kiev-45. Specific production of EPS of the aggressive strain in the biofilm formed on the steel is 3 orders higher than in the plankton cells. It has been established that the quantity of cells of sulphate-reducing bacteria adhered to steel decreases in the presence of the corrosion inhibitor N-decylpyridinium chloride (high-molecular compound of nitrogen-including PAR of the cationic type). It is shown that EPS synthesis is blocked in the biofilm formed by sulphate-reducing bacteria on steel under the effect of the corrosion inhibitor, while EPS production in plankton is stimulated.