[Biodiversity of sulfate-reducing bacteria growing on objects of heating systems].

It was shown that sulfate-reducing bacteria developed on the sections of Kyiv municipal heating systems, which are exploited in conditions of different temperatures. The bacteria were different as to their morphological and physiological properties. The bacteria of Desulfovibrio genus were revealed on the sections, which were exploited at a temperature of 35-40 degrees C and bacteria of Desulfomicrobium and Desulfotomaculum genera were revealed on the sections with a higher temperature such as 60 degrees C.

[Lectin-binding analysis of the biofilm exopolymeric matrix carbohydrate composition of corrosion-aggressive bacteria].

The carbohydrate components of biofilms of corrosion-aggressive bacteria were studied by transmisstion electron microscopy using lectins labeled with colloidal gold. N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, and neutral carbohydrates D-glucose and D-mannose were found within the exopolymeric matrix. Lectins with equal carbohydrate specificity demonstrated different degrees of interaction with the carbohydrate components of bacterial biofilms.

[Role of polymer complexes in the formation of biofilms by corrosive bacteria on steel surfaces].

The composition of exopolymer complexes (EPCs), synthesized by the monocultures Desulfovibrio sp. 10, Bacillus subtilis 36, and Pseudomonas aeruginosa 27 and by microbial associations involved in the corrosion of metal surfaces has been studied. An analysis of the monosaccharide composition of carbohydrate components, as well as the fatty acid composition of the lipid part of EPCs, was carried out by gas-liquid chromatography (GLC).

[Role of exopolymeric substances of corrosion-aggressive bacteria in the biofilm formation on the steel surface].

It had been done the comparative study of the exopolymeric substances (EPS) synthesized by the sulfidogenic microbial community and monocultures of Desulfovibrio sp. 10, Bacillus subtilis 36 and Pseudomonas aeruginosa 27 under various growth models as biofilm and plankton was performed. It was established that biofilm-produced exopolymers contained increased amount of glucose and fucose, while planktonic ones had more amount of mannose and rhamnose.

[Taxonomic position of certain representatives of sulphate-reducing corrosive microbial community].

Sulfate-reducing bacteria and their heterotrophic satellites have been isolated from the biofilm formed on steel by sulfidogenic corrosive microbial community. Bacteria were characterized according to phenotypical features and investigated by the methods of molecular-genetic analysis. In accordance with the phenotypical features the studied strain of sulfate-reducing bacteria were related to Desulfovibrio genus, Gram-positive strains of heterotrophic satellites were related to Bacillus genus, B.

[Development of mono- and associative cultures of sulphate-reducing bacteria and formation of exopolymeric complex].

Differences were found in development of the monoculture of sulphate-reducing bacteria Desulfovibrio sp. Kyiv-10 and artificial associations of cultures of sulphate reducing bacteria with heterotrophic satellites under development in a form of biofilm or plankton. Correlation between exopolymers synthesis in the biofilm and steel corrosion velocity has been found.

[Dynamics of successive changes in sulphidogenic microbial association under the conditions of formation of the biofilm on steel surface].

Dynamics of successive changes in the artificial associative culture of sulphate-reducing bacteria was investigated under biofilm formation on steel 3 specimens. It was shown that the ammonificating, denitrificating and iron-reducing bacteria were associative satellites of sulphate-reducing bacteria in the biofilm. Heterotrophic satellites ofsulphate-reductors with domination ofammonificating bacteria developed in the first hours of exposition in the microbial association.

[Effect of corrosion inhibitor on the producing of exopolymer complex by sulphate-reducing bacteria].

It is established that the specific productivity of exopolymer complex (EPM) synthesized by the cells of sulphate-reducing bacteria in a biofilm was 1.5 times higher than in plankton. A sharp increase of the specific productivity of EPM in the biofilm is observed when corrosion inhibitor is introduced in the environment.

[Adhesion of sulphate-reducing bacteria to steel under cathode polarization].

Adhesion of different (as to their corrosion aggression) strains of sulphate-reducing bacteria to steel has been studied under cathode polarization at various potentials: -800, -900, -1000, -1200 mV. It has been established that cathode polarization differently affects the adhesion of strain of sulphate-reducing bacteria with various aggression to steel. Correlation between the bacterial strains aggression and the number of cells adhered to metal have been noted.

[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.

[Stages of biofilm formation by sulfate-reducing bacteria].

Taxis to Fe3+ ions and adhesion to steel-3 of sulphate-reducing bacteria different by corrosion activity have been investigated. It has been shown that taxis activity of cells from the Postgate medium "B" was higher than from the buffer. Aggressive strains Desulfovibrio indonensis, Desulfovibrio sp.

[Effect of various anions on the rate of microbe-induced corrosion].

Experimental corroboration of correctness of theoretical thermodynamic calculations of e.m.f.