Characteristics of sulfate-reducing bacteria isolated from technogenic ecotopes

Abstract

The metabolic and corrosion activity of sulfate-reducing bacteria isolated from technogenic ecotopes was investigated. The sulfate-reducing bacteria had significant hydrogen sulfide production (representatives of Desulfovibriо genus had synthesized hydrogen sulfide up to 430±14–475±23 mg/L, Desulfotomaculum genus – 410±16–460±20 mg/L. Strain Desulfomicrobium sp. ТС4 had the highest production of this compound (485±24 mg/L). Investigated sulfate-reducing bacteria were corrosive-relevant. The most corrosive bacteria were isolated from soils near the surface of the gas main pipeline. Under the action of Desulfotomaculum sp. K1/3 and Desulfovibrio sp. K2/3 corrosion rates of the steel coupons were 0.1±0.004 and 0.09±0.0031 g/m2×hour, respectively at 5 exposition day. Under the action of Desulfotomaculum sp. ТС3 and Desul­fomicrobium sp. ТС4 strains isolated from heating systems corrosion rates were 0.086±0.0035 and 0.07±0.0021 g/m2×hour, respectively. Collection strain Desulfovibrio vulgaris 644 had the smallest corrosion rate (0.047±0.0023 g/m2×hour) among investigated bacteria from technogenic ecotopes. Corrosion rate is significantly increased to 0.081±0.0036 g/m2×hour during the exposition period. Correlation was noted between hydrogen sulfide production and corrosion activity of investigated sulfate-redu­cing bacterial strains.

Keywords

• sulfate-reducing bacteria
• hydrogen sulfide
• microbial corrosion
• corrosive aggressiveness