Dissimilatory sulfate reduction in bacteria Desulfovibrio desulfuricans under the influence of high concentrations of zinc chloride

Abstract

The capasity of the sulfate reducing bacteria Desulfovibrio desulfuricans ІМВ K-6 to grow at influence of zinc salts high concentrations was investigated. As known, heavy metals have inhibitory influence on the most microorganisms at the concentration 0.5–2.5 mM. The investigation of zinc chloride influence on the growth of D. desulfuricans ІМВ K-6 demonstrated that low concentrations Zn2+ (0.5–2.5 mM) have not essential inhibitory influence on that bacteria. That is why the high concentrations of zinc ions (up to 16 mM) were investigated. It was discovered that the level of biomass accumulation changed depending on the zinc ions concentration in the medium. At the increase of Zn2+concentration to 10–16 mM the decline of biomass is marked, that, probably, is the consequence of influence of this metal on the processes of cellular cycle. Sulfate reducing bacteria D. desulfuricans ІМВ K-6 can reduce sulfates to hydrogen sulfide in the presence of sulfates and organic compounds in the medium (dissimilatory sulfate reduction). Heavy metals at the concentration 2–3 mM inhibit this process. It was discovered the inhibitory influence of zinc ions on the dissimilatory sulfate reduction process of D. desulfuricans ІМВ K-6 that shows up in the cell reduced capacity to sulfate reduction and hydrogen sulfide formation in the medium with the high concentrations of Zn2+.

Keywords

• sulfate reducing bacteria
• dissimilatory sulfate reduction
• desulfovibrio desulfuricans
• hydrogen sulfide
• sulfates
• heavy metals