Sulfate, nitrate and nitrite ions reduction by bacteria of Desulfovibrio genus upon the influence of ferrum (III), chrome (VI) and mangan (IV) compounds
O. Moroz, S. Hnatush, Ch. Bohoslavets, G. Yavorska, B. Borsukevych
Ivan Franko National University of Lviv
4, Hrushevskyi St., Lviv 79005, Ukraine
It was established that sulfur reducing bacteria Desulfovibrio desulfuricans IMV K-6, Desulfovibrio sp. Yav-6 and Desulfovibrio sp. Yav-8, isolated from the Yavorivske lake, with different intensity reduced during the process of anaerobic respiration the Fe3+, Cr6+ and Mn4+ at concentration of 3.47 mM their compounds in Kravtsov-Sorokin medium. Addition of C6H5O7Fe, K2Cr2O7, MnO2 at concentrations of 0.5; 2.5; 3.5 mM to incubation mixture causing inhibition of biomass accumulation and carried out by bacteria dissimilation sulfate, nitrate and nitrite reduction. For toxic influence on metabolic activity of bacteria investigated compounds of metals can be placed in a next sequence: MnO2, K2Cr2O7 and C6H5O7Fe. Mn (IV) oxide, potassium dichromate and Fe (III) citrate at concentration of 3.5 mM in incubation mixture inhibited level of sulfate ions reduction in medium with SO42- in 1.9; 1.8 and 1.7 folds, level of nitrate ions reduction in medium with NO3- in 5.1; 5.0 and 3.9 folds, level of nitrite ions reduction in medium with NO2- in 5.7; 5.0 and 4.7 folds accordingly. Carried out by bacteria of Desulfovibrio genus dissimilation nitrate and nitrite reduction appeared more sensible to the negative action of C6H5O7Fe, K2Cr2O7 and MnO2 comparatively with the process of dissimilation sulfate reduction.
Keywords: sulfur reducing bacteria, heavy metals, hydrogen sulfide, ammonium ions, sulfate, nitrate and nitrite ions