Influence of salts of metals on nitrate reduction by sulfate reducing bacteria

Abstract

It was established that strains of sulfate reducing bacteria Desulfovibrio desulfuricans ІМV K-6, Desulfovibrio sp. Yav-6 and Desulfovibrio sp. Yav-8 isolated from Yavorivske lake, were able to carry out dissimilatory nitrate reduction in medium without sulfates. Addition of nitrate ions to medium negatively influenced on level of sulfate ions reduction by bacteria, since during growth in medium with ammonium chloride and equimolar quantity (3.5 mM) of sulfates and nitrates, bacteria reduced only up to 37.2% sulfate ions present in medium. After 10 days of growth in medium without sulfates and ammonium chloride but with cysteine and nitrates, bacteria of all strains almost completely utilized nitrate ions present in medium with formation of up to 2.3 mM NH4+. Significant decrease in sulfate reducing bacteria growth was observed upon the influence of 2 mM plumbum, cobalt, cadmium and nickel salts and 3 mM ferrum, zinc, magnium and cuprum salts. Plumbum, cobalt, cadmium, nickel, magnium, ferrum, cuprum and zinc salts in 3 mM concentration which were added to medium without sulfated and ammonium chloride with cysteine and nitrates, inhibited less than 3.8 times bacteria growth, and 4 times – the intensity of nitrates ammonification by cells.

Keywords

• sulfate reducing bacteria
• nitrate
• nitrite
• ammonium
• metal salts