Abstract
Chlororespiring, sulfate-reducing bacterium Desulfovibrio dechloracetivorans strain SF3 is capable of dissimilatively reducing Fe(Ⅲ), Cr(Ⅵ) and Co(Ⅲ). Acetate, ethanol, hydrogen, formate, pyruvate, lactate and citrate can be used as electron donors for soluble Fe(Ⅲ) reduction, whereas poorly crystalline Fe(Ⅲ)-oxide can be reduced only in the presence of pyruvate or H2. Our experimental results show that the ratio of Fe(Ⅲ)-EDTA reduced to acetate consumed is 776±035, and no growth companied the Fe(Ⅲ) reduction in the presence of acetate. Reduction of Cr(Ⅵ) and Co(Ⅲ) can be stimulated by hydrogen, pyruvate and lactate, but addition of acetate had no effect. To our knowledge, it is the first report that an SRB (sulfate-reducing bacteria) can utilize acetate as an electron donor for soluble Fe(Ⅲ) reduction but not for insoluble Fe(Ⅲ), and Cr(Ⅵ), Co(Ⅲ) reduction, which indicates that a complex electron transfer system is hired by strain SF3 for metal reduction.
Abstract
Chlororespiring, sulfate-reducing bacterium Desulfovibrio dechloracetivorans strain SF3 is capable of dissimilatively reducing Fe(Ⅲ), Cr(Ⅵ) and Co(Ⅲ). Acetate, ethanol, hydrogen, formate, pyruvate, lactate and citrate can be used as electron donors for soluble Fe(Ⅲ) reduction, whereas poorly crystalline Fe(Ⅲ)-oxide can be reduced only in the presence of pyruvate or H2. Our experimental results show that the ratio of Fe(Ⅲ)-EDTA reduced to acetate consumed is 776±035, and no growth companied the Fe(Ⅲ) reduction in the presence of acetate. Reduction of Cr(Ⅵ) and Co(Ⅲ) can be stimulated by hydrogen, pyruvate and lactate, but addition of acetate had no effect. To our knowledge, it is the first report that an SRB (sulfate-reducing bacteria) can utilize acetate as an electron donor for soluble Fe(Ⅲ) reduction but not for insoluble Fe(Ⅲ), and Cr(Ⅵ), Co(Ⅲ) reduction, which indicates that a complex electron transfer system is hired by strain SF3 for metal reduction.
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