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Isolation and Characterization of Altererythrobacter sp. DT for Biotreatment of and Sulfur Production from Thiosulfate-Bearing Industrial Wastewater

Gu, XiangYang, Dou, PeiChong
Water, air, and soil pollution 2017 v.228 no.1 pp. 28
Altererythrobacter, bacteria, bioremediation, carbon, metabolism, methionine, microbial growth, nucleotide sequences, pH, peptones, ribosomal DNA, saline soils, sequence analysis, sulfates, sulfur, temperature, thiosulfates, wastewater, yeast extract
The objectives of the present study are to isolate thiosulfate-degrading bacterium and optimize its degradative conditions including temperature, pH, and thiosulfate concentrations required for bioremediation purposes. A heterotrophic thiosulfate-degrading bacterial strain DT was successfully isolated from saline soil and identified as Altererythrobacter sp. based on its physicochemical properties and 16S rDNA sequence analysis. It was a naturally occurring methionine auxotrophic strain that utilized only peptone, yeast extract, or several amino acids as the sole carbon source. Altererythrobacter sp. DT degraded thiosulfate via a distinctive disproportionation reaction which was characterized by accumulation of sulfate and elemental sulfur at a molar ratio of 1:1. Optimal conditions for both bacterial growth and thiosulfate metabolism were 25–30 °C and pH 6, respectively. In a fed-batch treatment system receiving liquid polysulfide wastewater, a high degradation rate of 407.3 mg S₂O₃²⁻/(L h) and an elemental sulfur yield of nearly 50% were achieved for immobilized DT cells, indicating great potential of strain DT for future application in the treatment of and microbial production of elemental sulfur from thiosulfate-bearing industrial wastewater.