Arsenic release from paddy soil by a dissimilatory arsenate-reducing bacterium Geobacter sp. OR-1

在此之前，我们已经成功地从日本水稻土中分离出一种新的砷酸盐还原细菌Gearosp. OR-1。本研究从砷污染土壤中分离到一株新的砷酸盐还原菌Anaeromyxaperasp. PSR-1。将这些菌株接种到无菌水稻土中，砷的释放再现。XANES分析表明，这些菌株能够减少吸附在土壤固相上的砷酸盐。此外，菌株还能释放吸附在水铁矿上的砷。我们还确定了这些菌株的基因组序列草图。初步的基因组草图分析发现，菌株OR-1的两个砷岛含有多个arsA和arsD基因，并可能异化砷酸盐还原酶基因（arrAB）也被发现。

Previously, we have succeeded to isolate a novel arsenate-reducing bacterium Geobacter sp. OR-1 from Japanese paddy soil. In this study, we isolated a new arsenate-reducing bacterium Anaeromyxobacter sp. PSR-1 from arsenic-polluted soil. When these bacterial strains were inoculated into sterile paddy soil, arsenic release was reproduced. XANES analysis revealed that these strains were able to reduce arsenate adsorbed on soil solid phase. In addition, the strains could release arsenic adsorbed on ferrihydrite. We also determined draft genome sequences of these strains. Preliminary draft genome analysis of strain OR-1 identified two arsenic islands containing multiple arsA and arsD genes, and possible dissimilatory arsenate-reductase genes (arrAB) were also found.