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

在此之前，我们已经成功地分离到一株新的砷还原细菌--地杆菌。或-1来自日本稻田。在本研究中，我们分离到了一株新的砷还原细菌--厌氧粘细菌。从砷污染土壤中分离到PSR-1。当这些细菌菌株接种到无菌水稻土中时，砷的释放被重现。XANES分析表明，这些菌株能够减少土壤固相吸附的砷。此外，菌株还能释放吸附在水铁石上的砷。我们还测定了这些菌株的基因组草稿序列。对菌株OR-1的初步基因组分析表明，有两个砷岛含有多个ARSA和ARSD基因，并发现可能的异化砷酸还原酶基因(Arrab)。

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.