Bacillus flexus strain SSAI1 isolated from agro-industry waste, Tuem, Goa, India displayed high arsenite resistance as minimal inhibitory concentration was 25 mM in mineral salts medium. This bacterial strain exposed to 10 mM arsenite demonstrated rapid arsenite oxidation and internalization of 7 mM arsenate within 24 h. The Fourier transformed infrared (FTIR) spectroscopy of cells exposed to arsenite revealed important functional groups on the cell surface interacting with arsenite. Furthermore, scanning electron microscopy combined with electron dispersive X-ray spectroscopy (SEM-EDAX) of cells exposed to arsenite revealed clumping of cells with no surface adsorption of arsenite. Transmission electron microscopy coupled with electron dispersive X-ray spectroscopic (TEM-EDAX) analysis of arsenite exposed cells clearly demonstrated ultra-structural changes and intracellular accumulation of arsenic. Whole-genome sequence analysis of this bacterial strain interestingly revealed the presence of large number of metal(loid) resistance genes, including aioAB genes encoding arsenite oxidase responsible for the oxidation of highly toxic arsenite to less toxic arsenate. Enzyme assay further confirmed that arsenite oxidase is a periplasmic enzyme. The genome of strain SSAI1 also carried glpF, aioS and aioE genes conferring resistance to arsenite. Therefore, multi-metal(loid) resistant arsenite oxidizing Bacillus flexus strain SSAI1 has potential to bioremediate arsenite contaminated environmental sites and is the first report of its kind.

弯曲芽孢杆菌从印度果阿图姆的农业工业废料中分离出的 SSAI1 菌株表现出高亚砷酸盐抗性，因为矿物盐培养基中的最小抑制浓度为 25 mM。这种暴露于 10 mM 亚砷酸盐的菌株在 24 小时内表现出快速的亚砷酸盐氧化和 7 mM 砷酸盐的内化。暴露于亚砷酸盐的细胞的傅里叶变换红外 (FTIR) 光谱揭示了细胞表面与亚砷酸盐相互作用的重要官能团。此外，扫描电子显微镜与暴露于亚砷酸盐的细胞的电子色散 X 射线光谱 (SEM-EDAX) 相结合，显示细胞聚集成团，表面没有亚砷酸盐吸附。透射电子显微镜与亚砷酸盐暴露细胞的电子色散 X 射线光谱 (TEM-EDAX) 分析相结合，清楚地表明了砷的超微结构变化和细胞内积累。该菌株的全基因组序列分析有趣地揭示了存在大量金属（样）抗性基因，包括aioAB基因编码亚砷酸盐氧化酶，负责将剧毒的亚砷酸盐氧化成毒性较小的砷酸盐。酶分析进一步证实亚砷酸氧化酶是一种周质酶。SSAI1菌株的基因组还携带glpF、aioS和aioE基因，赋予对亚砷酸盐的抗性。因此，耐多金属亚砷酸盐氧化的弯曲芽孢杆菌菌株SSAI1具有生物修复亚砷酸盐污染环境场地的潜力，是同类研究中的首次报道。