Department of Soil Science and Center for Advanced Studies in Agriculture and Food, KU Institute for Advanced Studies, Kasetsart University, 50 Phahon Yothin Rd., Cha-Tuchak, Bangkok 10900, Thailand.
World J Microbiol Biotechnol. 2012 May;28(5):2287-92. doi: 10.1007/s11274-012-1034-1. Epub 2012 Mar 16.
An agar plate screening assay was used to determine whether 100 arsenic-resistant bacterial isolates, previously obtained from arsenic-contaminated soils, had the ability to transform arsenite and arsenate. Ninety-five percent of the isolates were capable of reducing arsenate on agar plates. The isolates also grew in the presence of high concentrations of arsenite, but none of the bacterial isolates oxidized arsenite to arsenate under the growth conditions tested. About 14 % (13 of 95) of the tested isolates transformed high levels of arsenate (33-70 μM) when tested using the molybdenum blue method. Partial sequence analysis of 16S rDNA genes indicated that the isolates belonged to two broad taxonomic groups: Firmicutes and Proteobacteria. Ten isolates were assigned to four species in the genus Bacillus, and three isolates belonged to two species in the genera Enterobacter and Ochrobactrum. Taken together these results indicate that phylogenetically diverse bacteria isolated from arsenic-contaminated soils in an old tin mine area in Thailand have the ability to transform arsenate to arsenite.
琼脂平板筛选试验用于测定先前从砷污染土壤中获得的 100 株砷抗性细菌分离株是否具有将亚砷酸盐和砷酸盐转化为砷的能力。95%的分离株能够在琼脂平板上还原砷酸盐。这些分离株也能在高浓度亚砷酸盐存在的情况下生长，但在测试的生长条件下，没有一种细菌分离株能将亚砷酸盐氧化为砷酸盐。在用钼蓝法测试时，约 14%（95 个测试分离株中的 13 个）的测试分离株能将高浓度的砷酸盐（33-70 μM）转化。16S rDNA 基因的部分序列分析表明，这些分离株属于两个广泛的分类群：Firmicutes 和 Proteobacteria。10 个分离株被分配到芽孢杆菌属的四个种，3 个分离株属于肠杆菌属和弧菌属的两个种。综合这些结果表明，从泰国一个旧锡矿区砷污染土壤中分离出的具有不同系统发育的细菌具有将砷酸盐转化为亚砷酸盐的能力。
