[目的]为获取兼具砷氧化还原功能的多功能菌株.[方法]通过多次分离、纯化,先从广西河池砷污染地区的水源洞水样中筛选出砷耐受菌,再从砷耐受菌中筛选出在好氧条件下既能还原As(V)又能氧化As(Ⅲ)的多功能菌株CLL-B7.[结果]经测定16S rDNA的序列,鉴定菌株属于Microbacterium sp,,GenBank中的注册号是JF975617.该菌株能耐受高达115 mmol/L As(V)和40 mmol/L As(Ⅲ),不能利用除营养肉汤外的多种有机碳源,在pH 6条件下生长情况最好.该菌株在3d内几乎能完全还原10 mmol/L As(V),并从第7天开始表现出砷氧化功能.[结论]该菌株能在好氧环境下进行砷还原,可能利用有机碳源作为电子供体.%[Objective] The research aimed to obtain bacteria with both arsenite-oxidizing and arsenate-reducing abilities. [ Method] A number of arsenite-resistant bacteria were isolated from arsenic-contaminated aquifers in Hechi, Guangxi Province. Among them, a rarely reported strain named CLL-B7 with both arsenite-oxidizing and arsenate-reducing abilities was screened and identified. [ Result J The phylogenetic analysis indicated that the strain belonged to the genus Microbacterium. The 16S rRNA gene sequence was deposited in the GenBank database under accession number JF975617. Strain CLL-B7 only grew in LB but couldn't use other organic carbon sources. And the optimal pH for its growth was 6. The strain was tolerant to 40 mmol/L arsenite and 115 mmol/L arsenate, which was able to reduce 10 mmol/l, arsenate in the first three days but the oxidation of arsenite was observed on day 7. [Conclusion] The strain could reduce arsenate in aerobic conditions indicating that it used organic carbon as the electron donor.
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