Gao Peng, Zeng Xibai, Bai Lingyu, Wang Yanan, Wu Cuixia, Duan Ran, Su Shiming
Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Environment, Ministry of Agriculture, Zhongguancun South Street No 12, Beijing, 100081, People's Republic of China.
College of Resource and Environment, Hunan Agricultural University, Changsha, Hunan Province, People's Republic of China.
Curr Microbiol. 2017 Sep;74(9):1108-1113. doi: 10.1007/s00284-017-1293-z. Epub 2017 Jul 4.
Bacteria capable of arsenate [As(V)] reduction can be used for remediation of As-contaminated soils via bio-extraction. In this study, As-resistant bacteria were isolated and their abilities to resist and reduce As(V) as well as As bio-extracted from soils naturally contaminated with As were studied. The results indicated that three isolates (2-2, 4-3, and 8-5) showed greater abilities to resist As(V) than other isolates. When the isolates were exposed to 10 mg L As(V), As(V) contents decreased, while arsenite [As(III)] increased over time. In comparison, isolates 2-2 and 4-3 completely reduced As(V) into As(III) within 6 h. According to phylogenetic analysis of the 16S rRNA gene, isolates 2-2, 4-3, and 8-5 were most closely related to Pseudomonas taiwanensis, P. monteilii, and Pseudomonas sp., respectively. Total As contents in soils significantly (P < 0.05) decreased after bacterial extraction. The maximum As removal of 21.6% was observed following inoculation of isolate 2-2 into soil-1. Bacterial extraction weakened the binding between As and the soil solid phase, resulting in As removal from the soil.
能够还原砷酸盐[As(V)]的细菌可用于通过生物提取修复受砷污染的土壤。在本研究中，分离出抗砷细菌，并研究了它们抵抗和还原As(V)以及从天然受砷污染土壤中生物提取砷的能力。结果表明，三个分离株（2-2、4-3和8-5）比其他分离株表现出更强的抗As(V)能力。当分离株暴露于10 mg L As(V)时，As(V)含量随时间下降，而亚砷酸盐[As(III)]增加。相比之下，分离株2-2和4-3在6小时内将As(V)完全还原为As(III)。根据16S rRNA基因的系统发育分析，分离株2-2、4-3和8-5分别与台湾假单胞菌、蒙特利假单胞菌和假单胞菌属关系最为密切。细菌提取后土壤中的总砷含量显著（P < 0.05）下降。将分离株2-2接种到土壤1中后，观察到最大砷去除率为21.6%。细菌提取减弱了砷与土壤固相之间的结合，从而导致砷从土壤中去除。
