Wu Geng, Huang Liuqin, Jiang Hongchen, Peng Yue'e, Guo Wei, Chen Ziyu, She Weiyu, Guo Qinghai, Dong Hailiang
State Key Laboratory of Biogeology and Environmental Geology, China University of GeosciencesWuhan, China.
State Key Laboratory of Biogeology and Environmental Geology, China University of GeosciencesBeijing, China.
Front Microbiol. 2017 Jul 14;8:1336. doi: 10.3389/fmicb.2017.01336. eCollection 2017.
Thioarsenates are common arsenic species in sulfidic geothermal waters, yet little is known about their biogeochemical traits. In the present study, a novel sulfate-reducing bacterial strain TC-1 was isolated from a sulfidic hot spring in Tengchong geothermal area, Yunnan Province, China. The gene, encoding anaerobic arsenite oxidase, was successfully amplified from the genome of strain TC-1, indicating it has a potential ability to oxidize arsenite under anaerobic condition. In anaerobic arsenite oxidation experiments inoculated with strain TC-1, a small amount of arsenate was detected in the beginning but became undetectable over longer time. Thioarsenates (AsOS with = 1-4) formed with mono-, di- and tri-thioarsenates being dominant forms. Tetrathioarsenate was only detectable at the end of the experiment. These results suggest that thermophilic microbes might be involved in the formation of thioarsenates and provide a possible explanation for the widespread distribution of thioarsenates in terrestrial geothermal environments.
硫代砷酸盐是硫化物地热水中常见的砷物种，但对其生物地球化学特征知之甚少。在本研究中，从中国云南省腾冲地热区的一个硫化物温泉中分离出了一种新型硫酸盐还原细菌菌株TC-1。从菌株TC-1的基因组中成功扩增出编码厌氧亚砷酸盐氧化酶的基因，表明其具有在厌氧条件下氧化亚砷酸盐的潜在能力。在用菌株TC-1接种的厌氧亚砷酸盐氧化实验中，开始时检测到少量砷酸盐，但在较长时间后变得无法检测到。形成了硫代砷酸盐（AsOS，n = 1-4），其中单硫代砷酸盐、二硫代砷酸盐和三硫代砷酸盐为主要形式。四硫代砷酸盐仅在实验结束时可检测到。这些结果表明嗜热微生物可能参与了硫代砷酸盐的形成，并为硫代砷酸盐在陆地地热环境中的广泛分布提供了一种可能的解释。
