Arsenite Oxidation Characteristics and Molecular Identification of Arsenic-Oxidizing Bacteria Isolated from Soil

Arsenite oxidation characteristics were studied through domesticated bacteria from soil added arsenic artificially, which came from Dinghu Mountain Natural Reserve of Zhaoqing, Guangdong, China. Two individual bacterial strains were selected as arsenite-oxidizing bacteria by reaction of silver nitrate and detected in community DNA fingerprints generated by PCR coupled with denaturing gradient gel electrophoresis. Physiological, biochemical and arsenite oxidation characteristics of arsenic-oxidizing bacteria were researched. They were gram-negative and rod-shaped bacteria, which were 99% related to Alcaligenes sp.(strain H) and 100% related to Agrobacterium sp. (strain Q) respectively. The arsenic-oxidizing experiment showed that the optimal temperature and pH were 30°Cand 9.0 respectively for both strains. Strain H was an efficient arsenite-oxidizing bacteria. It oxidized As(III) by nearly 100% after 21 hours. Therefore, It was detected as the most perspective strains in this study.