Isolation and Identification of Two Novel Alkaligenous Arsenic(III)‐Oxidizing Bacteria From a Realgar Mine, China

Abstract

Two novel As(III)‐oxidizing bacterial strains were isolated from highly arsenic‐contaminated (2938.6 mg/kg) soils. The phylogenetic tree based on the bacterial 16S rRNA sequences indicated that the two strains were closely related to Brevibacterium yomogidense and Bacillus beijingensis strain YMD‐2, respectively, and were therefore named Brevibacterium sp. YZ‐1 (YZ‐1) and Bacillus beijingensis YZ‐2 (YZ‐2). The strains YZ‐1 and YZ‐2 with vigorous tolerance to As(III) (1500 mg/L) can oxidize 73.5 and 66 mg/L As(III) in 72 h, respectively. Moreover, the two strains were alkaligenous and YZ‐2 increased the pH in the culture medium more effectively than YZ‐1 in 3 days. The optimum culture initial pH and temperature to oxidize As(III) were 8 and 30–31°C, respectively. The results indicate that it is promising to develop a cost‐effective and eco‐friendly bioremediation strategy to alkaline arsenic‐contaminated soils with the two strains, Brevibacterium sp. YZ‐1 and B. beijingensis YZ‐2.