Screening and genome analysis of arsenite-oxidizing strain Bosea sp. AS-1

Abstract:

[Objective] In this study, we aimed to characterize the community structure of arsenite-oxidizing bacteria in Xikuangshan of Hunan Province, and the whole genome of an arsenite-antimonite-oxidizing strain Bosea sp. AS-1 (Abbreviation:AS-1). [Methods] Arsenite-oxidizing bacterial strains were isolated from the samples collected in Xikuangshan, and 16S rRNA genes were sequenced for phylogenic analysis. Whole genome of strain AS-1 was sequenced and analyzed using relevant software and databases for genome assembly, gene prediction and functional annotation. [Results] The arsenite-oxidizing bacteria in Xikuangshan were mainly distributed in α-, β-, γ-Proteobacteria and Firmicutes. AS-1's genome contained one circular chromosome with a size of 5.536 Mb and two plasmids of 189.9 kb and 112.1 kb, respectively. Further analysis on AS-1's genomic data reveal many genes related to arsenic and antimony metabolism, as well as flagella formation, flagellar movement, and biofilm formation. These genes may be involved in AS-1's resistance to high level of arsenic and antimony in environment. Besides, several carbon-fixation genes and sulfur-oxidizing genes were also found in the genome of AS-1, suggesting that AS-1 may grow autotrophically and oxidize sulfur. [Conclusion] Subsequent experiments confirmed autotrophic growth of AS-1.