Complete Genome Sequence and Iron-Sulfur Oxidation Characteristics of The Newly Isolated Acidithiobacillus Ferrooxidans YQ-N3

Abstract Acidithiobacillus ferrooxidans (A. ferrooxidans) is a chemoautotroph that can simultaneously oxidize Fe2+, S, and reduced sulfur compounds. Therefore, this bacterium plays a key role in the natural cycles of Fe and S. In this study, a novel A. ferrooxidans strain was isolated from sediments of a river polluted by the acid mine drainage (AMD) of an abandoned mine in Shanxi, China, after which it was characterized via whole-genome sequencing. Furthermore, its functional genes related to iron and sulfur metabolism and response to environmental stress were analyzed, and its capacity to oxidize FeSO4·7H2O, S0, and FeS2 as an energy source was preliminarily discussed. The whole-genome sequencing results revealed that A. ferrooxidans YQ-N3 has a 3,217,720 bp genome, which is comprised of one circular chromosome and five circular plasmids (Plasmid A, Plasmid B, Plasmid C, Plasmid D, Plasmid E). Among these, Plasmid E had not been previously described in this species, and its genome contains various functional genes related to iron and sulfur, drug resistance, and heavy metal resistance. A. ferrooxidans YQ-N3 can increase the oxidation rate of Fe2+ and S0 and enhance the hydrophilicity of S0. Moreover, this strain can accelerate FeS2 oxidation and the formation of secondary minerals. The present study demonstrated that the newly isolated A. ferrooxidans YQ-N3 could bio-oxidize iron and sulfur under acidic conditions, which was supported by our genome analysis results. Collectively, our findings provide important insights into the role and potential of A. ferrooxidans in biogeochemistry and industrial applications.