Microbiology and Biotechnology Research: An Overview Vol. 7

Microorganisms of the Acidithiobacillus genus were widely used in mineral bioleaching for industrial extraction ofvarious value metals. In this study, the isolation, characterisation, mineral bioleaching, whole genome sequencing and genomics analysis of the bioleaching strain, Acidithiobacillus ferriphilus strain QBS3, from a heavy-metal-rich sulfide acid mine drainagewas reported. This strain is a Gram-negative, micron-sized and rod-shaped bacterium with small red colonies and exhibits fast oxidation rates ofmore than 0.35 g/(L·h) for ferrous ions and more than 0.2g/(L·d) for element sulfur, and strong toxic ions resistance withminimum inhibitory concentrations (MIC) of 1000 mM for Zn(II),100 mM for As(III) and 120 mM for As(V). QBS3 also has high mineral bioleaching ability, for instance, in sphalerite bioleaching, about 20% of zinc was extracted in 14 days at 1% pulp density, and, in arsenopyrite bioleaching, about 80% leaching efficiency was obtained at a pulp concentration of 1% after 30 days. The genome of QBS3 was sequenced, annotated and analysed. The whole genome consists of one circular chromosome and one circular plasmid containing many genomic islands, prophages, CRISPRs, etc. Abundant and redundant genes related to mineral bioleaching were identified from the sequence of the genome. By the integration of characterisation, mineral bioleaching, and genomics analysis of the strain, the putative mechanism models of sphalerite bioleaching, arsenopyrite bioleaching and arsenic resistance of A. ferriphilus QBS3 were proposed. The isolated strain, the released genome sequence and the study findings in this study will greatly contribute to future applications and theoretical research of mineral bioleaching.