Transcriptomic Analysis of the Strain Acidiplasma sp. YE-1 During the Oxidation of Sulfide Minerals Pyrite and Arsenopyrite.

Extremely acidophilic iron- and sulfur-oxidizing bacteria and archaea are used in the processing of different sulfide ores and concentrates (biohydrometallurgical technologies); therefore, studying their metabolic pathways and regulation is an urgent task. Thus, the goal of this work was to compare differential gene expression in the thermoacidophilic archaeal strain, representative of the genus Acidiplasma, a predominant microbial group in bioleach reactors, during growth in the presence of ferrous iron and elemental sulfur as well as pyrite and arsenopyrite, which are the most widespread sulfide minerals, and to obtain novel data on the mechanisms of interaction of microorganisms and sulfide minerals. Transcriptomic analysis revealed metabolic pathways involved in ferrous iron and sulfur oxidation (key processes in sulfide mineral oxidation) and determined their expression dependence on different substrates. It was shown that the blue copper protein sulfocyanin may play an important role in both iron and sulfur oxidation, while sulfur oxidation also involves genes encoding well-known proteins for reduced inorganic sulfur compounds (RISC), sulfur oxygenase reductase (SOR), and thiosulfate quinone oxidoreductase (TQO). The results obtained in the present study may be used in further work to improve biohydrometallurgical technologies.