Bioleaching process by organisms in metal mining. Review

The problem of soil contamination by heavy metals, acid mine drainage, wastewater dumping sites, the problem of ore shortage, and many more forces people to seek better mining techniques. However, new mining techniques have to be eco-friendly and suit the environmental assessment policy. Bacteria are incredibly versatile organisms with high adaptability, which can live, adapt and thrive particularly everywhere. Sulfide-associated environments harbour diverse bacterial communities capable of metal sulfide oxidation, a process vital for bioleaching and biomining. This review explores the bacterial composition of these environments, focusing on acidophilic bacteria and archaea that drive sulfide mineral dissolution through iron and sulfur oxidation. This paper discusses the oxidation of metal sulfides via two primary pathways, determined by physicochemical characteristics of minerals. Biofilm formation and extracellular polymeric substances (EPS) significantly influence bioleaching efficiency, while quorum sensing and molecular interactions shape microbial consortia. Understanding these microbial processes is essential for the optimization of biomining, the development of hydrometallurgy, and mitigating the negative effects of ore depletion or metal contamination, such as acid mine drainage.