Microbial Bioinorganic Interactions in Metal-contaminated Environments: Mechanisms, Biogeochemical Consequences, and Bioremediation Opportunities

Abstract

Metal-contaminated environments ranging from acid mine drainage systems and tailings ponds to    industrially impacted soils and groundwater are not merely passive repositories of pollutants. These interactions include metal binding to cell surfaces and extracellular polymers, intracellular trafficking and sequestration, enzymatic detoxification and efflux, and most consequentially microbially driven redox transformations that couple metal cycling to carbon, sulfur, nitrogen, and iron metabolisms. In anaerobic and microaerophilic zones, metal reduction by electroactive bacteria can precipitate or immobilize metals (e.g., U(VI) reduction), while in oxidizing niches, microbial oxidation accelerates sulfide mineral dissolution and liberates acidity and metals. This review synthesizes journal evidence on the molecular and community-level strategies microbes use to persist under metal stress, the major bioinorganic pathways controlling metal fate, and the practical implications for engineered remediation.