Microbial-Clay Mineral Interactions: Mechanisms and Applications in Environmental Remediation

Microbial-clay mineral interactions play a pivotal role in environmental remediation, biogeochemical cycling, and the long-term evolution of the Earth's systems. This review critically synthesizes the fundamental mechanisms, reactive pathways, and environmental implications of microbial-clay mineral interactions. Clay minerals, owing to their large specific surface area, high cation exchange capacity, and tunable surface charge, are shown to sustain microbial metabolism by offering physical shelter and serving as sources of essential nutrients. Concurrently, microorganisms mediate the dissolution, structural alteration, and neoformation of clay phases via proton production, electron transfer reactions, and genetic regulatory networks, thereby establishing a dynamic synergistic relationship. In environmental remediation, clay-microorganism complexes have been demonstrated to promote heavy metal stabilization. They concurrently expedite the breakdown of organic contaminants, including polycyclic aromatic hydrocarbons (PAHs). Nevertheless, major knowledge gaps persist, especially concerning the multiscale complexity of interfacial behaviors and still-elusive molecular-scale interaction mechanisms. Finally, several priority directions for the future are proposed, including the integration of metagenomics and molecular modeling, the design of biomarker-based monitoring tools, and the scalable translation of bench-scale discoveries and laboratory insights into field-scale remediation technologies. Collectively, this work advances fundamental knowledge of key microbe-mineral biogeochemical processes and provides a scientific basis for the development of sustainable, nature-based environmental remediation strategies.