Extracellular polymeric substances and biofilms in mineral-metal interactions: insights into process chemistry and technological advances in recovery of metals

Extracellular polymeric substances (EPS) and biofilms are an integral part of microorganisms that are involved in several key mechanisms to drive metal dissolution and recovery. These mechanisms improve microbial adhesion to mineral surfaces simultaneously improving metal solubilization. EPS portrays multifunctional roles by providing structural support to biofilms enabling adhesion to mineral surfaces. Quorum sensing (QS), a central process, regulates these metabolic processes by managing microbial communication and gene expression. These mechanisms together create a framework that improves leaching efficiency and metal dissolution. With a lot of potential for biotechnological research applications, the contribution of EPS-biofilm interaction within bioleaching as well as the downstream systems for metal recovery is slowly gaining momentum. This review highlights the current mechanistic insights into EPS–metal interactions, biofilm-mediated adhesion and QS regulation highlighting their integrated role in advancing metal dissolution/extraction technologies. AI-OMICS approaches integrate microbial data with predictive modelling, offering powerful strategies to improve bioleaching efficiency and sustainability. Emphasis is also placed on recent advances in microbial consortia engineering, process optimization, and the potential of QS modulation to enhance bioleaching of wastes bearing minerals and metals.