Interactions between microbial extracellular polymeric substances and biochar, and their potential applications: a review

Abstract This review synthesizes the current understanding of the interactions between microorganisms, extracellular polymeric substances (EPS), and biochar and their collective application in environmental remediation. Microorganisms and their EPS play pivotal roles in biofilm formation, enhancing microbial resistance to environmental stress, and facilitating pollutant degradation. Biochar, derived from biomass pyrolysis, provides a porous structure that offers a habitat for microorganisms and is an efficient adsorbent for organic pollutants. The synergistic effects of microbial−EPS−biochar interactions improve pollutant removal capacity and soil fertility. The review highlights four fundamental mechanisms of these interactions: adhesion and interfacial processes, shelter and nutrient transfer, signaling, bioregulation, and microbial electron transfer with biochar. Integrating biochar with microbial systems has demonstrated potential in treating heavy metals (HM) and organic pollutants and enhancing soil properties. However, the review also identifies gaps in knowledge, and emphasizes the need for further research to elucidate the long-term effects of biochar on microbial communities and EPS and to optimize the application of these interactions for sustainable environmental management. Graphical Abstract