In the journal BiocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More, Kayoumu et al., explore how microorganisms, extracellular polymeric substances (EPS), and biochar interact to improve environmental remediation. This review highlights the synergistic effects of these interactions in removing pollutants and enhancing soil fertility.

The review identifies four key mechanisms driving the effectiveness of microbial-EPS-biochar interactions. First, biochar’s surface characteristics influence EPS adhesion, which, in turn, affects microbial attachment and growth. EPS also act as adhesion agents between microbial cells, aiding in biofilm formation. Second, the porous structure of biochar shelters microorganisms and provides a reliable carbon source, while EPS facilitates carbon transfer between microorganisms and biochar. Third, microorganisms communicate through chemical signals, with EPS acting as signaling mediators. Biochar can also disrupt microbial cell signaling. Fourth, biochar influences microbial metabolic reactions by acting as an electron donor or acceptor.

The interactions between microbial EPS and biochar have shown promise in several environmental applications. For example, they enhance anaerobic ammonium oxidation, a crucial process for removing nitrogen from wastewater. Additionally, these interactions aid in the immobilization of heavy metals, reducing their environmental impact. Biochar-microbial composites also enhance the degradation of organic pollutants. Furthermore, the interactions between biochar, microorganisms, and EPS improve soil structure by enhancing aggregate stability and porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More. These interactions also increase soil nutrient availability, promoting plant growth and overall soil health.

While the synergistic effects of microbial-EPS-biochar interactions offer significant potential for environmental remediation, further research is needed. Long-term studies should assess the impacts of different biochar types, application rates, and microbial compositions to fully understand and optimize these interactions.

SOURCE: Kayoumu, M., Wang, H., & Duan, G. (2025). Interactions between microbial extracellular polymeric substances and biochar, and their potential applications: a review. Biochar, 7(62). https://doi.org/10.1007/s42773-025-00452-4