Unveiling the black box: Multi-omics reveal how biochar supercharges synthetic biofilms for superior bioremediation

Biofilms formed by flora can be sustainably applied in a variety of fields such as bioremediation, wastewater treatment, corrosion prevention, and agricultural production. However, highly practical biofilms often result in low microbial activity, due to undesired impacts including environmental stress and microbial competition. Leveraging the advantages of carrier materials, we aimed to enhance the degradation efficiency and resilience of biofilms by integrating biochar. In this study, the biochar with excellent economic benefits and adsorption capacity was prepared and selected as the carrier material. The growth characteristics, pollutant removal performance, and nutrient cycling within biochar-based biofilms were systematically investigated. The result validated the pollutant remediation efficiency of biofilms increased by 14∼18 % after adding biochar, and found a positive nutrient cycling existing within the biochar-based biofilms. Subsequently, the enhanced remediation mechanisms of biochar-based biofilms at the molecular level were explored through metagenomic and metabolomic analyses. Our results indicate superior strengths of biochar-based biofilms in both metabolic activity and beneficial genes compared to monocultured biofilms. This study aims to improve the stability of biofilms formed by functional flora and reveal their potential in bioremediation for contaminants.