Metagenomic characterization of anaerobic fermentation in weathered coal for biomethane production enhanced by landfill leachate

Metagenomic sequencing technology was applied to evaluates the microbial diversity, functional activity, and synergistic relationships during the anaerobic fermentation process of landfill leachate and weathered coal, aiming to assess the key metabolic pathways in the combined anaerobic fermentation process of leachate and weathered coal. The results indicate that co-fermentation significantly enhances the production of biogenic methane. Furthermore, co-fermentation promotes the abundance of Paracoccus that involved in the degradation of organic pollutants, and enriches methane-producing archaea such as Methanothrix and Methanoculleus. Significant increases in carbohydrate enzymes such as lignin-degrading enzyme AAs, as well as GH2, GH43, GT4. The relative abundance of genes related to toluene degradation in co-anaerobic fermentation is 2.5 times and 1.3 times that of singular weathered coal and landfill leachate, respectively. The addition of leachate promotes the metabolic pathway of acetate conversion to methane. This research provides mechanistic studies on the treatment of waste leachate and weathered coal, and provides new ideas for environmental protection and clean energy.