Decipher syntrophies and adaptive response towards enhancing conversion of propionate to methane under psychrophilic condition.

Propionate is a key intermediate in anaerobic digestion (AD) under low operational temperatures, which can destabilize the process. In this study, the supplementation of syntrophic cold-tolerant consortia and trace elements significantly improved the performance of psychrophilic (20 °C) reactor, increasing methane production to 91 % of mesophilic reactor levels and reducing propionate concentrations to less than 2 % of those in untreated psychrophilic reactors. Multi-omics analyses revealed that psychrophilic conditions downregulated the methylmalonyl-CoA and aceticlastic methanogenesis pathways.

Effects of digestate-encapsulated biochar on plant growth, soil microbiome and nitrogen leaching.

The increasing amount of food waste and the excessive use of mineral fertilizers have caused detrimental impacts on soil, water, and air quality. Though digestate derived from food waste has been reported to partially replace fertilizer, its efficiency requires further improvement. In this study, the effects of digestate-encapsulated biochar were comprehensively investigated based on growth of an ornamental plant, soil characteristics, nutrient leaching and soil microbiome.