Design of electroactive consortium synthesizing flora enables synergistic biomass-to-bioenergy conversion.

Abstract

Efficient biomass-to-energy conversion is key to sustainable development. We engineered a dual-functional synthetic microbial communities(SMC) (<i>Bacillus subtilis</i> XJU-1, XJU-2, <i>Bacillus cereus</i> XJU-3, and <i>Enterobacter hormaechei</i> XJU-5) to simultaneously degrade marine biomass and generate electricity in microbial fuel cells (MFCs). Using porous nickel-molybdenum foam as the anode, the 2-L MFCs achieved 941.67 mV and 443.67 mW m^-3. Multi-omics analyses showed that vitamin B₆ and amino acid pathways boosted NADH/FADH₂ production, while higher SDH and COX activities enhanced electron transfer. The community converted 77%-90% of seven marine substrates into soluble nutrients, which correlated with increased power output. Four MFCs connected in series delivered 2187.17 mV and 598.13 mW m^-3, and a 28-L MFCs generated stably for 30 days. Effluents rich in nitrogen, phosphorus, and potassium suggest potential use as diluted liquid fertilizers, supporting integrated bioenergy production and resource recycling.