Engineering Microbial Consortium Biohybrid System to Efficiently Produce Electricity from Lignocellulose Biomass.

Converting lignocellulose into bioelectricity through a bioelectrocatalytic system (BES) has emerged as a promising approach to addressing environmental pollution and energy regeneration challenges. However, practical application of BES is significantly constrained by the fact that the electroactive biocatalyst lacks the essential metabolic pathways and enzymes required for utilizing lignocellulose for cell growth and power generation. Here, to realize clean electricity production from lignocellulose hydrolysate, an artificial microbial consortium comprising , , and was developed. In this consortium, is responsible for converting glucose into lactate; metabolizes glucose and xylose into riboflavin; and then employs lactate as an electron donor and riboflavin as an electron shuttle to facilitate electricity generation. Subsequently, to increase substrate conversion efficiency of the microbial consortium, three key genes , , and encoding lactate dehydrogenase, GTP cyclohydrolase, and d-lactate dehydrogenase, were expressed in , , and , respectively, which accelerated glucose-to-lactate conversion, riboflavin synthesis, and lactate metabolism. Also, to accelerate the extracellular electron transfer (EET) capacity of the microbial consortium, the gene from encoding the outer membrane -type cytochrome was further expressed in . Finally, to further enhance the interfacial EET capability of the microbial consortium, a 3D microbiota biohybrid system @CF&GO consisting of carbon felts and graphene oxide was developed to reduce the internal resistance of BES. The results showed that the artificial biohybrid system could obtain a maximum power density of ∼739.40 mW m using lignocellulosic hydrolysate as the carbon source. This system expands the range of carbon sources available to for efficient power generation from the lignocellulosic hydrolysate.