Geobacter-Clostridium DIET Community

A syntrophic two-member consortium consisting of Geobacter sulfurreducens and Clostridium pasteurianum that performs direct interspecies electron transfer (DIET) during glycerol fermentation. G. sulfurreducens acts as an exoelectrogen, oxidizing acetate and transferring electrons directly to C. pasteurianum via electrically conductive pili (nanowires). These electron transfers induce a metabolic shift in C. pasteurianum's glycerol fermentation pathway, redirecting carbon flux away from ethanol and butanol production toward increased 1,3-propanediol (PDO) and butyrate production. This represents a unique application of DIET where electron transfer serves not to drive methanogenesis but to modulate fermentation pathways, achieving a 37% increase in 1,3-propanediol and 38% increase in butyrate production. The bacteria establish physical contact through nanowires, enabling electron exchange without relying on diffusible hydrogen or formate carriers. This coculture demonstrates how controlled interspecies electron transfer can be exploited to optimize production of industrially relevant metabolites like 1,3-propanediol.