Interaction between clostridium thermocellum ATCC 27405 and thermoanaerobacterium saccharolyticum DSM 7060 on cellulosic and lignocellulosic substrates: substrate attachment, concentration dynamics, and ethanol production

Abstract

Second generation biofuel research and bioethanol production via consolidated bioprocessing has the potential to become a viable alternative to finite fossil fuel reserves. Further advances have to be made in order to make this biotechnology more economically feasible. The focus of this study was to use cellulotyc C. thermocellum in a consortium with hemicellulotyc T. saccharolyticum to investigate the dynamics of their interaction with respect to cellulosic and lignocellulosic substrate attachment, respective numbers, and extent of solid substrate hydrolysis and desired end product formation. T. saccharolyticum's partial adherence to cotton and switchgrass has demonstrated limited need for substrate colonization and hence reduced competition with C. thermocellum. Real-time PCR analysis indicated that T. saccharolyticum can proliferate under low carbon supplementation, and efficiently utilize the metabolites produced from C. thermocellum's hydrolysis of cotton and switchgrass. The interaction between the two thermophiles on both substrates demonstrated a potential for increased bioethanol production.