2-23: The effect of co-culture of Clostridium thermocellum and Thermoanaerobacterium thermosaccharolyticum in the digestion of Avicel and switchgrass

Clostridium thermocellum can rapidly degrade cellulose. However, C. thermocellum does not utilize pentose as carbon source, which commonly exists in lingo-cellulosic biomass. Hemicellulose represents about 30%-40% of total carbohydrate in plant biomass. Its efficient utilization is important to increase the total product yield. Thermoanaerobacterium thermosaccharolyticum DSM 571 can utilize pentose as carbon source and employs a variety of enzymes for the efficient degradation of hemi-cellulose, starch, amylose and pullulan. In this study, we try to evaluate whether co-culture of C. thermocellum 27405 and T. thermosaccharolyticum DSM 571 can increase cellulose degradation. Co-culture of C. thermocellum 27405 and T. thermosaccharolyticum DSM 571 and monoculture of C. thermocellum 27405 will be compared using Avicel and untreated switchgrass as substrate. We will report cellulose degradation, ethanol production, pH changes, and remaining xylose concentration in supernatant. We will also show increased cellulose degradation in co-culture using untreated switchgrass as substrate.