P69: Conversion of switchgrass to soluble carbohydrates using a native fungal species isolated from switchgrass bales

Different lignocellulosic bioenergy feedstocks have different polymeric compositions. These diferences make it difficult for any one enzyme system to efficiently convert all lignocellulosic feedstocks to soluble carbohydrates, which can subsequently be fermented. Therefore, development of feedstock-specific enzyme systems for more efficient conversion to soluble carbohydrates is desired. One strategy could be to explore the use of naturally existing microflora on these feedstocks. The naturally occuring microflora should have the enzymatic tools for more efficient conversion of a specific feedstock. The goal of this study was to screen the naturally occuring fungi on switchgrass bales in order to isolate a fungus for enzyme production to hydrolyze switchgrass specifically. A fungal isolate was obtained and selected for further study.  This strain was identified to be Trichoderma atroviride. This strain produced both cellulase and hemicellulases when grown on switchgrass. The culture also showed high beta-glucosidase activity. The presence of high amount of beta-glucosidase activity is required to prevent any cellulase inhibition due to accumulation of cellobiose, especially at high solids loading required for second generation biofuels.