INVESTIGATION OF PHANEROCHAETE CHRYSOSPORIUM AND CLOSTRIDIUM THERMOCELLUM FOR IMPROVED SACCHARIFICATION OF LIGNOCELLULOSE UNDER NONSTERILE CONDITIONS

Current research efforts are directed at developing competitive processes that can utilize lignocellulose as a feedstock for biorefineries. The purpose of this study was to investigate methods of processing lignocellulosic material so that its monosacharides can be more easily accessed for fermentation, the lack of which is hindering the economics and widescale adoption of lignocellulosic biorefining. The monosaccharides are of interest because they can be used by Clostridium beijerinckii downstream of P. chrysosporium and C. thermocellum in a sequential bioprocess to produce butanol. Butanol is an attractive biofuel because it can be utilized without modifying current transportation infrastructure. Butanol is also used as a starting material in organic synthesis. In the first study, the potential for C. thermocellum\u27 s (ATCC 27405) cellulase system to operate outside its optimal temperature range in a high-solids environments was assessed by quantification of the fermentation products lactate, acetate, and ethanol and by quantification of xylose, glucose, and cellobiose remaining. Additionally, the lignin degrading white-rot fungus Phanerochaete chrysosporium RP 78 was investigated as a potential pretreatment for lignocellulose. Elevated temperatures required for Clostridium thermocellum fermentation were examined as a means to improve poor competiveness that is characteristic of P. chrysosporium on unsterile corn stover substrate