(529e) Detecting Biological Networks In Clostridium Thermocellum Using Computational Approaches

Lignocellulosic plant biomass has long been recognized as a potential low-cost and sustainable source of mixed sugars for production of biofuels and other value-added chemicals. Lignocellulosic biomass comes from plant cell wall which is a composite structure with crystalline cellulose, hydrated hemicellulose, and lignin as major components. Corn stover, switchgrass, miscanthus, woodchips and the byproducts of lawn and tree maintenance are some of the more popular cellulosic materials for biofuel production. Production of biofuels from lignocellulose has the advantage of abundant and diverse raw material compared to sources like corn and cane sugars, but requires a greater amount of processing to make the sugar monomers available to the microorganisms that are typically used to produce ethanol by fermentation. Plants have evolved superb mechanisms for resisting assault on their cell wall structural sugars from the microbial and animal kingdoms, collectively known as biomass recalcitrance. Current technologies for the biological conversion of lignocellulosic biomass generally include pretreatment of biomass, hydrolysis of polysaccharides, and fermentation of C5 and C6 sugars.

Clostridium thermocellum is an anaerobic, thermophilic bacterium. C. thermocellum has garnered great research interest due to its cellulolytic and ethanologenic abilities, being capable of directly converting a cellulosic substrate into ethanol. This makes it useful in converting biomass into a usable energy source. The degradation of the cellulose is carried out in the bacterium by a large extracellular cellulase system called a cellulosome, which contains nearly 20 catalytic subunits. The cellulase system of the bacterium significantly differs from fungal cellulases due to its high activity on crystalline cellulose. In this work, I will present our recent work on understanding and improving the process of biologically converting biomass into biofuels through computational systems biology approaches. Specifically, I will focus my presentation on elucidating of a number of key regulatory pathways in cellulolytic organisms relevant to bioenergy production.