Unlocking Biomass Energy: A Computational Study on Cellulose Recalcitrance

Giovanni Bellesia, T-6/CNLS; Ramakrishnan Parthasarathi, T-6; Antonio Redondo, T-DO; Shishir Chundawat, Bruce Dale, Great Lakes Bioenergy Center; S. Gnanakaran, T-6 Cellulose, an abundant component of lignocellulosic biomass, is self-assembled in plant cell walls as crystalline nanofibers. It can be hydrolyzed to monomeric glucose that can eventually be converted to biofuels (e.g., alcohols, alkanes) via microbial fermentation or chemical catalysis. The degradation of cellulose polymers to sugar monomers is currently an inefficient and expensive process. We used multiresolution computer simulations to investigate the molecular origin of cellulose recalcitrance to degradation. In particular, we focused on two cellulose crystalline forms that display different degrees of recalcitrance to degradation: cellulose I-beta (the natural crystalline form of cellulose) and the less recalcitrant cellulose III(I) obtained from cellulose I-beta by treatment with liquid ammonia.