Shyretha Brown, Xianyi Zhang, Hongfei Wang, Ziyu Dai, Li Tan, and Bin Yang. In Proceedings of the 34th Symposium on Biotechnology for Fuels and Chemicals. New Orleans, LA. May, 2012.

The enzymatic hydrolysis of cellulose by cellulases, a key process in biological conversion of biomass to biofuels and bio-based chemicals, is a thermodynamically challenging catalytic process that requires understanding of both substrate-related and enzyme-related effects. However, dynamic changes of substrate structure and the functionality of various cellulases components during enzymatic hydrolysis have not been well understood yet due to lacking of real-time techniques to monitor hydrolysis. Through introducing fresh enzyme to enzyme-free and partially converted cellulose, “restart” experiments provide a valuable tool to compare interrupted hydrolysis with uninterrupted hydrolysis in order to assess how substrate and enzymes change with conversion. For this research, we have applied the “restart” method, in conjunction with cutting-edge imaging and analytical technologies, including a novel broadband stimulated Raman spectroscopy and femtosecond broadband stimulated Raman spectroscopy, which uses a two laser beam, to further investigate the dynamic characteristics of cellulose, oligomers, glucose, and cellulase protein during enzymatic hydrolysis. Our experiments demonstrated that broadband stimulated Raman spectroscopy is capable of monitoring cellulase and/or cellulose and its interactions. Thus, a new degradation intermediates profile for the enzymatic hydrolysis of cellulose which associated with cellulase structure and conformation changes will be addressed in our presentation. In addition, a single light source and laser wavelength of Raman spectroscopy, to In situ characterization dynamic change of cellulose structure and the functionality of various cellulase components during enzymatic hydrolysis will also be discussed.