Linking Glycan Accessibility to Cellulolytic Enzymes to Cell Wall Porosity and Swelling Capacity in Diverse Pretreated Biomass

The purpose of this work is to link the surface and pore properties of nano-scale pores within plant cell walls to enzymatic hydrolysis, enzyme adsorption, and enzyme accessibility through an understanding of the properties impacting swelling and cell wall porosity, and understand how these properties evolve during pretreatments and enzymatic hydrolysis. This involves the role of surface properties in influencing: (1) water infiltration into the cell wall and cell wall swelling, (2) cellulolytic enzyme accessibility to binding sites within the cell wall, and (3) enzyme binding to chemically and physically modified surfaces within the cell wall. For this, we propose to investigate the limitations of cell wall porosity and inaccessible surface area to enzymes.  Specifically, using diverse biomass modified by diverse pretreatments or delignifications, we will relate composition and water properties including water swelling capacity, the water settling volume, and DSC-determined freezing point depression of cell wall-associated water within pores to cellulolytic enzyme, carbohydrate binding module (CBM), and polymer probe accessibility within the porous cell wall.