Biomass recalcitrance, the use of enzymes and their component-parts to better elucidate cellulose amorphogenesis and fiber structure

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The innate resistance of lignocellulosic materials, particularly the cellulosic component, to enzymatic and chemical attack is due to the physical, mechanical and chemical structures/mechanisms that nature has evolved in these materials to prevent access and disassembly of the plant cell wall’s major components. This is problematic if we hope to deconstruct biomass substrates to valuable chemical intermediates or to modify them to enhance their fiber properties. The work described in the detailed proposal hopes to make use of our expertise in pretreatment/pulp modification, enzyme characterization/action and enzyme-substrate interaction to better understand the physical, mechanical and chemical impacts of fiber structure and to see if poorly understood mechanisms such as the suggested “amorphogenesis” step of cellulose deconstruction can be better elucidated. To do this we will produce a range of pretreated and highly characterized biomass/pulp substrates (using our steam pretreatment, organosolv and pulping equipment) and traditional pulp and paper methods (coarseness, fiber strength, FQA, Kajani, etc.) as well as methods we have developed or refined in our lab (Simons Stain, use of Cellulose Binding Modules for amorphous/crystalline regions of cellulose) to assess changes in the biomass substrate. We will also make use of crystalline nanocellulose (CNC), nanofibrillated cellulose (NFC) and cellulose filaments (CF) substrates that have been produced and characterized by colleagues at the US Forest Products Lab, FP Innovations, Inventia, Alberta Innovates, etc. We will use individual and cocktails of enzymes and their component-parts, such as swollenin, expansin, CBM’s, (both produced and purified in house as well as supplied by collaborators in industry and in other research groups) to investigate the relationship between biomass structure, ultrastructure, composition and resistance to enzymatic modification and deconstruction. The overall goal is to develop a better understanding of enzyme mediated biomass deconstruction/modification. The work will strengthen the synergies between pretreatment/pulping processes and enzymatic modifications to improve both the fiber characteristics of cellulosic materials (such as increasing their absorbency or strength) and the potential of the biomass-derived sugar platform (by increasing the rate and completeness of cellulose hydrolysis). It is hoped that, with a better understanding of mechanisms such as enzyme-mediated amorphogenesis, this will help us both better understand how biomass deconstruction/delamination/disaggregation might occur and help with potential applications such as producing super adsorbent pulp/tissue paper or more easily degraded biomass substrates that could form that bases of a biochemically based sugar platform for fuels and chemicals production.