A new approach to a deep understanding of biomass recalcitrance

Washington State University, Pullman WA

Investigators

Abstract

Institution: Washington State University Title: A new approach to a deep understanding of biomass recalcitrance Intellectual Merit The resistance of lignocellulosic biomass to enzymes designed to break down the cellulose fraction to fermentable sugars is a long-standing technical barrier in the development of bioprocess engineering platforms for biomass conversion technology. Knowledge of intricate substrate and enzyme interactions is needed to develop strategies to reduce enzyme cost by improving enzyme performance. The goal of this proposed research is to demonstrate a new approach to investigating biomass recalcitrance by creating a new set of biomass reference substrates. The reference substrates will possess an integral fiber structure as well as homogeneous and well-characterized chemical and physical properties across all biomass fiber structural levels. It is hypothesized that using these reference substrates to systematically examine substrate-enzyme interactions will provide new insights into fundamental issues underlying biomass recalcitrance. The specific objectives of proposed research are to: 1) prepare reference substrates, which include chemically-pulped/bleached lignocellulosic biomass, model lignin-carbohydrate composites, and nanocrystalline cellulosic materials with a diverse level of physiochemical properties; 2) study the enzymatic hydrolysis characteristics of these reference substrates; and 3) investigate enzyme and substrate interactions at fiber, fiber topographic, fibril, and molecular levels through X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Outcomes from this proposed research have the potential to help guide the genetic improvement of cellulase enzymes for more efficient biomass conversion process. Broader Impacts The proposed educational and outreach activities will focus on three core efforts: 1) training undergraduate and graduate students from underrepresented groups to pursue careers in bioconversion research and development; 2) development of a summer program with MESA (Mathematics Engineering Science Achievement) program at Washington State University to promote the awareness of clean technology and biomass economy at high schools in Yakima Valley and TriCities regions; 3) development of new courses and teaching module to effectively transfer knowledge from biomass conversion topics to chemical engineering and biosystems engineering education.