Pretreated lignocellulosic substrates must be further treated by chemical and/or enzymatic hydrolysis to produce fermentable sugars. However, the complexity of the lignocellulosic matrix makes it especially recalcitrant to enzymatic activity, and a number of enzymes must be utilized in order to achieve significant rates and extent of hydrolysis. Enzyme production has been identified as costly processes on an industrial scale. The enzyme hydrolysis stage can generate chemical inhibitors that adversely affect hydrolysis rates as well as the subsequent microbial fermentation. Accordingly, research must be directed at:
- improving the efficiency and lowering the costs of enzyme hydrolysis to yield fermentable sugars;
- reducing the production of inhibitory compounds during enzyme hydrolysis; and
- enhancing the integration of substrate pretreatment and enzyme hydrolysis steps with subsequent fermentation stages.
Theme Leader: Adrian Tsang
Overall Aims: Develop the lignocellulolytic enzymes or enzyme cocktails needed for the effective and economical hydrolysis of the pretreated biomass components (cellulose, hemicellulose, lignin) into fermentable sugars and building blocks for high-value products. The specific research thrusts include the following three projects: 1) Engineer improvements on a "workhorse" microorganism for discovering and producing novel enzymes on an industrial scale; 2) produce and engineer novel enzymes for the efficient hydrolysis and modification of lignocellulose; and 3) develop and optimize enzyme cocktails to hydrolyze the various pretreated feedstocks for ethanol production.