13-01: Development of a minimal bacterial cellulase set from Acidothermus cellulyticus

Much of what is known about the function of cellulytic enzymes is based on work done using a minimal cellulase system derived from T. reesei, a combination of cellobiohydrolases I and II, an endoglucanase, and a beta-glucosidase. Despite much effort, a similar bacterial set has not been developed. Furthermore, many of the bacterial cellulytic enzymes cloned and expressed to date have significantly different pH and temperature optima, preventing their effective substitution for individual fungal enzymes in the set.   In an attempt to generate a bacterial minimum cellulase set compatible with T. reesei enzymes, we have cloned, expressed, and characterized 18 full-length glycosyl hydrolase genes from Acidothermus cellulyticus.  Results from experiments with individual enzymes and mixtures of the enzymes suggest that cellulose hydrolysis by Acidothermus cellulyticus proceeds via a different path than used by the T. reesei enzymes.