RESAB - Rational engeneering of cellulases for improved saccharification of biomass

Second generation bioethanol from lignocellulosic biomass is a key candidate for rapid reductions of fossil fuel consumption in the transport sector. However, the conversion of recalcitrant plant material to fermentable sugars remains a major challenge. This so-called saccharification process can be carried out in an environmentally sound way by a physical pretreatment followed by enzymatic hydrolysis, but the catalytic efficiency of the latter must be improved to increase commercial viability. One promising road to improvements is to replace key wild-type enzymes used currently with enzyme variants (mutants) that are optimized for industrial conditions. This project will develop such variants through rational protein engineering.
The pivotal point will be the interplay between scientific elucidation of factors and mechanisms that limit cellulolytic enzyme activity on one hand, and the design and production of specific variants that are less prone to the limiting factor, on the other. The necessary competences are already established with respectively the university- and industrial partners, and the project is set up to harvest the synergy of their synchronization.
Specifically we will use real-time enzyme assays and explicit kinetic modeling to obtain fundamental understanding of the regulation of cellulolytic activity. This understanding will be used as basis for rational and semi-rational choices for amino acid replacements, and variant candidates identified in this way, will be produced by site-directed mutagenesis.
The iteration of design and experimental analysis will serve to elucidate both the industrial potential of the variants and the soundness of the scientific interpretations and -predictions.