Undergraduate Honors Theses

Thesis Defended

Fall 2013

Document Type

Thesis

Department

Chemistry & Biochemistry

First Advisor

Dr. Zhongping Tan

Abstract

There exists a pressing necessity for the emergence of alternative liquid fuel sources apart from fossil fuels. The second greatest fuel source produced currently is derived from biomass through first and second generation biofuels. One major limitation towards implementing the more sustainable second generation biofuels is the efficient saccharification of lignocellulosic biomass (derived primarily from agricultural and forest waste and the most abundant biomass source on Earth) by cellulase enzymes. Towards this end, there is a large effort to enhance to stability and productivity of cellulases through various methods such as amino acid substitutions, domain shuffling, and glycosylation manipulation. Reported here is the positive impact of Oglycosylation manipulation of the carbohydrate binding module (CBM) of the industrially relevant Cel7A cellulase. We found that O-glycans could enhance the CBM affinity towards crystalline cellulose and could modulate adsorption productivity onto model cellulose systems. Lastly, it was confirmed that the Cel7A CBM can adsorb Kraft lignin and additionally that adsorption could be inhibited through glycosylation. These results will help open the door to a more rationally driven experimental approach to glycosylation in cellulases. Moreover, through the predicted cellulase activity enhancement that could be gained through glycosylation manipulation it is hopeful that the emergence of second generation biofuels will be a more immediate reality.

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