Tuesday, April 20, 2010
10-45

Enzyme characterization of monocomponent enzymes and saccharification of ionic liquid pretreated lignocellulosic biomass

Christopher J. Barr1, Constance A. Schall1, and Jeffrey A. Mertens2. (1) Chemical and Environmental Engineering, University of Toledo, 2801 W. Bancroft St., Toledo, OH 43606, (2) Fermentation Biotechnology, USDA - ARS NCAUR, 1815 N. University St, Peoria, IL 61604

Lignocellulosic biomass is comprised of cellulose and hemicellulose, sources of polysaccharides, and lignin, a macromolecule with extensive aromaticity.  Terrestrial biomass can provide a renewable carbon based feedstock for fuel and chemical production.  However, recalcitrance of biomass to deconstruction poses the primary barrier to its commercial use as a feedstock.  Ionic liquid (IL) pretreatment followed by enzymatic hydrolysis can be used to saccharify the biomass into its monomeric sugars at a rate much higher than traditional pretreatment and hydrolysis methods.  Due to the amorphous structure of IL pretreated biomass, there are possibilities for creating simplified enzyme mixtures that can produce high glucan and xylan conversion to monomeric sugars at reduced enzyme loadings. 

In preparation for the hydrolysis, clones of Aspergillus nidulans cellulases and hemicellulases from the Fungal Stock Center at the University of Missouri are being expressed, isolated, purified and characterized for activity, thermal stability and substrate specificity.  Other enzyme sources include isolation and purification of component enzymes from commercial cellulase and hemicellulase mixtures. Enzymes which are critical for saccharification of biomass substrate are indentified.  Saccharification of IL-pretreated lignocellulosic biomass using defined enzyme mixtures are examined for efficacy in saccharification.