ARS | Publication request: PRETREATMENT AND HYDROLYSIS OF DISTILLER'S GRAINS TO FERMENTABLE SUGARS: AN INTEGRATED APPROACH BY THE MIDWEST CONSORTIUM FOR SUSTAINABLE BIOBASED PRODUCTS AND ENERGY

Submitted to: Corn Utilization Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 7, 2006
Publication Date: June 7, 2006
Citation: Cotta, M.A., Dien, B.S., Li, X., Ladisch, M., Mosier, N., Tyner, W., Woodson, R., Blaschek, H., Dale, B., Shanks, B., Verkade, J. 2006. Pretreatment and hydrolysis of distiller's grains to fermentable sugars: an integrated approach by the Midwest Consortium for sustainable biobased products and energy [abstract]. Corn Utilization. Paper No. 24.

Technical Abstract: Corn Distiller’s grains (DG) contain significant amounts of carbohydrates and protein. Further refining DG provides opportunities to increase its value by converting the fermentable carbohydrates to additional biofuels while simultaneously increasing the protein and decreasing the fiber contents of the residuals; opening up additional feed markets for the modified DG. A collaborative project has been planned among several Midwestern research groups with the combined expertise to develop and characterize new processing technologies for DG. The scope of the work is summarized below. 1. Chemical analysis: Distillers’ Dried Grains with Solubles (DDGS) were found to consist of (dry matter basis): 16.0% cellulose, 5.2% starch, 8.2% xylan, 10.7% oil (ethanol extractables), and 26.4% crude protein. 2. Pretreatments of DG: DG was treated with either buffered hot-water or ammonia fiber explosion (AFEX). Cellulose from the pretreated material was determined to be highly digestible with commercial cellulases. 3. Developing enzymes for saccharifying fibers to fermentable sugars: Commercial and custom blends of enzymes are being evaluated for further saccharifying xylan oligomers to arabinose, galactose, and xylose. Commercial enzyme preparations evaluated include pectinases and xylanases. Custom enzymes are being produced by culturing hydrolytic enzyme producing fungi on pretreated DG and harvesting the spent broth. 4. Fermentation to ethanol and butanol: DG associated sugars will be evaluated as a feedstock for fermentation to ethanol and butanol using: Ethanologenic E. coli strain FBR5, xylose fermenting yeast strain, or hyper-butanol producing Clostridium spp. strain. 5. Techno-economic and life-cycle analyses: Data gathered from the above steps will ultimately be used to derive processing models for the various pretreatments and bioproducts. These process options will be compared in terms of production and over-all environmental costs. The poster will review recent progress in each of the above mentioned research topics.