T74
Microbial lipid production from AFEXTM pretreated corn stover using an oleaginous yeast strain
Tuesday, April 29, 2014
Exhibit/Poster Hall, lower level (Hilton Clearwater Beach)
Yaping Xue1, Mingjie Jin2, Patricia J. Slininger3, Bruce S. Dien3, Bruce Dale4 and Venkatesh Balan5, (1)Department of Chemical Engineering and Materials Science, Michigan State University, Biomass Conversion Research Lab (BCRL), Lansing, MI, (2)Chemical Engineering and Materials Science,Great Lakes Bioenergy Research Center (GLBRC), Michigan State University, Lansing, MI, (3)National Center for Agricultural Utilization Research, USDA-ARS, Peoria, IL, (4)Department of Chemical Engineering and Materials Science, Michigan State University, DOE Great Lakes Bioenergy Research Center, Lansing, MI, (5)Department of Chemical Engineering and Materials Science,Great Lakes Bioenergy Research Center (GLBRC),Michigan State University, Biomass Conversion Research Laboratory (BCRL), Lansing, MI
The fatty acid profile of oleaginous yeast lipids is very similar to vegetable oils which have been used as substrate for biodiesel production. Yeast lipids offer great potential for biodiesel and jet fuel applications. Compared to vegetable lipids and animal lipids, the production of microbial lipids offers shorter life cycles, less labor, less vulnerability to location, season and climate, and easier scale up. Thus, microbial lipids might become a future biodiesel and jet fuel feedstock.

Commercial production of microbial lipids depends on the availability of carbohydrates in large quantities and at low cost. Lignocellulosic biomass may be one source of low-cost fermentable carbohydrates. Pretreatment prior to enzymatic hydrolysis is essential for achieving high sugar yields from lignocellulosic biomass. Among various pretreatment methods, Ammonia Fiber Expansion (AFEXTM) offers  low sugar degradation and moderate cost. This presentation describes our efforts in microbial lipid production from AFEXTM pretreated corn stover (AFEX-CS) using a native Lipomyces strain screened from many oleaginous yeast strains in AFEX-CS hydrolysate. Both glucose and xylose are consumed by this strain. The effects of different solids loading, degradation products, and minimal washing of AFEX-CS on lipids fermentation were investigated. Lipid concentrations of 8.4 g/L (in 120 h) and 10.7 g/L (in 96 h) were achieved in 7.5% glucan loading AFEX-CS hydrolysate and minimal washed AFEX-CS hydrolysate, respectively. Biomass degradation products did not affect yeast growth but did inhibit lipid biosynthesis. Process configurations for lipid production will also be discussed.

AFEX is a trademark of MBI, Lansing, Michigan.