Production of single cell oil from Lipomyces starkeyi ATCC 56304 using biorefinery by-products

Single cell oil (SCO) is a valuable noncrop-based renewable oil source. Hemicellulose derived sugars can be utilized to produce SCO using the oleaginous yeast Lipomyces starkeyi ATCC 56304. Bran by-products were tested as hemicellulose-rich feedstocks for the production of SCO. Whole and destarched corn and wheat bran hydrolysates were produced using hydrothermal and dilute sulfuric acid (0%, 0.5%, 1.0%, v/v) pretreatment along with enzymatic hydrolysis. Whole bran hydrolysates produced from hydrothermal pretreatment generated the highest average oil yields of 126.7 and 124.3 mg oil/g sugar for both wheat and corn bran, respectively. 1.0% acid pretreatment was effective for the destarched bran generating a hemicellulose hydrolysis efficiency of 94% and 84% for wheat and corn bran, respectively, resulting in the highest oil yield of 70.7 mg oil/g sugar. The results indicate pretreated corn and wheat bran hydrolysates can serve as viable feedstocks for oleaginous yeast SCO bioconversion.