2022 Annual Meeting
Fed-Batch Cultivation As a Bioprocess Tool to Increase Lipid Accumulation and Carotenoid Production in Rhodosporidim Toruloides
Microbial lipids are a promising alternative oil source for the production of biofuels, food additives, pharmaceuticals, and chemicals. Using wood hydrolysate as a carbon source for cultivation can make microbial lipid production more economically feasible. In batch cultures, the oleaginous yeast Rhodosporidim toruloides is capable of accumulating up to 70% of its dry cell weight as lipids. In addition, R. toruloides has the capacity to produce valuable compounds like carotenoids. R. toruloides strains 1588 and 7191 were cultivated under fed-batch conditions as a tool to increase lipid accumulation and lipid productivity. Fed-batch cultures were run for 168 h in a bench-scale bioreactor using either synthetic media or undetoxified wood hydrolysate. R. torulides-7191 achieved the best lipid accumulation, biomass production, and carotenoid production at 67.5% (w/w), 19.3 g/L, 21.2 mg/L respectively when grown in synthetic media. In hydrolysate R. torulides-7191 maintained high lipid accumulation, but achieved maximum biomass and carotenoid concentrations of only 4.6 g/L and 3.68 mg/L. Lipids produced contained stearic, palmitic, and oleic fatty acids. This study shows the fed-batch fermentation process is an excellent tool to improve lipid accumulation and carotenoid production using R. toruloides, but that for some strains, hydrolysate can negatively affect growth.