Single cell oil production by Lipomyces starkeyi: Biphasic fed-batch fermentation strategy providing glucose for growth and xylose for oil production

Abstract

The aim of this study was to produce single cell oil (SCO) from Lipomyces starkeyi ATCC 56304 using a biphasic fed-batch fermentation strategy. Fed-batch fermentations were performed to compare oil production using glucose, xylose, mixed-sugars (1:1 ratio of glucose:xylose), and a biphasic system supplying glucose for cell growth and xylose for oil production. The fermentation using xylose as the sole carbon source generated an oil yield of 0.16gg−1 and a productivity of 0.12gL−1h−1, two-times the oil yield (0.08gg−1) and productivity (0.06gL−1h−1) achieved with glucose. At 120h, the biphasic fermentation produced a greater oil productivity (0.13gL−1h−1) compared to the mixed-sugar fermentation (0.09gL−1h−1) but similar oil productivities (0.14gL−1h−1) were achieved for both at longer fermentation times. The biphasic fermentation generated a final oil yield of 0.17gg−1 and an oil content of 60.1% (w w−1), but oil productivity showed minor improvement at 0.14gL−1h−1 after 255h. Oleic acid accounted for at least 65% of the fatty acid content, suggesting that oil from L. starkeyi has potential for application in the biofuel and oleochemical industries.