Yarrowia lipolytica is an oleaginous yeast species recognized for its exceptional ability to produce and accumulate high levels of intracellular lipids. The fatty acid composition of the lipids produced by Y. lipolytica is diverse and highly dependent on culture conditions. This study aimed to investigate the effects of different culture conditions on the fatty acid composition of microbial oil derived from Y. lipolytica yeast. The primary objective was to identify the variations in oil composition produced under different culture conditions in the fed-batch mode.

Initially, inoculum cultures were prepared in 1.0 dm³ YPG medium (yeast extract: 10.0 g; peptone: 20.0 g; glucose: 20.0 g; pH 5.0) and incubated at 28 °C for 24 hours with continuous shaking. Y. lipolytica was then cultured in a 4 L laboratory bioreactor using the fed-batch method. The bioreactor was maintained at 28 °C, with the agitator speed adjusted from 200 to 600 rpm during fed-batch culture to regulate aeration and to keep the oxygen level within 20% of the initial substrate oxygenation using a cascade system. The culture was periodically fed with fresh YPG medium at specific intervals to sustain yeast growth and lipid production. Two variants of culture conditions were employed, with a partial renewal of the growth culture at different time intervals (24 hours and 12 hours).

The results showed that changes in culture conditions did not lead to significant differences in the fatty acid composition. For instance, the fatty acid compositions obtained at 24-hour and 12-hour intervals were similar and mostly contained palmitic (C16:0), oleic (C18:1), and linoleic (C18:2) acids. The composition was mimicking rapeseed oil. Still, the culture mode influenced microbial oil yield. The obtained data may guide future research involving Yarrowia lipolytica as a platform for sustainable oil production.