α-Farnesene production from lipid by engineered Yarrowia lipolytica

Producing high value-added products from waste lipid feedstock by microbial cell factory has great advantages to minimize the pollution as well as improve the economic value of wasted oils and fats. Yarrowia lipolytica is a non-conventional oleaginous yeast and can grow on a variety of hydrophobic substrates. In this study, we explored its ability to synthesize alpha-farnesene, an important sesquiterpene, using lipid feedstock. Based on the alpha-farnesene production strain, we constructed previously, we identified that Erg12 was the key limiting factor to further increase the alpha-farnesene production. The alpha-farnesene production was improved by 35.8% through increasing the copy number of ERG12 and FSERG20 on oleic acid substrate. Expression of heterologous VHb further improved alpha-farnesene production by 12.7%. Combining metabolic engineering with the optimization of fermentation conditions, the alpha-farnesene titer and yield reached 10.2 g/L and 0.1 g/g oleic acid, respectively, in fed-batch cultivation. The alpha-farnesene synthesis ability on waste cooking oil and other edible oils were also explored. Compared with using glucose as carbon source, using lipid substrates obtained higher alpha-farnesene yield and titer, but lower by-products accumulation, demonstrating the advantage of Y. lipolytica to synthesize high value-added products using lipid feedstock.