Liu Yinghang, Wang Zhaoxuan, Cui Zhiyong, Qi Qingsheng, Hou Jin
State Key Laboratory of Microbial Technology, Shandong University, Binhai Road 72, Qingdao, 266237, People's Republic of China.
CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, People's Republic of China.
Bioresour Bioprocess. 2021 Aug 23;8(1):78. doi: 10.1186/s40643-021-00431-0.
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 α-farnesene, an important sesquiterpene, using lipid feedstock. Based on the α-farnesene production strain, we constructed previously, we identified that Erg12 was the key limiting factor to further increase the α-farnesene production. The α-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 α-farnesene production by 12.7%. Combining metabolic engineering with the optimization of fermentation conditions, the α-farnesene titer and yield reached 10.2 g/L and 0.1 g/g oleic acid, respectively, in fed-batch cultivation. The α-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 α-farnesene yield and titer, but lower by-products accumulation, demonstrating the advantage of Y. lipolytica to synthesize high value-added products using lipid feedstock.
利用微生物细胞工厂从废弃脂质原料生产高附加值产品，对于最大限度减少污染以及提高废油脂的经济价值具有巨大优势。解脂耶氏酵母是一种非常规产油酵母，能够在多种疏水底物上生长。在本研究中，我们探索了其利用脂质原料合成重要倍半萜α-法尼烯的能力。基于我们之前构建的α-法尼烯生产菌株，我们确定Erg12是进一步提高α-法尼烯产量的关键限制因素。通过在油酸底物上增加ERG12和FSERG20的拷贝数，α-法尼烯产量提高了35.8%。异源VHb的表达进一步使α-法尼烯产量提高了12.7%。将代谢工程与发酵条件优化相结合，在分批补料培养中，α-法尼烯的效价和产率分别达到10.2 g/L和0.1 g/g油酸。还探索了解脂耶氏酵母在废食用油和其他食用油上合成α-法尼烯的能力。与使用葡萄糖作为碳源相比，使用脂质底物可获得更高的α-法尼烯产量和效价，但副产物积累较少，这证明了解脂耶氏酵母利用脂质原料合成高附加值产品的优势。
