State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu Road South, Nanjing 211816, China.
Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, No. 30, Puzhu Road South, Nanjing 211816, China.
ACS Synth Biol. 2021 Nov 19;10(11):3129-3138. doi: 10.1021/acssynbio.1c00405. Epub 2021 Oct 29.
Bioconversion of acetate, a byproduct generated in industrial processes, into microbial lipids using oleaginous yeasts offers a promising alternative for the economic utilization of acetate-containing waste streams. However, high acetate concentrations will inhibit microbial growth and metabolism. In this study, the acetate utilization capability of PO1f was successively improved by overexpressing the key enzyme of acetyl-CoA synthetase (ACS), which resulted in an accumulation of 9.2% microbial lipids from acetate in shake flask fermentation. By further overexpressing the second key enzymes of acetyl-CoA carboxylase (ACC1) and fatty acid synthase (FAS) in , the lipid content was increased to 25.7% from acetate. Finally, the maximum OD of 29.2 and a lipid content of 41.7% were obtained with the engineered strain by the adoption of cosubstrate (glycerol and acetate) fed-batch fermentation, which corresponded to an increase of 68 and 95%, respectively. These results presented a promising strategy for economic and efficient microbial lipid production from the waste acetate.
利用产油酵母将工业过程中产生的副产物乙酸转化为微生物油脂，为经济利用含乙酸的废物流提供了一种有前途的方法。然而，高浓度的乙酸会抑制微生物的生长和代谢。在这项研究中，通过过表达关键酶乙酰辅酶 A 合成酶（ACS），成功地提高了 PO1f 对乙酸的利用能力，在摇瓶发酵中乙酸积累了 9.2%的微生物油脂。通过进一步过表达第二关键酶乙酰辅酶 A 羧化酶（ACC1）和脂肪酸合酶（FAS），从乙酸中积累的油脂含量增加到 25.7%。最后，通过采用共底物（甘油和乙酸）分批补料发酵，工程菌的最大 OD 值达到 29.2，油脂含量达到 41.7%，分别提高了 68%和 95%。这些结果为从废乙酸中经济高效地生产微生物油脂提供了一种很有前景的策略。
