Danhui Hao1, Haiqin Chen2,3, Guangfei Hao1,4, Bo Yang1,4, Baixi Zhang1,4, Hao Zhang1,4, Wei Chen1,4, Yong Q Chen1,4,5. 1. State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, People's Republic of China. 2. State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, People's Republic of China. haiqinchen@jiangnan.edu.cn. 3. Synergistic Innovation Center for Food Safety and Nutrition, Wuxi, 214122, People's Republic of China. haiqinchen@jiangnan.edu.cn. 4. Synergistic Innovation Center for Food Safety and Nutrition, Wuxi, 214122, People's Republic of China. 5. Departments of Cancer Biology and Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA.
Abstract
OBJECTIVE: To increase the commercial value of oleaginous fungus Mortierella alpina by incorporation of trans-10,cis-12 conjugated linoleic acid (CLA) into the polyunsaturated fatty acids (PUFAs) of M. alpina via Propionibacterium acnes isomerase (PAI) conversion. RESULTS: The PAI gene and the codon optimization version were heterologously expressed in M. alpina via Agrobacterium tumefaciens-mediated transformation (ATMT). Coding usage modification significantly improved the translation of PAI transcripts and trans-10,cis-12 CLA was produced up to 1.2 mg l(-1), which corresponds to approx. 0.05% of the total fatty acid (TFA). Since PAI prefers free linoleic acid as a substrate rather than any other forms, 5 μM long-chain acyl CoA synthetase inhibitor was added and the trans-10,cis-12 CLA content increased approx. 24-fold to 29 mg l(-1), reaching up to 1.2% (w/w) of the TFA in M. alpina. CONCLUSION: Heterologous expression of PAI in M. alpina by ATMT methods is a practicable way in biosynthesis of CLA and this system may be a feasible platform for industrial production of CLA.
OBJECTIVE: To increase the commercial value of oleaginous fungus Mortierella alpina by incorporation of trans-10,cis-12 conjugated linoleic acid (CLA) into the polyunsaturated fatty acids (PUFAs) of M. alpina via Propionibacterium acnes isomerase (PAI) conversion. RESULTS: The PAI gene and the codon optimization version were heterologously expressed in M. alpina via Agrobacterium tumefaciens-mediated transformation (ATMT). Coding usage modification significantly improved the translation of PAI transcripts and trans-10,cis-12 CLA was produced up to 1.2 mg l(-1), which corresponds to approx. 0.05% of the total fatty acid (TFA). Since PAI prefers free linoleic acid as a substrate rather than any other forms, 5 μM long-chain acyl CoA synthetase inhibitor was added and the trans-10,cis-12 CLA content increased approx. 24-fold to 29 mg l(-1), reaching up to 1.2% (w/w) of the TFA in M. alpina. CONCLUSION: Heterologous expression of PAI in M. alpina by ATMT methods is a practicable way in biosynthesis of CLA and this system may be a feasible platform for industrial production of CLA.