Mengya Zhao1, Chuanbo Zhang1, Haibin Wang1, Shifan He1, Wenyu Lu2,3,4. 1. School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China. 2. School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China. wenyulu@tju.edu.cn. 3. Key Laboratory of System Bioengineering (Tianjin University), Ministry of Education, Tianjin, People's Republic of China. wenyulu@tju.edu.cn. 4. Georgia Tech Shenzhen Institute, Tianjin University, Tangxing Road 133, Nanshan District, Shenzhen, 518071, People's Republic of China. wenyulu@tju.edu.cn.
Abstract
OBJECTIVE: To produce valerenic acid (VA) in Saccharomyces cerevisiae by engineering a heterologous synthetic pathway. RESULT: Valerena-4,7(11)-diene synthase (VDS) derived from Valeriana officinalis (valerian) was expressed in S. cerevisiae to generate valerena-4,7(11)-diene as the precursor of VA. By overexpressing the key genes of the mevalonate pathway ERG8, ERG12 and ERG19, and integrating 4 copies of MBP (maltose-binding protein)-VDS-ERG20 gene expression caskets into the genome, the production of valerena-4,7(11)-diene was improved to 75 mg/L. On this basis, the cytochrome P450 monooxygenase LsGAO2 derived from Lactuca sativa was expressed to oxidize valerena-4,7(11)-diene to produce VA, and the most effective VA production strain was used for fermentation. The yield of VA reached 2.8 mg/L in the flask and 6.8 mg/L in a 5-L bioreactor fed glucose. CONCLUSIONS: An S. cerevisiae strain was constructed and optimized to produce VA, but the valerena-4,7(11)-diene oxidation by LsGAO2 is still the rate-limiting step for VA synthesis that needs to be further optimized in future studies.
OBJECTIVE: To produce valerenic acid (VA) in Saccharomyces cerevisiae by engineering a heterologous synthetic pathway. RESULT: Valerena-4,7(11)-diene synthase (VDS) derived from Valeriana officinalis (valerian) was expressed in S. cerevisiae to generate valerena-4,7(11)-diene as the precursor of VA. By overexpressing the key genes of the mevalonate pathway ERG8, ERG12 and ERG19, and integrating 4 copies of MBP (maltose-binding protein)-VDS-ERG20 gene expression caskets into the genome, the production of valerena-4,7(11)-diene was improved to 75 mg/L. On this basis, the cytochrome P450 monooxygenase LsGAO2 derived from Lactuca sativa was expressed to oxidize valerena-4,7(11)-diene to produce VA, and the most effective VA production strain was used for fermentation. The yield of VA reached 2.8 mg/L in the flask and 6.8 mg/L in a 5-L bioreactor fed glucose. CONCLUSIONS: An S. cerevisiae strain was constructed and optimized to produce VA, but the valerena-4,7(11)-diene oxidation by LsGAO2 is still the rate-limiting step for VA synthesis that needs to be further optimized in future studies.
Authors: Vincent Ricigliano; Santosh Kumar; Scott Kinison; Christopher Brooks; S Eric Nybo; Joe Chappell; Dianella G Howarth Journal: Phytochemistry Date: 2016-02-23 Impact factor: 4.072
Authors: Yun-Soo Yeo; S Eric Nybo; Amar G Chittiboyina; Aruna D Weerasooriya; Yan-Hong Wang; Elsa Góngora-Castillo; Brieanne Vaillancourt; C Robin Buell; Dean DellaPenna; Mary Dawn Celiz; A Daniel Jones; Eve Syrkin Wurtele; Nick Ransom; Natalia Dudareva; Khaled A Shaaban; Nidhi Tibrewal; Suman Chandra; Troy Smillie; Ikhlas A Khan; Robert M Coates; David S Watt; Joe Chappell Journal: J Biol Chem Date: 2012-12-14 Impact factor: 5.157