Fermentative production and direct extraction of (−)-α-bisabolol in metabolically engineered Escherichia coli

Microbial Cell Factories

Research

Bong Hyun Sung¹  Byoung Su Kim²  Seon-Won Kim³  Younghwan Kang⁴  Yaoyao Fu⁴  Heung Chae Jung⁴  Gui Hwan Han⁴  Seong Keun Kim⁵  Seung-Goo Lee⁵  Dae-Hee Lee⁵  Paul Kyung-Seok Yoon⁶ 

[1] Bioenergy and Biochemical Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 34141, Daejeon, Republic of Korea;Department of Biotechnology, Chonnam National University, 550749, Yeosu, Republic of Korea;Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, 52828, Jinju, Republic of Korea;Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 34141, Daejeon, Republic of Korea;Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 34141, Daejeon, Republic of Korea;Biosystems and Bioengineering Program, University of Science and Technology (UST), 34113, Daejeon, Republic of Korea;Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 34141, Daejeon, Republic of Korea;Department of Chemical and Biological Engineering, Korea University, 02841, Seoul, Republic of Korea;

关键词: (−)-α-Bisabolol;    (−)-α-Bisabolol synthase;    Mevalonate pathway;    Farnesyl diphosphate synthase;    In situ extraction;    Vegetable oils;    Escherichia coli;   

DOI  :  10.1186/s12934-016-0588-2

 received in 2016-06-09, accepted in 2016-11-02,  发布年份 2016

来源: Springer

【 摘 要 】

Background(−)-α-Bisabolol, also known as levomenol, is an unsaturated sesquiterpene alcohol that has mainly been used in pharmaceutical and cosmetic products due to its anti-inflammatory and skin-soothing properties. (−)-α-Bisabolol is currently manufactured mainly by steam-distillation of the essential oils extracted from the Brazilian candeia tree that is under threat because its natural habitat is constantly shrinking. Therefore, microbial production of (−)-α-bisabolol plays a key role in the development of its sustainable production from renewable feedstock.ResultsHere, we created an Escherichia coli strain producing (−)-α-bisabolol at high titer and developed an in situ extraction method of (−)-α-bisabolol, using natural vegetable oils. We expressed a recently identified (−)-α-bisabolol synthase isolated from German chamomile (Matricaria recutita) (titer: 3 mg/L), converted the acetyl-CoA to mevalonate, using the biosynthetic mevalonate pathway (12.8 mg/L), and overexpressed farnesyl diphosphate synthase to efficiently supply the (−)-α-bisabolol precursor farnesyl diphosphate. Combinatorial expression of the exogenous mevalonate pathway and farnesyl diphosphate synthase enabled a dramatic increase in (−)-α-bisabolol production in the shake flask culture (80 mg/L) and 5 L bioreactor culture (342 mg/L) of engineered E. coli harboring (−)-α-bisabolol synthase. Fed-batch fermentation using a 50 L fermenter was conducted after optimizing culture conditions, resulting in efficient (−)-α-bisabolol production with a titer of 9.1 g/L. Moreover, a green, downstream extraction process using vegetable oils was developed for in situ extraction of (−)-α-bisabolol during fermentation and showed high yield recovery (>98%).ConclusionsThe engineered E. coli strains and economically viable extraction process developed in this study will serve as promising platforms for further development of microbial production of (−)-α-bisabolol at large scale.

【 授权许可】

CC BY   
© The Author(s) 2016