Biosynthesis of chiral 3-hydroxyvalerate from single propionate-unrelated carbon sources in metabolically engineered E. coli

Microbial Cell Factories

Research

Hsien-Chung Tseng¹  Catey L Harwell¹  Kristala LJ Prather²  Collin H Martin³ 

[1] Department of Chemical Engineering, Massachusetts Institute of Technology, 02139, Cambridge, MA, USA;Department of Chemical Engineering, Massachusetts Institute of Technology, 02139, Cambridge, MA, USA;Synthetic Biology Engineering Research Center (SynBERC), Massachusetts Institute of Technology, 02139, Cambridge, MA, USA;Department of Chemical Engineering, Massachusetts Institute of Technology, 02139, Cambridge, MA, USA;Synthetic Biology Engineering Research Center (SynBERC), Massachusetts Institute of Technology, 02139, Cambridge, MA, USA;Dow Chemical Company, 19477, Spring House, PA, USA;

关键词: PHBV;    Levulinic Acid;    Multiple Cloning Site;    Single Carbon Source;    Threonine Deaminase;   

DOI  :  10.1186/1475-2859-9-96

 received in 2010-09-28, accepted in 2010-11-27,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundThe ability to synthesize chiral building block molecules with high optical purity is of considerable importance to the fine chemical and pharmaceutical industries. Production of one such compound, 3-hydroxyvalerate (3HV), has previously been studied with respect to the in vivo or in vitro enzymatic depolymerization of biologically-derived co-polymers of poly(3-hydroxybutyrate-co-3-hydroxyvalerate). However, production of this biopolymeric precursor typically necessitates the supplementation of a secondary carbon source (e.g., propionate) into the culture medium. In addition, previous approaches for producing 3HV have not focused on its enantiopure synthesis, and thus suffer from increased costs for product purification.ResultsHere, we report the selective biosynthesis of each 3HV stereoisomer from a single, renewable carbon source using synthetic metabolic pathways in recombinant strains of Escherichia coli. The product chirality was controlled by utilizing two reductases of opposing stereoselectivity. Improvement of the biosynthetic pathway activity and host background was carried out to elevate both the 3HV titers and 3HV/3HB ratios. Overall, shake-flask titers as high as 0.31 g/L and 0.50 g/L of (S)-3HV and (R)-3HV, respectively, were achieved in glucose-fed cultures, whereas glycerol-fed cultures yielded up to 0.19 g/L and 0.96 g/L of (S)-3HV and (R)-3HV, respectively.ConclusionsOur work represents the first report of direct microbial production of enantiomerically pure 3HV from a single carbon source. Continued engineering of host strains and pathway enzymes will ultimately lead to more economical production of chiral 3HV.

【 授权许可】

Unknown   
© Tseng et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.