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Systematic metabolic engineering of Escherichia coli for high-yield production of fuel bio-chemical 2,3-butanediol

Paper ID Volume ID Publish Year Pages File Format Full-Text
31533 44810 2014 12 PDF Available
Title
Systematic metabolic engineering of Escherichia coli for high-yield production of fuel bio-chemical 2,3-butanediol
Abstract

•2,3-BD was selected as the target biofuel produced through recombinant E. coli.•Gene clusters in several native strains were compared for 2,3-BD production.•Expression of the most efficient gene cluster was optimized using different promoters.•Fermentative conditions were optimized by extracellular metabolite profile analysis.•2,3-BD production was highly acquired by systematically engineered E. coli.

The production of biofuels by recombinant Escherichia coli is restricted by the toxicity of the products. 2,3-Butanediol (2,3-BD), a platform and fuel bio-chemical with low toxicity to microbes, could be a promising alternative for biofuel production. However, the yield and productivity of 2,3-BD produced by recombinant E. coli strains are not sufficient for industrial scale fermentation. In this work, the production of 2,3-BD by recombinant E. coli strains was optimized by applying a systematic approach. 2,3-BD biosynthesis gene clusters were cloned from several native 2,3-BD producers, including Bacillus subtilis, Bacillus licheniformis, Klebsiella pneumoniae, Serratia marcescens, and Enterobacter cloacae, inserted into the expression vector pET28a, and compared for 2,3-BD synthesis. The recombinant strain E. coli BL21/pETPT7-EcABC, carrying the 2,3-BD pathway gene cluster from Enterobacter cloacae, showed the best ability to synthesize 2,3-BD. Thereafter, expression of the most efficient gene cluster was optimized by using different promoters, including PT7, Ptac, Pc, and Pabc. E. coli BL21/pET-RABC with Pabc as promoter was superior in 2,3-BD synthesis. On the basis of the results of biomass and extracellular metabolite profiling analyses, fermentation conditions, including pH, agitation speed, and aeration rate, were optimized for the efficient production of 2,3-BD. After fed-batch fermentation under the optimized conditions, 73.8 g/L of 2,3-BD was produced by using E. coli BL21/pET-RABC within 62 h. The values of both yield and productivity of 2,3-BD obtained with the optimized biological system are the highest ever achieved with an engineered E. coli strain. In addition to the 2,3-BD production, the systematic approach might also be used in the production of other important chemicals through recombinant E. coli strains.

Keywords
Escherichia coli; 2,3-Butanediol; Metabolic engineering; Promoter; Fermentation; Biofuel
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Publisher
Database: Elsevier - ScienceDirect
Journal: Metabolic Engineering - Volume 23, May 2014, Pages 22–33
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us