Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6964988 | Metabolic Engineering Communications | 2018 | 9 Pages |
Abstract
(R)-acetoin is a four-carbon platform compound used as the precursor for synthesizing novel optically active materials. Ethylene glycol (EG) is a large-volume two-carbon commodity chemical used as the anti-freezing agent and building-block molecule for various polymers. Currently established microbial fermentation processes for converting monosaccharides to either (R)-acetoin or EG are plagued by the formation of undesirable by-products. We show here that a cell-free bioreaction scheme can generate enantiomerically pure acetoin and EG as co-products from biomass-derived D-xylose. The seven-step, ATP-free system included in situ cofactor regeneration and recruited enzymes from Escherichia coli W3110, Bacillus subtilis shaijiu 32 and Caulobacter crescentus CB 2. Optimized in vitro biocatalytic conditions generated 3.2â¯mM (R)-acetoin with stereoisomeric purity of 99.5% from 10â¯mM D-xylose at 30â¯Â°C and pH 7.5 after 24â¯h, with an initial (R)-acetoin productivity of 1.0â¯mM/h. Concomitantly, EG was produced at 5.5â¯mM, with an initial productivity of 1.7â¯mM/h. This in vitro biocatalytic platform illustrates the potential for production of multiple value-added biomolecules from biomass-based sugars with no ATP requirement.
Keywords
EMPflavin adenine dinucleotideThDPIn vitro metabolic engineeringIPTGBSANAD+bovine serum albuminEthylene glycolsodium dodecyl sulfate-polyacrylamide gel electrophoresisSDS-PAGEoxidized nicotinamide adenine dinucleotideisopropyl-β-d-thiogalactopyranosideCofactor regenerationFADEnantiomeric excessThiamine diphosphated-Xyloselysogeny brothNADHPETPolyethylene terephthalatepentose phosphatereduced nicotinamide adenine dinucleotidehigh-pressure liquid chromatographyHPLCGas chromatography
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Bioengineering
Authors
Xiaojing Jia, Robert M. Kelly, Yejun Han,