title: Improvement of the production efficiency of L-(+)-tartaric acid by heterogeneous whole-cell bioconversion.
abstract: An Escherichia coli-engineered bacterium with cis-epoxysuccinate hydrolase (ESH) activity was used to catalyze the stereospecific hydrolysis of cis-epoxysuccinic acid to L-(+)-tartaric acid. The effect of the substrate composition on the production efficiency of L-(+)-tartaric acid was investigated. Based on the sodium-type homogeneous substrate system, a heterogeneous substrate system, composed of 1.2 M sodium-type substrate and 1.8 M calcium-type substrate, was designed to improve ESH catalytic efficiency. After process optimization, a catalytic efficiency of 9.37 × 10(-3) g U(-1) h(-1) was obtained with fed-batch mode in the heterogeneous substrate system, about a twofold increase compared to the traditional bioconversion process with Nocardia tartaricans cells. The scale-up tests were carried out in a 15-m(3) stirred tank reactor, which indicated that the heterogeneous substrate system had great application prospect for the L-(+)-tartaric acid industrial production.
authors.affiliation: National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
authors.forename: Ziqiang
authors.initials: Z
authors.lastname: Wang
authors.forename: Yunshan
authors.initials: Y
authors.lastname: Wang
authors.forename: Hong
authors.initials: H
authors.lastname: Shi
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Su
mesh_terms: D061249:Batch Cell Culture Techniques; D055162:Biocatalysis; D019149:Bioreactors / Q000382:microbiology; D001709:Biotechnology / Q000379:methods*; D001711:Biotransformation; D004926:Escherichia coli / Q000235:genetics; D005818:Genetic Engineering; D006867:Hydrolases / Q000235:genetics / Q000378:metabolism; D009615:Nocardia / Q000166:cytology / Q000235:genetics* / Q000378:metabolism*; D013379:Substrate Specificity; D013644:Tartrates / Q000378:metabolism*
chemical_list: D013644:Tartrates; D006867:Hydrolases; C492296:cis-epoxysuccinate hydrolase, Nocardia tartaricans; C029768:tartaric acid