Wang Ziqiang, Wang Yunshan, Shi Hong, Su Zhiguo
National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
Appl Biochem Biotechnol. 2014 Apr;172(8):3989-4001. doi: 10.1007/s12010-014-0830-5. Epub 2014 Mar 6.
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.
利用具有顺式环氧琥珀酸水解酶（ESH）活性的大肠杆菌工程菌催化顺式环氧琥珀酸立体选择性水解生成L-(+)-酒石酸。研究了底物组成对L-(+)-酒石酸生产效率的影响。基于钠型均相底物体系，设计了一种由1.2 M钠型底物和1.8 M钙型底物组成的非均相底物体系，以提高ESH的催化效率。经过工艺优化，在非均相底物体系中采用补料分批模式获得了9.37×10(-3) g U(-1) h(-1)的催化效率，与传统的利用酒石酸诺卡氏菌细胞的生物转化工艺相比提高了约两倍。在15 m(3)搅拌釜式反应器中进行了放大试验，结果表明该非均相底物体系在L-(+)-酒石酸工业化生产中具有广阔的应用前景。
