文献类型：期刊文献

英文题名：A novel nitrilase from Ralstonia eutropha H16 and its application to nicotinic acid production

作者：Fan, Haiyang[1];Chen, Lifeng[1];Sun, Huihui[2];Wang, Hualei[1];Ren, Yuhong[1];Wei, Dongzhi[1]

机构：[1]East China Univ Sci & Technol, New World Inst Biotechnol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Chinese Acad Fishery Sci, Yellow Sea Fisheries Res Inst, Qingdao 266071, Shandong, Peoples R China

年份：2017

卷号：40

期号：8

起止页码：1271

外文期刊名：BIOPROCESS AND BIOSYSTEMS ENGINEERING

收录：;EI(收录号：20172303739073);WOS:【SCI-EXPANDED(收录号:WOS:000405490000012)】；

基金：This work was supported by the National Natural Science Foundation of China (Grant No. 21406068/B060804), the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：Nitrilase; Ralstonia eutropha; Nicotinic acid; Biotransformation

摘要：A novel aliphatic nitrilase, REH16, was found in Ralstonia eutropha H16 and overexpressed in Escherichia coli BL21(DE3), and its enzymatic properties were studied. The temperature and pH optima were 37 A degrees C and 6.6, respectively, and the best thermostability of the nitrilase was observed at 25 A degrees C, which preserved 95% of activity after 120 h of incubation. REH16 has a broad hydrolytic activity toward aliphatic and heterocyclic nitriles and showed high tolerance of 3-cyanopyridine; this enzyme could hydrolyze as high as 100 mM 3-cyanopyridine completely. To improve the 3-cyanopyridine conversion efficiency in an aqueous reaction system, water-miscible organic solvents were tested, and ethanol (10% v/v) was chosen as the optimal co-solvent. Finally, under optimized conditions, using the fed-batch reaction mode, total of 1050 mM 3-cyanopyridine was hydrolyzed completely in 20.8 h with eight substrate feedings, yielding 129.2 g/L production of nicotinic acid and thus showing a potential for industrial application.