文献类型：期刊文献

英文题名：Engineered Expression Vectors Significantly Enhanced the Production of 2-Keto-D-gluconic Acid by Gluconobacter oxidans

作者：Shi, Yuan-yuan[1];Li, Ke-fei[1];Lin, Jin-ping[1];Yang, Sheng-li[1];Wei, Dong-zhi[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China

年份：2015

卷号：63

期号：22

起止页码：5492

外文期刊名：JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY

收录：;EI(收录号：20152500952446);WOS:【SCI-EXPANDED(收录号:WOS:000356316800022)】；

基金：This study was financially supported by the National Key Basic Research Development Program of China (Grant 2012CB721003), the Natural Science Foundation of China (Grant 21276084), the Shanghai Natural Science Foundation (Grant 15ZR1408600), the National Major Science and Technology Projects of China (Grant 2012ZX09304009), and the Fundamental Research Funds of the Central Universities.

语种：英文

外文关键词：expression vectors; plasmid copy number; Gluconobacter oxidans; overexpression; 2-keto-D-gluconic acid

摘要：2-Keto-d-gluconic acid (2KGA), a precursor of the important food antioxidant erythorbic acid, can be produced by Gluconobacter oxidans. To genetically engineer G. oxidans for improved 2KGA production, six new expression vectors with increased copy numbers based on pBBR1MCS-5 were constructed via rational mutagenesis. The utility of the mutant vectors was demonstrated by the increased ga2dh mRNA abundance, enzyme activity, and 2KGA production when the ga2dh gene was overexpressed using these vectors. Among the obtained constructs, G. oxidans/pBBR-3510-ga2dh displayed the highest oxidative activity toward gluconic acid (GA). In a batch biotransformation process, the G. oxidans/pBBR-3510-ga2dh strain exhibited 2KGA productivity (0.63 g/g CWW/h) higher than that obtained using strain G. oxidans/pBBR-ga2dh (0.40 g/g CWW/h). When sufficient oxygen was supplied during the biotransformation, up to 480 g/L GA was exhausted in 45 h by the G. oxidans/pBBR-3510-ga2dh strain and approximately 486 g/L 2KGA was produced, generating the productivity of 0.54 g/g CWW/h.