Doo Eun-Hee, Lee Won-Heong, Seo Hyo-Seel, Seo Jin-Ho, Park Jin-Byung
Department of Food Science & Engineering, Ewha Womans University, Seoul 120-750, Republic of Korea.
J Biotechnol. 2009 Jun 15;142(2):164-9. doi: 10.1016/j.jbiotec.2009.04.008. Epub 2009 May 3.
The biocatalytic efficiency of recombinant Corynebacterium glutamicum expressing the chnB gene encoding cyclohexanone monooxygenase (CHMO) of Acinetobacter calcoaceticus NCIMB 9871 was investigated. Optimization of an expression system and induction conditions enabled the recombinant biocatalyst to produce CHMO to a specific activity of ca. 0.5 U mg(-1) protein. Tight control of feeding of an energy source (i.e., glucose) and dissolved oxygen tension during fed-batch culture-based biotransformation allowed the cells to produce epsilon-caprolactone to a concentration of 16.0 g l(-1). The specific and volumetric productivity for cyclohexanone oxidation were 0.12 g g drycells(-1)h(-1) (17.5 U g(-1) of dry cells) and 2.3 g l(-1)h(-1) (330 U l(-1)), respectively. These values correspond to over 5.4- and 2.7-fold of recombinant Escherichia coli expressing the same gene under similar reaction conditions. It could be concluded that the recombinant C. glutamicum is a promising biocatalyst for Baeyer-Villiger oxidations.
研究了表达编码乙酸钙不动杆菌NCIMB 9871环己酮单加氧酶（CHMO）的chnB基因的重组谷氨酸棒杆菌的生物催化效率。表达系统和诱导条件的优化使重组生物催化剂产生的CHMO比活性约为0.5 U mg(-1)蛋白质。在基于补料分批培养的生物转化过程中，严格控制能量源（即葡萄糖）的进料和溶解氧张力，使细胞能够产生浓度为16.0 g l(-1)的ε-己内酯。环己酮氧化的比生产率和体积生产率分别为0.12 g g干细胞(-1)h(-1)（17.5 U g(-1)干细胞）和2.3 g l(-1)h(-1)（330 U l(-1)）。这些值分别是在相似反应条件下表达相同基因的重组大肠杆菌的5.4倍和2.7倍以上。可以得出结论，重组谷氨酸棒杆菌是用于拜耳-维利格氧化反应的有前途的生物催化剂。
