Zou Chun, Duan Xuguo, Wu Jing
State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.
School of Biotechnology, Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.
J Ind Microbiol Biotechnol. 2016 Apr;43(4):495-504. doi: 10.1007/s10295-015-1719-1. Epub 2015 Dec 26.
In this study, the pullulanase gene from Bacillus deramificans was efficiently expressed in Brevibacillus choshinensis. The optimal medium for protein expression was determined through a combination of single-factor experiments and response surface methodology. The initial pH of the medium and the culture temperature were optimized. The pullulanase yield increased 10.8-fold through medium and condition optimization at the shake-flask level. From the results of these experiments, the dissolved oxygen level was optimized in a 3-L fermentor. Under these optimized conditions, the pullulanase activity and the specific pullulanase productivity reached 1005.8 U/mL and 110.5 × 10(3) U/g dry cell weight, respectively, with negligible intracellular expression. The Brevibacillus choshinensis expression system has proven to be valuable for the extracellular production of pullulanase.
在本研究中，解淀粉芽孢杆菌的支链淀粉酶基因在长孢短芽孢杆菌中得到高效表达。通过单因素实验和响应面法相结合的方式确定了蛋白质表达的最佳培养基。对培养基的初始pH值和培养温度进行了优化。在摇瓶水平上，通过培养基和培养条件的优化，支链淀粉酶产量提高了10.8倍。根据这些实验结果，在3-L发酵罐中对溶解氧水平进行了优化。在这些优化条件下，支链淀粉酶活性和比支链淀粉酶生产率分别达到1005.8 U/mL和110.5×10³ U/g干细胞重量，细胞内表达可忽略不计。长孢短芽孢杆菌表达系统已被证明对于支链淀粉酶的胞外生产具有重要价值。
