He Penghui, Zhang Zeying, Cai Dongbo, Chen Yaozhong, Wang Hao, Wei Xuetuan, Li Shunyi, Chen Shouwen
Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, 430062, People's Republic of China.
College of Food Engineering, Wuchang Institute of Technology, Wuhan, 430065, People's Republic of China.
Biotechnol Lett. 2017 Sep;39(9):1389-1394. doi: 10.1007/s10529-017-2359-5. Epub 2017 May 23.
To improve target protein production by manipulating expression levels of alanine racemase in Bacillus licheniformis.
The gene of dal was identified to be responsible for alanine racemase function. Based on the selection marker of dal, a food-grade expression system was constructed in B. licheniformis, and effects of different dal expression levels mediated by promoters on α-amylase production were investigated. The highest α-amylase activity (155 U/ml) was obtained in BL10D/pP43SAT-PtetDal, increased by 27% compared with that of the control strain BL10/pP43SAT in tetracycline-based system (123 U/ml). Moreover, the dal transcriptional level was not correlated positively with that of amyL.
A food-grade system for high-level production of α-amylase was constructed in B. licheniformis, revealing that expression levels of selection marker significantly affected target protein production.
通过调控地衣芽孢杆菌中丙氨酸消旋酶的表达水平来提高目标蛋白产量。
鉴定出dal基因负责丙氨酸消旋酶功能。基于dal的筛选标记，在地衣芽孢杆菌中构建了食品级表达系统，并研究了启动子介导的不同dal表达水平对α-淀粉酶产生的影响。在BL10D/pP43SAT-PtetDal中获得了最高的α-淀粉酶活性（155 U/ml），与基于四环素系统中的对照菌株BL10/pP43SAT（123 U/ml）相比提高了27%。此外，dal转录水平与amyL的转录水平没有正相关。
在地衣芽孢杆菌中构建了用于高水平生产α-淀粉酶的食品级系统，表明筛选标记的表达水平显著影响目标蛋白产量。
