Enhanced extracellular gamma glutamyl transpeptidase production by overexpressing of PrsA lipoproteins and improving its mRNA stability in Bacillus subtilis and application in biosynthesis of L-theanine
Enhanced extracellular gamma glutamyl transpeptidase production by overexpressing of PrsA lipoproteins and improving its mRNA stability in Bacillus subtilis and application in biosynthesis of L-theanine
复制标题
通过过表达 PrsA 脂蛋白增强细胞外 γ 谷氨酰转肽酶的产生并提高其在枯草芽孢杆菌中的 mRNA 稳定性以及在 L-茶氨酸生物合成中的应用。
DOI：
10.1016/j.jbiotec.2019.06.302
复制
发表时间：
2019-08-20
影响因子：
4.1
通讯作者：
Rao, Zhiming
中科院分区：
文献类型：
--
作者：
Yang, Taowei;Irene, Komera;Rao, Zhiming
L-theanine, an amino acid known for its favourable taste and linked with health benefits, can be prepared by enzymatic synthesis using gamma-glutamyltranspeptidase (GGT; E.C 2.3.2.2). In the present study, a novel GGT from Bacillus pumilus ML413 was expressed in Bacillus subtlis 168 and exhibited high stability at low temperature (40 degrees C) and alkaline pH 10, compared to the other GGTs. To enhance GGT production, firstly, PrsA lipoproteins was overexpressed in the host which resulted in the extracellular GGT activity doubled. Subsequently, a suitable poly (A/T) tail (TTTAAA) was selected and added to the 3'-terminal of ggt gene, which increased the mRNA stability of ggt gene by 58% and the activity of GGT by 60%. Finally, under optimized fed batch system, L-theanine yield was 53 g l(-1) within 16 h. In this study, we demonstrate a convenient strategy of increasing theanine yield using GGT overexpressing in a safe host B. subtilis 168.
