Wang Jingrui, Tang Wei, Zheng Yongna, Xing Zhuqing, Wang Yanping
Key Laboratory of Food Nutrition and Safety, College of Food Engineering and Biotechnology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, 300457, China.
Arch Microbiol. 2016 Sep;198(7):611-8. doi: 10.1007/s00203-016-1217-5. Epub 2016 Apr 15.
A novel lactic acid bacteria strain Lactobacillus kefiranofaciens ZW3 exhibited the characteristics of high production of exopolysaccharide (EPS). The epsN gene, located in the eps gene cluster of this strain, is associated with EPS biosynthesis. Bioinformatics analysis of this gene was performed. The conserved domain analysis showed that the EpsN protein contained MATE-Wzx-like domains. Then the epsN gene was amplified to construct the recombinant expression vector pMG36e-epsN. The results showed that the EPS yields of the recombinants were significantly improved. By determining the yields of EPS and intracellular polysaccharide, it was considered that epsN gene could play its Wzx flippase role in the EPS biosynthesis. This is the first time to prove the effect of EpsN on L. kefiranofaciens EPS biosynthesis and further prove its functional property.
一种新型乳酸菌菌株开菲尔糖乳杆菌ZW3表现出高胞外多糖（EPS）产量的特性。位于该菌株eps基因簇中的epsN基因与EPS生物合成相关。对该基因进行了生物信息学分析。保守结构域分析表明，EpsN蛋白含有MATE-Wzx样结构域。然后扩增epsN基因以构建重组表达载体pMG36e-epsN。结果表明，重组体的EPS产量显著提高。通过测定EPS和细胞内多糖的产量，认为epsN基因在EPS生物合成中可以发挥其Wzx翻转酶的作用。这是首次证明EpsN对开菲尔糖乳杆菌EPS生物合成的影响，并进一步证明其功能特性。
