重组大肠杆菌补救途径合成 2′-岩藻糖基乳糖的分子克隆和产物合成分析

2′-Fucosyllactose (2′-FL) is one of the most abundant oligosaccharides found in human milk, which delivering many health benefits to the neonate. It is now available in some commercial infant formulas with great market potentials. In this study, salvage pathway was constructed by comparing α-1,2-fucosyltransferases from different sources, and choosing the co-expression of fucT2 from Helicobacter pylori and fkp. Then by over-expressing the substrate transporter LacY and product transporter Tpyb or SetA, the extracellular concentration of 2′-FL was greatly increased. Comparing the production capacity of BL21(DE3), C41(DE3), and JM109(DE3), the 2′-FL synthetic strain J2-V8 was obtained. Finally, through the optimization of fermentation conditions, the extracellular concentration of 2′-FL was 2. 67 g/L in shaker for 48 h, which was 5 times higher than that of the initial strain, and the conversion rate was 0. 82 mol/mol L-fucose, which provided a reference for the biological production technology of 2′-FL.