Abstract：
2\'-Fucosyllactose (2\'-FL) is a kind of fucosylated human milk oligosaccharide (HMO), representing the most abundant oligosaccharide in breast milk. We conducted systematic studies on three canonical α1,2-fucosyltransferases (WbgL, FucT2, and WcfB) to quantify the byproducts in a lacZ- and wcaJ-deleted Escherichia coli BL21(DE3) basic host strain. Further, we screened a highly active α1,2-fucosyltransferase from Helicobacter sp. 11S02629-2 (BKHT), which exhibits high in vivo 2\'-FL productivity without the formation of byproducts difucosyl lactose (DFL) and 3-FL. The maximum 2\'-FL titer and yield reached 11.13 g/L and 0.98 mol/mol of lactose, respectively, in shake-flask cultivation, both approaching the theoretical maximum value. In a 5 L fed-batch cultivation, the maximum 2\'-FL titer reached 94.7 g/L extracellularly with a yield of 0.98 mol of 2\'-FL/mol of lactose and productivity of 1.14 g L-1 h-1. Our reported 2\'-FL yield is the highest from lactose reported to date.
摘要：
2'-岩藻糖基乳糖(2'-FL)是一种岩藻糖基化人乳寡糖(HMO),代表母乳中最丰富的低聚糖。我们对三种典型的α1,2-岩藻糖基转移酶（WbgL，FucT2和WcfB）来定量lacZ和wcaJ缺失的大肠杆菌BL21（DE3）碱性宿主菌株中的副产物。Further,我们从螺杆菌中筛选出了一种高活性的α1,2-岩藻糖基转移酶。11S02629-2(BKHT),其表现出高的体内2'-FL生产率,而不形成副产物二岩藻糖基乳糖(DFL)和3-FL。最大2'-FL滴度和产量达到11.13g/L和0.98mol/mol乳糖，分别,在摇瓶培养中，都接近理论最大值。在5升补料分批培养中，最大2'-FL滴度在细胞外达到94.7g/L，产量为0.98mol2'-FL/mol乳糖，生产率为1.14gL-1h-1。我们报告的2'-FL产量是迄今为止报告的乳糖中最高的。
