Engineering a colanic acid biosynthesis pathway in E. coli for manufacturing 2’-fucosyllactose

• DOI: 10.1016/j.procbio.2020.04.017
• Publication Date: 2020-04-19T22:30:34Z
• Authors: Qiao Chen; Haiying Wu; Minghua Ji; Yukang Xie; Sijie Li; Yiqing Li; Jiping Shi; Junsong Sun
• Keywords: 0106 biological sciences; 01 natural sciences

Abstract Human milk oligosaccharides (HMOs) are beneficial for infants’ health and growth. As one of the most abundant oligosaccharides in human milk, 2′-fucosyllactose (2′-FL) has been approved to supplement in infant formula. Microbial synthesis of 2′-FL achieved in E. coli tends to use a T7-expression system for the heterologous expression of the fucosyltransferase and/or enzymes involved in fucose metabolism. In this paper, we report a novel bioconversion route of 2′-FL by engineering a low pH triggered colanic acid (CA) synthetic pathway, found in E. coli S17−3, which supplies GDP- l -fucose for in vivo 2′-FL formation catalyzed by the heterologous α-1,2-fucosyltransferases. In medium added with 10 g/L lactose and 20 g/L glycerol, recombinant S17−3 was able to produce 0.617 g/L of 2′-FL. The concentration of 2′-FL came to 1.029 g/L when a heterologous pathway for the synthesis of polyhydroxybutyrate was additionally introduced in the engineered S17−3.