Engineered super-enzyme paves way for high-yield human milk oligosaccharide

2’-Fucosyllactose (2’-FL), the most abundant human milk oligosaccharides (HMOs), plays crucial biological roles in regulation of intestinal microbiota, inhibition of pathogen adhesion, and immune enhancement. Scientists have explored and characterized an efficient α-1,2-fucosyltransferase (FucT2) from Helicobacter himalayensis, which was introduced into recombinant strains engineered for overexpression of the de novo 2’-Fucosyllactose (2’-FL) biosynthetic pathway.
To enhance the titer of 2’-FL, they adopted a dual-module bypass gene knockout strategy to redirect metabolic flux using the CRISPR/Cas9 system. The Rcs cascade regulatory system was engineered to enhance precursor supply, and genes encoding glycosyltransferase and β-galactosidase were knocked out by disrupting substrate decomposition pathways. Through the composite application of global regulation and fermentation condition optimization, the titer of 2’-FL reached 11.02 g/L with fed-batch fermentation.
This study established a superior biocatalyst of α-1,2-fucosyltransferase as a key rate limiting part for 2’-FL manufacturing. It also developed an efficient microbial production platform with dual-module metabolic bypass knockout combined with global regulation for valuable human milk oligosaccharides with pharmaceutical and food applications.
The work entitled “Enhanced biosynthesis of 2’-Fucosyllactose in Escherichia coli through α-1,2-fucosyltransferase mining and pathway optimization” was published on Systems Microbiology and Biomanufacturing (published on Jan. 2, 2026).