Provided herein are host cells capable of producing a human milk oligosaccharide (HMO), such as yeast cells that are deficient in expression or activity of an endogenous oxidoreductase. Also provided are fermentation compositions including the disclosed host cells, as well as related methods of producing and recovering HMOs generated by the host cells.

A recombinant yeast for producing lacto-N-triose, and an application thereof, belonging to the bioengineering field wherein the recombinant yeast includes an amino acid sequence of a -N-acetylglucosaminyl transferase and a coding nucleic acid sequence thereof, and/or a disruption of a marker gene. The technical solution of the recombinant yeast has the advantages of easy availability of raw materials, simple and feasible method, suitable for industrial production, and excellent application prospects.