The disclosure discloses genetically engineered bacteria producing lacto-N-neotetraose and a production method thereof, and belongs to the fields of metabolic engineering and food biotechnology. To solve the problem of low yield of lacto-N-neotetraose produced by a microbial method in the prior art, through exogenous expression of lgtA and lgtB, reasonable combination and regulation of overexpression of lacY, pgm, galE, galT and galK in a lacto-N-neotetraose synthesis pathway, knockout of lacZ expression in an Escherichia coli host, and optimization of a carbon source in the culture process, the disclosure achieves the objectives of regulating the carbon flux of a metabolic pathway and improving the yield of lacto-N-neotetraose. In a shake flask experiment, the yield of lacto-N-neotetraose produced by E. coli increased from 304 mg/L to 1031 mg/L, laying a foundation for industrial production of the lacto-N-neotetraose.

The invention relates to a genetically modified microorganism for making a oligosaccharide, preferably of 3-8 monosaccharide units, more preferably of 3-5 monosaccharide units, particularly a HMO, which comprises one or more genes encoding a sucrose utilization system, so the microorganism can use sucrose as a carbon and energy source.

The invention relates to a genetically modified microorganism for making a oligosaccharide, preferably of 3-8 monosaccharide units, more preferably of 3-5 monosaccharide units, particularly a HMO, which comprises one or more genes encoding a sucrose utilization system, so the microorganism can use sucrose as a carbon and energy source.

The invention relates to a genetically modified microorganism for making a recombinant oligosaccharide, preferably of 3-8 monosaccharide units, more preferably of 3-5 monosaccharide units, particularly a HMO, which comprises one or more genes encoding a sucrose utilization system, so the microorganism can use sucrose as a carbon and energy source. The one or more genes encoding a sucrose utilization system are preferably one or more genes encoding a heterologous PTS-dependent sucrose utilization transport system, such as the scr genes.

This disclosure is in the technical field of synthetic biology and metabolic engineering. More particularly, this disclosure is in the technical field of cultivation of metabolically engineered cells. This disclosure describes a method for the production of a glycosylated product derived from UDP-GlcNAc and comprising a di- or oligosaccharide that is composed of at least two different monosaccharide subunits by a cell as well as the separation of the glycosylated product from the cultivation. Furthermore, this disclosure provides a metabolically engineered cell for production of a glycosylated product derived from UDP-GlcNAc and comprising a di- or oligosaccharide that is composed of at least two different monosaccharide subunits. This disclosure also provides a cell excreting a di- or oligosaccharide out of the cell.

This invention relates to a method of producing mixtures of various human milk oligosaccharides (HMOs) with unique HMO blend profiles, consisting predominantly of LNFP-I and LNT and of other HMOs in less significant amounts. The less abundant HMOs might be 2-FL, LNT-II or DFL. The strategies for achieving specific HMO blends include strain engineering and fermentation methods.

The invention relates to a genetically modified microorganism for making a recombinant oligosaccharide, preferably of 3-8 monosaccharide units, more preferably of 3-5 monosaccharide units, particularly a HMO, which comprises one or more genes encoding a sucrose utilization system, so the microorganism can use sucrose as a carbon and energy source. The one or more genes encoding a sucrose utilization system are preferably one or more genes encoding a heterologous PTS-dependent sucrose utilization transport system, such as the scr genes.

The present disclosure relates to the production of sialylated Human Milk Oligosaccharides (HMOs), in particular to the production of sialyl-lacto-N-tetraose a (LST-a), from precursor oligosaccharides and the genetic engineering of suitable cells for use in said production, as well as to methods for producing said sialylated HMOs.