New sialyltransferases for in vivo synthesis of lst-c

A method for producing at least one sialylated human milk oligosaccharides (HMO), the method comprising culturing a genetically modified cell comprising,

• a. a recombinant nucleic acid sequence encoding an enzyme with α-2,6-sialyltransferase activity, wherein said enzyme is selected from the group consisting of:
• i. HAC1268 comprising or consisting of the amino acid sequence of SEQ ID NO:
• 2 or an amino acid sequence with at least 90% identity to SEQ ID NO:
• 2,
• ii. Shal comprising or consisting of the amino acid sequence of SEQ ID NO:
• 1 or an amino acid sequence with at least 90% identity to SEQ ID NO:
• 1,
• iii. Valg2 comprising or consisting of the amino acid sequence of SEQ ID NO:
• 3 or an amino acid sequence with at least 90% identity to SEQ ID NO:
• 3;
• iv. Pmult comprising or consisting of the amino acid sequence of SEQ ID NO:
• 4 or an amino acid sequence with at least 90% identity to SEQ ID NO:
• 4;
• and
• v. Plst6_119 comprising or consisting of the amino acid sequence of SEQ ID NO:
• 5 or an amino acid sequence with at least 90% identity to SEQ ID NO:
• 5, and
• b. a recombinant nucleic acid sequence encoding an enzyme with a β-1,4-galactosyltransferase activity;
• wherein at least one of the sialylated HMOs is LST-c.