Recombinant microorganisms, plants, and plant cells are disclosed that have been engineered to express a mutant AROM polypeptide and/or mutant catechol-O-methyltransferase polypeptide alone or in combination with one or more vanillin biosynthetic enzymes or UDP-glycosyltransferases (UGTs). Such microorganisms, plants, or plant cells can produce vanillin or vanillin beta-D-glucoside.

2-6-Sialyltransferase (2,6ST) variants having improved 2-6-specific sialidase activity as compared to the native 2,6ST enzymes are described. The variants include GT80 sialyltransferases such as P. damselae Pd2,6ST. Methods for making de-sialylated products and screening sialidase activity are also described.

The invention relates to a method for producing derivatives of O--glucosylated flavonoid, comprising at least one step of incubating a glucansucrase with a flavonoid and at least one sucrose, the flavonoid being a flavonoid which is monohydroxylated or hydroxylated in a non-vicinal manner on the B cycle. The invention also relates to novel O--glucosylated flavonoid derivatives, and to the use thereof. ##STR00001##

The invention relates to a method for producing derivatives of O--glucosylated flavonoid, comprising at least one step of incubating a glucansucrase with a flavonoid and at least one sucrose, the flavonoid being a flavonoid which is monohydroxylated or hydroxylated in a non-vicinal manner on the B cycle. The invention also relates to novel O--glucosylated flavonoid derivatives, and to the use thereof. ##STR00001##

A heparin skeleton synthase originates from Neisseria animaloris, with an amino acid sequence as shown in SEQ ID NO.2 and a nucleotide sequence of the coding gene as shown in SEQ ID NO.1. Its recombinant expression level is 6.8 times that of the existing heparin skeleton synthase KfiA from Escherichia coli K5, and total enzyme activity per fermentation liquor is 5.22 times that of the heparin skeleton synthase KfiA. The heparin skeleton synthase mutants obtained through site-directed mutagenesis of the sites No. 16, No. 25, No. 30, No. 111, No. 165, and No. 172 in the amino acid sequence of the said heparin skeleton synthase all have high expression levels.

The present invention relates to an isolated DNA molecule encoding a fagopyritol synthase. A method for producing a fagopyritol, an insulin mediator, an insulin mediator analog, an insulin mediator homolog, or an insulin mediator inhibitor is also described. The method includes providing a fagopyritol synthase, providing a substrate comprising a galactosyl donor and a galactosyl acceptor, and combining the fagopyritol synthase with the substrate under conditions effective produce a fagopyritol, an insulin mediator, an insulin mediator analog, an insulin mediator homolog, or an insulin mediator inhibitor.

The present invention relates to an isolated DNA molecule encoding a fagopyritol synthase. A method for producing a fagopyritol, an insulin mediator, an insulin mediator analog, an insulin mediator homolog, or an insulin mediator inhibitor is also described. The method includes providing a fagopyritol synthase, providing a substrate comprising a galactosyl donor and a galactosyl acceptor, and combining the fagopyritol synthase with the substrate under conditions effective produce a fagopyritol, an insulin mediator, an insulin mediator analog, an insulin mediator homolog, or an insulin mediator inhibitor.

Recombinant microorganisms, plants, and plant cells are disclosed that have been engineered to express a mutant AROM polypeptide and/or mutant catechol-O-methyltransferase polypeptide alone or in combination with one or more vanillin biosynthetic enzymes or UDP-glycosyltransferases (UGTs). Such microorganisms, plants, or plant cells can produce vanillin or vanillin beta-D-glucoside.

Recombinant microorganisms, plants, and plant cells are disclosed that have been engineered to express a mutant AROM polypeptide and/or mutant catechol-O-methyltransferase polypeptide alone or in combination with one or more vanillin biosynthetic enzymes or UDP-glycosyltransferases (UGTs). Such microorganisms, plants, or plant cells can produce vanillin or vanillin beta-D-glucoside.

Recombinant microorganisms, plants, and plant cells are disclosed that have been engineered to express a mutant AROM polypeptide and/or mutant catechol-O-methyltransferase polypeptide alone or in combination with one or more vanillin biosynthetic enzymes or UDP-glycosyltransferases (UGTs). Such microorganisms, plants, or plant cells can produce vanillin or vanillin beta-D-glucoside.