Acetolactate decarboxylase variants having improved specific activity

A composition comprising a recombinant polypeptide having acetolactate decarboxylase (ALDC) activity comprising

• (i) at least 95% amino acid identity to amino acid sequence of SEQ ID NO:
• 3 and wherein the polypeptide comprises at least one amino acid substitution at position 62 with reference to the position numbering of the sequence shown in SEQ ID NO:
• 3 or
• (ii) a functional fragment of (i) having a specific activity greater than or equal to the specific activity of (i) and zinc at concentration of about 1 μM to about 200 mM.

A method for increasing the activity and/or stability of a recombinant polypeptide having acetolactate decarboxylase (ALDC) activity comprising

• (i) at least 95% amino acid identity to amino acid sequence of SEQ ID NO:
• 3 and wherein the polypeptide comprises at least one amino acid substitution at position 62 with reference to the position numbering of the sequence shown in SEQ ID NO:
• 3 or
• (ii) a functional fragment of (i) having a specific activity greater than or equal to the specific activity of (i) wherein said method comprises the step of adding zinc to a composition comprising the recombinant polypeptide so that said zinc is present in said composition at a concentration of about 1 μM to about 200 mM.

A cultivation media for a recombinant host cell capable of producing a recombinant polypeptide having acetolactate decarboxylase (ALDC) activity comprising

• (i) at least 95% amino acid identity to amino acid sequence of SEQ ID NO:
• 3 and wherein the polypeptide comprises at least one amino acid substitution at position 62 with reference to the position numbering of the sequence shown in SEQ ID NO:
• 3 or
• (ii) a functional fragment of (i) having a specific activity greater than or equal to the specific activity of (i) comprising zinc at a concentration of about 1 μM to about 1 mM.

A beer, wine, cider, perry or sake fermentation media or maturation media comprising a composition comprising

• a) a recombinant polypeptide having acetolactate decarboxylase (ALDC) activity comprising
• (i) at least 95% amino acid identity to amino acid sequence of SEQ ID NO:
• 3 and wherein the polypeptide comprises at least one amino acid substitution at position 62 with reference to the position numbering of the sequence shown in SEQ ID NO:
• 3 or
• (ii) a functional fragment of (i) having a specific activity greater than or equal to the specific activity of (i), and;
• b) zinc;
• wherein said composition comprises zinc at a concentration of about 1 μM to about 200 mM.

A method for beer, wine, cider, perry or sake production comprising adding a composition comprising a recombinant polypeptide having acetolactate decarboxylase (ALDC) activity comprising

• (i) at least 95% amino acid identity to amino acid sequence of SEQ ID NO:
• 3 and wherein the polypeptide comprises at least one amino acid substitution at position 62 with reference to the position numbering of the sequence shown in SEQ ID NO:
• 3 or
• (ii) a functional fragment of (i) having a specific activity greater than or equal to the specific activity of (i) and zinc to a media suitable for the beer, wine, cider, perry or sake production.