The present invention relates to variant phytase enzymes having altered properties.
1. A non-naturally occurring phytase variant, wherein the variant
comprises substitution(s) D125A corresponding to the position numbering of SEQ ID NO: 1,
has at least 95% sequence identity inclusive of the variant substitution(s) with amino acid residues 34-446 of SEQ ID NO: 1, and
has phytase enzymatic activity.
2. The phytase variant according to claim 1 , wherein the variant further comprises substitutions A122T, T167I, F197S, T209K, A211P, K240E, A242S, S281L, Q289Y, A294E and N303K.
3. The phytase variant according to claim 1 , wherein the variant has the sequence of SEQ ID NO: 3.
4. The phytase variant of claim 1 , wherein the substitution(s) consists of D125A.
5. A non-naturally occurring phytase variant, wherein the variant comprises substitution(s) D98A corresponding to the position numbering of SEQ ID NO:4, has at least 95% sequence identity to SEQ ID NO:4 and has phytase enzymatic activity.
6. A non-naturally occurring phytase variant, wherein the variant comprises 98% sequence identity to amino acid residues positions 34-446 of SEQ ID NO: 1 and comprises a substitution at position D125 of SEQ ID NO: 1 and has phytase enzymatic activity.
7. A phytase variant according to claim 1 having enhanced thermal stability as compared to the phytase of SEQ ID NO: 2.
8. An enzyme composition comprising the phytase of claim 1 .
9. An enzyme composition comprising the phytase of claim 5 .
10. The enzyme composition of claim 8 , wherein said composition is an animal feed composition.
11. The enzyme composition of claim 8 , wherein said composition is used in a starch liquefying process.
12. The enzyme composition of claim 8 , wherein said composition is used in an alcohol fermentation process.
13. The enzyme composition of claim 8 , further comprising an enzyme selected from the group of glucoamylase, alpha amylase, proteases, cellulases, xylanases and combinations thereof.
14. A fermentation medium comprising the phytase of claim 1 produced from a culture of filamentous fungal cells.
15. The fermentation medium of claim 14 , wherein the filamentous fungal cells are Trichoderma cells.
16. The fermentation medium of claim 15 , wherein the Trichoderma cells are T. reesei.
17. The fermentation medium of claim 14 , wherein the phytase comprises the amino acid sequence of SEQ ID NO: 3.