YEAST EXPRESSING THERMOSTABLE ALPHA-AMYLASES FOR HYDROLYSIS OF STARCH

1 . A recombinant yeast host cell comprising a heterologous nucleic acid molecule encoding a heterologous polypeptide having thermostable alpha-amylase activity, wherein the heterologous polypeptide comprises the amino acid sequence of:

SEQ ID NO: 57, a variant or a fragment thereof;

SEQ ID NO: 58, a variant or a fragment thereof;

SEQ ID NO: 54, a variant or a fragment thereof;

SEQ ID NO: 55, a variant or a fragment thereof; or

SEQ ID NO: 56, a variant or a fragment thereof.

2 . (canceled)

3 . The recombinant yeast host cell of claim 1 expressing a first heterologous polypeptide and a second heterologous polypeptide.

4 . The recombinant yeast host cell of claim 3 , wherein the first heterologous polypeptide has the amino acid sequence of SEQ ID NO 57, is a variant or a fragment thereof and the second heterologous polypeptide has the amino acid sequence of SEQ ID NO: 58, is a variant thereof or a fragment thereof.

5 . The recombinant yeast host cell of claim 1 , wherein the heterologous polypeptide further comprises a signal sequence.

6 . The recombinant yeast host cell of claim 5 , wherein the signal sequence is a native signal sequence.

7 . The recombinant yeast host cell of claim 6 , wherein the heterologous polypeptide comprises the amino acid sequence of:

SEQ ID NO: 4, a variant or a fragment thereof;

SEQ ID NO: 5, a variant or a fragment thereof;

SEQ ID NO: 1, a variant or a fragment thereof;

SEQ ID NO: 2, a variant or a fragment thereof; or

SEQ ID NO: 3, a variant or a fragment thereof.

8 . The recombinant yeast host cell of claim 5 , wherein the signal sequence is an heterologous signal sequence.

9 . The recombinant yeast host cell of claim 8 , wherein the heterologous signal sequence is from an invertase protein, an AGA2 protein, or an alpha-mating factor protein.

10 . The recombinant yeast host cell of claim 9 , wherein the heterologous signal sequence has the amino acid sequence of SEQ ID NO: 48, 51, or 70, a variant thereof, or a fragment thereof.

11 . The recombinant yeast host cell of claim 1 , wherein the heterologous polypeptide is a secreted polypeptide or a cell-associated polypeptide.

12 . (canceled)

13 . The recombinant yeast host cell of claim 11 , wherein the cell-associated polypeptide is a membrane-associated polypeptide.

14 . The recombinant yeast host cell of claim 13 , wherein the membrane-associated polypeptide is a tethered heterologous polypeptide.

15 .- 17 . (canceled)

18 . The recombinant yeast host cell of claim 14 , wherein the tethered heterologous polypeptide comprises a tethering moiety from a SED1 protein, a SPI1 protein, a CCW12 protein, a CWP2 protein, a TIR1 protein, a PST1 protein, a combination of a AGA1 and a AGA2 protein, or a variant thereof or a fragment thereof.

19 .- 21 . (canceled)

22 . The recombinant yeast host cell of claim 1 , wherein the heterologous polypeptide is an intracellular polypeptide.

23 . The recombinant yeast host cell of claim 22 , wherein the heterologous polypeptide has the amino acid sequence of any one of SEQ ID NO: 59 to 63 and wherein:

the first amino acid residue after the methionine residue at position 1 has been removed;

the first two consecutive amino acid residues after the methionine residue at position 1 have been removed; and/or

at least one lysine, tyrosine, serine, or glutamic acid residue has been added after the methionine residue at position 1.

24 . The recombinant yeast host cell of claim 23 , wherein the heterologous polypeptide has the amino acid sequence of:

SEQ ID NO: 64, a variant or a fragment thereof;

SEQ ID NO: 65, a variant or a fragment thereof;

SEQ ID NO: 66, a variant or a fragment thereof;

SEQ ID NO: 67, a variant or a fragment thereof;

SEQ ID NO: 68, a variant or a fragment thereof; or

SEQ ID NO: 69, a variant or a fragment thereof.

25 . The recombinant yeast host cell of claim 1 , wherein the heterologous polypeptide has alpha-amylase activity at a temperature of at least 60° C., 65° C., 70° C., 75° C., 80° C., 85° C., 90° C., 95° C. or 99° C.

26 . The recombinant yeast host cell of claim 1 , wherein the heterologous nucleic acid molecule is operatively associated with an heterologous promoter sequence for allowing the expression of the polypeptide during propagation.

27 . The recombinant yeast host cell of claim 1 , wherein the heterologous nucleic acid molecule further encodes a chimeric protein comprising the heterologous polypeptide fused to a starch binding domain.

28 . (canceled)

29 . The recombinant yeast host cell of claim 1 , which is a cell of genus Saccharomyces sp. or a cell of species Saccharomyces cerevisiae.

30 .- 32 . (canceled)

33 . A composition comprising the recombinant yeast host cell of claim 1 and at least one of a glucoamylase or starch.

34 . A yeast product made from the recombinant yeast host cell of claim 1 .

35 .- 36 . (canceled)

37 . A process for hydrolyzing starch, the process comprising contacting the recombinant yeast host cell of claim 1 with a medium comprising starch.

38 .- 44 . (canceled)