Yeast expressing a heterologous alpha-amylase for ethanol production
Described herein are recombinant fermenting organisms having a heterologous polynucleotide encoding an alpha-amylase and/or a heterologous polynucleotide encoding a trehalase. Also described are processes for producing a fermentation product, such as ethanol, from starch or cellulosic-containing material with the recombinant fermenting organisms.
1. A method of producing a fermentation product from a starch-containing or cellulosic-containing material comprising:
(a) saccharifying the starch-containing or cellulosic-containing material; and
(b) fermenting the saccharified material of step (a) with a recombinant yeast cell;
wherein the recombinant yeast cell comprises a heterologous polynucleotide encoding an alpha-amylase having a mature polypeptide sequence with at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 126.
2. The method of claim 1 , wherein the alpha-amylase has a mature polypeptide sequence comprising or consisting of the amino acid sequence of SEQ ID NO: 126.
3. The method of claim 1 , wherein saccharification of step (a) occurs on a starch-containing material.
4. The method of claim 3 , comprising liquefying the starch-containing material by contacting the material with an alpha-amylase prior to saccharification.
5. The method of claim 4 , wherein liquefying the starch-containing material and/or saccharifying the starch-containing material is conducted in presence of exogenously added protease.
6. The method of claim 1 , wherein fermentation and saccharification are performed simultaneously in a simultaneous saccharification and fermentation (SSF).
7. The method of claim 1 , comprising recovering the fermentation product from the from the fermentation.
8. The method of claim 1 , wherein the fermentation product is ethanol.
9. The method of claim 1 , wherein the recombinant yeast cell comprises a heterologous polynucleotide encoding a glucoamylase or a protease.
10. The method of claim 1 , wherein the recombinant yeast cell is a Saccharomyces cerevisiae cell.
11. A recombinant yeast cell comprising a heterologous polynucleotide encoding an alpha-amylase having a mature polypeptide sequence with at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 126.
12. The recombinant yeast cell of claim 11 , wherein the alpha-amylase has a mature polypeptide sequence comprising or consisting of the amino acid sequence of SEQ ID NO: 126.
13. The recombinant yeast cell of claim 11 , wherein the fermenting organism comprises a heterologous polynucleotide encoding a glucoamylase or a protease.
14. The recombinant yeast of claim 11 , wherein the cell is a Saccharomyces cerevisiae cell.
15. The recombinant yeast of claim 11 , wherein the alpha-amylase has a mature polypeptide sequence with at least 97% sequence identity to the amino acid sequence of SEQ ID NO: 126.
16. The method of claim 1 , wherein the alpha-amylase has a mature polypeptide sequence with at least 97% sequence identity to the amino acid sequence of SEQ ID NO: 126.
17. The method of claim 1 , wherein the alpha-amylase has a mature polypeptide sequence with at least 98% sequence identity to the amino acid sequence of SEQ ID NO: 126.
18. The method of claim 1 , wherein the alpha-amylase has a mature polypeptide sequence with at least 99% sequence identity to the amino acid sequence of SEQ ID NO: 126.
19. The recombinant yeast of claim 11 , wherein the alpha-amylase has a mature polypeptide sequence with at least 98% sequence identity to the amino acid sequence of SEQ ID NO: 126.
20. The recombinant yeast of claim 11 , wherein the alpha-amylase has a mature polypeptide sequence with at least 99% sequence identity to the amino acid sequence of SEQ ID NO: 126.