Process for the production of ethanol
The invention relates to a process for the production of ethanol comprising fermenting a (optionally liquefied) corn slurry under anaerobic conditions in the presence of a recombinant yeast; and recovering the ethanol, wherein said recombinant yeast functionally expresses a heterologous nucleic acid sequence encoding a glucoamylase having an amino acid sequence according to SEQ ID NO: 1 or which glucoamylase is a functional homologue thereof having a sequence identity of at least 80%, or which glucoamylase is a functional homologue which is derived, by way of one or more amino acid substitutions, deletions or insertions, from the amino acid sequence of SEQ ID NO: 1, and wherein the process comprises dosing a glucoamylase at a concentration of 0.05 g/L or less.
1. A process for production of ethanol comprising:
fermenting a corn slurry under anaerobic conditions in the presence of a recombinant yeast; and
recovering the ethanol,
wherein said recombinant yeast expresses a heterologous nucleic acid sequence encoding a glucoamylase that has at least 80% sequence identity to the nucleic acid sequence of SEQ ID NO: 1; and wherein the process comprises dosing the fermentation with a glucoamylase at a concentration of 0.05 g/L or less, expressed as the total amount of glucoamylase enzyme in grams per liter of corn slurry.
2. The process according to claim 1 , wherein the yeast is selected from the group consisting of Saccharomycetaceae; Kluyveromyces; Pichia; Brettanomyces ; and Issatchenkia.
3. The process according to claim 2 , wherein the yeast is Saccharomyces cerevisiae.
4. The process according to claim 1 , wherein the corn slurry is liquefied and the fermenting comprises fermenting liquefied corn slurry under anaerobic conditions in the presence of the recombinant yeast.
5. The process according to claim 1 , wherein the corn slurry is combined with another fermentable carbohydrate composition.
6. The process according to claim 1 , wherein the corn slurry is combined with corn stover hydrolysate and/or corn fiber hydrolysate, and fermented under anaerobic conditions in the presence of the recombinant yeast.
7. The process according to claim 1 , wherein starch, lignocellulose, pectin, or any combination thereof is contacted with an enzyme composition, wherein at least one sugar is produced; and wherein the at least one sugar is fermented to give a fermentation product, wherein fermentation is conducted with the recombinant yeast.
8. The process according to claim 1 , wherein glucoamylase is dosed at a concentration between 0.005 g/L and 0.05 g/L.
9. The process according to claim 1 , wherein the process is carried out without dosing any glucoamylase.
10. The process according to claim 1 , wherein the heterologous nucleic acid sequence has at least 85% sequence identity to the nucleic acid sequence of SEQ ID NO: 1.
11. The process according to claim 1 , wherein the heterologous nucleic acid sequence has at least 90% sequence identity to the nucleic acid sequence of SEQ ID NO: 1.
12. The process according to claim 1 , wherein the heterologous nucleic acid sequence has at least 95% sequence identity to the nucleic acid sequence of SEQ ID NO: 1.
13. The process according to claim 1 , wherein the heterologous nucleic acid sequence has at least 98% sequence identity to the nucleic acid sequence of SEQ ID NO: 1.
14. The process according to claim 1 , wherein the heterologous nucleic acid sequence has at least 99% sequence identity to the nucleic acid sequence of SEQ ID NO: 1.
15. The process according to claim 1 , wherein the heterologous nucleic acid sequence has 100% sequence identity to the nucleic acid sequence of SEQ ID NO: 1.