Processes of producing fermentation products
The invention relates to processes of producing a fermentation product, comprising liquefying a starch containing material with an alpha-amylase; pre-saccharifying and/or saccharifying and fermenting using a fermentation organism in the presence of a carbohydrate source generating enzyme and a cellulolytic composition The invention also relates to methods of dewatering whole stillage.
1. A method of dewatering whole stillage comprising:
(a) liquefying a starch-containing material with an alpha-amylase; optionally pre-saccharifying the liquefied material before step (b);
(b) saccharifying the liquefied material;
(c) fermenting using a fermentation organism;
(d) separating the fermented material into a fermentation product and whole stillage;
(e) dewatering the whole stillage;
wherein a carbohydrate-source generating enzyme and a cellulolytic composition comprising a beta-glucosidase having a Relative ED50 loading value of less than 1.00 are present or added during the optional presaccharification step, saccharification step (b), and/or fermentation step (c), or simultaneous saccharification and fermentation, and wherein the beta-qlucosidase is the Aspergillus fumiqatus beta-qlucosidase of SEQ ID NO: 6 or a variant thereof having at least 85% sequence identity to the amino acid sequence of SEQ ID NO: 6 and which comprises one or more substitutions selected from the group consisting of L89M, G91L, F100D, I140V, I186V, S283G, N456E, and F512Y.
2. The method of claim 1 , wherein a protease having at least 85% sequence identity to SEQ ID NO: 13 herein, is added together with the carbohydrate source generating enzymes and cellulolytic composition.
3. The method of claim 1 , wherein the cellulolytic composition is added to the whole stillage.
4. The method of claim 3 , comprising the steps of:
i) subjecting whole stillage to the cellulolytic composition;
ii) separating the material into a solid fraction and a liquid fraction.
5. The method of claim 1 , wherein the hemicellulase content in the cellulolytic composition constitutes less than 10 weight percent or less than 5 weight percent of the celluloytic composition.
6. The method of claim 1 , wherein the variant has one of the following sets of substitutions:
F100D+S283G+N456E+F512Y;
L89M+G91L+I186V+I140V; and
I186V+L89M+G91L+I140V+F100D+S283G+N456E+F512Y.
7. The method of claim 1 , wherein the beta-glucosidase has at least 60% sequence identity to the amino acid sequence of SEQ ID NO: 6.
8. The method of claim 1 , wherein the beta-glucosidase has at least 70% sequence identity to the amino acid sequence of SEQ ID NO: 6.
9. The method of claim 1 , wherein the beta-glucosidase has at least 80% sequence identity to the amino acid sequence of SEQ ID NO: 6.
10. The method of claim 1 , wherein the beta-glucosidase has at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 6.
11. The method of claim 1 , wherein the beta-glucosidase has at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 6.
12. The method of claim 1 , wherein the cellulolytic composition comprises one or more of the following components
(i) an Aspergillus fumigatus cellobiohydrolase I;
(ii) an Aspergillus fumigatus cellobiohydrolase II;
(iii) an Aspergillus fumigatus beta-glucosidase; and
(iv) a Penicillium sp. GH61 polypeptide having cellulolytic enhancing activity thereof.
13. The process of claim 1 , wherein the carbohydrate-source generating enzyme is a glucoamylase.
14. The process of claim 1 , wherein the carbohydrate-source generating enzyme is a combination of a glucoamylase and an alpha-amylase.