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 process of producing a fermentation product, comprising
(a) liquefying a starch-containing material with an alpha-amylase;
(b) saccharifying the liquefied material;
(c) fermenting using a fermentation organism;
wherein a carbohydrate-source generating enzyme and a cellulolytic composition comprising a beta-glucosidase having at least 95% sequence identity to amino acids 20 to 863 of SEQ ID NO: 6 are present or added during the saccharification step (b), fermentation step (c), or a simultaneous saccharification and fermentation, wherein the beta-glucosidase comprises one or more substitutions selected from the group consisting of L89M, G91L, F100D, 1140V, 1186V, S283G, N456E, and F512Y.
2. The process of claim 1 , wherein the hemicellulase content in the cellulolytic composition constitutes less than 10 wt. % or less than 5 wt. % of the cellulolytic composition.
3. The process of claim 1 , wherein the cellulolytic composition further comprises one or more of the following components:
an Aspergillus fumigatus cellobiohydrolase I as shown in SEQ NO: 2 or a variant thereof having at least 95% sequence identity to amino acids 27 to 532 of SEQ ID NO: 2;
(ii) an Aspergillus fumigatus cellobiohydrolase II as shown in SEQ NO: 4 or a variant thereof having at least 95% sequence identity to amino acids 20 to 454 of SEQ ID NO: 4 and
(iii) a Penicillium sp. GH61 polypeptide having cellulolytic enhancing activity as shown in SEQ NO: 8 or a variant thereof having at least 95% sequence identity to amino acids 26 to 253 of SEQ ID NO: 8.
4. The process of claim 1 , wherein the beta-glucosidase comprises a substitution set selected from the group consisting of:
F100D+S283G+N456E+F512Y;
L89M+G91L+I186V+I140V; and
I186V+L89M+G91L+U140V+F100D+S283G+N456E+F512Y, using SEQ ID NO: 6 for numbering.
5. The process of claim 1 , wherein a trehalase is present or added during the saccharification step (b), fermentation step (c), or simultaneous saccharification and fermentation.
6. The process of claim 5 , wherein the trehalase is a Trichoderma trehalase having at least 95% sequence identity to SEQ ID NO: 12.