Processes for Producing a Fermantation Product

Abstract

The present invention relates to processes for producing a fermentation product, such as ethanol, from milled starch-containing material comprising (a) saccharifying the milled starch-containing material with a glucoamylase having an amino acid sequence shown in SEQ ID NO: 2 , or a glucoamylase being at least 70 % identical thereto, at a temperature below the initial gelatinization temperature of said starch-containing material, (b) fermenting using a fermenting organism.

1 . A process for producing a fermentation product from milled starch-containing material comprising:
 (a) saccharifying milled starch-containing material with a glucoamylase having an amino acid sequence shown in SEQ ID NO: 2, or a glucoamylase being at least 70% identical thereto, at a temperature below the initial gelatinization temperature of said starch-containing material,   (b) fermenting using a fermenting organism.   
     
     
         2 . The process of  claim 1 , wherein the process is carried out for a period of 1 to 250 hours. 
     
     
         3 . The process of  claim 1 , wherein the process is carried out at a pH in the range between 3 and 7. 
     
     
         4 . The process of  claim 1 , wherein the dry solid content (DS) lies in the range from 20-55 wt.-%. 
     
     
         5 . The process of  claim 1 , wherein the sugar concentration is kept at a level below about 3 wt. % during saccharification and fermentation. 
     
     
         6 . The process of  claim 1 , wherein a slurry comprising water and milled starch-containing material is prepared before step (a). 
     
     
         7 . The process of  claim 1 , wherein the milled starch-containing material is prepared by milling starch-containing material to a particle size of 0.1-0.5 mm. 
     
     
         8 . The process of  claim 1 , wherein the milled starch-containing material is granular starch obtained by dry or wet milling. 
     
     
         9 . The process of  claim 1 , wherein the milled starch containing material is whole grains. 
     
     
         10 . The process of  claim 1 , wherein the saccharification is carried out simultaneously. 
     
     
         11 . The process of  claim 10 , wherein the temperature during fermentation is between 28° C. and 36° C. 
     
     
         12 . The process of  claim 1 , wherein the glucoamylase is derived from  Athelia rolfsii . 
     
     
         13 . The process of  claim 1 , wherein the glucoamylase is present in an amount of 0.001 to 10 AGU/g DS 
     
     
         14 . The process of  claim 1 , wherein an acid alpha-amylase is present. 
     
     
         15 . The process of  claim 14 , wherein the acid alpha-amylase is a fungal alpha-amylase. 
     
     
         16 . (canceled) 
     
     
         17 . The process of  claim 14 , wherein the fungal acid alpha-amylase is a hybrid enzyme comprising an alpha-amylase catalytic domain (CD) and a carbohydrate-binding module (CBM) and optionally linker or a wild-type fungal acid alpha-amylase catalytic domain (CD) and a carbohydrate-binding module (CBM) and optionally a linker. 
     
     
         18 . The process of  claim 17 , wherein the CBM is derived from  Aspergillus kawachii  alpha-amylase,  Athelia rolfsii  glucoamylase, or  Aspergillus niger  glucoamylase. 
     
     
         19 . The process of  claim 17 , wherein the CBM is derived from  Athelia rolfsii  glucoamylase,  A. niger  glucoamylase or  A. kawachii  alpha-amylase. 
     
     
         20 - 33 . (canceled) 
     
     
         24 . The process of  claim 14 , wherein the acid alpha-amylase is derived from a strain of  Aspergillus .