Heterologous alpha amylase expression in aspergillus

Abstract

The present invention relates to the co-expression and production of a heterologous alpha amylase and an endogenous glucoamylase in an Aspergillus strain and enzyme compositions including the same.

1 . A  Trichoderma  fungal strain comprising DNA encoding a glucoamylase and DNA encoding a heterologous alpha amylase comprising an amino acid sequence having at least 95% sequence identity to SEQ ID NO: 3, wherein both the glucoamylase and the heterologous alpha amylase are expressed and secreted by the  Trichoderma  fungal strain. 
     
     
         2 . The  Trichoderma  strain of  claim 1 , wherein the strain is an  T. reesei, T. viride, T. koningii , or  T. harzianum  strain. 
     
     
         3 . The  Trichoderma  strain of  claim 2 , wherein the  Trichoderma  strain is  T. reesei  strain. 
     
     
         4 . The  Trichoderma  strain of  claim 2 , wherein the secreted glucoamylase comprises at least 40% of the total amount of secreted protein from the strain. 
     
     
         5 . A culture medium comprising the  Trichoderma  strain of  claim 1 . 
     
     
         6 . An enzyme composition obtained from the culture medium of  claim 1 . 
     
     
         7 . (canceled) 
     
     
         8 . A  Trichoderma  strain comprising a) DNA encoding an endogenous glucoamylase and b) DNA encoding a heterologous alpha amylase having at least 95% sequence identity to SEQ ID NO: 3, wherein the  Trichoderma  strain expresses both the glucoamylase and the heterologous alpha amylase and overproduces the glucoamylase. 
     
     
         9 . A culture medium comprising the  Trichoderma  strain of  claim 8 . 
     
     
         10 . A method of producing an alpha amylase in a  Trichoderma  cell which comprises, culturing the  Trichoderma  fungal strain of  claim 1  under conditions suitable for the expression and production of the heterologous alpha amylase and producing the heterologous alpha amylase. 
     
     
         11 . (canceled) 
     
     
         12 . The method according to  claim 10 , wherein the  Trichoderma  is a  T. reesei  strain. 
     
     
         13 - 14 . (canceled) 
     
     
         15 . A method for producing an acid stable alpha amylase and a glucoamylase in a filamentous fungal host cell comprising
 a) obtaining the fungal strain of  claim 1 ,   b) cultivating the transformed host cell in a suitable culture medium to allow expression of the alpha amylase and the glucoamylase, and   c) producing the alpha amylase and the glucoamylase.   
     
     
         16 . The method according to  claim 15  further comprising recovering the produced glucoamylase and alpha amylase. 
     
     
         17 . The method according to  claim 15 , wherein the filamentous host cell is a  Trichoderma  strain. 
     
     
         18 . The method according to  claim 17 , wherein the  Trichoderma  strain is  T. reesei  strain. 
     
     
         19 . The method according to  claim 17 , wherein the secreted glucoamylase comprises at least 40% of the total amount of secreted protein from the cells. 
     
     
         20 . A method of hydrolyzing starch comprising contacting a substrate containing starch with the enzyme composition of  claim 6  under suitable conditions for starch hydrolysis and obtaining hydrolyzed starch. 
     
     
         21 . The method according to  claim 20 , wherein the starch is granular starch. 
     
     
         22 . The method according to  claim 21 , wherein the contacting is at a temperature below the gelatinization temperature of the granular starch in the substrate. 
     
     
         23 . The method according to  claim 20 , wherein the substrate is a grain or fractionated part thereof.