Metabolic engineering for improved xylose utilisation of saccharomyces cerevisiae

Abstract

The present invention relates to a method for preparing an ethanol producing, xylose utilizing strain of Saccharomyces cerevisiae comprising genes for overexpression of xylose reductase, xylitol dehydrogenase and xylulokinase, wherein in addition to said genes for production o phosphoacetyltransferase, and acetaldehyde dehydrogenase are introduced and optionally overexpressed.

1 . A method for preparing an ethanol producing, xylose utilizing strain of  Saccharomyces cerevisiae  comprising genes for overexpression of xylose reductase, xylitol dehydrogenase and xylulokinase, wherein in addition to said genes, the genes for production of phosphoacetyltransferase, and acetaldehyde dehydrogenase are introduced and, overexpressed, wherein the gene encoding for phosphoacetyltransferase is cloned from a bacterium that produces ethanol or a protozoa, the gene encoding for acetaldehyde dehydrogenase is cloned from  Entamoeba histolytica , and wherein the strain is deleted with regard to the gene expressing the endogenous aldehyde dehydrogenase Δald6.  
   
   
       2 . The method according to  claim 1 , wherein a gene for production of phosphoketolase is further introduced, and optionally overexpressed.  
   
   
       3 . (canceled)  
   
   
       4 . The method according to  claim 2 , wherein the gene encoding phosphoketolase is cloned from any heterofermentative lactic acid bacterium selected from the group consisting of  Lactobacillus pentosus, Lactobacillus plantarum , and  Leuconostoc mesenteroides.    
   
   
       5 - 7 . (canceled)  
   
   
       8 . The method according to  claim 1 , wherein the gene encoding for phosphoacetyltransferase is cloned from the protozoa  Entamoeba histolytica  and  Giardia lablia.    
   
   
       9 - 14 . (canceled)