Patent ID: 9228178
Filing Date: 2016-01-05
CPC Classification: C12N,C12P,C12Y,Y02E

Claim Text:
1. A recombinant Hansenula polymorpha strain comprising at least one gene encoding a xylitol dehydrogenase enzyme, at least one gene encoding a xylose reductase enzyme, and at least one gene encoding a xylulokinase enzyme, each of said genes being operably linked to at least one promoter that overexpresses said genes in said H. polymorpha strain when compared to a corresponding parent H. polymorpha strain that is identical but lacking said genes, wherein said recombinant H. polymorpha strain produces 4.0 to 7.4 fold more ethanol when fermented in a media containing xylose than the corresponding parent H. polymorpha strain not containing said genes, wherein said gene encoding a xylose reductase enzyme encodes a xylose reductase enzyme which comprises all of SEQ ID NO: 4 except for two substitutions at positions 341 and 343, wherein said substitutions are the replacement of a lysine residue at a position corresponding to position 341 of SEQ ID NO: 4 with an arginine and the replacement of an arginine at a position corresponding to position 343 of SEQ ID NO: 4 with an aspartic acid, and wherein said recombinant Hansenula polymorpha strain further comprises at least one nucleic acid encoding a pyruvate decarboxylase enzyme endogenous to the parent H. polymorpha strain operably linked to a promoter that overexpresses said pyruvate decarboxylase enzyme in the recombinant H. polymorpha strain when compared to said parent H. polymorpha strain.