Patent ID: 8232089
Filing Date: 2012-07-31
Classification: C12N,C12P,Y02E

Abstract:
1. A recombinant yeast microorganism for producing isobutanol, the recombinant yeast microorganism comprising an isobutanol producing metabolic pathway, wherein said isobutanol producing metabolic pathway comprises the following substrate to product conversions: (i) pyruvate to acetolactate; (ii) acetolactate to 2,3-dihydroxyisovalerate; (iii) 2,3-dihydroxyisovalerate to α-ketoisovalerate; (iv) α-ketoisovalerate to isobutyraldehyde; and (v) isobutyraldehyde to isobutanol; wherein said recombinant yeast microorganism expresses: an exogenous nucleic acid encoding dihydroxy acid dehydratase to catalyze the conversion of 2,3-dihydroxyisovalerate to α-ketoisovalerate, said exogenous nucleic acid encoding dihydroxy acid dehydratase comprising an amino acid motif which is at least 90% identical to the motif of SEQ ID NO: 27, wherein said dihydroxy acid dehydratase is active in the cytosol of said recombinant yeast microorganism, and wherein the recombinant yeast microorganism has been engineered to inactivate one or more endogenous pyruvate decarboxylase (PDC) genes.