Patent ID: 8765433

Claim:
A recombinant microbial host cell comprising: a biosynthetic pathway for production of isobutanol, the biosynthetic pathway comprising a substrate to product conversion catalyzed by a polypeptide with alcohol dehydrogenase activity, wherein the polypeptide with alcohol dehydrogenase activity has at least 90% identity to the amino acid sequence of SEQ ID NO:31 and either or both of the following characteristics: (a) the K M value for isobutyraldehyde is lower for said polypeptide relative to a control polypeptide having the amino acid sequence of SEQ ID NO:26; and (b) the k cat /K M value isobutyraldehyde for said polypeptide is higher relative to a control polypeptide having the amino acid sequence of SEQ ID NO:26.