Variant of formate dehydrogenase and use thereof

A variant protein of a formate dehydrogenase, which has a β-nicotinamide-adenine-dinucleotide-phosphate-dependent formate dehydrogenase activity, can be constructed by introducing a site-specific mutation into an aspartic acid residue located at position-222 in the amino acid sequence for a formate dehydrogenase variant originated from Mycobacterium vaccae . The protein exhibits a high formate dehydrogenase activity in the presence of an organic solvent. The variant is useful for the production of an alcohol using a ketone as a starting material.