TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preparation (Disclosed): Preparation of the recombinant microorganism is by standard recombinant techniques. Preferred Components: The butanol biosynthetic pathway is: 1-butanol biosynthetic pathway; 2-butanol biosynthetic pathway; or isobutanol biosynthetic pathway. The 1-butanol biosynthetic pathway comprises at least one gene encoding a polypeptide that performs at least one substrate to product conversion comprising: acetyl-coenzyme A to acetoacetyl-coenzyme A catalyzed by acetyl coenzyme A acetyltransferase; acetoacetyl-coenzyme A to 3-hydroxybutyryl-coenzyme A catalyzed by 3-hydroxybutyryl-coenzyme A dehydrogenase; 3-hydroxybutyryl-coenzyme A to crotonyl-coenzyme A catalyzed by crotonase; crotonyl-coenzyme A to butyryl-coenzyme A catalyzed by butyryl coenzyme A dehydrogenase; butyryl-coenzyme A to butyraldehyde catalyzed by butyraldehyde dehydrogenase; or butyraldehyde to 1-butanol catalyzed by 1-butanol dehydrogenase. The 2-butanol biosynthetic pathway comprises at least one gene encoding a polypeptide that performs at least one substrate to product conversion comprising: pyruvate to alpha -acetolactate catalyzed by acetolactate synthase; alpha -acetolactate to acetoin catalyzed by acetolactate decarboxylase; acetoin to 2,3-butanediol catalyzed by butanediol dehydrogenase; 2,3-butanediol to 2-butanone catalyzed by butanediol dehydratase; or 2-butanone to 2-butanol catalyzed by 2-butanol dehydrogenase. The isobutanol biosynthetic pathway comprises at least one gene encoding a polypeptide that performs at least one substrate to product conversion comprising: pyruvate to acetolactate catalyzed by acetolactate synthase; acetolactate to 2,3-dihydroxyisovalerate catalyzed by acetohydroxy acid isomeroreductase; 2,3-dihydroxyisovalerate to alpha -ketoisovalerate catalyzed by dihydroxy acid dehydratase; alpha -ketoisovalerate to isobutyraldehyde catalyzed by a branched chain keto acid decarboxylase; or isobutyraldehyde to isobutanol catalyzed by branched-chain alcohol dehydrogenase. The microorganism is from a genus comprising Saccharomyces (preferred), Clostridium, Zymomonas, Escherichia, Salmonella, Serratia, Erwinia, Klebsiella, Shigella, Rhodococcus, Pseudomonas, Bacillus, Lactobacillus, Enterococcus, Alcaligenes, Paenibacillus, Arthrobacter, Corynebacterium, Brevibacterium, Schizosaccharomyces, Kluyveromyces, Yarrowia, Pichia, Zygosaccharomyces, Debaryomyces, Candida, Brettanomyces, Pachysolen, Hansenula, Issatchenkia, Trichosporon, or Yamadazyma. The heterologous GPD is a naturally occurring GPD. The heterologous GPD comprises the sequence of a GPD from an organism comprising Leishmania mexicana, Dunaliella viridis, Jaculus orientalis, Archaeoglobus fulgidus, Rickettsia prowazekii, Beggiatoa alba, Kangiella koreensis, Aspergillus oryzae, Candida versatilis, Escherichia coli, or Oryctolagus cuniculus. The heterologous GPD is an engineered GPD. The engineered GPD/enzyme comprises at least one substitution at a residue corresponding to position 42, 44, 45, 71, 73, 75, 95, 124,126,129,151,152,183,184, 185, 246, 310, 336, 337, or 339 of SEQ ID NO: 195. The engineered GPD/enzyme comprises at least one substitution at a residue corresponding to position 73 of SEQ ID NO: 195. The engineered GPD/enzyme comprises at least one substitution at a residue corresponding to position 129 of SEQ ID NO: 195. The engineered GPD/enzyme comprises a substitution at a residue corresponding to position 73 of SEQ ID NO: 195 and a substitution at a residue corresponding to position 129 of SEQ ID NO: 195. The microorganism comprises a ketol-acid reductoisomerase that utilizes NADH. The microorganism comprises a butanol biosynthetic pathway that comprises at least one gene that is heterologous to the recombinant microorganism, where the microorganism comprises a deletion or disruption of an endogenous gene encoding GPD, and the recombinant microorganism has improved production of butanol compared to a microorganism that lacks the engineered GPD enzyme. The recombinant microorganism is grown under anaerobic conditions. The K(m) for NADH of the GPD is 0.01-1 mM. EXAMPLE - No suitable example given.