synthesis |
synthetic pathway for n-butanol production from acetyl coenzyme at 70°C, using beta-ketothiolase Thl, 3-hydroxybutyryl-CoA dehydrogenase Hbd, and 3-hydroxybutyryl-CoA dehydratase Crt from Caldanaerobacter subterraneus subsp. tengcongensis, trans-2-enoyl-CoA reductase Ter from Spirochaeta thermophila and bifunctional aldehyde dehydrogenase AdhE and and butanol dehydrogenase in vitro. n-Butanol is produced at 70°C, but with different amounts of ethanol as a coproduct, because of the broad substrate specificities of AdhE, Bad, and Bdh. A reaction kinetics model, validated via comparison to in vitro experiments, is used to determine relative enzyme ratios needed to maximize n-butanol production. By using large relative amounts of Thl and Hbd and small amounts of Bad and Bdh, >70% conversion to n-butanol is observed in vitro, but with a 60% decrease in the predicted pathway flux |
Thermoanaerobacter sp. |