| abstract |
A recombinant carboxydotrophic acetogen microorganism that is adapted to produce one or more products and a reduced amount or not substantially produce 2,3-butanediol by fermentation of a substrate comprising carbon monoxide, the microorganism comprising one or more genetic modifications that alter the route of biosynthesis of 2,3-butanediol, compared to an original microorganism, where the one or more genetic modifications that alter the biosynthesis pathway of 2,3-butanediol are selected from: (a) at least one genetic modification that alters the expression and / or activity of one or more enzymes capable of converting pyruvate into acetolactate; (b) at least one genetic modification that alters the expression and / or activity of one or more enzymes capable of converting acetolactate to acetoin; (c) at least one genetic modification that alters the expression and / or activity of one or more enzymes capable of converting acetoin to 2,3-butanediol; and (d) combinations thereof. |