Abstract: The present invention provides a modified strain of the bacterium Lactococcus lactis obtainable by a method that comprises a step of fusion of two protoplasts from two Lactococcus lactis parental strains which, compared to the wild type strain of Lactococcus lactis from which they derive, show: (a) an increased ability to produce acetoin and/or 2,3-butanediol (2,3-BDO), and (b) a decreased ability to produce lactic acid, when cultured under aerobic conditions, and wherein the modified strain of Lactococcus lactis has an increased ability to produce 2,3-BDO of at least 20 times the amount produced by the wild type strain, an increased ability to produce acetoin of at least 20 times the amount produced by the wild type strain and a decreased ability to produce lactic acid of at least 10 times the amount produced by the wild type strain, when cultured under aerobic conditions. Also provided are methods to produce acetoin and 2,3-BDO.

Abstract: The present invention provides a modified strain of the bacterium Lactococcus lactis obtainable by a method that comprises a step of fusion of two protoplasts from two Lactococcus lactis parental strains which, compared to the wild type strain of Lactococcus lactis from which they derive, show: (a) an increased ability to produce acetoin and/or 2,3-butanediol (2,3-BDO), and (b) a decreased ability to produce lactic acid, when cultured under aerobic conditions, and wherein the modified strain of Lactococcus lactis has an increased ability to produce 2,3-BDO of at least 20 times the amount produced by the wild type strain, an increased ability to produce acetoin of at least 20 times the amount produced by the wild type strain and a decreased ability to produce lactic acid of at least 10 times the amount produced by the wild type strain, when cultured under aerobic conditions. Also provided are methods to produce acetoin and 2,3-BDO.

Abstract: It is provided a process for the preparation of methyl ethyl ketone by electroreduction of acetoin in aqueous media using a high hydrogen overvoltage cathode made of lead, the process comprising the steps of a) forming a solution by mixing acetoin with an aqueous medium and a supporting electrolyte soluble in such a medium, and b) electrolyzing said solution continuously or discontinuously in an electrochemical reactor by applying a voltage between an anode and the cathode using a direct current power supply at a current density from 500 to 5000 A/m2.

Abstract: The invention relates to a process for manufacturing 2,3-butanediol by hydrogenation of acetoin using a heterogeneous hydrogenation catalyst and under conditions leading to a selectivity higher than 90%. In a preferred embodiment, the hydrogenation is carried out in the presence of no solvent or in the presence of a solvent like water or 2,3-butanediol.

Abstract: The invention relates to a process for manufacturing 2,3-butanediol by hydrogenation of acetoin using a heterogeneous hydrogenation catalyst and under conditions leading to a selectivity higher than 90%. In a preferred embodiment, the hydrogenation is carried out in the presence of no solvent or in the presence of a solvent like water or 2,3-butanediol.