2,3-butanediol production from biowastes with bacillus licheniformis: A preliminary study

2,3-Butanediol (2,3-BDO) is a promising platform compound which could be used to produce valuable derivatives such as methyl ethyl ketone and 1,3-butadiene. The biotechnological production of 2,3-BDO has been mainly studied with Klebsiella sp. under microaerophilic conditions. However the pathogenicity of these strains makes this process not industrially desirable. The aim of this work was to study the possibility of producing 2,3-BDO with the non pathogenic microorganism Bacillus licheniformis ATCC-9789 using different sugars and biowastes as substrates. Shaken flask experiments were carried out using different monosaccharides commonly occurring in plant hydrolyzates (hexoses and pentoses), agroindustrial biowastes (sugar beet molasses and cheese whey) and the di-and monosaccharides occurring in them. Flask fermentation of glucose produced 8.2±0,1 g/L 2,3-BDO after 18 hours, corresponding to a 40.4±1.0 g2,3-BDO/100g glucose yield. Under the same conditions, mannose was converted to 7.8±0.2 g/L 2,3-BDO with a yield of 39.4±1.8 g2,3-BDO/100g mannose. Pentoses (xylose and arabinose) were little or not consumed with no production of 2,3-BDO. Biowastes used at 20 g/L provided the corresponding sugars at approximately 10 g/L initial concentrations. While lactose in cheese whey was not used and converted into 2,3-BDO, 2.6±0.3 g/L 2,3-BDO were produced after 14.5 hours from sucrose occurring in molasses, corresponding to a yield of 26.6±3.4 g2,3-BDO/100g sucrose. Molasses appear therefore the most interesting feedstock for the production of 2,3-BDO with Bacillus licheniformis ATCC 9789.