Method of 2,3-butanediol production from glycerol and acid-pretreated rice straw hydrolysate by newly isolated strains: pre-evaluation as an integrated biorefinery process.

The present study validated a bioconversion technology for the production of 2,3-butanediol (2,3-BD) using sugars, glycerol and lignocellulosic material by three newly isolated strains-two Klebsiella sp. and one Serratia sp. One Klebsiella sp. afforded a high diol production yield (0.45 g/g) using the less common sugar arabinose and Serratia sp. was used for the first time to convert glycerol to 2,3-BD and afforded a yield of 0.43 g/g. Furthermore, acid-pretreated rice straw hydrolysate was used to determine the feasibility of its conversion to 2,3-BD. Both cellulose and hemicellulose hydrolysate were successfully fermented to 2,3-BD and acetoin by the isolates with yields for the diol between 0.39 and 0.44 g/g (equivalent to 78-88% of the maximum yield). These results demonstrate that 2,3-butanediol can be considered as the main product or a value-added byproduct of biofuel production and then potentially improve the economy of lignocellulosic biorefinery.