Process optimization for producing 2, 3-butanediol by fermentation of cotton stalk hydrolysate after detoxification

2,3-Butanediol is an important chemical product. Utilization of cotton stalk hydrolysate instead of starch for 2,3 -butanediol production can ensure food security and reduce costs. Cotton stalk was hydrolyzed by dilute acid in this research. The detoxification of furfural and phenol from cotton stalk dilute acid hydrolysate was performed by microwave assistant?heating-activated carbon adsorption method, the optimized technical conditions were determined as activated carbon 1%, microwave power 330 W and detoxification time 10 min. The detoxification ratio of furfural was 81.2% and 92.3% of phenol, and the loss of total sugar was only 10.6%. The batch cultures showed that the biomass of Klebsiella pneumoniae XJ-Li and the yield of 2,3-butanediol reached to peak value when the total sugar concentration was 40 g/L in media. The results of research demonstrated that the inhibition effect of high concentration of cotton stalk hydrolysate on the growth and metabolic of microorganism could be reduced by fed-batch fermentation. The multiplexed regulation method of adding 60 mg/L of vitamin C into media and maintaining pH of broth at 5.5 was applied, and 45.1 g/L of 2,3-butanediol was reached with the yield of 0.45 g/g. The cornhusk dilute acid hydrolysate after detoxification can be the substitution of glucose as a carbon source for producing succinic acid by anaerobic fermentation. Fermentation experiments showed that it is feasible to produce 2,3-butanediol by fermentation using cotton stalks hydrolyzate detoxified as a carbon source .