Xylitol Production by Candida tropicalis 31949 from Sugarcane Bagasse Hydrolysate

Application of microbial fermentation of xylose to produce xylitol can not only turn waste into useful products and conserve resources, but also protect the environment. Currently, more than 100 kinds of microorganisms are known to ferment xylose, among which Candida tropicalis has strong xylose conversion ability and high tolerance to inhibitors such as furfural, acetate, and phenolics in xylose mother liquor. The present study focused on fermenting xylose hydrolysate from sugarcane bagasse to produce xylitol using C. tropicalis strain 31949. The effects of inoculum age, inoculum quantity, and initial xylose concentration on xylitol fermentation by C. tropicalis 31949 were discussed. The following optimum fermentation conditions were determined: inoculum quantity, 10%; inoculum age, 26 h; and initial xylose concentration, 100 g/L. Under these optimal fermentation conditions, C. tropicalis 31949 could ferment sugarcane bagasse hydrolysate, which was pretreated by vacuum concentration and activated carbon detoxification decoloration, to produce 62.9800 g/L xylitol.