Production of xylitol from mixed sugars of xylose and arabinose without co-producing arabitol

Xylitol is a natural food sweetener, dental caries reducer and sugar substitute for diabetics. During production of xylitol by fermentation, arabinose present in hemicellulosic hydrolysates is converted to arabitol which is difficult to separate in a cost-effective way. Ninety-nine yeast strains were evaluated for production of arabitolfree xylitol from a mixture of xylose and arabinose. Among these yeast strains, five best xylitol producers with least arabitol production were: Barnettozyma populi Y-12728, Bar. californica Y-1680, Bar. californica Y-11750, Cyberlindnera mrakii Y-1364 and Bar. salicaria NRRL Y-6780. These five strains were evaluated for xylitol production from undetoxified corn stover hemicellulosic hydrolysate. Bar. populi Y-12728 produced xylitol without arabitol production from the undetoxified hydrolysate. This is the first report on the evaluation of naturally isolated yeast strains for production of xylitol from mixed sugars of xylose and arabinose and corn stover hemicellulosic hydrolysate without arabitol co-production.