Submitted to: Society of Industrial Microbiology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/28/1997
Publication Date: N/A
Technical Abstract: Xylitol is a natural, anticariogenic sweetener, safe for diabetic applications. Although xylitol is conventionally produced by chemical conversion of xylose from wood fiber, fermentation of corn fiber hydrolysates may be an attractive alternative. Pichia guilliermondii strain NRRL Y-12723 efficiently converted xylose to xylitol. However, cultures grown on a mixture of glucose, xylose and arabinose, in ratios characteristic of corn fiber hydrolysates, preferentially utilized glucose and only slowly metabolized pentose sugars, with low yields of sugar alcohols. We developed a two-step, sequential fermentation scheme for production of xylitol and arabitol from mixed sugars. During the diauxic lag period following glucose consumption, cells were removed from mixed sugar cultures and replaced with cells from early stationary phase cultures grown on xylose. These secondary fermentations converted approximately 25% of initial xylose and 75% of initial arabinose to xylitol and arabitol, respectively.