Repeated fed‐batch production of xylitol by Candida magnoliaeTISTR 5663

Abstract

AbstractBackgroundXylitol is an important commercial sweetener that can be produced by fermentation. Previous studies of xylitol production have not been able to combine a high final product concentration, and a high average productivity and yield, in a single process.ResultsHigh‐cell density cultures of the yeast Candida magnoliae TISTR 5663 were used to produce xylitol by repeated fed‐batch fermentations under oxygen limiting conditions involving feeding of xylose and nitrogen. Xylitol yields of 0.727, 0.719 and 0.720 g g−1 were obtained at average biomass concentrations of 21, 48, and 50 g L−1, respectively, using an initial xylose concentration of ∼60 g L−1 under controlled conditions (agitation rate 300 rpm, aeration rate 1.0 vvm, pH 7.0, 30°C). For a total duration of 750 h of a repeated fed‐batch fermentation, an average xylitol productivity of 1.149 g L−1 h−1 was attained within the fed‐batch periods. The final xylitol concentration was in the range 235–284 g L−1 depending on the stage of feeding.ConclusionThe fed‐batch xylitol production developed in this work combined high final product concentration, xylitol productivity and yield in a single process.© 2012 Society of Chemical Industry