초록
<P><B>Abstract</B></P><P><B>Background</B></P><P><B>Xylitol 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.</B></P><P><B>Results</B></P><P><B>High‐cell density cultures of the yeast <I>Candida magnoliae</I> 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<SUP>−1</SUP> were obtained at average biomass concentrations of 21, 48, and 50 g L<SUP>−1</SUP>, respectively, using an initial xylose concentration of ∼60 g L<SUP>−1</SUP> 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<SUP>−1</SUP> h<SUP>−1</SUP> was attained within the fed‐batch periods. The final xylitol concentration was in the range 235–284 g L<SUP>−1</SUP> depending on the stage of feeding.</B></P><P><B>Conclusion</B></P><P><B>The 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</B></P>