Repeated fed-batch production of xylitol by Candida magnoliae TISTR 5663

Authors

  • Sarote Sirisansaneeyakul,

    Corresponding author
    1. Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University, Kasetsart University, Bangkok, Thailand (CASTNAR, NRU-KU, Thailand)
    • Department of Biotechnology, Faculty of Agro-Industry, Kasetsart University, Bangkok, Thailand
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  • Siwaporn Wannawilai,

    1. Department of Biotechnology, Faculty of Agro-Industry, Kasetsart University, Bangkok, Thailand
    2. Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University, Kasetsart University, Bangkok, Thailand (CASTNAR, NRU-KU, Thailand)
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  • Yusuf Chisti

    1. School of Engineering, Massey University, Palmerston North, New Zealand
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Correspondence to: S. Sirisansaneeyakul,

Department of Biotechnology, Faculty of Agro-Industry, Kasetsart University,

Bangkok 10900, Thailand.

E-mail: sarote.s@ku.ac.th

Abstract

Background

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.

Results

High-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.

Conclusion

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

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