title: Benzoate-induced stress enhances xylitol yield in aerobic fed-batch culture of Candida mogii TISTR 5892.
abstract: Production of the natural sweetener xylitol from xylose via the yeast Candida mogii TISTR 5892 was compared with and without the growth inhibitor sodium benzoate in the culture medium. Sodium benzoate proved to be an uncompetitive inhibitor in relatively poorly oxygenated shake flask aerobic cultures. In a better controlled aerobic environment of a bioreactor, the role of sodium benzoate could equally well be described as competitive, uncompetitive or noncompetitive inhibitor of growth. In intermittent fed-batch fermentations under highly aerobic conditions, the presence of sodium benzoate at 0.15gL(-1) clearly enhanced the xylitol titer relative to the control culture without the sodium benzoate. The final xylitol concentration and the average xylitol yield on xylose were nearly 50gL(-1) and 0.57gg(-1), respectively, in the presence of sodium benzoate. Both these values were substantially higher than reported for the same fermentation under microaerobic conditions. Therefore, a fed-batch aerobic fermentation in the presence of sodium benzoate is promising for xylitol production using C. mogii.
authors.affiliation: Department of Biotechnology, Faculty of Agro-Industry, Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok 10900, Thailand; Center for Advanced Studies in Tropical Natural Resources (CASTNAR), National Research University-Kasetsart University (NRU-KU), Chatuchak, Bangkok 10900, Thailand. Electronic address: siwaporn540@yahoo.com.
authors.forename: Siwaporn
authors.initials: S
authors.lastname: Wannawilai
authors.affiliation: Department of Biotechnology, Faculty of Agro-Industry, Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok 10900, Thailand; Center for Advanced Studies in Tropical Natural Resources (CASTNAR), National Research University-Kasetsart University (NRU-KU), Chatuchak, Bangkok 10900, Thailand. Electronic address: sarote.s@ku.ac.th.
authors.forename: Sarote
authors.initials: S
authors.lastname: Sirisansaneeyakul
authors.affiliation: School of Engineering, Massey University, Private Bag 11 222, Palmerston North, New Zealand. Electronic address: Y.Chisti@massey.ac.nz.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Chisti
mesh_terms: D000332:Aerobiosis; D001565:Benzoates / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects*; D014993:Xylitol / Q000378:metabolism*
chemical_list: D001565:Benzoates; D014993:Xylitol
keywords: Candida mogii; Oxygen transfer; Sodium benzoate; Xylitol