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Xylitol production by Candida tropicalis from corn cob hemicellulose hydrolysate in a two‐stage fed‐batch fermentation process
Author(s) -
Li Minghua,
Meng Xiumei,
Diao Enjie,
Du Fangling
Publication year - 2012
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.2732
Subject(s) - xylitol , hemicellulose , hydrolysate , fermentation , xylose , food science , candida tropicalis , chemistry , aeration , hydrolysis , biochemistry , yeast , organic chemistry
Abstract BACKGROUND: Xylitol, a sugar alcohol widely used in food and pharmaceutical industries, can be produced through biological reduction of xylose present in hemicellulose hydrolysates by Candida tropicalis . However, the aeration rate and by‐products originating from hemicellulose hydrolysis strongly inhibit the production of xylitol in a fermentation process. A two‐stage fed‐batch fermentation system was developed to reduce these inhibitory effects and to improve xylitol production from corn cob hemicellulose hydrolysates by C. tropicalis . RESULTS: Results of batch fermentations indicated that high xylitol production could be obtained from C. tropicalis at an initial xylose concentration of 80 g L −1 in corn cob hydrolysate medium at an aeration rate of 0.4 vvm at the micro‐aeration stage. In the two‐stage fed‐batch fermentation process, 96.5 g L −1 xylitol was obtained after 120 h, giving a yield of 0.83 g g −1 and a productivity of 1.01 g L −1 h −1 , which were 12.16% and 65.57% higher than those in a batch fermentation. CONCLUSION: High xylitol production can be achieved in a two‐stage fed‐batch fermentation process, in which the negative effects of aeration rate and inhibitory compounds on xylitol formation can be considerably reduced. Copyright © 2011 Society of Chemical Industry