• KSBB Journal
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• v.19 no.3
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• pp.226-230
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• 2004

Fermentation characteristics of D-xylose into xylitol by Candida mogii ATCC 18364, a potential xylitol producer from rice straw hemicellulose hydrolyzates, were investigated. The influences of the most important operational variables on xylitol production were examined. The best results in xylitol production were obtained in shake-flask fermentations when 3.0 g/L initial cell concentration of 12 hr-old cells grown in D-glucose containing medium were used as inoculum. The oxygen availability is a critical factor in xylose fermentation, therefore, xylose conversion into xylitol was investigated in a 2-L fermenter at different stirring rates. Maximum xylitol production was obtained with an aeration rate of 1 vvm at a stirring rate of 200 rpm.

• KSBB Journal
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• v.21 no.6 s.101
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• pp.493-497
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• 2006

Two stage fermentations of glucose/xylose mixture which is similar composition with rice straw hemicellulose hydrolysate were performed by Candida mogii ATCC 18364. In first stage, glucose was consumed rapidly for cell growth in aerobic condition (2 vvm, 300 rpm), then D-xylose was used for xylitol production in semi-aerobic condition (1 vvm, 300 rpm). After 4 days of fermentation, about $24\;g/{\ell}$ xylitol was produced with a yield of 0.58 g/g and volumetric productivity of $0.25\;g/{\ell}{\cdot}h$. To improve the xylitol yield by reduction of xylose consumption for cell growth and maintenance, D-glucose was continuously supplemented during the second stage of fermentation. By D-glucose feeding of $6.8\;g/{\ell}{\cdot}$ day, xylitol was produced up to $29\;g/{\ell}$ with a yield of 0.8 g/g and volumetric productivity $0.30\;g/{\ell}{\cdot}h$ which are 1.2-1.3 times higher than those obtained without D-glucose feeding.