Increased xylitol production rate during long-term cell recycle fermentation of Candida tropicalis.
Long-term cell recycle fermentations of Candida tropicalis were performed over 14 rounds of fermentation. The average xylitol concentrations, fermentation times, volumetric productivities and product yields for 14 rounds were 105 g l(-1), 333 h, 4.4 g l(-1) h(-1) and 78%, respectively, in complex medium; and 110 g l(-1), 284 h, 5.4 g l(-1) h(-1) and 81%, respectively, in a chemically defined medium. These productivities were 1.7 and 2.4 times those with batch fermentation in the complex and chemically defined media, respectively. The xylitol yield from xylose with cell recycle fermentation using the chemically defined medium was 81% (w/w), which was 7% greater than the xylitol yield with batch fermentation (74%); both modes of fermentation gave the same yield using the complex medium. These results suggest that the chemically defined medium is more suitable for production of xylitol than complex medium.
Kim
Teak-Bum
TB
Department of Bioscience and Biotechnology, Sejong University, Seoul 143-747, Korea.
Lee
Yong-Joo
YJ
Kim
Pil
P
Kim
Chang Sup
CS
Oh
Deok-Kun
DK
D041022:Candida tropicalis / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D005285:Fermentation; D013997:Time Factors; D014993:Xylitol / Q000096:biosynthesis*
D003470:Culture Media; D014993:Xylitol