Changho Cho*, Shinobu Aruga*, Masahiro Hatsu*, Tohru Suzuki*, Keiichi Kawai* and Kazuhiro Takamizawa*

* Faculty of Agriculture, Gifu University

+ Correspondence should be addressed to Kazuhiro Takamizawa:
(1-1 Yanagido, Gifu-city 501-1193 Japan)

Abstract

Hemicellulose is a major component of plant waste and a polysaccharide of D-xylose. D-xylose can be obtained by decomposition of hemicellulose. In spite of the abundant existence of D-xylose, its value has not been well considered. Xylitol, a sugar alcohol widely used as a food additive and in diabetes therapy, was selected as a targeting compound for value-added use of D-xylose, and its microbiological production from peanut shell was studied. A combined treatment of steam explosion, calcium precipitation, mixed resin (anion-exchange and absorbing resin) treatment, and concentration treatment of peanut shell was developed and used for medium of xylitol production by Candida tropicalis IFO 0618. Initial cell concentration was found to be a very important factor for fermentation. Levels under 5.0 g/l of inoculation condition, 0.23 g/l/hr of production rate, 54.7 % of yield, and 8.7 g/l of xylitol were respectively obtained. Gross D-xylose extraction yield from peanut shells by this newly developed method was approximately 20%.

Key words: Candida tropicalis, hemicellulose, xylitol, D-xylose, Agricultural waste