Chitosan productivity enhancement in Rhizopus oryzae YPF-61A by D-psicose.
The effect of the rare sugar D-psicose on chitosan production by Rhizopus oryzae was studied. The fungus was not able to utilize D-psicose as a sole source of carbon, either for germination of the spores or for growth of the vegetative cells. In a medium containing a low amount of D-glucose, however, D-psicose supplementation between 5 and 12 g/l caused enhancement of the productivity of chitinous substances, especially chitosan, in the cell walls. Substantial changes in the chitosan molecule were not observed from FT-IR or 1H NMR data. It was inferred that a percentage age of the D-psicose added was transformed into another rare sugar tentatively identified as D-tagatose. It was concluded that D-psicose activates the synthesis of chitosan in the cell walls probably through its transformation into another sugar such as D-tagatose.
Yoshihara
Kazutoshi
K
National Institute of Advanced Industrial Science and Technology, Shikoku Center, 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan. kazu-yoshihara@aist.go.jp
Shinohara
Yoshihiro
Y
Hirotsu
Takahiro
T
Izumori
Ken
K