Immobilization of Aureobasidium pullulans strain RP-1 cells by adsorpt
ion on the ion exchange resins triethylaminoethyl-cellulose, diethylam
inoethyl-cellulose and phosphocellulose, were investigated. Pullulan p
roduction by the fungal cells immobilized on triethylaminoethyl-cellul
ose was slightly greater than by the cells immobilized on diethylamino
ethyl-cellulose or phosphocellulose when the corn syrup-grown cells we
re adsorbed at pH 2.0, 6.0 and 7.0. When the cells were adsorbed on th
e resins between pH 2.5 and 5.0, similar polysaccharide concentrations
were produced by the immobilized cells. The highest polysaccharide le
vels were elaborated by strain RP-1 cells immobilized at pH 2.0 on any
of the resins tested. Pullulan synthesis ranged from highest to lowes
t for cells adsorbed at pH 2.0 on triethylaminoethyl-cellulose, diethy
laminoethyl-cellulose and phosphocellulose, respectively, which corres
ponded to their level of fungal cell immobilization. At least two 7 da
y cycles of pullulan elaboration by cells immobilized on the resins at
pH 2.0 was demonstrated, but polysaccharide synthesis diminished for
cells immobilized on diethylaminoethyl-cellulose or phosphocellulose d
uring the second cycle.