Recombinant Escherichia coli cells which produce a thermostable alpha-amylase were immobilized in a kappa-carrageenan gel and the effects of incubation conditions on release of the enzyme in a glycine supplemented growth medium were investigated using a T-shape flask and a bioreactor. Glycine promoted the release of the enzyme during T-shape hash cultivation, although the viability of the immobilized cells was reduced significantly with an increase in glycine concentration. In the presence of 1% glycine, maximum enzyme release from the free cells occurred at pR 6.5, while the increase in the initial pH promoted release of the enzyme from the immobilized cells and increased the viability of the cells in the beads. Although the enzyme release in the bioreactor under pH control was faster at higher pH, the optimum condition was obtained with the pH controlled at 7-7.5, because enzyme stability was lower at higher pH values.