Figure 3: Effects of temperature (a) and pH (b) on the activity of the free and immobilized cells, Thermal (c) and pH (d) stability of the free and immobilized cells. a: 5 mg cells, 10 g glycerol/l, sodium phosphate buffer (pH 6), temperature ranging from 20-50°C; b: 5 mg cells, 10 g glycerol/l, 100 mM sodium phosphate buffer (pH from 5to 8.5), at 30°C; c: The samples were pre-incubated at temperature ranging from 25 to 50°C for 12 hours and the residual activity was measured at pH 6.0 at 30°C; d: The samples were pre-incubated at pH ranging from 5 to 8.5 for 12 hours and the residual activity was measured at pH 6.0 at 30°C.