Immobilization of Avocado Phytase on Epoxy-Activated Sepabead EC-EP and its Application in Soymilk Phytate Hydrolysis

Figures & data

Table 1. Immobilization of avocado phytase on Sepabead EC-EP

Free Enzyme					Immobilized Enzyme
Activity (Unit)	Protein (mg)	Specific Activity (U/mg)	Bound Protein (mg)	Protein binding yield (%)	Activity (Unit)	Specific Activity (U/mg)	Activity Yield (%)
0.14	0.58	0.24	0.46	79.3	0.08	0.17	70.8
0.28	1.16	0.24	0.90	77.6	0.11	0.12	50.0
0.56	2.32	0.24	1.76	75.9	0.13	0.07	29.2
1.12	4.64	0.24	3.42	73.7	0.17	0.05	20.8

Figure 1.  The effect of temperature on the activity of free (▴) and immobilized (▪) phytase activity (activities were assayed at indicated temperatures by using 2 mM sodium phytate prepared in 0.1 M acetate buffer at pH 5.0).

Figure 2.  Thermal stability of free (▴) and immobilized (▪) phytase (after incubation at indicated temperatures activities were assayed at 37°C by using 2 mM sodium phytate prepared in 0.1 M acetate buffer at pH 5.0).

Figure 3.  The effect of pH on the activity of free (▴) and immobilized (▪) phytase (activities were assayed at 37°C by using 2 mM sodium phytate prepared in appropriate buffer solution).

Figure 4.  pH stability of free (▴) and immobilized (▪) phytase (after incubation at indicated pH's activities were assayed at 37°C by using 2 mM sodium phytate prepared in 0.1 M acetate buffer at pH 5.0).

Figure 5.  Repeated use of immobilized phytase at 37°C (▴) and 60°C (▪) (activities were assayed at 37°C by using 2 mM sodium phytate prepared in 0.1 M acetate buffer at pH 5.0).

Figure 6.  Storage stability of free (▴) and immobilized (▪) phytase (activities were assayed at 37°C by using 2 mM sodium phytate prepared in 0.1 M acetate buffer at pH 5.0).

Table 2. The effects of some minerals and ions on free (a) and immobilized (b) enzymes

Effector	0.1 mM	1.0 mM	2.5 mM
(a)
Control	100	100	100
FeCl3.6 H2O	91.8	91.3	86.2
CaCl2	92.4	92.4	95.9
MgCl2.6 H2O	95.9	95.4	83.2
CuSO4.5 H2O	87.8	79.1	57.7
Tartarat	97.5	93.9	97.0
Citric acid	117.9	112.2	108.2
Na2MoO4.2 H20	50.5	47.5	43.4
NaF	89.8	88.3	84.2
ZnSO4.7 H2O	93.4	85.7	76.5
MnCl2.4 H2O	92.9	98.0	101.5
(b)
Control	100	100	100
FeCl3.6 H2O	95.5	87.3	77.3
CaCl2	83.6	86.4	90.0
MgCl2.6 H2O	100.0	85.5	80.9
CuSO4.5 H2O	90.9	87.3	63.6
Tartarat	91.8	96.4	92.7
Citric acid	120.0	109.1	103.6
Na2MoO4.2 H20	73.6	67.3	63.6
NaF	96.4	91.8	88.2
ZnSO4.7 H2O	94.5	89.1	79.1
MnCl2.4 H2O	85.5	92.7	94.5

Figure 7.  Hydrolysis of phytate in batch-stirred tank reactor with free (▴) and immobilized (▪) phytase.