To determine pH stability of PSB phytates, 350 ll of the enzyme was preincubated with 350 ll
of different buffers such as 0.1 M glycine–HCl buffer (pH 2.0–3.0), 0.1 M acetate buffer (pH 4.0, 5.0, 6.0 and 6.5),
0.1 M Tris–HCl (pH 7.0 and 9.0) at 4 _C for 2 h, in absence of phytic acid.
After incubation, phytase activity was estimated
in incubated samples using standard phytase assay with sodium acetate buffer.
The residual enzyme activity was calculated.
Graph was plotted between pH vs % residual activity.