CHARACTERISTICS OF PHYTASES AND ACID PHOSPHATASES EXTRACTED FROM DIFFERENT PLANT SOURCES

Abstract

This study aimed to define the properties of phytases and acid phosphatases extracted from raw, soaked and germinated cereals (wheat, barley, sorghum and maize germ) and legumes (faba bean, lentil, kidney bean and pea). The enzymes were extracted by acetate buffer and partially purified by precipitation in acetone. The optimum pH, temperature and substrate concentration were identified, besides, the effect of incubation time, thermal inactivation and the presence of metal salts on the activities of these enzyme. In addition, the effect of soaking and germination process on phytase and acid phosphatase activities were also studied.

The results could be summarized as the following:

I- Phytases:

A- Characterization of phytase extracted from cereal grains and legume seeds:

1- The maximum activity of phytase was found at pH 5.0 for wheat, barley and sorghum and at pH 5.5 for maize germ. The optimum activity of phytase extracted from lentil and pea was attained at pH 5.0 while, it was at pH5.2 for faba bean and kidney bean.

2- The optimum temperature required for the phytase extracted from wheat and barley was 55°C, while it was 50°C for sorghum and maize germ.phytase. The optimal temperature was 50°C for faba bean, lentil and kidney bean phytase, while it was 45°C for pea phytase.

3- The optimum substrate concentration for phytase extracted from • 96 hr­ germinated wheat, barley and sorghum was 2.0 mM, while it was l.5 mM sodium phytate for maize germ. The activity of phytase was partially inhibited