PRODUCTION AND CHARACTERIZATION OF Β-GALACTOSIDASE ENZYME IN THE PLANT EXTRACT FROM (ZIZIPHUS SPINA-CHRISTI) AND ITS APPLICATION IN MILK

In the development of a medicinal plant, β-galactosidase (EC 3.2.1.23) is essential (Ziziphus spina-christi). The enzyme activity was measured by its ability to hydrolyze the substrate 2-nitrophenyl β-D-galactopyranoside (ONPG). The maximum enzyme activity was at 50 ° C and at pH 5.5. The enzyme's Km and Vmax values were 3.65 mM and 0.18 μmol / min, respectively. HgCl2 and KCN completely inhibit the activities of β-galactosidase (Ziziphus spina-christi). Lactose in milk was reduced by 38.5 and 70 percent by β-galactosidase from (Ziziphus spina-christi), respectively, after 4h incubation. This result showed that the β-galactosidase enzyme in the extract of leaves (Ziziphus spina-christi) can be used for industrial and medical applications.