米曲霉A-1植酸酶快速纯化及酶学性质

Quick Purification of Phytase from Aspergillus oryzae A-1 and Enzymatic Characterization

为进一步了解米曲霉A-1植酸酶,利用超滤及Mono Q阴离子纯化柱纯化,分离出米曲霉A-1的植酸酶Phy A1,分子量约为45kDa,Phy A1在pH 5.5时酶活最高,pH 4.0～9.0较稳定,最适温度为45℃,在60℃以下内切酶稳定性较好。Mg2+、Mn2+对Phy A1植酸酶活性有较好的激活作用。以植酸钠为底物,应用Lineweaver-Burk双倒数作图法得到米氏常数Km为42μmol/L。

In order to know phy A-1 in deep,a phytase （Phy A1） was purified from the enzyme extract of A. oryzae A-1 through QuixStandTM benchtop hollowfiber uhrafihration system and Mono Q anion- exchange chromatography. The optimal working temperature for Phy A1 was 45℃ and enzyme was stable under 60℃. The optimal pH for Phy A1 was 5.5, and enzyme was stable at pH 4. 0-10.0, Mg2＋ and Mn2＋ had significant stimulative effects. The Km of Phy A1 determined from Lineweaver-Burk plots was 42 μmol/L with sodium phytate as the substrate.