中文摘要：

运用基因工程技术,将克隆到的淀粉液化芽孢杆菌Bacillus amyloliquefaciens DSM 1061新型中性植酸酶基因（GenBank登录号为HM747163）构建到表达载体pET22b（＋）上,并在E.coli BL21（DE3）中进行高效表达。电泳结果表明该酶分子质量约为42kD,目的蛋白占大肠杆菌可溶性蛋白30%左右。利用Ni-NTA琼脂糖凝胶进行亲和纯化,酶学性质研究表明,其最适温度为60℃,最适pH值为7.0,最大酶比活力为15U/mg。60℃时以植酸钠为底物的Km值为0.30mmol/L。

英文摘要：

A new neutral phytase gene（phyc） from Bacillus amyloliquefaciens DSM 1061（GenBank： HM747163） was cloned into expression vector pET22b（＋）.The phytase was expressed in Escherichia coli BL21（DE3）.The molecule weight of the phytase protein was about 42 kD determined by SDS-PAGE.The expressed phytase was about 30% of the total soluble protein of E.coli.The recombinant protein was purified by 6×His-Tagged Protein Purification Kit.Optimal pH value and temperature of the phytase were 7.0 and 60 ℃,respectively.Under the optimum conditions,the activity was 15 U/mg.The Km value of the phytase for hydrolysis of sodium phytate under 60 ℃ was 0.30 mmol/L.