摘要
从5株霉菌中筛选出1株产胞外植酸酶最高的菌株(Aspcrgillusoryxae;简称霉菌3号)。经发酵,硫酸铵分级沉淀,Sephadex G—100凝胶过滤、SE—Sephadex G—50层析和电泳分离,获得2种植酸同工酶.此两种酶的分子量为40000d,等电点分别为4.5和4.8,最适pH为2.7和5.6,最适温度为50℃,K_m值为50μmol/L。SDS、Fe_^(2+)对酶活力无影响;Mn^(2+)、Ca^(2+)、Mg^(2+)有激活作用;Cu^(2+)有抑制作用。
Two isoenzymes of phytase were purified from cultural filtration of a high -yielding strain (Aspergillus orgzae), which producing extracellular phytase had been isolated from 5 strains of mold, by ammonium sulfate precipitation ,Sephadex G-100 chromatography,SE-Sephadex G-50 chromatography and PAGE. Their molecular weight are commonly 40000 dalton. The optima pH are respectively 2. 7 and 5. 6 ,pI are respectively 4. 5 and 4. 8. Optima temperature is 50℃.Km for sodium phytate is 50uM. Their activity can be activated by Ca+++,Mg++,Mn++, inhibited by Cu++ and unaffected by SDS and Fe2+.
出处
《四川大学学报（自然科学版）》
CAS
CSCD
1993年第2期253-259,共7页
Journal of Sichuan University(Natural Science Edition)
关键词
米曲霉
植酸酶
植酸钠
mold, phytase. sodium phytate.
