黑曲霉变异株A-828酸性植酸酶的生物合成和性质的研究

经钴60及原生质体紫外联合诱变后,筛选出一株高产植酸酶的菌株(A-828),酶活力达到66,000U/mL,为出发株的17倍。通过滤膜超滤浓缩和Bio-gel P-150层析纯化,纯化倍数为11.2倍,活力回收率为37.7%。SDS-PAGE分析表明,变异株植酸酶的分子量约为66kDa,酶学实验结果表明:该酶的最适pH有两个,分别为2.5和5.5,但在2.5时所表现的活力是5.5时的5倍,酶的最适温度为55℃。在20-60℃保温20min,活力不改变。2mmol/L的Fe2+、Cu2+、Cr3+抑制了酶的活性,但同样浓度Ca2+、Mn2+、EDTA、DTT对酶的活力影响不显著。

The biological synthesis, purification and characterization of an acid phytase from Aspergillus niger A-828

Screening out a novel Aspergillus niger strain (A-828) which expresses high active acid phytase through combination mutation by Co-60 and UV. To research its enzymatic characterization, the acid phytase was purified by the steps of ultrafiltration and Bio-gel-P-150 chromatography. The purification ratio and yield was 11.2 and 29%. Result shows that its molecular weight was estimated to be about 66kDa by SDS-PAGE. The phytase activity of A-828 reached to the 66,000U/mL, 17 fold than origin. Its optimum pH of...