产植酸酶菌株的分离筛选研究

Isolation and Screening of Phytase-Producing Strains

研究了产植酸酶菌株分离筛选的方法 ,筛选得到分别适宜液态发酵和固态发酵的酶活力较高的黑曲霉XH和黑曲霉PA两菌株。在液态发酵KH2 PO4 对植酸酶产生有促进作用 ,其最佳用量为 8mg %;在固态发酵KH2 PO4 的添加对植酸酶的产生无明显促进作用。 2菌株所产植酸酶具有相似的酶学性质 ,最适作用温度为 5 5℃ ,当底物 pH为 3～ 5具有较高的酶活力。

The isolation and screening methods of phytase-producing strains were studied. Two strains producing high phytase activity were selected, one was Aspergillus niger XH suitable growing in liquid-state, the other was Aspergillus niger PA suitable growing in solid-state. Phytase production was promoted in liquid-state fermentation by adding KH 2PO 4 in the medium with the optimal amount at 8mg%, but was not promoted in solid-state fermentation. The phytases produced by the two strains has similar enzymological characteristics. The optimal temperature enzymatic catalysis was 55℃. When the pH of the substrate was at 3～5, the enzyme has fairly high activity.