海洋低温β-半乳糖苷酶菌株筛选、鉴定及酶的分离纯化

Isolation,identification and enzyme purification of a strain producing cold-activity β-galactosidase from marine

筛选自黄海海泥产β-半乳糖苷酶的菌株CD6,依据形态学特征、生理生化特征及分子生物学特征鉴定为土生拉乌尔菌(Raoultella terrigena)。通过透析、超滤和柱层析方法分离纯化菌株β-半乳糖苷酶,测定该酶的最适反应温度为20℃,30℃剩余相对酶活85%;超过35℃酶活力即迅速下降,确定其为低温酶。

A strain CD6 from Huanghai sea mud was identified as Raoultella terrigena according to its morpholo- gy, taxonomical properties and molecular characterization. The purified β-galactosidase was obtained through dialysis, uhrafiltration, and column chromatography. Researches on the β-galactosidase showed that its optimal temperature was 25℃ and it was defined as cold-activity enzyme.