枯草芽孢杆菌MN菌株由来胶原蛋白酶的纯化与生化性质

从传统小麦粉发酵食品中分离得到一株革兰氏阳性且为兼性需氧的内生芽孢杆菌,命名为枯草芽孢杆菌MN菌株,该菌能产生胶原蛋白酶,其16S核糖体核酸序列与枯草芽孢杆菌显示99%的同源性.通过一系列的离子交换层析与分子筛层析,该菌分泌产生的胶原蛋白酶被分离纯化到单一条带,通过分子筛层析预测该胶原蛋白酶的分子量为33 kDa,其活性最适反应温度与酸碱度分别为55℃和pH 11.0,而且该酶的热稳定性与酸碱度稳定性分别为50℃和pH5.0～11.0.

Purification and Characterization of A Collagenolytic Enzyme from Bacillus subtilis MN

One Gram-positive and aerobic endospore-forming rod bacterium was isolated,designated Bacillus subtilis MN.It pro- duced one collagenolytic enzyme from traditional fermented wheat flour food.Assay of the 16S Rrna sequence of the isolated strain revealed it to be 99%identical to Bacillus subtilis.The collagenolytic enzyme Was purified to electrophoretic homogeneity from a cul-ture supematant by a series of column chromatiographies.The calculated molecular mass of the purified enzyme determined by gel ill- tration Was 33 kDa.The collagenolytic enzyme showed optimal activity at 55℃and Ph 11.0,and was stable below 50℃and at Ph 5.0～11.0. pe