高效利用棉籽糖菌种的筛选及酶学性质研究

Strain screening and enzyme characteristics for efficiently utilizing raffinose

为筛选出可高效利用棉籽糖的菌种并对其酶学性质进行研究,采用高效液相色谱法测定了棉籽糖含量,平板计数法测定菌种生长量, pNPG法测定α-半乳糖苷酶酶活。结果显示,该实验筛选出屎肠球菌、粪肠球菌和凝结芽孢杆菌3株可以高效利用棉籽糖的菌种,发酵后培养基中棉籽糖剩余含量分别为0、0.36%和 1.05%(质量分数)。屎肠球菌α-半乳糖苷酶最适pH值为5,最适温度为45 ℃。粪肠球菌α-半乳糖苷酶最适pH为5,最适温度为50 ℃。凝结芽孢杆菌α-半乳糖苷酶最适pH为8,最适温度为45 ℃。所产α-半乳糖苷酶具有较为稳定的酶学性质,可为今后饲料和食品中棉籽糖的去除提供研究方向。

This study aimed to screen strains that could efficiently utilize raffinose and to illustrate their enzymatic characteristics. The raffinose content, strain growth, and α-galactosidase activity were measured. The isolates that could efficiently utilize raffinose belonged to Enterococcus faecium, Enterococcus faecalis , and Bacillus coagulans . The residual contents of raffinose in the medium after fermenting with E. faecium , E. faecalis , and B. coagulans were 0, 0.36%, and 1.05%, respectively. The optimum pH of the α-galactosidase from E. faecium , E. faecalis and B. coagulans were 5, 5, and 8, respectively, and the optimum temperatures were 45 ℃, 50 ℃ and 45 ℃, respectively. This study provides research directions for removing raffinose from feeds and foods in the future.