动物肠道益生菌地衣芽孢杆菌的筛选及培养基的优化

Selection of Bacillus Licheniformins for Probiotics and their Fermentation Conditions Optimized

为了研制新型微生态制剂,以常用益生菌株——地衣芽孢杆菌(Bacillus licheniformis)为试验菌株,在测定了初发菌株的极限耐受性后,运用紫外诱变技术筛选到了一株耐酸性较强,耐胆汁,耐高温的地衣芽孢杆菌D-11。其极限耐受条件为:pH4.18,胆盐浓度0.4g/L,温度58℃。并通过试验对该菌株进行了形态和生理生化特征的鉴定。最后通过单因素和正交试验对地衣芽孢杆菌D-11的发酵培养基成分配比进行了选择和优化,为以后的工业化生产提供依据。结果显示当培养基的配比浓度为:玉米淀粉15g/L、豆粕粉90g/L、玉米浆6g/L时菌体的培养效果最好。

In order to develop new style Microecologics preparation, the Bacillus licheniformis was tested as the testing strain. After measuring critical tolerance of the testing strain, one strain, Bacillus licheniformis D-11, which had stronger acid resistance, bile resistance and high temperature resistance was found by ultraviolet mutagenic technology. The critical conditions were： pH 4.18, concentration of bile salt 0.4 g/L, temperature 58℃. Then, the characteristics were identified about shape, physiologic and biochemical of the mutagenic stain. At last, the single factor experiments and orthogonal experiments were carried out to determinate the optimal proportion of ingredient of fermentation medium. The results indicated that the optimal proportions were： cornstarch 15 g/L, defatted soybean powder 90 g/L, corn steep liquor 6 g/L. It will provide gist for commercial process in future.