饲用枯草芽孢杆菌制剂制备工艺研究.doc

饲用枯草芽孢杆菌制剂制备工艺研究 摘要枯草芽孢杆菌(Bacillus subtilis) 是常用的饲用微生态制剂之一，因其具有较高的蛋白酶、脂肪酶和淀粉酶活性，具有较强的生物夺氧能力、耐高温高压、易贮存等特点，对促进动物营养的消化吸收、提高动物的饲料转化率、防病和促进生长起到重要作用，因而被越来越多地研制成饲用微生态制剂。本文以枯草芽孢杆菌为对象，系统地研究了枯草芽孢杆菌制剂的制备工艺，其中包括发酵培养基的优化研究、发酵罐培养研究和发酵后处理促芽孢形成的研究，基本形成了一套完整的生产工艺。结果表明：蔗糖为最佳碳源、蛋白胨为最佳氮源，MgSO4·7H2O和MnSO4均对枯草芽孢杆菌的生长有促进作用。通过正交试验确定了最佳的培养基组成为：蔗糖15 g/L、蛋白胨4 g/L、NaCl 5 g/L、KH2PO4 2 g/L、K2HPO4·3H2O 4 g/L，MnSO4 0.4 g/L、MgSO4·7H2O 2 g/L 、pH 7.0。发酵罐培养验证了由正交试验确定的最佳培养基。采用了两种不同的方式促使芽孢形成：一是加入金属离子促芽孢形成。Mn2+对芽孢形成促进作用最强，在Mn2+的作用下，发酵液中的最终芽孢形成率达到28.5 %。另一是干燥促芽孢形成，干燥能够极大地促进芽孢的形成，其中尤其以冷冻干燥效果最佳，其芽孢形成率达到95.9 %，喷雾干燥的方式达到93.5 %。在各种干燥促芽孢形成的方式中，冷冻干燥时芽孢率最高，较为理想。而喷雾干燥的芽孢的率也相当高，只是略低于冷冻干燥，且喷雾干燥周期短，操作简单，耗能低，成本也低，适合大规模工业生产。 关键词：枯草芽孢杆菌；微生态制剂；芽孢；培养基优化；促芽孢形成 Research on the Preparation process of Feeding Bacillus subtilis probiotics Abstract：Bacillus subtilis is one kind of strain which is commonly used in feeding probiotics. Because of its high protease,lipase and amylase activities, It has a strong biological capture oxygen capacity, tolerance to high temperature and high pressure and easy storage features, which plays an important role in promoting the digestion and absorption of animal nutrition, improving feed conversion rate of animals, preventing disease and the promoting growth, which has been more and more used to research on feeding probiotics. In this paper, the research object is Bacillus subtilis, the preparation formulations of Bacillus subtilis probiotics were studied systemly, including the optimization of fermentation medium, bioreactor culture study and fermentation post-treatment to promote sporulation were studied, formed a complete production processes. The results showed that: sucrose is the best carbon source, peptone as the best nitrogen source, both MgSO4 ? 7H2O and MnSO4 can promote the growth of Bacillus subtilis. Though orthogonal test, the best composition of the medium was been determined: sucrose 15 g/L, peptone 4 g/L, NaCl 5 g/L, KH2PO4 2 g/L, K2HPO4·3H2O 4 g/L, MnSO4 0.4 g/L, MgSO4 ? 7H