一株枯草芽孢杆菌的鉴定及液体发酵工艺优化

发布时间：2018-06-06 22:08

  本文选题：菌株DY + S　； 参考：《中国饲料》2017年05期

【摘要】：从鸡肠道筛选出一株菌,命名为DY032,经16S r DNA分子鉴定和系统发育分析,该菌种为枯草芽孢杆菌。在摇瓶发酵条件下,采用单因素试验,对菌株DY032的培养基配方进行优化,确定了影响发酵液菌体数和芽孢数的5个因素,分别为淀粉、鱼粉、豆饼粉、MnSO_4·H_2O和CaCO_3,其适宜浓度分别为20、10、10、0.05、0.05 g/L,进一步通过L_(16)(4~5)正交试验确定以上5因素的最佳配比。为放大培养,在最优培养基基础上,利用10 L发酵罐,采用L_9(3~4)正交试验设计,以芽孢数为指标,对菌株DY032的培养温度、pH值、搅拌转速、通气量4个条件进行优化。结果表明:菌株DY032培养基最优配方为:淀粉16 g/L,鱼粉10 g/L,豆饼粉10 g/L,Mn SO4·H2O 0.05 g/L,Ca CO30.03 g/L。最优发酵罐培养条件为:培养温度37℃,pH值6.5,转速200 r/min,通气量5 L/min,最终芽孢数可达51.95×108cfu/m L。
[Abstract]:A strain of Bacillus subtilis was isolated from chicken intestine and named DY032.The strain was identified by 16s r DNA molecular identification and phylogenetic analysis. Under the condition of shaking flask fermentation, single factor test was used to optimize the medium formulation of strain DY032. Five factors affecting the number of bacteria and spores of fermentation broth were determined, which were starch and fish meal, respectively. The optimum ratio of the above five factors was determined by the orthogonal test. The optimum concentration of MNSO4H2O and CaCO3 was 2010 / 100.05g / L, respectively, and the optimum proportion of the above five factors was determined by the orthogonal test. In order to enlarge the culture, on the basis of the optimum culture medium, using 10L fermenter and L _ 9 / 3 ~ (4) orthogonal experimental design, the cultivation temperature and pH value, stirring speed and aeration volume of strain DY032 were optimized by taking the number of spores as the index. The results showed that the optimum medium of DY032 was as follows: starch 16 g / L, fish meal 10 g / L, soybean meal 10 g / L, mn so 4 H 2O 0.05 g / L, Ca CO 3 0.03 g / L. The optimum culture conditions were as follows: culture temperature 37 鈩，

本文编号：1988261