發(fā)布時間：2018-06-06 22:08

  本文選題：菌株DY + S��； 參考：《中國飼料》2017年05期

【摘要】：從雞腸道篩選出一株菌,命名為DY032,經16S r DNA分子鑒定和系統(tǒng)發(fā)育分析,該菌種為枯草芽孢桿菌。在搖瓶發(fā)酵條件下,采用單因素試驗,對菌株DY032的培養(yǎng)基配方進行優(yōu)化,確定了影響發(fā)酵液菌體數和芽孢數的5個因素,分別為淀粉、魚粉、豆餅粉、MnSO_4·H_2O和CaCO_3,其適宜濃度分別為20、10、10、0.05、0.05 g/L,進一步通過L_(16)(4~5)正交試驗確定以上5因素的最佳配比。為放大培養(yǎng),在最優(yōu)培養(yǎng)基基礎上,利用10 L發(fā)酵罐,采用L_9(3~4)正交試驗設計,以芽孢數為指標,對菌株DY032的培養(yǎng)溫度、pH值、攪拌轉速、通氣量4個條件進行優(yōu)化。結果表明:菌株DY032培養(yǎng)基最優(yōu)配方為:淀粉16 g/L,魚粉10 g/L,豆餅粉10 g/L,Mn SO4·H2O 0.05 g/L,Ca CO30.03 g/L。最優(yōu)發(fā)酵罐培養(yǎng)條件為:培養(yǎng)溫度37℃,pH值6.5,轉速200 r/min,通氣量5 L/min,最終芽孢數可達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，

本文編號：1988261