拮抗香蕉枯萎病菌的海洋细菌TC-1发酵条件优化

通过对6种培养基进行筛选得到海洋拮抗细菌TC-1在BPDB培养基发酵的无菌发酵液对香蕉枯萎病菌(Fusarium oxysporum f.sp.cubense)的抑菌活性最好。在BPDB培养基基础上,通过正交试验优化培养基成分及用量,得到最佳配方为马铃薯200 g,牛肉膏20 g,葡萄糖20 g,玉米粉7 g、蛋白胨7 g,蒸馏水1 000 mL,pH自然;通过正交试验对发酵条件的装瓶量、培养温度、初始pH、发酵时间和转速5个因素进行了优化,得到最优发酵条件为:装瓶量20%,培养温度27℃,初始pH自然,发酵时间72 h,摇床转速200 r/min;在最佳培养基和最佳发酵条件下,TC-1的无菌发酵液抑菌圈直径为24.3 mm,与优化前抑菌圈直径20.7 mm相比,抑菌活性提高了17.4%。

Optimization of Fermentation Conditions of Marine-derived Antagonistic Bacterium Strain TC-1 against Fusarium oxysporum f.sp. cubense Race 4 Causing Banana Vascular Wilt

The antifungal activity of the cell-free fermentation liquid (CFL) from six culture media after strain TC-1 was incubated for 48 h were estimated by using Oxford cup method.The results showed that the diameter of inhibition halos of CFL from BPDB medium were the biggest among the six screened culture media.To increased the antifungal of CFL,the components and dosages of five organic mixtures to be added in the foundational BPDB medium were optimized by orthogonal experiments.The result showed that the optimization medium contained potato 200 g,beef extract 20 g,D-glucose 20 g,corn flour 7 g and peptone 7 g in 1 000 mL deionized water.The L25(56) orthogonal experiments results showed the optimization fermentation condition were as follows,medium quantity 20%,cultivating temperature 27 ℃,initialization pH of the fermentation medium 5 mm,fermentation time 96 h,rotation speed 120 r /min.The average diameter of inhibition halos of CFL from the optimum fermentation condition and culture medium was 24.3 mm;the antifungal activity was increased by 17.4%,compared inhibition zone diameter of 20.7 mm before optimization.