抑制烟草黑胫病的混合菌株优化

Optimization of mixed strains against the growth of Phytophthora parasitica var.nicotianae

通过正交试验筛选混合菌株有效抑制烟草黑胫病病原菌(Phytophthora parasitica)菌丝的生长,其中1107、1205、1601、5801和7403五株芽孢杆菌(Bacillus)在室内NYBD培养基上培养,参照5因素3水平正交试验设计进行混菌比例优化。结果表明,1107菌株在生物量和抑菌活性方面都表现出了显著性。5株芽孢杆菌(1×108 CFU/m L)的最优组合为芽孢菌株1107、7403、1601、5801的添加量均为1.2 m L,芽孢菌株1205添加量为0.6 m L。在此优化条件下,生物量(OD600 nm值)为3.18±0.02,抑菌圈直径为(24.22±0.68)mm,分别比单独培养的菌株或其他混合菌株都显著提高。

Mixed strains which suppress the growth of Phytophthora parasitica var. nicotianae mycelial were screened by orthogonal experiment. Bacillus strains 1107, 1205, 1601, 5801 and 7403 were cultured in NYBD medium, and the optimal mixed strain proportion was optimized by 5 factors 3 levels orthogonal experiment. Results indicated that biomass and bacteriostatic activity of strain 1107 were significant. The results showed that the optimum mixed strains （1×10^8 CFU/mL） addition were Bacillus 1107 1.2 ml, Bacillus 7403 1.2 ml, Bacillus 1601 1.2 ml, Bacillus 5801 1.2 ml, Bacillus 1205 0.6 ml. Under this condition, the OD600nm was 3.18±0.02 and the inhibition zone diameter reached （24.22±0.68） mm, greatly increased than other mixed strains and the single cultured ones.