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为了最大程度增强马唐生防菌Col-68在发酵过程中产孢能力以及次生代谢产物除草活性,试验以Col-68发酵滤液对马唐种子根、芽生长的抑制率为活性指标,综合不同培养条件下菌株产孢的差异,利用单因素筛选试验筛选出了适合该菌株发酵的不同碳氮源、碳氮比及初始碳源适宜浓度。研究结果表明,在初始pH=6.5,每300 mL锥形瓶装液120 mL,接种100μL菌原液,28℃、160 r.min-1震荡培养10 d的最佳发酵条件下,菌株活性差异显著,以蔗糖为碳源时Col-68活性、产孢量以及对马唐根长抑制率最高,蔗糖浓度在30～50 g.L-1时菌株产孢量以及对马唐根长抑制率较高,发酵最适宜利用的氮源为硝酸钠,最佳碳氮比则为2.5∶1.0。同时,不同条件下的发酵滤液对马唐根生长的抑制率均明显高于对芽生长的抑制率。
In order to maximize the spore-forming capacity and the secondary metabolite herbicidal activity of the biocontrol strain Col-68, the inhibitory rate of Col-68 fermented filtrate on root and shoot growth was taken as the activity index, Under different strains of sporulation, different carbon and nitrogen sources, carbon and nitrogen ratios and suitable initial carbon source concentrations for the fermentation of the strain were screened by single factor screening test. The results showed that under the optimal conditions of initial pH = 6.5, 120 mL of conical flask liquid, 120 mL of inoculum, 100 mL of bacterial suspension, shaking culture at 160 ℃ for 10 days at 28 ℃, the activity of the strain was significantly different, When sucrose was used as carbon source, the activity of Col-68, the amount of sporulation and the inhibitory rate to Colza root were the highest, while the sporulation rate and the inhibition rate of Maltodextrin were the highest when the concentration of sucrose was 30 ~ 50 gL-1. The source of nitrogen is sodium nitrate and the optimum ratio of carbon to nitrogen is 2.5: 1.0. At the same time, the fermentation filtrate under different conditions on the growth inhibition of horseradish were significantly higher than the inhibition of bud growth.