小枣黑疔病拮抗放线菌的筛选与发酵优化.

【Objective】The aim was to screen out antagonistic Actinomycetes and optimize the fermentation conditions. 【Method】Filter paper diffusing method was used to screen antagonistic Actinomycetes on Alternaria sp. causing black spot of Jujube from 26 strains endophyte-Actinomycetes of Lerodendranthus spicatus(Thunb.), 17 strains of Laggera pterodonta(DC.) Benth. and 12 strains Actinomycetes spp. of Daqing Oil Field. Then single factor experimental method was exploited to optimize the fermentation conditions of the strain with the highest inhibition activities. 【Result】One antagonistic Actinomycetes BEG-46 was selected from root of Clerodendranthus spicatus(Thunb.) C. Y. Wu, which exhibited the highest antagonistic activity(inhibition zone width up to 13.6 mm). The optimal fermentation conditions for antifungal substance production of BEG-46 were natural pH value, 2 g/L glucose, 20 g/L yeast, 2 g/L peptone, 4 g/L NaCl, 4 g/L CaCO3, liquid medium shaking for 7 days at 28 °C. After optimized, the inhibition activity of fermentation broth of BEG-46 increased by 118.3%. 【Conclusion】The inhibition activity of fermentation broth of BEG-46 was obviously increased in optimized fermentation conditions. [ABSTRACT FROM AUTHOR]