短短芽孢杆菌Brevibacillus brevs HAB-5主要抑菌活性成分的分析及其特性研究

本文采用乙醇低温沉淀法及 Sephadex G-50凝胶柱等手段分离纯化短短芽孢杆菌 Brevibacillus brevs HAB-5主要活性成分。针对芒果炭疽病菌C7-2，菌株HAB-5发酵产生抑菌活性物质的最佳培养基为改良的LB，命名为ZS，其最佳发酵条件为28℃、2 d和装液量为50 mL/250 mL。菌株HAB-5总蛋白没有拮抗活性，但HAB-5菌液的上清液能产生较强的抑菌效果；同时，在单独培养和与病原菌对峙培养下，取距HAB-5菌落1 cm处的培养基（MB）均对病原菌产生了明显的抑菌圈。菌株HAB-5上清液经硫酸铵沉淀不具有抑菌活性，但采用低温乙醇法等提取具有抑菌作用的菌株HAB-5上清液或MB，其粗提物均产生较强的抑菌效果，再经Sephadex G-50凝胶柱过柱和SDS-PAGE分析，在14.4 kD位置均具有较强信号的条带。因此，菌株HAB-5主要抑菌活性物质为肽类，其中14.4 kD大小的肽类是菌株HAB-5重要抑菌成分。

Analysis on the Key Antagonistic Active Compositions of Brevibacillus brevs HAB-5 and Its Characteristics

In this study the active antagonistic components from Brevibacillus brevs HAB-5 strain were isolated and purified mainly through low-temperature ethanol precipitation and Sephadex G-50 Gel column. The optimal fermentation medium ZS of HAB-5 was developed from LB to make HAB-5 produce the strongest antagonistic activity against Colletotrichum gloeosporioides Pen C7-2, and the optimal culture condition was incubation at 28 ℃for 2 d with medium liquid volume in 50 mL/250 mL. Total bacterial proteins from HAB-5 did not show antagonism against the pathogen, but its supernatant exhibited strong antifungal effect. In the meantime, the medium block (MB), taken 1 cm from HAB-5 colony from ZS medium produced a significant inhibition zone against the pathogen. The HAB-5 supernatant treated by ammonium sulfate did not have antifungal activity, however, the crudes that were extracted from the supernatant or MB through low-temperature ethanol precipitation showed strong antifungal effect against the pathogen. Furthermore, the SDS-PAGE analysis of the crudes purified with Sephadex G-50 gel column showed a single electrophoresis band at 14.4 kD. Therefore, our results indicate that the primary antagonistic activity of peptides and the peptide with 14.4 kD may play an important role in it.