多粘类芽孢杆菌发酵液对脐橙果树内生菌的抑菌研究

Study on the Bacteriostasis of Paenibacillus polymyxa FermentationLiquid on Endophytes of Navel Orange Fruit Trees

目的:验证一种多粘芽孢杆菌发酵液对脐橙果树内生菌抑制特性,为筛选治理黄龙病的药物奠定基础。方法:纯化培养黄龙病果树内生菌,经16S rDNA鉴定菌属,选择和黄龙病菌有相关性的内生菌为药敏实验菌株,以青霉素G、四环素、利福平、链霉素、吡哌酸、氨苄西林和多粘类芽孢杆菌发酵液为对比抑菌药物,分析抑菌差异以便筛选合适的内生菌抑菌药物。结果:分离获得黄龙病菌的相关性内生菌6株,药敏实验发现链霉素对所有菌株无药敏,青霉素G、利福平、氨苄西林对细杆菌属具有高药敏性,四环素对代尔夫特菌属和不动杆菌属具有高药敏性,发酵液对代尔夫特菌属和伯克霍尔德菌属具有高的药敏性,其中,利福平对所有菌株均有药敏性,四环素仅对伯克霍尔德菌属无药敏性。结论:多粘类芽孢杆菌发酵液对黄龙病果树内生菌有优良的抑制效果。

Objective:To verify the inhibitory properties of a fermentation broth of Paenibacillus polymyxa on the endophytes of navel orange fruit trees,and to lay the foundation for screening drugs to cure Huanglongbing.Method:Endophytic bacteria in Huanglong disease fruit trees were purified and cultivated.After the identification of bacterial genera through 16S rDNA,endophytes related to Huanglongbing bacteria were selected as drug sensitivity test strains.Bacteriostatic drugs such as penicillin G,tetracycline,rifampicin,streptomycin,pipemidic acid,ampicillin and Paenibacillus polymyxa fermentation broth were used as comparative bacteriostatic agents to analyze differences in inhibition in order to screen suitable endophytic antibacterial drugs.Results:Six strains of endophytic bacteria related to Huanglong were isolated.The drug susceptibility test found that streptomycin was not susceptible to all strains,Penicillin G,rifampicin,and ampicillin had high drug susceptibility to the genus Microbacterium sp..Tetracycline was highly susceptible to Delftia sp.and Acinetobacter sp.,and the fermentation broth had high drug sensitivity against Delftia sp.and Burkholderia sp..Among them, rifampicin was effective against all strains, whereas tetracycline showed no drug sensitivityto Burkholderia sp. . Conclusion:The fermentation broth of Paenibacillus polymyxa exhibits excellentinhibitory effects on endophytic bacteria in citrus tress affected by Huanglongbing.