茶叶活性成分对梨火疫病菌的抑制活性及稳定性研究

研究茶叶活性成分对梨火疫病菌的抑菌活性及其稳定性,旨在为田间病害防治提供依据。采用打孔法测定茶叶活性成分对梨火疫病菌的抑菌活性及最小抑菌浓度(MIC),并进一步探讨温度、pH和紫外线照射对绿茶提取物茶多酚抑菌活性稳定性的影响。结果表明,抑菌活性绿茶提取物茶多酚>壳寡糖,茶皂素没有抑菌活性;绿茶提取物茶多酚MIC为40 mg/mL。绿茶提取物茶多酚10~60℃时抑菌活性保持稳定,但经高温80~100℃处理后,抑菌活性略有下降;在pH 2时抑菌活性增强,碱性条件下抑菌活性减弱;经紫外处理10~50 min后,抑菌活性随着照射时间的增加而减弱。茶叶活性物质对梨火疫病菌有一定的抑菌活性,且绿茶提取物茶多酚具有较稳定的抑菌活性,为其作为天然的农药防治梨火疫病提供依据。

Tea Active Ingredients: The Bacteriostatic Activity Against Erwinia amylovora and Stability

The aims are to study the bacteriostatic activity of tea active ingredients against Erwinia amylovora and their stability, and to provide a basis for disease control in field. The bacteriostatic activity of tea extracts against E. amylovora and the minimum inhibitory concentration (MIC) were determined by punch method, and the effects of temperature, pH and UV irradiation on the bacteriostatic activity and stability of green tea extract tea polyphenols were further studied. The results showed that the bacteriostatic activity of tea polyphenols was higher than that of chitosan oligosaccharides, tea saponin had no bacteriostatic activity, and MIC of green tea extract tea polyphenols was 40 mg/mL. The bacteriostatic activity of green tea extract tea polyphenols remained stable at 10-60°C, but it was decreased slightly after being treated at 80-100°C. The bacteriostatic activity was increased at pH 2, and the bacteriostatic activity was decreased under alkaline condition. The bacteriostatic activity was decreased with the increase of irradiation time after UV treatment for 10-50 min. Tea active substances had certain bacteriostatic activity against E. amylovora, and green tea extract tea polyphenols had stable bacteriostatic activity and could be used as a natural pesticide control E. amylovora of pear.