药用白花泡桐内生细菌的分离鉴定及抑菌活性检测

摘要

为开发新的抑菌活性物质,以湘西药用白花泡桐叶片为材料,采用组织分离法从药用白花泡桐叶片中分离内生细菌,通过对峙培养法检测内生细菌发酵液对2株病原真菌的抑菌活性,根据菌株形态、生理生化特性及16S rRNA基因序列系统发育分析对活性菌株进行鉴定.结果表明:从白花泡桐叶片中筛选出对水稻纹枯病菌(Rhizoctonia solani)和烟草拟黑根霉菌(Thielaciopsis basicola)生长有抑菌作用的5株内生细菌,其中,JDB-1菌株抑菌活性最强,其形态特征、生理生化特征与枯草芽孢杆菌(Bacillus subtilis)的特征基本一致,而其16S rRNA基因序列在系统发育树中与枯草芽孢杆菌同属一个类群,序列同源性达99%,即JDB-1菌株为枯草芽孢杆菌.%To explore new materials with antifungal activity, endophytic bacteria was isolated from surface-sterilized fresh leaves of Xiangxi medicinal Paulownia fortunei, and the antifungal bacteria was screened from these isolates by using confront culture method, while the antifungal bacteria were identified based on phenotypical and biochemical properties as well as its 16S rRNA gene sequence. The results showed that 5 antifungal bacterial strains from Paulownia fortunei leaves, which inhibited the growth of Rhizoctonia solani and Thielaciopsis basicola, were screened out. One of them, strain JDB-l had the strongest antifungal activity. According to the results of phenotypical and biochemical properties, 16S rRNA gene sequence and its molecular phylogenetic tree, JDB-1 was identified as Bacillus subilis.