明党参内生菌的分离鉴定及其对金黄色葡萄球菌的抑制作用

Isolation and Identification of Endophytes from Radix Changii( Changium smyrnioides Wolff ) and Its Inhibitory Effect on Staphylococcus aureus

研究郑州市栽培明党参内生菌资源状况,筛选出对金黄色葡萄球菌具有拮抗作用的内生菌。采用平板培养法从明党参中分离内生细菌,通过混菌法和牛津杯双层平板扩散法筛选出对金黄色葡萄球菌具有明显抑制作用的菌株,并通过培养特征、形态特征、生化特征、全自动微生物质谱检测、16SrDNA基因序列分析和系统进化树分析对菌株进行了分类学鉴定。在明党参中共分离到29株内生细菌,通过初筛和复筛后,筛选出对金黄色葡萄球菌具有明显抑制作用的4株菌株NMY1、NMJ10、NMG10、PMG3,其中NMJ10对金黄色葡萄球菌的抑菌圈直径达20.3mm,经鉴定菌株NMJ10和菌株PMG3为芽胞杆菌属新菌种(Bacillusspp.),菌株NMY1为枯草芽胞杆菌(B.subtilis),菌株NMG10为假蕈状芽胞杆菌(B.pseudomycoides)。明党参内生菌具有多样性,其中芽胞杆菌属为优势菌株,有拮抗金黄色葡萄球菌活性高的菌株存在,其代谢产物对金黄色葡萄球菌有较高抑制作用,为抗菌药源成分的开发提供了新的来源。

Resource conditions of endophytes in cultivated radix changii ( Changium smyrnioides Wolff) in Zhengzhou City were investigated and screened endophytes that possessing antagonistic effect on Staphylococcus aureus. The en- dogenous bacteria were isolated from C. smyrnioides by plate culture method,strains with significant antagonistic effect on S. aureus were selected by mixed strains method and Oxford cup double plate diffusion method,and combined with culture characteristics,morphological characteristics,biochemical characteristics,automatic microbial mass spectrom- etry detection,16S rDNA gene sequence analysis and phylogenetic tree analysis,the strains were identified by taxo- nomic identification. Twenty-nine endophytic bacteria were isolated from C. smyrnioides. After initial screening and re-screening,four strains NMY1,NMJ10,NMG10,and PMG3 with significant antagonistic effect on S. aureus were selected. Among them the diameter of antibacterial ring of strain NMJ10 against S. aureus reaches 20. 3 mm. According to the identification,strain NMJ10 and PMG3 were new strains of Bacillus ( Bacillus spp.),strain NMY1 was ini- tially identified as Bacillus subtilis,and strain NMG10 was B. pseudomycoides. Endophytes in C. smyrnioides had di- versity and Bacillus were the dominant strains. There also exist strains with antagonism against S. aureus,and their metabolites have a high inhibitory effect against S. aureus,which can provide a new source to develop antibacterial medicines.