菌株CHZ5的分离、鉴定及其聚酮合成酶基因的PCR验证

Isolation and Identification of Strain CHZ5 and Its Polyketone Synthase Gene Validation by PCR

为了获得具有聚酮合成酶(PKS)活性的野生菌株并验证PKS功能基因,本研究采用组织分离技术凤丹牡丹根部组织内生菌进行了分离培养,试验共获得16株内生菌,分别编号为CHZ1~CHZ16。8株菌与芍药白粉菌病原的平板对峙试验显示,CHZ1、CHZ2、CHZ5和CHZ6菌株表现出抑菌活性,其中抑菌作用最强的是CHZ5,抑菌带宽度平均达到了9.0 mm,故将CHZ5初步定性为产聚酮合成酶活性菌株。采用PKS-Ⅰ和PKS-Ⅱ的兼并引物对CHZ5菌株PKS基因进行PCR扩增,PCR产物测序结果证实该菌株含有PKS-Ⅰ和PKS-ⅡPKS功能基因。综合CHZ5菌株的表型特征、生化特征和16S rDNA分析结果,初步将其确定为链霉菌属Streptomyces菌株,暂命名为Streptomyces sp.CHZ5。CHZ5菌株可作为牡丹病害生防菌、PKS基因簇研究、牡丹此生天然产物和专用菌肥开发等研究的良好备用材料。

In order to obtain the wild strain with polyketide synthase(PKS)activity and verify PKS function gene,the tissue isolation technique was used to isolate and culture the endophytic bacteria from the root of Feng Dan peony.The results showed that 16 endophyte living pure cultures were obtained,which were numbered from CHZ1,to CHZ16;Plate confrontation test between the 8 strains and erysiphe paeoniae,and the results showed that CHZ1,CHZ2,CHZ5 and CHZ6 strains had antibacterial activity,the most effective bacteriostasis was CHZ5,and the average width of the bacteriostatic band reached 9 mm.Therefore,CHZ5 was initially identified as a polyketide synthase producing strain.PCR amplification was performed on the PKS gene of CHZ5 strain by the PKS-Ⅰand PKS-Ⅱmerging primers,which further confirmed that the strain had PKS functional gene.Through the phenotypic characteristics,biochemical characteristics and 16 S rDNA analysis results of CHZ5 strain,this study identified it as Streptomyces strain,and temporarily named Streptomyces sp.CHZ5.Good spare materials CHZ5 strain can be used for peony disease biocontrol bacteria,PKS gene cluster in the research and development of peony natural products and special fertilizer development etc.