一株海洋梅久兰链霉菌的分离鉴定及其抗真菌作用研究

摘要

采用梯度稀释分离法从连云港海域海水、海泥、近海土壤、海洋动物以及海洋植物样品中，分离出海洋放线菌22株，采用平板对峙培养法测定不同放线菌菌株的抑菌作用，有9个放线菌菌株有抑菌作用。其中ZW-1菌株的抑制活性最强，该菌株及其发酵液对供试的小麦雪腐镰刀菌(Fusarium nivale)、小麦赤霉病菌(Fusarium graminearum)、斑点落叶病菌(Alternaria alternata)、油菜菌核病菌(Sclerotinia sclerotiorum)、菠菜早疫病菌(Alternaria solani)、玉米圆斑病菌(Helminthosporium carbonum)、西瓜枯萎病菌(Fusarium oxysporum f.sp.niveum)、棉花枯萎病菌(Fusarium oxysporum f.sp.vasinfectum)等8种植物病原真菌都有较强的抑制作用，可导致病原真菌菌丝细胞壁膨大，原生质体收缩，同时可抑制菠菜早疫病菌(A. solani)分生孢子的萌发和芽管的伸长。通过培养特性、细胞形态观察、生理生化实验和16S rDNA序列分析，将海洋放线菌ZW-1菌株鉴定为梅久兰链霉菌(Streptomyces mediolani)。%A total of 22 strains of marine actinomycetes were isolated from seawater, sea mud, offshore soils, marine animals and marine plant samples collected from the sea area near Lianyungang by gradient dilution method. The antimicrobial activity of these strain isolates was tested by plate confrontation method. It was found that 9 of them had antimicrobial activity. Strain ZW-1 had the strongest antimicrobial activity, and it and its fermentation broth possessed strong inhibitory effects on 8 plant pathogenic fungi includingFusarium nivale, Fusarium graminearum,Alternaria alternate, Sclerotinia sclerotiorum,Alternaria solani,Helminthosporium carbonum,Fusarium oxysporum f.sp.niveum, andFusarium oxysporum f.sp.vasinfectum. In addition to causing cell wall expansion and protoplast contraction in pathogenic fungal mycelia, this strain and its fermentation broth could inhibit the germination ofA. solani conidiophores and the elongation of germ tubes. Based on its culture characteristics, morphology, physiological and biochemical properties, and 16S rDNA sequence, ZW-1 strain was identifi ed asStreptomyces mediolani.