一株生防圆突起链霉菌的分类鉴定

Taxonomy of the Streptomyces torulosus strain exhibiting potential for biological control

菌株SCY311是从河南省凤凰山土壤样品中分离到的,对多种植物病原真菌具有拮抗活性的一株放线菌。为了明确其分类地位,在形态特征、培养特征、生理生化特征、细胞壁组分测定等传统分类学方法的基础上,测定和分析了菌株的16S rRNA基因序列。结果表明,菌株SCY311在高氏一号培养基上生长良好,基内菌丝呈褐色;气生菌丝灰色至鼠灰色,不产生可溶性色素,无吸水现象;孢子链卷曲,末端形成闭合或开放螺旋;孢子椭圆或圆柱状,表面形成结节状突起;生理生化特征和在国际链霉菌计划(ISP)培养基上的培养特征与圆突起链霉菌Streptomyces torulosus基本一致;菌株SCY311的16S rRNA序列与S.torulosus的16S rRNA序列同源性为99.9%。因此,将菌株SCY311鉴定为圆突起链霉菌。

The actinomycete strain SCY311,which exhibited antifungal activity against various plant pathogenic fungi,was isolated from the soil samples collected from Fenghuang Mountain in Henan province in China.Identification of strain SCY311 was conducted by the methods of traditional and molecular biological taxonomy,including determination of morphological characteristics,cultural characteristics,physiological and biochemical properties,cell wall components and 16S rRNA se-quences analysis.Results showed that strain SCY311 grew well on Gause′s synthetic agar plate.The color of substrate mycelium appeared brown,while that of aerial mycelium went from gray to mouse gray.The strain SCY311 neither produced the soluble pigment nor exhibited hygroscopicity.Spores were arranged in coil chains and the branched spore chains formed open or closed spirals.Spores were oval or columned in ship and the spore wall ornamentation category was knobby.Physiological proper-ties and cultural characteristics of the strain SCY311 on the ISP media were in close agreement with that of the Streptomyces torulosus.The 16S rRNA gene sequence of strain SCY311 showed 99.9% similarity to that of S.torulosus.Based on the results above,the strain SCY311 was identified as S.torulosus.