一株产紫红色色素的沙雷氏菌的分离与鉴定

[目的]为有效预防和控制由沙雷氏菌引起的多种疾病提供依据。[方法]以华蓥山香菇作为研究材料,从其表面中分离出了1株产紫红色色素的细菌,采用形态学、生理生化方法对其进行初步鉴定;提取基因组DNA,采用16S rRNA的通用引物,PCR扩增16S rDNA基因片段,克隆入pMD-18T载体,转化E.coliDH5α,筛选阳性重组质粒鉴定后测序;通过多序列比对和同源性分析,构建系统发育树。[结果]该菌株革兰氏染色阴性,与沙雷氏菌属菌的同源性最高,命名为Serratiasp.JG05。扩增得到序列大小为1 506 bp,系统发育树表明JG05与Serratiasp.BBTR23的亲缘关系最近,核苷酸水平有99.20%的相似性。[结论]该研究为进一步研究这种附生菌与香菇的共生关系,以及它们之间的作用机制奠定了基础。

Isolation and Identification of a Serratia Strain Producing purple Pigment

[Objective] The aim was to provide the basis for the preventing and controlling many kinds of diseases caused by Serratia effectively.[Method] With Huayingshan mushroom as research material,a strain producing purple pigment was isolated from its surface and identified preliminarily by morphological method and physiological and biochemical methods.The genomic DNA was extracted and a fragment of 16S rDNA gene was amplified by PCR using the universal primers of 16S rRNA,then the fragment was cloned into pMD-18T vector,transformed into E.coli DH5α,and then the positive recombinant plasmids were screened,identified and sequenced.The phylogenic tree was constructed through multiple sequence alignment and homology analysis.[Result] The strain showed the negative result after gram stain and it had highest homology with Serratia,which was named Serratia sp.JG05.The sequence with the length of 1 506 bp was obtained by amplification and the phylogenic tree showed that the genetic relationship between the JG05 and Serratia sp.BBTR23 was closest and they had 99.20% similarity at nucleotide acid level.[Conclusion] The research laid the foundation for the further study of the symbiotic relationship between the attached bacteria and mushroom and their function mechanism.