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.