The predation characteristics and 16S rDNA sequence analysis of Bdellovibrio-and-like organism strain JU-PX1

Abstract:

[Objective] The predation ability, morphological characteristics and 16S rDNA characteristics of Bdellovibrio-and-like organism (BALO) strain JU-PX1 will be studied. [Methods] The predation ability of JU-PX1 have been studied by double-layer agar and conical flask culture. The morphological characteristics of JU-PX1 were examined with optical microscope and transmission electron microscope. Using BALOs-specific primer and universal primer, 16S rDNA fragment of JU-PX1 were obtained by PCR amplification. [Results] Seven of the ten strains tested, especially Escherichia coli and Vibrio parahaemolyticus, could be hunted by JU-PX1. JU-PX1 exhibited typical BALOs pattern, showing vibrioid cell with a single polar flagellum. The cell size was (0.2?0.5) μm×(0.8?1.2) μm, and there was also 3.2?μm elongating cell in exponential phase. Two kinds of 16S rDNA fragment of JU-PX1 were obtained by PCR amplification, which lengths were 831 bp and 1 515 bp, respectively. The 16S rDNA was analysed on phylogenetic tree by NCBI BLAST and MEGA 5.10. [Conclusion] BALO JU-PX1 had the closest relationship with Bacteriovorax litoralis and the similarity was 93%.