16S rRNA Cloning and Identification of a Strain Isolated from Intestinal Tract of Rex Rabbit

摘要

This study was conducted to identify bacterial strain He Nan-001 isolated from intestinal tract of healthy rex rabbit.The strain was identified by gram staining,and OD_(600) values at different culture time were measured to develop a bacterial growth curve.The metabolic pathways of the bacterium using sugar in fermentation was identified with biochemical tubes.Total RNA of the strain was extracted,and total cDNA was obtained by Oligo(dT) method.Primers were designed using Primer 5.0 bio-software according to the 16S rRNA sequence published in Gen Bank,through cloning,ligation to vector PMD18T,construction of PMD18T/16S rRNA vector and transformation into DH5α,plasmid was extracted and sequenced,and the sequencing result was compared with sequences in NCBI followed by drawing of phylogenetic tree.The strain was verified to be double-stranded gram-positive cocci,which could ferment glucose,mannose,maltose and sorbitol,producing acids production,but failed to ferment sucrose,serum inulin and β-galactosidase.The phylogenetic tree analysis showed that the isolated bacterium shared the highest homology with an India isolate,and belongs to diplostreptococcus.This study provides significance experimental data and theoretical guidance for further development and utilization of the bacterial strain.