Abstract:This work was aimed to develop a method for rapid identification of bacteria with high similarity of conserved sequences in DNA, and to identify a Bacillus strain collected from soil. The prokaryote strain was isolated and purified from the soil after diluting and coating the plate, which collected from the planting area with animal fertilizer in Tong'an National Agricultural Science and Technology Park, Xiamen. The 16S and gyrB gene of the strain were amplified by PCR and sequenced. The ATCC strains with similar sequences selected from Genbank were compared. After the 16S sequence and the gyrB sequence were linearly spliced, the phylogenetic tree was constructed with Paup*4.0, and the identification results were verified by physiological and biochemical methods. The 16S sequence and gyrB gene sequence were constructed separately, however, the strain was failed to be identified to specie level. After the joint construction, the Bacillus HX2016002 isolated from soil was identified as Bacillus cereus. This method obtained a high self-expanding phylogenetic tree, and the identification results were consistent with the physiological and biochemical experiments. The sequence analysis with the known Bacillus cereus in Genbank showed that the method was generally applicable in Bacillus cereus identification. The phylogenetic tree based on the combination of 16S and gyrB gene has the value of further research in the identification of genus strains with high conserved sequence similarity.
