Isolation and identification of a strain of Bacillus tropicus and study of its probiotic effect
This research aimed to screen high-efficiency plant rhizosphere growth-promoting strains,analyze the potential of strains for growth-promoting applications,and provide valuable strain resources for the development of microbial fertilizers.The rhizosphere soil was collected in Ledong Li Autonomous county,Hainan province,and the probiotic strains were isolated and screened by dilution coating method to study their ability to produce indoleacetic acid(IAA),siderophore,protease and phosphorus solubilization,and the new isolates were identified to species by 16S rRNA gene phylogenetic analysis and genome characteristics.A strain S03 producing a variety of pro-life substances was isolated,and the results based on 16S rRNA gene and phylogenetic tree analysis showed that the new isolate S03 was most closely related to NR 157736 Bacillus tropicus 1A01406,and combined with the results of genome-wide analysis,strain S03 was identified as Bacillus tropicus.Strain S03 was 5.42 Mb which was composed of a circular chromosome of 5420614 base pairs without plasmid and with base pairs G+C content of 36.02％,5666 protein-coding sequences.Bacillus tropicus S03 possesses genes related to the synthesis of biomass(IAA,siderophore,etc.)by comparative analysis of GO database.Bacillus tropicus S03 had good potential to promote growth,with IAA yield of 45.73 mg·L-1 and the solubilization capacity of inorganic phosphorus was 82.30 mg·L-1,and it also had the ability to produce protease and iron carriers.Bacillus tropicus S03 bacterial solution could significantly promote the growth of small rapeseed and improve the yield and quality.Bacillus tropicus S03 can dissolve inorganic phosphorus and produce probiotic substances such as IAA,siderophore and proteases,which have good potential for probiotic applications.
万方数据
维普
