Screening of antagonistic bacteria from gut of black soldier fly and the molecular identification of antimicrobial active substances

Abstract:

[Objective] The bacteria from gut of black soldier fly were screened gainst plant pathogenic bacteria, Molecular method was used to identify the active substances from the antagonist bacteria. [Methods] Eleven strains have been isolated with diluted coating method from the gut of black solider fly. The antagonistic strains were screened using the plate confrontation method. The species was identified through the physiological, biochemical experiments and 16S rRNA phylogenetic analysis. Primers of key genes of known lipopeptide, synthesis were designed and purpose fragements were amplified by PCR and sequenceing. [Results] A gut bacteria, named BSF-CL, was obtained with strong inhibitory effect to Xanthomonas oryzae PXo99 and Rhizoctonia solani AG-8, and identified as Bacillus subtilis. The result of PCR showed that strain BSF-CL possibly has the key genes which synthesis lipopeptide Iturin and Surfactin. We speculate that strain BSF-CL can synthesize lipopeptide iturin and surfactin. [Conclusion] A strong active Bacillus subtilis strain BSF-CL against bacterial and fungal pathogen was screened from the gut of black soldier fly. We preliminary speculated that the active substance may be lipopeptide iturin and surfactin through the molecular cloning and identification.