Antibacterial Potential of Streptomyces showdoensis BYC17 from the Nest of Odontotermes formosanus

Background: With the continuous exploration and application of antibiotics, many common diseases have been treated while the evolution of drug-resistant bacteria has increased. The immediate raised of antibiotic-resistance makes it necessary to research special microorganisms for finding novel bioactive substances against drug-resistant bacteria. Insect-associated microbes have special metabolic pathways and are valuable resource base for the research and development of new antibiotics. The Odontotermes formosanus has formed a unique self-defense mechanismin the long-term evolution. Hence, nest of O. formosanus is a potential material for screening actinomycetes and compounds with bacteriostatic activity.Methods: The strain BYC17 was identified by morphological observation and 16S rDNA sequencing analysis, and the bacteriostasis test of BYC17 was carried on. The active component was separated and purified after screening, and the structure of the active monomer compound was determined by spectral analysis. Finally, the bacteriostatic effect of the active monomer compound was tested.Results: BYC17 was identified as Streptomyces showdoensis with antimicrobial activity against all three test bacteria. The monomer compound BYC17-01 was isolated from BYC17 and identified as izumiphenazine A. Under the concentration of 90 μg/6 mm filter paper, the inhibition zones of the monomer compound BYC17-01 against Staphylococcus aureus, Escherichia coli and Micrococcus tetragenus were 13.0, 9.0 and 11.1 mm respectively.Conclusions: This study demonstrates that izumiphenazine A produced by strain BYC17 hold the potential to be used against various human pathogenic microorganisms, particularly S. aureus and M. tetragenus .