Preliminary identification of strain WA5-1-7 from intestinal tract of Periplaneta americana and study on its secondary metabolites with antimicrobial activity
Objectives A strain WA5-1-7 from the intestinal tract of Periplaneta americana with anti-Candida albicans activity was identified by morphology and molecular biology,and its secondary metabolites were isolated and purified.The monomers with antibacterial activity were screened.Methods The morphology of the strain was observed by gram staining and scanning electron microscopy.The 16S rRNA sequence of the strain was amplified by PCR and compared with the NCBI database by BLAST.Its phylogenetic tree was constructed by the N-J method.After fermentation,the crude extract was extracted by ethyl acetate solvent and separated by silica gel column chromatography,which was purified to obtain monomer compounds by Dextran gel column chromatography and HPLC.The structures of the compounds were identified by nuclear magnetic resonance and mass spectrometry,and their antimicrobial activity was detected.Results Strain WA5-1-7 was preliminarily identified as Streptomyces anulatus,and 10 monomer compounds were isolated from its crude extract.They were SF2738F(1),SF2738D(2),cyclo-(D-Pro-D-Leu)(3),SF2738A(collismycin A,4),Cyclo-(L-Phe-D-Pro)(5),SF2738C(6),indole-3-carboxaldehyde(7),daidzein(8),actinomycin X2(9)and actinomycin D(10).The compounds 4,9 and 10 showed strong antimicrobial activity.Conclusions The monomer compounds with antimicrobial activities were isolated from the intestinal Streptomyces secondary metabolites of Periplaneta americana,which laid the foundation for further exploration of the intestinal bacteria of Periplaneta americana.
NETL
NSTL
万方数据
