Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Isolation of membrane-active fraction of Streptomyces spp. from soil

Parisa Azerang¹, Soroush Sardari¹ , Farzad Kobarfard², Parviz Owlia³, Yekta Farmahini Farahani¹

¹Drug Design and Bioinformatics Unit, Medical Biotechnology Department, Pasteur Institute of Iran; ²Department of Medicinal Chemistry, School of Pharmacy, Shahid Beheshti University of Medical Sciences; ³Molecular Microbiology Research Center, Faculty of Medicine, Shahed University, Tehran 13164, Iran.

For correspondence:- Soroush Sardari Email: ssardari@hotmail.com Tel:+989122632484

Accepted: 21 April 2018 Published: 28 May 2018

Citation: Azerang P, Sardari S, Kobarfard F, Owlia P, Farahani YF. Isolation of membrane-active fraction of Streptomyces spp. from soil. Trop J Pharm Res 2018; 17(5):849-855 doi: 10.4314/tjpr.v17i5.15

© 2018 The authors.
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Abstract

Purpose: To isolate and characterize the membrane-active antimicrobial fraction and isolate metabolite produced by Streptomyces in soil samples from Iran

Methods: More than 60 Actinomycete strains were isolated from soil samples in Iran. A total number of 16 strains were studied using antimicrobial assay against Escherichia coli, Candida albicans and Staphylococcus aureus. Among these, three strains produced membrane-active metabolites based on artificial vesicle assay. Extracts of Streptomyces culture were obtained using ethyl acetate fractionation. Antimicrobial activity was evaluated by broth microdilution assay. Among these active extracts, one metabolite was isolated. Further fractionation and purification strategies were applied to finally identify the isolated metabolite using appropriate spectroscopic methods including thin layer chromatography (TLC), preparative thin-layer chromatography (PTLC), high performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR) and liquid chromatography–mass spectrometry (LC-MS).

Results: Three strains isolated from the soil samples, namely, strains 0811, 08346 and 08317 showed the highest antifungal and antimicrobial activity in Tryptic Soy Broth (TSB) and International Streptomyces Projects 2 (ISP2) medium in the range of 46.8 to 62.5 µg/ml. Strain 08346 was selected for further chemical profiling based on TLC pattern and membrane activity. It yielded a purified compound which was determined to be a novel aromatic amino alkyne, named Sourin.

Conclusion: Streptomyces-produced 08346 strain demonstrates good antimicrobial activities against bacteria and yeasts, suggesting its potential as an antimicrobial membrane-active agent.

Keywords: Actinomycetes, Secondary metabolites, Streptomycetes, Membrane-active agent