Isolation and characterization of marine sponge–associated Streptomyces sp. NMF6 strain producing secondary metabolite(s) possessing antimicrobial, antioxidant, anticancer, and antiviral activities

Nayer Mohamed Fahmy,Asmaa Mohamed Abdel-Tawab

doi:10.1186/s43141-021-00203-5

Abstract

BackgroundActinomycetes associated with marine sponge represent a promising source of bioactive compounds. Herein, we report the isolation, identification, and bioactivity evaluation of Streptomyces sp. NMF6 associated with the marine sponge Diacarnus ardoukobae. ResultsResults showed that the strain belonged to the genus Streptomyces, and it was designated as Streptomyces sp. NMF6 with the GenBank accession number MW015111. Ethyl acetate (EtOAc) extract of the strain NMF6 demonstrated a promising antimicrobial activity against Staphylococcus aureus, Enterococcus faecalis, Vibrio damsela, and Candida albicans and a strong antioxidant activity, which were confirmed by DPPH, ferric-reducing power, and phosphomolybdenum assays; results are expressed as ascorbic acid equivalents. NMF6 extract also demonstrated cytotoxicity against breast cancer cell line (MCF-7), hepatocellular carcinoma cell line (Hep-G2), and human colon carcinoma cell line (HCT-116); the selectivity index values were < 2. The extract showed promising antiviral activity against HSV-1, CoxB4, and hepatitis A viruses at concentrations that were nontoxic to the host cells, with the selectivity index values being 13.25, 9.42, and 8.25, respectively. GC-MS analysis of the extract showed the presence of 20 compounds, with bis(2-ethylhexyl) phthalate being the major component (48%). ConclusionsOur study indicates that the marine sponge–associated Streptomyces sp. NMF6 strain is a potential source of bioactive compounds that could be developed into therapeutic agents.

Highlights

Actinomycetes associated with marine sponge represent a promising source of bioactive compounds
Natural products obtained from different sources have provided important medicines for the treatment of diverse human and animal diseases and represent a potential source of more potent drugs to overcome the failure of conventional drugs [7, 8]
The isolates were screened for antimicrobial activity

Summary

Introduction

Actinomycetes associated with marine sponge represent a promising source of bioactive compounds. Exploration of novel drugs is crucial to overcome the failure of the currently used medications. Natural products obtained from different sources (including microorganisms, animals, and plants) have provided important medicines for the treatment of diverse human and animal diseases and represent a potential source of more potent drugs to overcome the failure of conventional drugs [7, 8]. Microorganisms are more amenable for the large-scale production of bioactive compounds and would overcome the limitations of obtaining drugs by field-harvesting of large quantities of macroorganisms [9]. Marine microorganisms could be considered as a relatively undervalued source for the discovery of bioactive compounds and could provide novel bioactive compounds in terms of structure and bioactivity [10, 11]. Actinomycetes are excellent producers of bioactive compounds possessing different biological activities such as antitumor, antibiotic, immunosuppressive, antioxidant, antiviral, and enzyme inhibition properties [12]

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Results

Discussion

Conclusion