Investigation of anti-microbial and cytotoxic potential of Streptomyces werraensis GRS9 derived from the sediments of river Ganga.

Abstract

The aim of the present work was to screen bacterial and actinomycetes strains from the sediments of river Ganga (India) as a promising source of anti-microbial and anti-cancer agents along with spectroscopic and chromatographic identification of bio-active compounds. The strain GRS9 exhibited broad-spectrum bio-activity against all the 15-test organisms incorporated in our study with minimum inhibitory concentrations (MICs) ranging from 16 µg/ml against Staphylococcus aureus MTCC3160 to 500 μg/ml for Escherichia coli (MTCC118). The cytotoxic profile of ethyl acetate extract was also evaluated against Human Colon Cancer Cell Line (HCT116) by Neutral Red Uptake (NRU) assay, followed by in silico study to determine its pre-qualification for drug suitability. The results indicated that Streptomyces werraensis GRS9 extract possessed anti-cancer properties (IC₅₀ = 22.95 µg/ml) and found suitable for further drug development as reflected in Absorption, Distribution, Metabolism and Excretion (ADME) prediction having no violation of Lipinski's rule of five. Bioactive compounds associated with GRS9 were identified by Gas Chromatography Mass Spectroscopy (GC-MS) and Fourier Transform Infrared Spectroscopy (FTIR), revealing 29 compounds along with 10 major compounds identified via National Institute of Standards and Technology (NIST) /Wiley library. These compounds include N-(4-methyl-1-Piperzinyl)-1-Napthamide (a compound of immense pharmacological potential especially in oncology) along with anti-microbials i.e. Dodecanamide and 1,2-Benzenedicarboxylic acid, Diethyl ester. The findings revealed our sediment isolate Streptomyces werraensis GRS9 to be a suitable candidate for the isolation and purification of bio-active compounds that may act as a source of anti-microbial and anti-cancer agents.