Chemical Profiling and Biological Screening of Some River Nile Derived-Microorganisms.

Momen M Lotfy,Mona Hetta,Mohamed A Zaki,Ahmed O El-Gendy,Noha M Gamaleldin,Mostafa E Rateb,Hossam M Hassan,Rabab Mohammed

doi:10.3389/fmicb.2019.00787

Abstract

AimsChemical and biological studies of the River Nile derived-microorganisms are limited. Hence, this work was carried out to screen the River Nile habitat. Identification of the isolated organisms, chemical profiling of their ethyl acetate extracts as well as screening of their antimicrobial, antileishmanial, antitrypanosomal, and antimalarial activities were investigated.MethodsIdentification of the microbial isolates were carried out using bacterial 16S rRNA and fungal 18S rRNA gene sequencing. Chemical profiling of the EtOAc extracts using LC-HRESIMS spectroscopy was carried out. The in vitro antimicrobial screening using the modified version of the CLSI method, antileishmanial and antitrypanosomal activities were screened using Leishmania donovani promastigote assay, L. donovani axenic amastigote assay, Trypanosoma brucei trypamastigotes assay and THP1 toxicity assay. The in vitro antimalarial activities against D6 (chloroquine sensitive) and W2 (chloroquine-resistant) strains of Plasmodium falciparum were evaluated.ResultsSeven isolated microorganisms were identified as Streptomyces indiaensis, Bacillus safensis, B. anthracis, Bacillus sp., and Aspergillus awamori. Chemical investigation of different extracts showed several bioactive compounds, identified as; nigragillin, 5-caboxybenzofuran and dyramide B from A. awamori and actinopolysporin B from S. indiaensis. On the other hand many nitrogenous compounds with high molecular weights showed no hits that may correspond to new long chain and/or cyclic peptides. The EtOAc extract of B. safensis fermentation broth showed the highest activity against P. falciparum D6 and P. falciparum W2 (IC50 = 25.94 and 27.28 μg/mL, respectively), while two isolates S. indiaensis and Bacillus sp. RN-011 extracts showed the highest antitrypanosomal activity (IC50 = 0.8 and 0.96 μg/mL).ConclusionThe River Nile could be a new source for production of promising bioactive leading compound where antimicrobial and antiparasitic activities may be correlated.

Highlights

Nature is an exceptional resource of new biologically active compounds with an astonishing chemical diversity such as that found in plant species, animals, and microorganisms (Butler et al, 2014)
Seven isolated microorganisms were identified as Streptomyces indiaensis, Bacillus safensis, B. anthracis, Bacillus sp., and Aspergillus awamori
The EtOAc extract of B. safensis fermentation broth showed the highest activity against P. falciparum D6 and P. falciparum W2 (IC50 = 25.94 and 27.28 μg/mL, respectively), while two isolates S. indiaensis and Bacillus sp

Summary

Introduction

Nature is an exceptional resource of new biologically active compounds with an astonishing chemical diversity such as that found in plant species, animals, and microorganisms (Butler et al, 2014). Ghana and other sub-Saharan African countries are considered as a source of a diverse array of aquatic habitats (Adelaide et al, 2012). About 27 isolates, out of the 119 recovered, have produced metabolites with antibacterial activity against at least one of the test organisms. The crude extract of the isolate MAI2 (a strain of Pseudomonas aeruginosa) was active against all tested organisms; Bacillus thuringiensis, Proteus vulgaris, Enterococcus faecalis, Staphylococcus aureus, B. subtilis, Escherichia coli, S. typhi, and Candida albicans with MICs ranging between 250 and 2000 μg/mL (Adelaide et al, 2012). SJY056 exhibited strong antagonistic activity against MRSA (Hongjian et al, 2013)

Methods

Results

Discussion

Conclusion