Full Length Research Paper

Antiviral activities of streptomycetes against tobacco mosaic virus (TMV) in Datura plant: Evaluation of different organic compounds in their metabolites

Ismet Ara*, Najat A. Bukhari, N. M. Aref, Mahera M. A. Shinwari, M. A. Bakir

Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 22452, Riyadh-11495, Kingdom of Saudi Arabia.

*Corresponding author. E-mail: ismetara@yahoo.com or iara@ksu.edu.sa. Tel: +966534509242 or +966 1478 9585. Ext. 1639.

Abbreviations: SEM: Scanning Electron Microscope; TEM: Transmission Electron Microscope; TMV: Tobacco Mosaic Virus.

Accepted 19 December, 2011

   Abstract

A total of 20 strains of actinomycetes were isolated from Al-Kharj (K) and Al-Madina (M) areas in Saudi Arabia. Among these strains, six were selected for antiviral activity screening which are K1, K2, K3, M1, M2 and M3. All the selected strains were characterized morphologically to be under the genus Streptomyces. Primary and secondary screenings were performed against seven human pathogenic microorganisms such as Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Salmonella suis ATCC 13076, Shigella sonnei ATCC 11060 and Candida albicans ATCC 1023. In the data, all the obtained six selected strains had shown a positive and very promising result with little variations. The bioactive compounds were extracted from the strains using solvent extraction methods. The tobacco mosaic virus (TMV) was obtained from tomato plants and the extract was prepared using a simple technique of homogenizing in water and filtration. Tobacco mosaic virus and the metabolites of streptomycetes strains were applied to the selected Datura metel plant leaves. After incubation for one week, it was found that the viral infection symptoms in the form of local lesions caused by the TMV were notably reduced on the plant leaves in the presence of bioactive metabolites. Further, in this study, gas chromatography-mass spectroscopy (GC-MS) analysis of all the crude metabolites of streptomycetes strains were performed for the determination of different compounds.

Key words: Antiviral activity, tobacco mosaic virus, actinomycetes, Streptomyces, Datura metel, GC-MS analysis, human pathogenic bacteria.