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BioMed Research International
Volume 2014, Article ID 182945, 7 pages
http://dx.doi.org/10.1155/2014/182945
Research Article

Antibacterial Activity of Pseudonocardia sp. JB05, a Rare Salty Soil Actinomycete against Staphylococcus aureus

1Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
2Department of Plant Biotechnology, Buali-Sina University of Hamedan, Iran
3Biotechnology Research Center, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
4Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Azarbaijan Shahid Madani University, Tabriz, Iran
5Department of Plant Biotechnology, Ferdowsi University of Mashhad, Mashhad, Iran

Received 29 May 2014; Revised 9 July 2014; Accepted 13 July 2014; Published 14 August 2014

Academic Editor: Medicharla V. Jagannadham

Copyright © 2014 Nesa Jafari et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Staphylococcus aureus is a Gram-positive bacterium that causes many harmful and life-threatening diseases. Some strains of this bacterium are resistant to available antibiotics. This study was designed to evaluate the ability of indigenous actinomycetes to produce antibacterial compounds against S. aureus and characterize the structure of the resultant antibacterial compounds. Therefore, a slightly modified agar well diffusion method was used to determine the antibacterial activity of actinomycete isolates against the test microorganisms. The bacterial extracts with antibacterial activity were fractionated by silica gel and G-25 sephadex column chromatography. Also, the active fractions were analyzed by thin layer chromatography. Finally, the partial structure of the resultant antibacterial compound was characterized by Fourier transform infrared spectroscopy. One of the isolates, which had a broad spectrum and high antibacterial activity, was designated as Pseudonocardia sp. JB05, based on the results of biochemical and 16S rDNA gene sequence analysis. Minimum inhibitory concentration for this bacterium was 40 AU mL−1 against S. aureus. The antibacterial activity of this bacterium was stable after autoclaving, 10% SDS, boiling, and proteinase K. Thin layer chromatography, using anthrone reagent, showed the presence of carbohydrates in the purified antibacterial compound. Finally, FT-IR spectrum of the active compound illustrated hydroxyl groups, hydrocarbon skeleton, and double bond of polygenic compounds in its structure. To the best of our knowledge, this is the first report describing the efficient antibacterial activity by a local strain of Pseudonocardia. The results presented in this work, although at the initial stage in bioactive product characterization, will possibly contribute toward the Pseudonocardia scale-up for the production and identification of the antibacterial compounds.