Avicenna J Med Biotech arij002 Avicenna Journal of Medical Biotechnology 2008-2835 2008-4625 Avicenna Research Institute ajmb264 Isolation and Identification of Phyllospheric Bacteria Possessing Antimicrobial Activity from <i>Astragalus obtusifolius</i>, <i>Prosopis juliflora</i>, <i>Xanthium strumarium</i> and <i>Hippocrepis unisiliqousa</i> MazinaniZohrehDepartment of Biostatistics and Computer, University of Social Welfare and Rehabilitation Sciences, Tehran, IranZamaniMarziehGenetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, IranSardariSoroushDepartment of Pathobiology, Faculty of Public Health, Tehran University of Medical Sciences , Tehran, Iran 9 1 31 37 21 12 2015 14 5 2016

<p>Background: The widespread utilization of antimicrobial compounds has caused emergence of resistant microorganisms in the world. Hence, the research to probe the products with antimicrobial features has led to finding natural habitats and discovering new pharmaceutical products.<br /> Methods: In this study, an attempt was made to explore the niche of novel habitat to isolate pyllospheric bacteria from the above ground parts (stems and leaves) of <em>Astragalus obtusifolius, Prosopis juliflora, Xanthium strumarium,</em> and <em>Hippocrepis unisiliqousa</em> to evaluate their antimicrobial features. The inhibitory effects of these strains on the growth of two fungi <em>(Aspergillus niger, Aspergillus fumigatus)</em>, two yeasts <em>(Saccharomyces cerevisiae, Candida albicans)</em> and six bacteria <em>(Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Salmonella typhi, Streptococcus pyogenes)</em> were tested.<br /> Results: In total, 113 bacterial strains were isolated. Twenty five bacterial strains (B-1 to B-25) indicated promising antimicrobial (antibacterial and antifungal) activities against aforementioned pathogens. The identification of the bacterial strains was ascertained by morphological, physiological, biochemical tests and two strains with the strongest antimicrobial activities were further characterized based on 16s rRNA sequencing. These two strains were identified as <em>Bacillus amyloliquefaciens</em>.<br /> Conclusion: Our results provide evidence that phyllospheric microorganisms are capable of producing some compounds with antimicrobial properties.</p>