Mr Hassan Alijani, Dr Soheila Matroodi, Dr Ali Sharafi, Dr Isaac Zamani,
Volume 23, Issue 147 (9-2016)
Abstract
Background: Silver nanoparticles have been widely used in various biomedical applications and drug delivery systems. The biosynthesis of nanoparticles has been proposed as a cost effective environmental friendly alternative to chemical and physical methods. In the present study, synthesis of nanoparticles using a novel Nocardiopsis sp. AHA2 has been attempted. We used culture supernatant of Nocardiopsis sp. AHA2 for the biologically synthesis of silver nanoparticles and study of its antimicrobial activity. Methods: marine Sediment samples were collected from depth of 10th centimeter. Serial dilution was mad for screening of marine actinomycetes using SCA medium. After Isolation and characterization of Nocardiopsis sp. AHA2, The reduction of silver ions occurred when silver nitrate solution (0.01 M) was treated with the Nocardiopsis sp. AHA2 culture supernatant at room temperature. nanoparticles were characterized by UV-visible, Zeta potential. Antimicrobial activity of the prepared silver nanoparticles against bacteria and fungi pathogens was assayed using well diffusion assay. Results: Silver nanoparticles were successfully synthesized in the culture supernatant of Nocardiopsis sp. AHA2. During the experiment, the appearance of a dark brown color indicated the formation of silver nanoparticles. In the UV-visible spectrum, maximum peak was observed between 420 nm, indicating the presence of AgNPs. AgNPs displayed antimicrobial activity against all used pathogenic microorganisms. Nocardiopsis sp. AHA2 can be a good candidate for the synthesis of the AgNPs using silver nitrate.
Hassan Alijani, Soheila Matroodi, Ali Sharafi, Issac Zamani,
Volume 24, Issue 162 (12-2017)
Abstract
Background: Actinomycetes have significant biosynthetic potential of secondary metabolites and promising resource for drug industry. These secondary metabolitesare diverse in biological, chemical structures and functions and the most prolific source of antimicrobial compounds. Most of these antimicrobial have beenisolated from soil-derived actinomycetes of the genus Streptomyces. The aim of this study was to isolate and identify Actinobacteria from Deylam intertidal sediments using 16S rDNA universal primers and screening of isolates for production of antimicrobial secondary metabolites by using disk palate assay.
Methods: Six isolates were isolated from soil samples collected from different sites. Allsix isolates were considered as Streptomyces sp. according to phylogentic study based on 16S rDNA gene. Isolates were analyzed for production of potent antimicrobial secondary metabolites using standard disk and well assay.
Results: Results showed that none of isolates supernatant had inhibitory effect on P. vulgarisand Klebsilla sp. the most inhibition zone of pathogenic bacteria was shown by AHA5 against S. typhi (9.2 mm). Altogether isolates supernatant showed more antifungal activity in comparison with antibacterial activity and the most inhibition zone was demonstrated by AHA1 supernatant against T. mentagrophytes pathogenic fungi with 21 mm diameters of zone of inhibition.
Conclusion: Our results highlighted thatmangrove Deylam intertidal sediments represented a reservoir for isolation of Actinobacteria, which are potential sources for discovery of antimicrobial secondarymetabolites.
