Objectives: The aim of the present study was to evaluate the anticandidal activity of biologically synthesized silver nanoparticles using the culture filtrate of Streptomyces sp.VITPK1. Materials and methods: Silver nanoparticles were synthesized using the culture filtrate of Streptomyces species isolated from brine spring located at Thoubal District, Manipur, India. The isolate was identified by molecular taxonomic characterization and designated as Streptomyces sp.VITPK1. The synthesized silver nanoparticles (AgNPs) were characterized by UV-visible spectra, X-ray diffraction (XRD) patterns, Energy Dispersive Analysis of X-rays (EDAX) and Fourier Transform Infrared (FTIR) analysis. The antifungal activity of the synthesized silver nanoparticles was evaluated against selected Candida species. Results: The synthesized AgNPs showed a surface plasmon resonance peak at 425. nm. XRD patterns showed the crystalline peaks at 38.15° (111), 44.35° (200), 64.52° (220) and 77.49° (311) matching with the diffraction facets of silver. The size of the AgNPs was in the range of 20-45. nm. The EDAX analysis revealed the presence of silver as the major metal in the sample. The synthesized AgNPs showed anticandidal activity against Candida albicans, Candida tropicalis and Candida krusei with a maximum zone of inhibition of 20. mm against C.albicans. Conclusions: The results of this study suggest that the green synthesis of silver nanoparticles using Streptomyces sp.VITPK1 have the ability to act against pathogenic Candida strains. © 2014 Elsevier Masson SAS.

Kannabiran K

Department of Bio-Medical Sciences

School of Bio Sciences and Technology

Vellore Campus

Sanjenbam P

Gopal J.V

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Journal de Mycologie Médicale

Actinomycetes-mediated biogenic synthesis of metal nanoparticles and their antimicrobial activities are well documented. Actinomycetes facilitate both intracellular and extracellular metal nanoparticles synthesis and are efficient candidates for the production of polydispersed, stable and ultra-small size metal nanoparticles. Secondary metabolites and new chemical entities derived from Actinomycetes have not been extensively studied for the synthesis of metal/metal oxide nanoparticles. The present review focuses on biogenic synthesis of metal nanoparticles from Actinomycetes and the scope for exploring Actinomycetes-derived compounds (enzymes, organics acids and bioactive compounds) as metal and metal oxide reducing agents for the synthesis of desired nanoparticles. This review also focuses on challenges faced in the applications of nanoparticles and the methods to synthesize biogenic metal nanoparticles with desired physiochemical properties such as ultra-small size, large surface to mass ratio, high reactivity etc. Methods to evade their toxicity and unique interactions with biological systems to improve their chance as an alternative therapeutic agent in medical and pharmaceutical industry are also discussed. © 2017 The Society for Applied Microbiology

Fulltext

Letters in Applied Microbiology

Actinomycetes-mediated biogenic synthesis of metal and metal oxide nanoparticles: progress and challenges

We present the microbial green synthesis of silver nanoparticles (NPs) by Streptomyces ghanaensis VITHM1 strain (MTCC No. 12465). The secondary metabolites in the cell free supernatant of this bacterium when incubated with 1 mmol/L AgNO3, mediated the biological synthesis of AgNPs. The synthesized AgNPs were characterized by UV-visible spectrum, X-ray diffraction (XRD), atomic force microscope, scanning electron microscopy equipped with energy dispersive spectroscopy, transmission electron microscopy, FT-IR spectroscopy, dynamic light scattering and zeta potential. They were highly stable and, spherical in shape with the average size of 30‒50 nm. The secondary metabolites involved in the formation of AgNPs were identified gas chromatographymass spectrography. The 3D structure of the unit cell of the synthesized AgNPs was determined using XRD data base. The synthesized AgNPs exhibited significant antibacterial activity against tested bacterial pathogens, and did not show haemolysis on human red blood cells. This green synthesis could provide a new platform to explore and use AgNPs as antibacterial therapeutic agents.[Figure not available: see fulltext.] © 2016, Higher Education Press and Springer-Verlag Berlin Heidelberg.

Frontiers of Chemical Science and Engineering

Streptomyces ghanaensis VITHM1 mediated green synthesis of silver nanoparticles: Mechanism and biological applications

Anticandidal activity of silver nanoparticles synthesized using Streptomyces sp.VITPK1

Antifungal drugs are inhibitors either of fungal cell wall biosynthesis or essential reaction steps of fungal metabolic pathways. In silico studies have proved to be very effective on screening small molecules to be used as drugs and identifying essential reactions and pathways as targets. The aim of the present study was to predict the interactions of compounds present in the ethyl acetate extract of Streptomyces sp. VITSTK7 against selected fungal drug target enzymes. The ethyl acetate extract of the isolate showed significant anti-Aspergillus activity against the selected Aspergillus pathogens. Presence of the three compounds (C22H37NO7, C17H24N4O6 and C24H28N2O5) in the extract was identified by GC-MS spectra and matched with reference compounds available in the MS spectra library, NIST (National Institute for Standards and Technology). These compounds were analysed for the interaction with five selected fungal target proteins 1AFR, 1EA1, 1LKP, 1ZHX and 3PD73i3E. Docking was done using Patch dock beta 1.3 version and analysed by pymol 1.3 version. The tested compounds C22H37NO7, C17H24N4O6 and C24H28N2O5 showed least binding energy of -254.64 kcal/mol, -248.71 kcal/mol and -338.57 kcal/mol respectively with 1ZHX. The result of this study revealed that all the three compounds from the strain had higher interaction with 1ZHX protein than with the other proteins. It shows that this strain could be the promising source for the antifungal drug. © 2013 International Association of Scientists in the Interdisciplinary Areas and Springer-Verlag Berlin Heidelberg.

Interdisciplinary Sciences: Computational Life Sciences

Interaction of Streptomyces sp. VITSTK7 compounds with selected antifungal drug target enzymes by in silico molecular docking studies

Objective: The aim of the present study was to assess the anti-Aspergillus activity of culture filtrate of Streptomyces sp. VITSTK7 and biologically synthesized Ag2O/Ag nanoparticles using the culture filtrate of VITSTK7. Material and methods: Silver nanoparticles were synthesized by biological reduction of silver nitrate using culture filtrate of Streptomyces sp. VITSTK7. The synthesized nanopaticles were characterized for surface plasma resonance peak, X-ray diffraction patterns, shape and size distribution. Inhibition of mycelial growth was used as an index of anti- Aspergillus activity of synthesized nanoparticles. Results: The synthesized nanoparticles were spherical shaped and monodespersive in nature and showed a single surface plasma resonance peak at 420. nm. X-ray diffraction patterns displayed typical peaks of crystalline silver oxide and size distribution histograms indicated production of 20-60-nm-size nanoparticles with average size of 35.2. nm. The synthesized nanoparticles showed anti- Aspergillus activity against Aspergillus niger, Aspergillus flavus and Aspergillus fumigatus with antifungal index in the range of 62-75%. Conclusion: Thus the bioconversion of Ag2O/Ag nanoparticles by Streptomyces sp. VITSTK7 could be employed to control Aspergillus pathogenesis. The results of this study suggest that the green synthesis of Ag2O/Ag nanoparticles using marine Streptomyces sp. VITSTK7 yielded 27.9nm sized particles with potential to act against pathogenic Aspergillus species. © 2013 Elsevier Masson SAS.

Journal	Data powered by TypesetJournal de Mycologie Médicale
Publisher	Data powered by TypesetElsevier BV
ISSN	1156-5233
Open Access	0