Silver and gold nanoparticles synthesized from Streptomyces sp. isolated from acid forest soil with special reference to its antibacterial activity against pathogens

Abstract

Biological systems such as bacteria, fungi or plants for synthesis of noble nanoparticles (NPs) are easy, inexpensive and eco-friendly. Obtained bioparticles due to its physico-chemical nature possess biologically active properties such as antimicrobial activity. In this study, the biological synthesis of silver (Ag) and gold (Au) nanoparticles using Streptomyces sp. strain NH21 isolated from acidic soil and its antibacterial activity against bacteria is presented. The physico-chemical properties of obtained particles were characterized. UV-Vis showed broad peak at 404 and 424 nm for AgNPs and 564 nm for AuNPs. Transmission electron microscopy studies showed small sized nanoparticles of 44 nm for supernatant and 8.4 nm for biomass synthesized AgNPs, and 10 nm for supernatant synthesized AuNPs, which was confirmed by nanoparticle tracking analyses. Fourier transform infrared spectroscopy revealed the presence of capping agents over metal-NPs. The negative Zeta potential values of metal-NPs indicated stability of biosynthesized particles. In vitro antibacterial activity and minimal inhibitory concentration of NPs was assessed against Gram-positive and Gram-negative bacteria. Unlike to gold-NPs, silver-NPs showed reliable antibacterial activity. Atomic force microscopy analysis recorded changes in cell morphology of tested bacterial strains after treatment with nanoparticles.

Antibiofilm, antimicrobial and cytotoxic activity of extracellular green-synthesized silver nanoparticles by two marine-derived actinomycete

“…The as-prepared AgNPs synthesized in the presence of actinomycete bacterial supernatants (i.e., F2 and F7) exhibit a characteristic surface plasmon band (SPR) at 460 nm, and the surface plasmon resonance (SPR) absorption spectral range was from 400 to 550 nm, indicating that AgNPs formed at different time intervals. These results were in agreement with previous studies represented by Składanowski et al 20 and Al-Dhabi et al 21…”

Antimicrobial and cytotoxic activity of silver nanoparticles synthesized from two haloalkaliphilic actinobacterial strains alone and in combination with antibiotics

“…Among the different micro-organisms used for the synthesis of metal nanoparticles, Actinomycetes are less studied (Golinska et al 2014). The nanoparticles synthesized from the members of Actinomycetes present polydispersity, stability and significant biocidal activities against various pathogens (Golinska et al 2015;Składanowski et al 2017;Wypij et al 2017).…”

Extracellular biosynthesis of silver nanoparticles using Streptomyces griseoplanus SAI-25 and its antifungal activity against Macrophomina phaseolina , the charcoal rot pathogen of sorghum

“…09 PBT 005 from sugarcane rhizosphere soil (Saravanakumar et al, 2014) and Streptomyces atrovirens from marine sediments (Subbaiya et al, 2017). Streptomyces are still being explored from broad range of environments from farm soil (Baygar and Ugur, 2017;Gupta et al, 2017) to amazon rainforest (Silva-Vinhote et al, 2017) and acid forest (Składanowski et al, 2017), for silver nanoparticles synthesis and also explored for broad range of applications including antipathogenicity, antioxidants and sensors.…”