Microbial Synthesis of Silver Nanoparticles by Streptomyces glaucus and Spirulina platensis

Abstract

Microbial synthesis of nanoparticles has a potential to develop simple, costeffective and eco-friendly methods for production of technologically important materials. In this study, for the first time a novelactinomycete strain Streptomyces glaucus71 MD isolated from a soy rhizosphere in Georgiais for the first time extensively characterized and utilized for the synthesis of silver nanoparticles. Scanning Electron Microscope (SEM) allowed observing extracellular synthesis of nanoparticles, which has many advantages from the point of view of applications. Production of silver nanoparticles proceeded extracellularlywith the participation of another microorganism, bluegreen microalgae Spirulinaplatensis (S. platensis). In this study it is shown that the production rate of the nanoparticles depends not only on the initial concentration of AgNO 3 but also varies with time in a nonmonotonic way. SEM study of silver nanoparticles remaining on the surface of microalgae revealed that after 1 day of exposure to 1 mM AgNO 3 nanoparticles were arranged as long aggregates along S. platensiscells strongly damaged by silver ions. However, after 5 days of exposure to silver S. platensiscells looked completely recovered and the nanoparticles were distributed more uniformly on the surface of the cells.

GOLD AND SILVER NANOPARTICLES IN Spirulina platensis BIOMASS FOR MEDICAL APPLICATION

“…The UV-Vis spectra of absorbance at concentrations of 10 -3 M of gold and silver compounds and different reaction time are given in Figures 1a and 1b, respectively [17,18]. In these figures, the peak intensity for nanoparticles of specific sizes increased as a function of the reaction time.…”

“…The synthesis of silver and gold nanoparticles by the biomass of S. platensis was studied in [17] and [18], respectively. The present work is a continuation of these studies.…”

Role of Actinomycete-Mediated Nanosystem in Agriculture

“…In comparison to bacteria and fungi, actinomycetes are known to secrete much higher amounts of enzymes, proteins, small molecules with reducing properties and secondary metabolites, and thereby it significantly enhances the biosynthesis of metal nanoparticles. In addition, as a prokaryote, actinomycetes can be easily subjected to genetic manipulations which help in the future to achieve better control over size and polydispersity of the nanoparticles (Tsibakhashvili et al 2011). It is observed that the time required for the completion of nanoparticle synthesis using both bacteria (Klaus et al 1999) and fungi (Mukherjee et al 2002) ranges between 24 and 120 h, whereas actinomycetes can be achieve in 24 h of incubation (Sadhasivam et al 2010).…”

“…BDUKAS10, an isolate of mangrove sediment (Sivalingam et al 2012), Streptomyces hygroscopicus isolated near the Pacific shore region (Sadhasivam et al 2010), Streptomyces sp. LK3 isolated from marine sediments (Karthik et al 2014), Streptomyces glaucus 71 MD isolated from a soybean rhizosphere (Tsibakhashvili et al 2011), Streptomyces sp. (09 PBT 005) 09 PBT 005 isolated from sugarcane rhizosphere soil (Saravanakumar et al 2014) and an antagonistic Streptomyces sp.-SBU3 isolated from terrestrial red garden soil from groundnut (Krishnakumar and Bai 2015).…”

Development of Biotechnology for Microbial Synthesis of Gold and Silver Nanoparticles

“…Some results of earlier investigations are presented in Refs. [26,27]. Strains of microorganisms belonging to Streptomyces and Arthrobacter genera have been studied as possible "nanofactories" for the development of clean and nontoxic methods of the synthesis of silver and gold nanoparticles.…”