Insight into eco-friendly fabrication of silver nanoparticles by Pseudomonas aeruginosa and its potential impacts

Abstract

Abstract. Although green synthesis of nanoparticles (NPs) has replaced conventio na l physicochemical methods owing to eco-friendly and cost effective nature but molecular mechanism is not known completely. Elucidation of the mechanism is needed to enhance the production of control size synthesis and for understanding the biomineralization process. Here we report the facile, extracellular biosynthesis of silver nanoparticles (AgNPs) by Pseudomonas aeruginosa JP1 through nitrate reductase mediated mechanism. AgNO3 was reduced to AgNPs by cell filtrate exposure. UV-visible spectrum of the reaction mixture depicted reduction of ionic silver (Ag + ) to atomic silver (Ag 0 ) by a progressive upsurge in surface plasmon resonance (SPR) band range 435-450 nm. X-ray diffraction analysis showed the 2θ values at 38.08°, 44.52°, 64.42° and 77.44° confirming the crystalline nature and mean diameter [6.5-27.88nm (Ave = 13.44 nm)] of AgNPs. Transmission electron microscopy analysis demonstrated the spherical AgNPs with size range 5-45 nm. Stabilizing proteins and rhamnolipids were recognized by Fourier transform infrared spectroscopy. Nitrate reductase was purified and characterized (molecular weight 65 kDa and specific activity = 5.6 U/mg). To probe the plausible mechanism purified enzyme was retreated with AgNO3. Characteristic SPR bands range (435-450 nm) and Particle-induced x-ray emission results also confirmed the synthesis of AgNPs (59679.5 ppm) in solution. These results demonstrated that, nitrate reductase as a principal reducing agent in the mechanistic pathway of AgNPs synthesis, which leads to the understanding of metal transformation and biomineralization processes for controlling the biogeochemical cycles of silver and other heavy metals.

Microcystis aeruginosa Synergistically Facilitate the Photocatalytic Degradation of Tetracycline Hydrochloride and Cr(VI) on PAN/TiO2/Ag Nanofiber Mats

“…This absorptive characteristic is mainly ascribed to a major role played by AgNPs in decreasing the band gap of TiO 2 . These findings also corroborate our previous studies [24][25][26].…”

Bioelectrochemical recovery of silver from wastewater with sustainable power generation and its reuse for biofouling mitigation

“…7). Interestingly, a high ratio of the plane (111) suggests that recovered AgNFs were dominated by (111) facets which is consistent with previous findings of the silver nanomaterials (Ali et al, 2017;Ali et al, 2016). peaks were appeared as a doublet due to spin-orbit coupling (3d5/2 and 3d3/2) at the binding energies of 368 eV and 374 eV respectively (Fig.…”

Synthesis, characterization and kinetic study of silver and gold nanoparticles produced by the archaeon Haloferax volcanii

“…The released material was analysed by LC-MS/MS and 574 proteins were identified. In many bacteria the synthesis of Ag NPs relies in the occurrence of enzymes with oxidoreductase activity (redox enzymes) such as nitrate reductase in Pseudomonas aureginosa (Ali et al 2017) and E. coli (Shahverdi et al 2007) or C-type cytochromes in Shewanella oneidensis (Huang et al 2015) and Desulfovibrio desulfuricans ATCC 29577 (Mabbett et al 2004). In archaea, the involvement of nitrate reductase has been reported in the biosynthesis of Ag NPs by Halococcus salifonidae BK3 (Das et al 2014).…”

“…In many bacteria the synthesis of Ag NPs relies in the occurrence of enzymes with oxidoreductase activity (redox enzymes) such as nitrate reductase in Pseudomonas aureginosa (Ali et al . 2017) and E. coli (Shahverdi et al . 2007) or C‐type cytochromes in Shewanella oneidensis (Huang et al .…”