Gold nanoparticles synthesized by Geobacillus sp. strain ID17 a thermophilic bacterium isolated from Deception Island, Antarctica

Abstract

BackgroundThe use of microorganisms in the synthesis of nanoparticles emerges as an eco-friendly and exciting approach, for production of nanoparticles due to its low energy requirement, environmental compatibility, reduced costs of manufacture, scalability, and nanoparticle stabilization compared with the chemical synthesis.ResultsThe production of gold nanoparticles by the thermophilic bacterium Geobacillus sp. strain ID17 is reported in this study. Cells exposed to Au3+ turned from colourless into an intense purple colour. This change of colour indicates the accumulation of intracellular gold nanoparticles. Elemental analysis of particles composition was verified using TEM and EDX analysis. The intracellular localization and particles size were verified by TEM showing two different types of particles of predominant quasi-hexagonal shape with size ranging from 5–50 nm. The mayority of them were between 10‒20 nm in size. FT-IR was utilized to characterize the chemical surface of gold nanoparticles. This assay supports the idea of a protein type of compound on the surface of biosynthesized gold nanoparticles. Reductase activity involved in the synthesis of gold nanoparticles has been previously reported to be present in others microorganisms. This reduction using NADH as substrate was tested in ID17. Crude extracts of the microorganism could catalyze the NADH-dependent Au3+ reduction.ConclusionsOur results strongly suggest that the biosynthesis of gold nanoparticles by ID17 is mediated by enzymes and NADH as a cofactor for this biological transformation.

Biosynthesis of Metal Nanoparticles: A Review

“…Correa-Llantén et al, 2013 [8], mentioned that the use of microorganisms in the synthesis of nanoparticles emerges as an ecofriendly and exciting approach, for production of nanoparticles due to its low energy requirement, environmental compatibility, reduced costs of manufacture, scalability, and nanoparticle stabilization compared with the chemical synthesis. The production of gold nanoparticles by the thermophilic bacterium Geobacillus sp.…”

Extremophile Current Challenges and New Gate of Knowledge by Nanoparticles Pathways.

“…It should be mentioned that this kind of bacteriasynthesize AuNP under high temperatures and involving four capacities of unknown enzymes. Moreover, intracellular quasi-hexagonal NPs (5-50nm)have been produced by ID17 when challenged in potassium phosphate buffer (20mM) and hydrogen tetrachloroaurate (1mM) [86].…”

Biocatalytic Formation of Gold Nanoparticles Decorated with Functional Proteins inside Recombinant Escherichia coli Cells

“…4b), we obtained clear bands corresponding to pG-BsGLD-H6C, implying that the His-Cys tag (H6C-tag) exhibited stronger binding affinity than the other endogenous proteins in the cytoplasm of the E. coli cells and actively participated to stabilize the Au NPs in aqueous solution. Although previous reports focused on the in vivo synthesis of metal NPs by microorganisms, [20][21][22] few have considered the identification of proteins decorating NPs that are synthesized in vivo. Hence, our findings provide important insights into the selective, controllable decoration of Au NPs with a functional protein in the cytoplasm of recombinant E. coli cells.…”

“…[20][21][22] However, their cultivation often needs specific conditions, and thus limiting their wide spread adoption. Hence, a general host organism would be preferable.…”