Silver Nanoparticles, Ions, and Shape Governing Soil Microbial Functional Diversity: Nano Shapes Micro.

Yujia Zhai,Willie J G M Peijnenburg,Marja Wouters,Ellard R Hunting,Martina G Vijver

doi:10.3389/fmicb.2016.01123

Abstract

Silver nanoparticles (AgNPs) affect microbial metabolic processes at single cell level or lab-culture strains. However, the impact of different AgNPs properties such as the particle, ion release, and shape on functional responses of natural soil microbial communities remain poorly understood. Therefore, we assessed the relative importance of particles and ions of AgNPs in bacterial toxicity and how the functional diversity of soil microbial communities were impacted by AgNPs shapes (i.e., plates, spheres, and rods) in laboratory incubations. Our results showed that the relative contribution of AgNPs(particle) increased with increasing exposure concentrations (accounted for about 60–68% of the total toxicity at the highest exposure level). In addition, the functional composition of the microbial community differed significantly according to different AgNPs shapes. The various properties of AgNPs thus can significantly and differentially affect the functional composition of microbial communities and associated ecosystem processes depending on the level of environmental exposure.

Highlights

Silver nanoparticles (AgNPs) are known for their anti-microbial properties and are broadly used in clothing, food industry, cosmetics, and medical devices (Kendra and Arturo, 2014; Theophel et al, 2014)
While most studies have focused on AgNPs toxicity on single bacterial species under laboratory conditions (e.g., Pal et al, 2007; McQuillan et al, 2011; Levard et al, 2012), a number of studies provided evidence that small size metal NPs are detrimental to natural soil microbial communities (Dinesh et al, 2012), affecting community composition (Kumar et al, 2011; Echavarri-Bravo et al, 2015; Sillen et al, 2015), bacterial biomass (Hänsch and Emmerling, 2010), and bacterial processes (Ge et al, 2011)
Most studies evaluating the relative importance of particle species and ion species of AgNPs were restricted to single bacterial species/strains, and the relative contributions of particle species and ion species of AgNPs to natural microbial communities remain uncertain

Summary

Introduction

Silver nanoparticles (AgNPs) are known for their anti-microbial properties and are broadly used in clothing, food industry, cosmetics, and medical devices (Kendra and Arturo, 2014; Theophel et al, 2014). Resulting from these industrial and medical applications, AgNPs are reported to end up in both soils and aquatic sediments (e.g., Schlich et al, 2013; Yu et al, 2013; McKee and Filser, 2016), with inherent risks for natural microbial communities that play a pivotal role in the functioning of ecosystems (Lau and Lennon, 2012). Most studies evaluating the relative importance of particle species and ion species of AgNPs were restricted to single bacterial species/strains, and the relative contributions of particle species and ion species of AgNPs to natural microbial communities remain uncertain

Methods

Results

Conclusion