Fe2+ Alleviated the Toxicity of ZnO Nanoparticles to Pseudomonas tolaasii Y-11 by Changing Nanoparticles Behavior in Solution.

Yuran Yang,Kaili Li,Can Zhang,Zhenlun Li

doi:10.3390/microorganisms9112189

Yuran Yang, Kaili Li + Show 2 more

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https://doi.org/10.3390/microorganisms9112189

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Journal: Microorganisms	Publication Date: Oct 20, 2021
Citations: 4	License type: CC BY 4.0

Affiliation: Southwest University, University of Queensland

Abstract

The negative effect of ZnO nanoparticles (ZnO-NPs) on the biological removal of nitrate (NO3−) has received extensive attention, but the underlying mechanism is controversial. Additionally, there is no research on Fe2+ used to alleviate the cytotoxicity of NPs. In this paper, the effects of different doses of ZnO-NPs on the growth and NO3− removal of Pseudomonas tolaasii Y-11 were studied with or without Fe2+. The results showed that ZnO-NPs had a dose-dependent inhibition on the growth and NO3− removal of Pseudomonas tolaasii Y-11 and achieved cytotoxic effects through both the NPs themselves and the released Zn2+. The addition of Fe2+ changed the behavior of ZnO-NPs in an aqueous solution (inhibiting the release of toxic Zn2+ and promoting the aggregation of ZnO-NPs), thereby alleviating the poisonous effect of ZnO-NPs on the growth and nitrogen removal of P. tolaasii Y-11. This study provides a theoretical method for exploring the mitigation of the acute toxicity of ZnO-NPs to denitrifying microorganisms.

Highlights

Studies have shown that ZnO nanoparticles (ZnO-NPs) can change the community structure of functional flora in activated sludge [8,9,11] and inhibit enzyme activity [6], inhibiting nitrogen removal [12]
To determine the universality of Fe2+ to alleviate the cytotoxicity of NPs, we further explored the effect of Fe2+ on the cytotoxicity of ZnO-NPs
The results showed that the high content of ZnO-NPs was the main source of their cytotoxicity

Summary

Introduction

Previous reports demonstrated that nitrate could be removed efficiently and at a low-cost by microorganisms through assimilatory and dissimilatory reactions [4,5]. Commodities containing ZnO-NPs will inevitably be released into the environment during production, use and abandonment [6,8,9]. It accumulates and deposits in activated sludge [10]. Studies have shown that ZnO-NPs can change the community structure of functional flora in activated sludge [8,9,11] and inhibit enzyme activity [6], inhibiting nitrogen removal [12]

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