Environmentally relevant concentrations of titanium dioxide nanoparticles pose negligible risk to marine microbes

Craig J. Dedman; Aaron M. King; Joseph A. Christie-Oleza; Gemma Louise Davies

doi:10.1039/d0en00883d

Environmentally relevant concentrations of titanium dioxide nanoparticles pose negligible risk to marine microbes

Craig J. Dedman^*, Aaron M. King, Joseph A. Christie-Oleza^*, Gemma Louise Davies^*

^*Corresponding author for this work

Chemistry

Research output: Contribution to journal › Article › peer-review

32 Citations (Scopus)

26 Downloads (Pure)

Abstract

Nano-sized titanium dioxide (nTiO₂) represents the highest produced nanomaterial by mass worldwide and, due to its prevalent industrial and commercial use, it inevitably reaches the natural environment. Previous work has revealed a negative impact of nTiO₂ upon marine phytoplankton growth, however, studies are typically carried out at concentrations far exceeding those measured and predicted to occur in the environment currently. Here, a series of experiments were carried out to assess the effects of both research-grade nTiO₂ and nTiO₂ extracted from consumer products upon the marine dominant cyanobacterium, Prochlorococcus, and natural marine communities at environmentally relevant and supra-environmental concentrations (i.e., 1 μg L^-1 to 100 mg L^-1). Cell declines observed in Prochlorococcus cultures were associated with the extensive aggregation behaviour of nTiO₂ in saline media and the subsequent entrapment of microbial cells. Hence, higher concentrations of nTiO₂ particles exerted a stronger decline of cyanobacterial populations. However, within natural oligotrophic seawater, cultures were able to recover over time as the nanoparticles aggregated out of solution after 72 h. Subsequent shotgun proteomic analysis of Prochlorococcus cultures exposed to environmentally relevant concentrations confirmed minimal molecular features of toxicity, suggesting that direct physical effects are responsible for short-term microbial population decline. In an additional experiment, the diversity and structure of natural marine microbial communities showed negligible variations when exposed to environmentally relevant nTiO₂ concentrations (i.e., 25 μg L^-1). As such, the environmental risk of nTiO₂towards marine microbial species appears low, however the potential for adverse effects in hotspots of contamination exists. In future, research must be extended to consider any effect of other components of nano-enabled product formulations upon nanomaterial fate and impact within the natural environment.

Original language	English
Pages (from-to)	1236-1255
Number of pages	20
Journal	Environmental Science: Nano
Volume	8
Issue number	5
Early online date	9 Apr 2021
DOIs	https://doi.org/10.1039/d0en00883d
Publication status	Published - 1 May 2021

Bibliographical note

Funding Information:
C. J. D. was supported by the NERC CENTA DTP studentship NE/L002493/1. J. A. C.-O. was funded by a NERC Independent Research Fellowship NE/K009044/1, Ramón y Cajal contract RYC-2017-22452 (co-funded by the Ministerio de Ciencia, Innovación y Universidades, the Agencia Estatal de Investigación (10.13039/100014440), and the European Social Fund (10.13039/501100004895)) and project PID2019-109509RB-I00 / AEI / 10.13039/501100011033. In addition, we thank the BBSRC/EPSRC Synthetic Biology Research Centre WISB (grant ref.: BB/M017982/1) for access to equipment. Particular thanks are given to Dr Steve Firth at University College London for assistance with EDS measurements, as well as Dr Robyn Wright and Dr Gabriel Erni Cassola for assistance with 16S and 18S rRNA amplicon sequencing and analysis.

Publisher Copyright:
© 2021 The Royal Society of Chemistry.

ASJC Scopus subject areas

Materials Science (miscellaneous)
General Environmental Science

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1039/d0en00883dLicence: Creative Commons: Attribution (CC BY)

DedmanC2021EnvironmentallyFinal published version, 4.99 MBLicence: Creative Commons: Attribution (CC BY)

Cite this

@article{5743d32842cc4e948efe144ffdc92072,

title = "Environmentally relevant concentrations of titanium dioxide nanoparticles pose negligible risk to marine microbes",

abstract = "Nano-sized titanium dioxide (nTiO2) represents the highest produced nanomaterial by mass worldwide and, due to its prevalent industrial and commercial use, it inevitably reaches the natural environment. Previous work has revealed a negative impact of nTiO2 upon marine phytoplankton growth, however, studies are typically carried out at concentrations far exceeding those measured and predicted to occur in the environment currently. Here, a series of experiments were carried out to assess the effects of both research-grade nTiO2 and nTiO2 extracted from consumer products upon the marine dominant cyanobacterium, Prochlorococcus, and natural marine communities at environmentally relevant and supra-environmental concentrations (i.e., 1 μg L-1 to 100 mg L-1). Cell declines observed in Prochlorococcus cultures were associated with the extensive aggregation behaviour of nTiO2 in saline media and the subsequent entrapment of microbial cells. Hence, higher concentrations of nTiO2 particles exerted a stronger decline of cyanobacterial populations. However, within natural oligotrophic seawater, cultures were able to recover over time as the nanoparticles aggregated out of solution after 72 h. Subsequent shotgun proteomic analysis of Prochlorococcus cultures exposed to environmentally relevant concentrations confirmed minimal molecular features of toxicity, suggesting that direct physical effects are responsible for short-term microbial population decline. In an additional experiment, the diversity and structure of natural marine microbial communities showed negligible variations when exposed to environmentally relevant nTiO2 concentrations (i.e., 25 μg L-1). As such, the environmental risk of nTiO2 towards marine microbial species appears low, however the potential for adverse effects in hotspots of contamination exists. In future, research must be extended to consider any effect of other components of nano-enabled product formulations upon nanomaterial fate and impact within the natural environment.",

author = "Dedman, {Craig J.} and King, {Aaron M.} and Christie-Oleza, {Joseph A.} and Davies, {Gemma Louise}",

note = "Funding Information: C. J. D. was supported by the NERC CENTA DTP studentship NE/L002493/1. J. A. C.-O. was funded by a NERC Independent Research Fellowship NE/K009044/1, Ram{\'o}n y Cajal contract RYC-2017-22452 (co-funded by the Ministerio de Ciencia, Innovaci{\'o}n y Universidades, the Agencia Estatal de Investigaci{\'o}n (10.13039/100014440), and the European Social Fund (10.13039/501100004895)) and project PID2019-109509RB-I00 / AEI / 10.13039/501100011033. In addition, we thank the BBSRC/EPSRC Synthetic Biology Research Centre WISB (grant ref.: BB/M017982/1) for access to equipment. Particular thanks are given to Dr Steve Firth at University College London for assistance with EDS measurements, as well as Dr Robyn Wright and Dr Gabriel Erni Cassola for assistance with 16S and 18S rRNA amplicon sequencing and analysis. Publisher Copyright: {\textcopyright} 2021 The Royal Society of Chemistry.",

year = "2021",

month = may,

day = "1",

doi = "10.1039/d0en00883d",

language = "English",

volume = "8",

pages = "1236--1255",

journal = "Environmental Science: Nano",

issn = "2051-8153",

publisher = "Royal Society of Chemistry",

number = "5",

}

TY - JOUR

T1 - Environmentally relevant concentrations of titanium dioxide nanoparticles pose negligible risk to marine microbes

AU - Dedman, Craig J.

AU - King, Aaron M.

AU - Christie-Oleza, Joseph A.

AU - Davies, Gemma Louise

N1 - Funding Information: C. J. D. was supported by the NERC CENTA DTP studentship NE/L002493/1. J. A. C.-O. was funded by a NERC Independent Research Fellowship NE/K009044/1, Ramón y Cajal contract RYC-2017-22452 (co-funded by the Ministerio de Ciencia, Innovación y Universidades, the Agencia Estatal de Investigación (10.13039/100014440), and the European Social Fund (10.13039/501100004895)) and project PID2019-109509RB-I00 / AEI / 10.13039/501100011033. In addition, we thank the BBSRC/EPSRC Synthetic Biology Research Centre WISB (grant ref.: BB/M017982/1) for access to equipment. Particular thanks are given to Dr Steve Firth at University College London for assistance with EDS measurements, as well as Dr Robyn Wright and Dr Gabriel Erni Cassola for assistance with 16S and 18S rRNA amplicon sequencing and analysis. Publisher Copyright: © 2021 The Royal Society of Chemistry.

PY - 2021/5/1

Y1 - 2021/5/1

N2 - Nano-sized titanium dioxide (nTiO2) represents the highest produced nanomaterial by mass worldwide and, due to its prevalent industrial and commercial use, it inevitably reaches the natural environment. Previous work has revealed a negative impact of nTiO2 upon marine phytoplankton growth, however, studies are typically carried out at concentrations far exceeding those measured and predicted to occur in the environment currently. Here, a series of experiments were carried out to assess the effects of both research-grade nTiO2 and nTiO2 extracted from consumer products upon the marine dominant cyanobacterium, Prochlorococcus, and natural marine communities at environmentally relevant and supra-environmental concentrations (i.e., 1 μg L-1 to 100 mg L-1). Cell declines observed in Prochlorococcus cultures were associated with the extensive aggregation behaviour of nTiO2 in saline media and the subsequent entrapment of microbial cells. Hence, higher concentrations of nTiO2 particles exerted a stronger decline of cyanobacterial populations. However, within natural oligotrophic seawater, cultures were able to recover over time as the nanoparticles aggregated out of solution after 72 h. Subsequent shotgun proteomic analysis of Prochlorococcus cultures exposed to environmentally relevant concentrations confirmed minimal molecular features of toxicity, suggesting that direct physical effects are responsible for short-term microbial population decline. In an additional experiment, the diversity and structure of natural marine microbial communities showed negligible variations when exposed to environmentally relevant nTiO2 concentrations (i.e., 25 μg L-1). As such, the environmental risk of nTiO2 towards marine microbial species appears low, however the potential for adverse effects in hotspots of contamination exists. In future, research must be extended to consider any effect of other components of nano-enabled product formulations upon nanomaterial fate and impact within the natural environment.

AB - Nano-sized titanium dioxide (nTiO2) represents the highest produced nanomaterial by mass worldwide and, due to its prevalent industrial and commercial use, it inevitably reaches the natural environment. Previous work has revealed a negative impact of nTiO2 upon marine phytoplankton growth, however, studies are typically carried out at concentrations far exceeding those measured and predicted to occur in the environment currently. Here, a series of experiments were carried out to assess the effects of both research-grade nTiO2 and nTiO2 extracted from consumer products upon the marine dominant cyanobacterium, Prochlorococcus, and natural marine communities at environmentally relevant and supra-environmental concentrations (i.e., 1 μg L-1 to 100 mg L-1). Cell declines observed in Prochlorococcus cultures were associated with the extensive aggregation behaviour of nTiO2 in saline media and the subsequent entrapment of microbial cells. Hence, higher concentrations of nTiO2 particles exerted a stronger decline of cyanobacterial populations. However, within natural oligotrophic seawater, cultures were able to recover over time as the nanoparticles aggregated out of solution after 72 h. Subsequent shotgun proteomic analysis of Prochlorococcus cultures exposed to environmentally relevant concentrations confirmed minimal molecular features of toxicity, suggesting that direct physical effects are responsible for short-term microbial population decline. In an additional experiment, the diversity and structure of natural marine microbial communities showed negligible variations when exposed to environmentally relevant nTiO2 concentrations (i.e., 25 μg L-1). As such, the environmental risk of nTiO2 towards marine microbial species appears low, however the potential for adverse effects in hotspots of contamination exists. In future, research must be extended to consider any effect of other components of nano-enabled product formulations upon nanomaterial fate and impact within the natural environment.

UR - http://www.scopus.com/inward/record.url?scp=85106560340&partnerID=8YFLogxK

U2 - 10.1039/d0en00883d

DO - 10.1039/d0en00883d

M3 - Article

AN - SCOPUS:85106560340

SN - 2051-8153

VL - 8

SP - 1236

EP - 1255

JO - Environmental Science: Nano

JF - Environmental Science: Nano

IS - 5

ER -

Environmentally relevant concentrations of titanium dioxide nanoparticles pose negligible risk to marine microbes

Abstract

Bibliographical note

ASJC Scopus subject areas

UN SDGs

Access to Document

Fingerprint

Cite this