title: Soil pH effects on the interactions between dissolved zinc, non-nano- and nano-ZnO with soil bacterial communities.
abstract: Zinc oxide nanoparticles (ZnO NPs) are used in an array of products and processes, ranging from personal care products to antifouling paints, textiles, food additives, antibacterial agents and environmental remediation processes. Soils are an environment likely to be exposed to manmade nanoparticles due to the practice of applying sewage sludge as a fertiliser or as an organic soil improver. However, understanding on the interactions between soil properties, nanoparticles and the organisms that live within soil is lacking, especially with regards to soil bacterial communities. We studied the effects of nanoparticulate, non-nanoparticulate and ionic zinc (in the form of zinc chloride) on the composition of bacterial communities in soil with a modified pH range (from pH 4.5 to pH 7.2). We observed strong pH-dependent effects on the interaction between bacterial communities and all forms of zinc, with the largest changes in bacterial community composition occurring in soils with low and medium pH levels (pH 4.8 and 5.9). The high pH soil (pH 7.2) was less susceptible to the effects of zinc exposure. At the highest doses of zinc (2500 mg/kg dw soil), both nano and non-nano particulate zinc applications elicited a similar response in the soil bacterial community, and this differed significantly to the ionic zinc salt treatment. The results highlight the importance of considering soil pH in nanotoxicology studies, although further work is needed to determine the exact mechanisms controlling the toxicity and fate and interactions of nanoparticles with soil microbial communities.
authors.affiliation: NERC Centre for Ecology & Hydrology, Benson Lane, Crowmarsh Gifford, Wallingford, OX10 8BB, UK. dasr@ceh.ac.uk.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Read
authors.affiliation: NERC Centre for Ecology & Hydrology, Benson Lane, Crowmarsh Gifford, Wallingford, OX10 8BB, UK.
authors.forename: Marianne
authors.initials: M
authors.lastname: Matzke
authors.affiliation: NERC Centre for Ecology & Hydrology, Benson Lane, Crowmarsh Gifford, Wallingford, OX10 8BB, UK.
authors.forename: Hyun S
authors.initials: HS
authors.lastname: Gweon
authors.affiliation: NERC Centre for Ecology & Hydrology, Benson Lane, Crowmarsh Gifford, Wallingford, OX10 8BB, UK.
authors.forename: Lindsay K
authors.initials: LK
authors.lastname: Newbold
authors.affiliation: NERC Centre for Ecology & Hydrology, Benson Lane, Crowmarsh Gifford, Wallingford, OX10 8BB, UK.|Department of Environmental Engineering, Technical University of Denmark, Miljoevej, building 113, 2800, Kgs Lyngby, Denmark.
authors.forename: Laura
authors.initials: L
authors.lastname: Heggelund
authors.affiliation: NERC Centre for Ecology & Hydrology, Benson Lane, Crowmarsh Gifford, Wallingford, OX10 8BB, UK.|LEITAT Technological Center, C/ de la Innovació, 2, 08225, Terrassa, Barcelona, Spain.
authors.forename: Maria Diez
authors.initials: MD
authors.lastname: Ortiz
authors.affiliation: NERC Centre for Ecology & Hydrology, Benson Lane, Crowmarsh Gifford, Wallingford, OX10 8BB, UK.
authors.forename: Elma
authors.initials: E
authors.lastname: Lahive
authors.affiliation: NERC Centre for Ecology & Hydrology, Benson Lane, Crowmarsh Gifford, Wallingford, OX10 8BB, UK.
authors.forename: David
authors.initials: D
authors.lastname: Spurgeon
authors.affiliation: NERC Centre for Ecology & Hydrology, Benson Lane, Crowmarsh Gifford, Wallingford, OX10 8BB, UK.
authors.forename: Claus
authors.initials: C
authors.lastname: Svendsen
mesh_terms: D001419:Bacteria / Q000187:drug effects; D002712:Chlorides; D005308:Fertilizers; D006863:Hydrogen-Ion Concentration; D059013:Microbial Consortia / Q000187:drug effects*; D053758:Nanoparticles / Q000633:toxicity*; D012722:Sewage / Q000737:chemistry; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000633:toxicity; D015032:Zinc / Q000633:toxicity*; D017967:Zinc Compounds; D015034:Zinc Oxide / Q000633:toxicity*
chemical_list: D002712:Chlorides; D005308:Fertilizers; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants; D017967:Zinc Compounds; C016837:zinc chloride; D015032:Zinc; D015034:Zinc Oxide
keywords: Bacteria; Nanotoxicology; Soil; Zinc oxide; pH