Soil pH effects on the interactions between dissolved zinc, non-nano- and nano-ZnO with soil bacterial communities

• Published in: Environmental science and pollution research international 2016-03, Vol.23 (5), p.4120-4128
• Main Authors: Read, Daniel S, Matzke, Marianne, Gweon, Hyun S, Newbold, Lindsay K, Heggelund, Laura, Ortiz, Maria Diez, Lahive, Elma, Spurgeon, David, Svendsen, Claus
• Format: Article
• Language: English
• Subjects: Antibacterial agents; antibiotics; antifouling agents; Antifouling substances; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bacteria; Bacteria - drug effects; bacterial communities; Catalytic oxidation; Chlorides; Community composition; community structure; Consumer products; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental cleanup; Environmental Health; Environmental restoration; Environmental science; fabrics; Fertilizers; Food additives; Hydrogen-Ion Concentration; Microbial activity; Microbial Consortia - drug effects; Nanomaterials; Nanoparticles; Nanoparticles - toxicity; organic fertilizers; Organic soils; personal care products; Personal grooming; remediation; Research Article; Sewage - chemistry; Sewage sludge; Sludge; Soil - chemistry; soil bacteria; Soil mechanics; Soil Microbiology; Soil pH; Soil Pollutants - toxicity; Soil properties; Studies; Textiles; Toxicity; Waste Water Technology; Water Management; Water Pollution Control; zinc; Zinc - toxicity; Zinc Compounds; zinc oxide; Zinc Oxide - toxicity; Zinc oxides
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-015-4538-z

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.