title: The impact of zero-valent iron nanoparticles upon soil microbial communities is context dependent.
abstract: Nanosized zero-valent iron (nZVI) is an effective land remediation tool, but there remains little information regarding its impact upon and interactions with the soil microbial community. nZVI stabilised with sodium carboxymethyl cellulose was applied to soils of three contrasting textures and organic matter contents to determine impacts on soil microbial biomass, phenotypic (phospholipid fatty acid (PLFA)), and functional (multiple substrate-induced respiration (MSIR)) profiles. The nZVI significantly reduced microbial biomass by 29 % but only where soil was amended with 5 % straw. Effects of nZVI on MSIR profiles were only evident in the clay soils and were independent of organic matter content. PLFA profiling indicated that the soil microbial community structure in sandy soils were apparently the most, and clay soils the least, vulnerable to nZVI suggesting a protective effect imparted by clays. Evidence of nZVI bactericidal effects on Gram-negative bacteria and a potential reduction of arbuscular mycorrhizal fungi are presented. Data imply that the impact of nZVI on soil microbial communities is dependent on organic matter content and soil mineral type. Thereby, evaluations of nZVI toxicity on soil microbial communities should consider context. The reduction of AM fungi following nZVI application may have implications for land remediation.
authors.affiliation: School of Applied Sciences, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK. m.pawlett@cranfield.ac.uk
authors.forename: Mark
authors.initials: M
authors.lastname: Pawlett
authors.forename: Karl
authors.initials: K
authors.lastname: Ritz
authors.forename: Robert A
authors.initials: RA
authors.lastname: Dorey
authors.forename: Sophie
authors.initials: S
authors.lastname: Rocks
authors.forename: Jeremy
authors.initials: J
authors.lastname: Ramsden
authors.forename: Jim A
authors.initials: JA
authors.lastname: Harris
mesh_terms: D000538:Aluminum Silicates; D000077215:Clay; D005227:Fatty Acids / Q000032:analysis; D006090:Gram-Negative Bacteria / Q000187:drug effects; D007501:Iron / Q000494:pharmacology*; D053768:Metal Nanoparticles; D038821:Mycorrhizae / Q000187:drug effects; D010743:Phospholipids / Q000737:chemistry; D012822:Silicon Dioxide; D012988:Soil Microbiology; D012989:Soil Pollutants
chemical_list: D000538:Aluminum Silicates; D005227:Fatty Acids; D010743:Phospholipids; D012989:Soil Pollutants; D012822:Silicon Dioxide; D007501:Iron; D000077215:Clay