title: Tungsten effects on microbial community structure and activity in a soil.
abstract: Tungsten, once deposited onto a soil as a result of private, industrial, and military activities, may persist as tungstate anion or, via polymerization, as a variety of poly-tungstate species, each with varying solubility and soil sorption characteristics. In this study, the impact of weathered tungsten on a soil microbial community was measured. Fatty acid analyses indicated that weathered tungsten at < or =2500 mg kg(-1) was associated with a significant increase in microbial biomass and that concentrations up to 6500 mg kg(-1) did not result in a significant decrease in measured biomass, relative to the control. Analysis of cellular fatty acids also identified significant microbial community shifts between 0 and 325, 1300 and 2600, and 3900 and 6500 mg W kg(-1) soil. In general, the positive effect of tungsten on microbial biomass coincided with an increase in Gram-negative bacterial fatty acids, whereas fatty acids indicative of actinomycetes and Gram-positive bacteria were more abundant at the highest soil tungsten concentrations. The weathered tungsten also inhibited N2 fixing activity of a free living diazotroph at > or =1300 mg W kg(-1) soil. These results indicate that tungsten in soil can alter both the structure and the function of an indigenous soil microbial community.
authors.affiliation: US Army ERDC-CRREL, 72 Lyme Rd., Hanover, NH 03755, USA. David.B.Ringelberg@usace.army.mil
authors.forename: D B
authors.initials: DB
authors.lastname: Ringelberg
authors.forename: C M
authors.initials: CM
authors.lastname: Reynolds
authors.forename: L E
authors.initials: LE
authors.lastname: Winfield
authors.forename: L S
authors.initials: LS
authors.lastname: Inouye
authors.forename: D R
authors.initials: DR
authors.lastname: Johnson
authors.forename: A J
authors.initials: AJ
authors.lastname: Bednar
mesh_terms: D000114:Acetylene / Q000378:metabolism; D016948:Azotobacter vinelandii / Q000187:drug effects*; D015415:Biomarkers; D018533:Biomass; D005227:Fatty Acids / Q000032:analysis; D006368:Helianthus / Q000254:growth & development; D009586:Nitrogen Fixation; D010084:Oxidation-Reduction; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000494:pharmacology*; D014414:Tungsten / Q000494:pharmacology*
chemical_list: D015415:Biomarkers; D005227:Fatty Acids; D012989:Soil Pollutants; D000114:Acetylene; D014414:Tungsten