M12 PM Remediation
Monday, 14 November 2005: 1:50 PM - 5:30 PM in 345-346

(HUM-1117-752189) Long-term effects of phytoremediation and metal contamination on indigenous soil microbial communities at the Anaconda Smelter site in Anaconda, Montana.

Humphries, J.¹, Bens, C.², Cox, S.¹, Neuman, D.³, Zak, J.¹, Hooper, M.¹, ¹ Texas Tech University, Lubbock, TX, USA² National Wildlife Research Center, USDA-Fort Collins, CO, USA³ Montana State University, Bozeman, MT

ABSTRACT- While metal contamination inhibits several of the biogeochemical processes maintained by soil microbial communities, remediation and reclamation activities may further modify natural soil environments. Soil surrounding the Anaconda Smelter site, in southern Deer Lodge County, Montana, is severely contaminated with metals, including copper, cadmium, lead, zinc, and the metalloid arsenic. Significant phytoremediation and reclamation strategies were implemented at this site in the early 1990s to help stabilize the soil profile and prevent off-site movement of contaminated residues. Soils were collected from this site during the summers of 2000 and 2005, to characterize the impacts of reclamation activities on the soil microbial communities over time. Biolog microtiter plates were used to evaluate soil microbial community function through carbon substrate utilization. Non-metric multidimensional scaling (NMDS) analysis was used to compare the substrate utilization patterns (SUPs) and soil parameters (metal concentration, pH, % moisture content, % organic matter, soil nutrients) between remediated and unremediated soils. Over time, the soil bacterial SUPs in the remediated soils were significantly shifted relative to the SUPs in the unremediated soils. In addition, shifts in the number of substrates utilized by bacteria and in total bacterial activity was observed. Estimates of genetic components of biodiversity (e.g., community DNA extraction, PCR amplification of eubacterial and archea bacterial 16S rDNA, denaturant gradient gel electrophoresis (DGGE) and DNA sequencing of unique species) will be used next to monitor the shifts in microbial community structure following phytoremediation amendments which will potentially increase the resolution of observed treatment related effects.

Key words: phytoremediation, microbial communities, multivariate analysis, BIOLOG