Phylogenetic and functional biomakers as indicators of bacterial community responses to mixed-waste contamination.
Environ Sci Technol
; 40(8): 2601-7, 2006 Apr 15.
Article
em En
| MEDLINE
| ID: mdl-16683598
ABSTRACT
Few studies have demonstrated changes in community structure along a contaminant plume in terms of phylogenetic, functional, and geochemical changes, and such studies are essential to understand how a microbial ecosystem responds to perturbations. Clonal libraries of multiple genes (SSU rDNA, nirK, nirS, amoA, pmoA, and dsrAB) were analyzed from groundwater samples (n = 6) that varied in contaminant levels, and 107 geochemical parameters were measured. Principal components analyses (PCA) were used to compare the relationships among the sites with respect to the biomarker (n = 785 for all sequences) distributions and the geochemical variables. A major portion of the geochemical variance measured among the samples could be accounted for by tetrachloroethene, 99Tc, No3, SO4, Al, and Th. The PCA based on the distribution of unique biomarkers resulted in different groupings compared to the geochemical analysis, but when the SSU rRNA gene libraries were directly compared (deltaC(xy) values) the sites were clustered in a similar fashion compared to geochemical measures. The PCA based upon functional gene distributions each predicted different relationships among the sites, and comparisons of Euclidean distances based upon diversity indices for all functional genes (n = 432) grouped the sites by extreme or intermediate contaminant levels. The data suggested that the sites with low and high perturbations were functionally more similar than sites with intermediate conditions, and perhaps captured the overall community structure better than a single phylogenetic biomarker. Moreover, even though the background site was phylogenetically and geochemically distinct from the acidic sites, the extreme conditions of the acidic samples might be more analogous to the limiting nutrient conditions of the background site. An understanding of microbial community-level responses within an ecological framework would provide better insight for restoration strategies at contaminated field sites.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Bactérias
/
Microbiologia da Água
/
Poluentes Químicos da Água
/
Poluentes Radioativos da Água
/
Genes Bacterianos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Environ Sci Technol
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Estados Unidos