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Insights into biodegradation through depth-resolved microbial community functional and structural profiling of a crude-oil contaminant plume

Microbial Ecology

By:
, , ,
DOI: 10.1007/s00248-014-0421-6

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Abstract

Small-scale geochemical gradients are a key feature of aquifer contaminant plumes, highlighting the need for functional and structural profiling of corresponding microbial communities on a similar scale. The purpose of this study was to characterize the microbial functional and structural diversity with depth across representative redox zones of a hydrocarbon plume and an adjacent wetland, at the Bemidji Oil Spill site. A combination of quantitative PCR, denaturing gradient gel electrophoresis, and pyrosequencing were applied to vertically sampled sediment cores. Levels of the methanogenic marker gene, methyl coenzyme-M reductase A (mcrA), increased with depth near the oil body center, but were variable with depth further downgradient. Benzoate degradation N (bzdN) hydrocarbon-degradation gene, common to facultatively anaerobic Azoarcus spp., was found at all locations, but was highest near the oil body center. Microbial community structural differences were observed across sediment cores, and bacterial classes containing known hydrocarbon degraders were found to be low in relative abundance. Depth-resolved functional and structural profiling revealed the strongest gradients in the iron-reducing zone, displaying the greatest variability with depth. This study provides important insight into biogeochemical characteristics in different regions of contaminant plumes, which will aid in improving models of contaminant fate and natural attenuation rates.

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Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Insights into biodegradation through depth-resolved microbial community functional and structural profiling of a crude-oil contaminant plume
Series title:
Microbial Ecology
DOI:
10.1007/s00248-014-0421-6
Volume
68
Issue:
3
Year Published:
2014
Language:
English
Publisher:
Springer
Contributing office(s):
National Research Program - Eastern Branch
Description:
10 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Microbial Ecology
First page:
453
Last page:
462
Number of Pages:
10
Country:
United States
State:
Minnesota
City:
Bemidji