当前位置： SCI文献检索 > Frontiers in Microbiology期刊下所有文献 > Groundwater Isolation Governs Chemistry and Microbial Community Structure along Hydrologic Flowpaths.

Groundwater Isolation Governs Chemistry and Microbial Community Structure along Hydrologic Flowpaths.

Abstract：

:This study deals with the effects of hydrodynamic functioning of hard-rock aquifers on microbial communities. In hard-rock aquifers, the heterogeneous hydrologic circulation strongly constrains groundwater residence time, hydrochemistry, and nutrient supply. Here, residence time and a wide range of environmental factors were used to test the influence of groundwater circulation on active microbial community composition, assessed by high throughput sequencing of 16S rRNA. Groundwater of different ages was sampled along hydrogeologic paths or loops, in three contrasting hard-rock aquifers in Brittany (France). Microbial community composition was driven by groundwater residence time and hydrogeologic loop position. In recent groundwater, in the upper section of the aquifers or in their recharge zone, surface water inputs caused high nitrate concentration and the predominance of putative denitrifiers. Although denitrification does not seem to fully decrease nitrate concentrations due to low dissolved organic carbon concentrations, nitrate input has a major effect on microbial communities. The occurrence of taxa possibly associated with the application of organic fertilizers was also noticed. In ancient isolated groundwater, an ecosystem based on Fe(II)/Fe(III) and S/SO4 redox cycling was observed down to several 100 of meters below the surface. In this depth section, microbial communities were dominated by iron oxidizing bacteria belonging to Gallionellaceae. The latter were associated to old groundwater with high Fe concentrations mixed to a small but not null percentage of recent groundwater inducing oxygen concentrations below 2.5 mg/L. These two types of microbial community were observed in the three sites, independently of site geology and aquifer geometry, indicating hydrogeologic circulation exercises a major control on microbial communities.

journal_name

Front Microbiol

journal_title

Frontiers in microbiology

authors

Ben Maamar S,Aquilina L,Quaiser A,Pauwels H,Michon-Coudouel S,Vergnaud-Ayraud V,Labasque T,Roques C,Abbott BW,Dufresne A

doi

10.3389/fmicb.2015.01457

subject

Has Abstract

pub_date

2015-12-22 00:00:00

pages

1457

issn

1664-302X

journal_volume

pub_type

杂志文章

在线工具

Groundwater Isolation Governs Chemistry and Microbial Community Structure along Hydrologic Flowpaths.