Skip to Main content Skip to Navigation
Journal articles

A soil microscale study to reveal the heterogeneity of Hg(II) impact on indigenous bacteria by quantification of adapted phenotypes and analysis of community DNA fingerprints

Abstract : Thr short term impact of 50 mu M Hg(II) on soil bacterial community structure was evaluated in different microenvironments of a silt loam soil in order to determine the contribution of bacteria located in these microenvironments to the overall bacterial response to mercury spiking. Microenvironments and associated bacteria, designated as bacterial pools, were obtained by successive soil washes to separate the outer fraction, containing loosely associated bacteria; and the inner fraction, containing bacteria retained into aggregates, followed by a physical fractionation of the inner fraction to separate aggregates according to their size (size fractions). Indirect enumerations of viable heterotrophic (VH) and resistant (Hg-R) bacteria were performed before and 30 days after mercury spiking. A ribosomal intergenic spacer analysis (RISA), combined with multivariate analysis, was used to compare modifications at the community level in the unfractionated soil and in the microenvironments. The spatial heterogeneity of the mercury impact was revealed by a higher increase of Hg-R numbers in the outer fraction and in the coarse size fractions. Furthermore, shifts in RISA patterns of total community DNA indicated changes in the composition of the dominant bacterial populations in response to Hg(TT) stress in the outer and in the clay size fractions. The heterogeneity of metal impact on indigenous bacteria, observed at a microscale level, is related to both the physical and chemical characteristics of the soil microenvironments governing mercury bioavailability and to the bacterial composition present before spiking.
Document type :
Journal articles
Complete list of metadata

https://hal.archives-ouvertes.fr/hal-00427100
Contributor : Stéphane Delmotte Connect in order to contact the contributor
Submitted on : Wednesday, October 28, 2009 - 4:47:35 PM
Last modification on : Tuesday, July 20, 2021 - 5:20:06 PM

Links full text

Identifiers

Collections

Citation

L. Ranjard, S. Nazaret, F. Gourbiere, J. Thioulouse, P. Linet, et al.. A soil microscale study to reveal the heterogeneity of Hg(II) impact on indigenous bacteria by quantification of adapted phenotypes and analysis of community DNA fingerprints. FEMS Microbiology Ecology, Wiley-Blackwell, 2000, 31 (2), pp.107-115. ⟨10.1111/j.1574-6941.2000.tb00676.x⟩. ⟨hal-00427100⟩

Share

Metrics

Record views

298