Open Access2,4‐D impact on bacterial communities, and the activity and genetic potential of 2,4‐D degrading communities in soil
Author(s) -
Gonod Laure Vieublé,
MartinLaurent Fabrice,
Chenu Claire
Publication year - 2006
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2006.00159.x
Subject(s) - biology , microorganism , mineralization (soil science) , pesticide degradation , biodegradation , soil microbiology , stable isotope probing , pesticide , microbial population biology , bacteria , ecology , environmental chemistry , soil water , genetics , chemistry
The key role of telluric microorganisms in pesticide degradation is well recognized but the possible relationships between the biodiversity of soil microbial communities and their functions still remain poorly documented. If microorganisms influence the fate of pesticides, pesticide application may reciprocally affect soil microorganisms. The objective of our work was to estimate the impact of 2,4‐D application on the genetic structure of bacterial communities and the 2,4‐D‐degrading genetic potential in relation to 2,4‐D mineralization. Experiments combined isotope measurements with molecular analyses. The impact of 2,4‐D on soil bacterial populations was followed with ribosomal intergenic spacer analysis. The 2,4‐D degrading genetic potential was estimated by real‐time PCR targeted on tfdA sequences coding an enzyme specifically involved in 2,4‐D mineralization. The genetic structure of bacterial communities was significantly modified in response to 2,4‐D application, but only during the intense phase of 2,4‐D biodegradation. This effect disappeared 7 days after the treatment. The 2,4‐D degrading genetic potential increased rapidly following 2,4‐D application. There was a concomitant increase between the tfdA copy number and the 14 C microbial biomass. The maximum of tfdA sequences corresponded to the maximum rate of 2,4‐D mineralization. In this soil, 2,4‐D degrading microbial communities seem preferentially to use the tfd pathway to degrade 2,4‐D.