title: Effect of 2,4,6-trinitrotoluene on soil bacterial communities.
abstract: To gain insight into the impact of 2,4,6-trinitrotoluene (TNT) on soil microbial communities, we characterized the bacterial community of several TNT-contaminated soils from two sites with different histories of contamination and concentrations of TNT. The amount of extracted DNA, the total cell counts and the number of CFU were lower in the TNT-contaminated soils. Analysis of soil bacterial diversity by DGGE showed a predominance of Pseudomonadaceae and Xanthomonadaceae in the TNT-contaminated soils, as well as the presence of Caulobacteraceae. CFU from TNT-contaminated soils were identified as Pseudomonadaceae, and, to a lesser extent, Caulobacteraceae. Finally, a pristine soil was spiked with different concentrations of TNT and the soil microcosms were incubated for 4 months. The amount of extracted DNA decreased in the microcosms with a high TNT concentration [1.4 and 28.5 g TNT/kg (dry wt) of soil] over the incubation period. After 7 days of incubation of these soil microcosms, there was already a clear shift of their original flora towards a community dominated by Pseudomonadaceae, Xanthomonadaceae, Comamonadaceae and Caulobacteraceae. These results indicate that TNT affects soil bacterial diversity by selecting a narrow range of bacterial species that belong mostly to Pseudomonadaceae and Xanthomonadaceae.
authors.affiliation: Unité de Génie Biologique, Université Catholique de Louvain, Place Croix du Sud 2/19, 1348 Louvain-la-Neuve, Belgium. isabelle.george@uclouvain.be
authors.forename: Isabelle
authors.initials: I
authors.lastname: George
authors.forename: Laurent
authors.initials: L
authors.lastname: Eyers
authors.forename: Benoît
authors.initials: B
authors.lastname: Stenuit
authors.forename: Spiros N
authors.initials: SN
authors.lastname: Agathos
mesh_terms: D001419:Bacteria / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004275:DNA, Ribosomal / Q000032:analysis / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000032:analysis / Q000235:genetics; D017422:Sequence Analysis, DNA; D012987:Soil / Q000032:analysis; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism / Q000494:pharmacology*; D013234:Stem Cells; D014303:Trinitrotoluene / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012987:Soil; D012989:Soil Pollutants; D014303:Trinitrotoluene