there was no direct relationship between both parameters (levels of in Hg contamination and DGGE profiles) found, especially in the water samples, perhaps because the Hg r concentrations by in all water samples were very low. However, the HgT concen- ions trations in the sediment samples were much higher than in the ides water samples, but there was still no correlation between the ind- Hgr concentration and the APB diversity. In contrast, use of soil microcosms spiked with inorganic Hg at 20 ug per gramof soil had a significant effect on soil microbial communities (Harris-Hellal et al., 2009).