Impact of heavy metal contamination on oxidative stress of Eisenia andrei and bacterial community structure in Tunisian mine soil

Abstract

The aims of this work were firstly to study the effect of heavy metal-polluted soils from Tunisian mine on earthworm biochemical biomarkers and on bacterial communities and therefore to analyze the interaction between earth worms and bacterial communities in these contaminated soils. For this purpose, we had introduced earthworm Eisenia andrei in six soils: one from mine spoils and five from agricultural soils, establishing a gradient of contamination. The response of worms to the presence of heavy metal was analyzed at the biochemical and transcriptional levels. In a second time, the impact of worm on bacterial community structure was investigated using automated ribosomal intergenic spacer analysis (ARISA) fingerprinting. An impact of heavy metal-contaminated soils on the oxidative status of E. andrei was observed, but this effect was dependent of the level of heavy metal contamination. Moreover, our results demonstrate that the introduction of earthworms E. andrei has an impact on bacterial community; however, the major change was observed in the less contaminated site. Furthermore, a significant correlation between earthworm oxidative status biomarkers and bacterial community structure was observed, mainly in the mine spoils. Therefore, we contribute to a better understanding of the relationships between epigenic earthworms and bacterial communities in heavy metal-contaminated soils.

Evidence of the Genotoxic Effect of Aloin on Earth Worms Eisenia Andrei

“…For a correct assessment of soil contamination, the use of bioassays to quickly screen exposure and to show potential effects of contaminants is mandatory. Due to their life-style, earthworms are the first to be exposed to soils contaminants and, therefore, an environmental pollutant occurs earlier and their harmful effects are more evident than in other organisms [6,26,27]. To our knowledge, this is the first study that aims to investigate the effects of aloin exposure on DNA alterations in a species that is relevant to soil ecology.…”

Enhancement of phytoremediation efficiency of Acacia mangium using earthworms in metal-contaminated soil in Bonoua, Ivory Coast

“…corethrurus can probably reduce the mobile form of metal while increase its stable form in the rhizosphere (Lemtiri et al, 2016, Boughattas et al, 2017. Boughattas et al, (2018) justified the decrease of Pb concentration in Acacia biomass under earthworm treatment by the fact that earthworm can reduced the amount of Pb associated with the soluble and exchangeable fraction.…”

“…Previous studies have reported the interactive role of earthworms in improving plant growth in noncontaminated soils (Braga et al, 2016). In addition to this, the benefit effect of earthworms in the remediation of metal contaminated soil has been very well demonstrated in numerous research (Boughattas et al, 2017(Boughattas et al, , 2018Lv et al, 2016;Lemtiri et al, 2016), but only few studies have been conducted to assess their role in improving plant metal uptake during phytoremediation in contaminated soils (Kaur et al, 2017).…”

Heavy metals pollution potentials in the National Iron Ore Mining Company, Itakpe

“…Sequential extraction is refers to the identification and quantification of the diverse distinct species, phases or forms that the metals occur [12]. It is sometimes referred to as Speciation, Fractionation or Selective extraction.…”