Microbial‐Enhanced Phytoremediation of Lead Contaminated Calcareous Soil by Centaurea cyanus L

Microbe‐assisted phytoremediation is a promising technology for remediation of potentially toxic element contaminated soils. A greenhouse study was conducted to assess the effect of Pseudomonas spp. and Glomus spp. on phytoremediation of a Pb‐contaminated calcareous soil by Centaurea cyanus L. The study was carried out as a factorial experiment arranged in a randomized complete block design with three replications. Factors are microbial inoculation in three levels (mix inoculation with Glomus spp. or Pseudomonas spp. and non‐inoculated) and four Pb concentrations (0, 250, 500, and 1000 mg kg−1) in soil. The results revealed that microbial inoculation significantly increased the shoot dry weight and Pb accumulation in C. cyanus compared to non‐inoculated plants. Comparison of microbial treatments indicated that higher shoot Pb concentration, shoot modified bioconcentration factor (shoot mBCF, 5.33–5.63) and translocation factor (TF, 1.09–1.2) are obtained for Pseudomonas spp. inoculation, while higher plant biomass, plant Pb accumulation, root Pb concentration, root mBCF (5.91–6.46) and lower TF (0.77–0.99) are recorded for Glomus spp. inoculation. These results show that Pseudomonas spp. and Glomus spp. are more effective in phyotoextraction and phytostabilization of Pb by C. cyanus, respectively. It could be concluded that Pseudomonas spp. and Glomus spp. would be a promising strategy in bioremediation of Pb‐contaminated soils, especially at medium levels of soil Pb contamination (250 and 500 mg kg−1). This study is carried out to assess the effect of microbial inoculation on phytoremediation of Pb‐contaminated soil by Centaurea cyanus L. The Pb‐contaminated soil is inoculated with arbuscular mycorrhizal fungi (AMF, a mixture of Glomus sp.) and plant‐growth‐promoting rhizobacteria (PGPR, a mixture of Pseudomonas sp.). AMF and PGPR significantly increases phytostabilization and phytoextraction of Pb by C. cyanus, respectively.