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Soil Microorganisms and Nematodes for Bioremediation and Amelioration

1.4.3 MICROBIAL CONSORTIUM OF PLANT GROWTH PROMOTING

RHIZOBACTERIA (PGPR) FOR BIOREMEDIATION

Microorganisms and plants are used in bioremediation, which is a widely

acknowledged and successful in-situ technique of treating heavy metal

contaminated soils. A plant-based phytoremediation is a typical approach

of contaminated soil bioremediation. Bioremediation that incorporates

both microbes and plants provides a more efficient clean-up of heavy

metal-polluted soils. The effectiveness of this strategy, however, is highly

dependent on the type and efficiency of the organisms involved. Plant growth-

promoting rhizobacteria (PGPR) are bacteria that colonize the rhizosphere of

plants and stimulate plant development (Kloepper, 1978) Heavy metals may

be removed from the environment through phytostabilization, phytoextrac­

tion, rhizofiltration, and phytovolatilization (Kumar et al., 2021). The PGPR

has the potential to enhance the phytoremediation of heavy metals through

promoting plant growths, transforming heavy metals, and/or alleviating

heavy metal stress (Zhuang et al., 2007). A conceptual model for the role of

PGPR in phytoremediation of heavy metals has been depicted in Figure 1.2.

FIGURE 1.2 Mechanism of bioremediation of heavy metals through PGPR.

The interaction between arbuscular mycorrhizal fungi (AMF) and PGPR

have a synergistic effect on plant due to channelization of rhizospheric P

(Bhardwaj et al., 2014). Mishra et al. (2016) reported enhanced uptake of Fe

by plants in Fe contaminated soil under combined action of AMF and PGPR