Microbial influence on metal mobility and application for bioremediation

Phytoextraction of soil cadmium and zinc by microbes-inoculated Indian mustard (Brassica juncea)

“…But only small fractions are in accessible form (in soil solution, as free metal ions and soluble metal complexes) and are readily available for plant uptake (Rao et al 2008). The substantial increase in bioavailabilty of Zn and Cd in response to bacterial and fungal inoculation, as observed in the present study, underlines the role of rhizospheric microbes in the synthesis of siderophores and chelators to solubilize and sequester metals from soil (Gadd 2004;Braud et al 2007). Microbial inoculation has also been observed to produce several organic acids and phytochelatins ensuring easy availability of metals to plants (Kamnev et al 2005), which in turn brings down the pH of soil towards acidic nature and thereby enhances metal bioavailability (Kunito et al 1998).…”

“…Phytoavailability of metals is strongly influenced by soil characteristics such as pH, cation exchange capacity (CEC), or organic matter content, any of which may limit successful soil remediation (Kayser et al 2000). One promising strategy to improve all these soil characteristics is microorganism-assisted phytoextraction, which rapidly ensures availability of metals by releasing compounds that can desorb metals from the soil matrix to form water-soluble metal complexes into the soil solution for plant uptake (Gadd 1993(Gadd , 2004Guo et al 1996;Jing et al 2007). Although recent studies have revealed that rhizospheric microorganisms are capable of enhancing metal phytoremediation (Carlot et al 2002;Abou-Shanab et al 2003a), as they are able to tolerate, survive and succeed when used in phytoremediation practices (Lucy and Glick 2004), the search for efficient plant-microbe interaction for this purpose is warranted.…”

Mercury affects the phylloplane fungal community of blueberry leaves to a lesser extent than plant age

“…Our aim in this study is not to push the system to known toxic levels or to test the effect of Hg on plant production. Many fungi can tolerate high concentrations of heavy metals, especially mycorrhizae (Orlowska et al 2013), and endophytes (Shen et al 2013) or as part of a microbial toolbox (Gadd 2004; Sprocati et al 2014) targeted for bioremediation. Instead, we selected ambient and elevated Hg values to better understand the effects of Hg atmospheric deposition on the fungal phylloplane community of a more natural system.…”

Use of Solid Waste from Thermoelectric Plants for the Cultivation of Microalgae

“…Mobilization is the process through which an initial insoluble state, corresponding to a solid phase, turns into a final soluble state in aqueous phase. Immobilization is the process through which an initial soluble state in aqueous phase turns into a final insoluble state in solid phase (Gadd 2004 …”