Phytoextraction of heavy metal polluted soils using Sedum plumbizincicola inoculated with metal mobilizing Phyllobacterium myrsinacearum RC6b

Abstract

h i g h l i g h t sIsolated Phyllobacterium myrsinacearum RC6b effectively mobilized metals in soils. RC6b inoculation enhanced growth and Cd and Zn uptake of Sedum plumbizincicola. Possible mechanisms are plant beneficial activities and soil metal mobilization. RC6b is a good candidate for microbially assisted phytoremediation. a r t i c l e i n f o t r a c tThe aim of this study was to investigate the effects of metal mobilizing plant-growth beneficial bacterium Phyllobacterium myrsinacearum RC6b on plant growth and Cd, Zn and Pb uptake by Sedum plumbizincicola under laboratory conditions. Among a collection of metal-resistant bacteria, P. myrsinacearum RC6b was specifically chosen as a most favorable metal mobilizer based on its capability of mobilizing high concentrations of Cd, Zn and Pb in soils. P. myrsinacearum RC6b exhibited a high degree of resistance to Cd (350 mg L À1 ), Zn (1000 mg L À1 ) and Pb (1200 mg L À1 ). Furthermore, P. myrsinacearum RC6b showed multiple plant growth beneficial features including the production of 1-aminocyclopropane-1-carboxylic acid deaminase, indole-3-acetic acid, siderophore and solubilization of insoluble phosphate. Inoculation of P. myrsinacearum RC6b significantly increased S. plumbizincicola growth and organ metal concentrations except Pb, which concentration was lower in root and stem of inoculated plants. The results suggest that the metal mobilizing P. myrsinacearum RC6b could be used as an effective inoculant for the improvement of phytoremediation in multi-metal polluted soils.

Combined remediation of Cd–phenanthrene co-contaminated soil by Pleurotus cornucopiae and Bacillus thuringiensis FQ1 and the antioxidant responses in Pleurotus cornucopiae

“…Similar results were reported in studies of cadmium accumulation in Juncus subsecundus and Sedum alfredii (Li and Wong, 2012). Previous studies reported that inoculation of metalresistant bacteria could increase the metal accumulation in plants (Chen et al, 2014;Ma et al, 2013), and organic pollutant-degrading bacterial inoculation also could enhance plants to accumulate more heavy metals . The increased metal accumulation by mushrooms after inoculation of metal-resistant microbes also have been reported (Ji et al, 2012;Jing et al, 2012).…”

Rhizobacteria ofPopulus euphraticaPromoting Plant Growth Against Heavy Metals

“…Similar phenomenon was reported before when phytochelatins increased long-distance root-to-shoot Cd 2+ transport and reduce Cd 2+ accumulation in roots (Gong, Lee and Schroeder 2003). Recently, Ma et al (2013) also reported an isolated strain of Phyllobacterium myrsinacearum RC6b effectively mobilized metals in soils and the RC6b inoculation enhanced growth and Cd and Zn uptake of Sedum plumbizincicola. In addition, Wang et al (2011) demonstrated that Agrobacterium radiobacter D14, which secreted the indole acetic acid and siderophore, increased the As tolerance of P. deltoides by promoting growth, increasing uptake efficiency, and enhancing As translocation.…”

Cultivable endophytic bacteria from heavy metal(loid)-tolerant plants

“…Mineral phosphate solubilization activity was assayed according to Kuklinsky-Sobral et al (2004). Indoleacetic acid (IAA) production was analyzed using a modified qualitative method (Ma et al 2013), and the ability of nitrogen fixing was estimated according to Mohan and Rajendran (2014). After being treated with Salkowski reagent for 30 min, appearance of a pale pink ring on the filter paper from LB medium was positive for the IAA assay.…”