Role of Plant Growth Promoting Rhizobacteria in Accumulation of Heavy Metal in Metal Contaminated Soil

Abstract

Heavy metal pollution by industrial, agricultural and municipal wastewater is a frequent phenomenon.Bioremediation is a biological process for cleaning up of pollutants from the environment.In the present study, B. megaterium and P. aeruginosa isolated from a weed Suaeda nudiflora at chemical polluted site from Ankleshwar, Gujarat was used for bioremediation.These isolates were characterized for their ability of metal assimilation like phosphorus and iron, and on the basis of their best assimilation ability, the isolates were selected for heavy metal tolerance like zinc and lead.B. megaterium and P. aeruginosa with highest heavy metal tolerance up to 200 mgl -1 were inoculated in maize plants by test tube inoculation method and analyzed for the growth promotion efficacy in heavy metal polluted soil.The plant inoculated with isolates showed 20% higher plant height, 20% longer root length and 5% greater dry weight as compared to non-inoculated control.Further analyses of leaves were carried out for the accumulation of heavy metal in maize.Results of the study showed positive growth response of maize on heavy metal polluted soil in green house condition and also accumulate a significant amount of zinc (587 mg kg-1) and lead (227 mg kg-1) in plants.The study concluded that the metal mobilizing PGPR could be used as an effective inoculant for improving the phytoremediation in multi-metal polluted soil, as well as for the reclamation of heavy metal polluted soil.