BIOREMEDIATION OF COPPER CONTAMINATED SOIL USING RHIZOSPHERE AND ROOT NODULE BACTERIA

Abstract

Increased industrialization and urbanization have led to heavy metal contamination newlineof the soil. It is the matter of great concern in recent times as it poses threat to all newlinelife forms. The existing physical and chemical remediation approaches for these newlinetoxic substances are too expensive and eco-unfriendly. Hence, the focus has been newlineshifted towards more feasible, eco-friendly and cost-effective remediation newlineapproaches. Biological remediation is one such naturally driven technology with newlinethe potential to overcome the drawbacks of other physical and chemical treatment newlinemethods. It is well known that the metal contaminated site harbours natural metaltolerant newlinemicrobial population that are capable of accumulating and immobilizing newlinethe metals from the contaminated environment and restrict their availability to the newlineother living beings. In recent times, endophytic bacteria too are gaining an newlinealarming attention in bioremediation of heavy metal contaminated soils. Keeping newlinethis in view, in the present study an attempt has been made to investigate the newlinebioremediation and phytoremediation potential of copper-tolerant bacteria isolated newlinefrom rhizosphere soil of Cynodon dactylon L. grown in brass effluent contaminated newlinesoil. Likewise, root nodule endophytic bacteria isolated from a leguminous plant newline(Vigna unguiculata L.) grown in uncontaminated soil was also explored for its newlinecopper bioremediation and phytoremediation potential. Copper-tolerant newlinerhizobacteria and root nodule endophytic bacteria showing good plant growth newlinepromoting factors (PGPF) and higher copper removal potential were chosen for newlinethe construction of phytoextraction system with plants Helianthus annuus L. var. newlineCO4 and Vigna unguiculata L. var. RS Gomati, respectively. The efficiency of newlinephytoextraction system was evaluated through seed germination, plant length, newlinechlorophyll, plant biomass and copper accumulation in the plant tissues. newlineTotal six copper-tolerant rhizobacterial colonies were isolated on nutrient media newlineafter enrichment in copper (II) sulphate (50 to 600 mg/L).