Evaluation of the effect of microorganisms in Arachis pintoi roots on the potential of copper absorption in land

Abstract

The research was carried out to evaluate the potential phytoextraction and phytostability of perennial peanut (Arachis pintoi) and to determine the influence of the isolated microorganisms from the root nodules of Arachis pintoi on coppercontaminated soil to improve the ability of treatment metal in soil pollution. Perennial peanuts were planted in the experimental pots which had unsterilized and sterilized soil. Different quanlities of CuSO4.5H2O were directly homogenized into sieved soil to formulate mixtures containing Cu in concentrations (mg/kg) of 200, 400 and 600. In addition, sterilized soil was contaminated by adding Cu with 400 mg/kg. The other pots had copper- contaminated sterilized soil and was added the isolated microorganisms from the root nodules of Arachis pintoi. Our results showed that the perennial peanut had high phytomass production and grew normally in the soil with 200 mg/kg of Cu. The copper accumulation was determined of 668.2, 107 and 561.2 mg/kg in the whole plant, roots and shoots, respectively in plants which were cultivated in the soil with 200 mg/kg of Cu. In the soil with 400 mg/kg and 600 mg/kg of Cu, the plants showed low biomass production and the plants had been poisonous. Both bioconcentration factors (BCF) and translocation factors (TF) were used to estimate a plant’s potential for the purpose of phytoremediation. The highest BCF and TF for Cu concentrations were 3.341 and 5.24 with 200 mg/kg of Cu, respectively. Both factors were higher than 1 therefore Archis pintoi is a potential plant for copper phytoextraction in copper contaminated sites at the concentration of 200-400 mg/kg. The isolated microrganism from the root nodules of Arachis pintoi on copper- contaminated soil was Burkholderia kururiensi PR1, which was a species of proteobacteria and stimulated plant growth. However, the result showed that Burkholderia kururiensi is unable to resistant to concentration of copper (25 mg/L). More research on the other isolated microorganisms of the root system to enhance the Cu accumulation in plants should be carried. Finally, these results showed the potential of the heavy metal phytoextraction of the perennial peanut in contaminated soil. It is easy to apply because of the low cost.