Cell and Tissue Journal

Abstract Aim:The contamination of soil by crude oil is an important environmental problem. Bioremediation have gained more attention in recent years as a low-cost technique for pollutant removal. The aim of this research was to investigate the ability of rhizospheral fungal strains collected from plants grown in a petroleum-polluted soil using different concentrations of pollutant. Material and Methods: In this research rhizospheral fungal strains were collected from the plants grown in the Tehran refinery area and cultured on the PDA media containing different concentrations (0-15%) of crude oil.   Efficiency of removal for each isolated fungi was determined after one month. Results: Results showed that, all fungi were able to remove petroleum at the concentrations of 1, 2, 4 and 6% (P≤0.01). In addition all the fungi except Diplosporium sp. and Penicillium sp., were able to decrease crude oil at the concentrations of 8, 10 and 15% (P≤0.05). Conclusion: It was concluded that the studied fungi were able to remove the crude oil from the growth media. Since Aspergillus sp < /em>. was relatively more effective therefore this fungus has the highest bioremediation potency of petroleum polluted environments.

Abstract Aim: Plant-microbe interactions are considered to be important processes determining the efficiency of phytoremediation of petroleum pollution. The use of legume-Rhizobium is a suitable method for modification of petroleum-contaminated soil. The aim of this study was to evaluate the phytoremediation potential of Acacia– Rhizobium symbiosis in petroleum-polluted soil. Material and methods: The three-day acacia-seedlings were transferred to hydroponic medium and inoculated with rhizobium. Then, the 13-days seedlings transferred to polluted soil with different concentration of crude oil, that is; 0% as control and 1-5% (vol. /Wight), at the start and end of the 90-days period. Soil samples were analyzed for hydrocarbon removal (total hydrocarbon, n-tridecan, n-tetradecan and n-pantadecan) by GC-FID. Contents of Pb, Zn and Cd were measured with atomic absorption from soil and plant roots. The data were statistically analyzed with the help of SPSS11 and Duncan ‘test. Results: The results showed accumulation of heavy metal in plant roots and it’s reducing in soil. Hydrocarbon reduction was found over the course of the experiment in all treatments. The maximum removal was obtained in plants inoculated with rhizobium at 4% treatment, in which inoculated-acacia removed 97-100% of the hydrocarbons from soil. There fore inoculation Rubinia  pseudoacacia with Rhizobia are effective in removing TPHs and heavy metals from petroleum polluted soil. Conclusion: Based upon these results, Rubinia pseudoacacia L. inoculated with rhizobium can be used as lead and cadmium bioaccumulator in petroleum pollution and was selected for the phytoremediation of petroleum-contaminated soil.