عنوان مقاله [English]
Biosorption is a most effective technology for the removal of such toxic substances as heavy metals. The objective of this study was four-fold: 1) to isolate lead resistant Pseudomonas strains, 2) to determine the optimal conditions of their growth, 3) to obtain the minimum inhibitory concentration of lead, and 4) to evaluate the bioremoval of lead from culture solutions. For the purposes of this study, oil-contaminated wastewater samples were collected from Khuzestan region and transferred to laboratory where they were homogenized and serially diluted up to 10-10 with sterile saline before they were cultured in Luria Bertani agar medium containing 5ppm of lead nitrate. Resistant strains were then isolated at 37°C for 24h. The samples were subsequently cultured in Macconkey agar for isolation of appropriate gram negative strains. Biochemical tests were used to identify the bacteria, 10 strains of which were screened as lead resistant ones from all the 24 isolates. The bacterial colonies were selected and tested with different concentrations (100- 2100 ppm) of lead for their resistance. The plates were then incubated at 37ºC for 24h and Mso1 was chosen from among the lead resistant colonies for further experiments. This strain showed resistance to chloramphenicol (30µg) and erythromycin (15µg) when subjected to the antimicrobial susceptibility test. Optimal growth conditions included a temperature of 40°C at 100 rpm and a pH level of 6 in the presence of lead by spectrophotometry at 600nm. Absorption tests showed that the Mso1 strain had a metal removal efficiency of 38.45% from an aqueous solution containing 100 ppm of lead over 24h. The results confirmed the capability of Pseudomonassp in the bioremediation of Pb-contaminated wastewaters.
10. Huang, Q., Chen, W., and Theng, B.K.G. (2008). “Role of bacteria and bacteria-soil composites in metal biosorption and remediating toxic metal-contaminated soil systems.” In: Soil mineral microbe-organic interaction, Springer Berlin Heidelberg, Pub., Berlin.
11. Abyar, H., Safahieh, A., Zolgharnian, H., and Zamani, A. (2012). “Survey of cadmium ions biosorption by Achromobacter piechaudii isolated from Persian Gulf sediments.” J. of Oceanography, 10, 19-25.
12. Perez, R.M., Albus, A., Gomez, J.M., and Cantero, D. (2007). “Biosorption of heavy metals by Pseudomonas aeruginosa isolated from petroleum contaminated site.” J. of Advanced Materials Research, 20, 615-618.
13. Edward raja, C., Anbazhagan, A., and Sadasivam selvam, G. (2006). “Isolation and characterization of a metal resistant Pseudomonas aeruginosa strain.” World J. of Microbiology and Biotechnology, 22, 577-585.
14. Volesky, B., and Holan, Z.R. (1995). “Biosorption of heavy metals.” J. of Biotechnology Progress,
15. Zolfaghari, M., Soleymani, D.M., Masodikhah, M., Motlagh, M., and Heydarpoor, A. (2012). “Prevalence and antimicrobial resistance of chromium-bearing microorganisms in industrial wastewaters of Qom.” Medical Sciences of Qom University, 6, 15-23. (In Persian)
16. Morello, J.A., Granato, P.A., and Mizer, H.E. (2002). Laboratory manual and workbook in microbiology,
7th Ed., McGraw Hill, N.Y.
17. Barati, B. (2005). Microbiology laboratory, Tehran University, Tehran. (In Persian)
18. Mohamadi, M. (2001). Notes on microbiology laboratory, Tehran University, Tehran. (In Persian)
19. Johncy Rani, M., Hemambika, B., Hemapriya, J., and Rajesh Kannan, V. (2010). “Comparative assessment of heavy metal removal by immobilized and dead bacterial cells: A biosorption approach.” African J. of Environmental Science and Technology, 4(2), 77-83.
20. Khorasani, H. (2013). “Biosorption of chromium and lead by Pseudomonas spp related to Khuzestan oil contaminated soils.” M.Sc. Thesis, I.A.U., Tonekabon Branch. (In Persian)
21. Fotoohi, S.H. (2011). “Evaluation of cadmium removal from waste of Angouran's lead and zinc by native isolated bacterial strains.” M.Sc. Thesis, I.A.U., Tonekabon Branch. (In Persian)
22. Leung, W.C., Wong, M-F., Chua, H., Lo, W., Yu, P.H.F., and Leung, C.K. (2000). “Removal and recovery of heavy metals by bacteria isolated from activated sludge treating industrial effluents and municipal wastewater.” J. of Water Science and Technology, 41(12), 233-240.
23. El Bestawy, E., Abu Rass, M., and Abdel-Kawi, M.A. (2013). “Removal of lead and oil hydrocarbon from oil refining-contaminated wastewater using Pseudomonas spp.” J. of Natural Sciences Research, 3(11),
24. Kumar, A., Singh, B., and Datt, V. (2010). “Biosorption of heavy metals by four acclimated microbial species, Bacillus spp., Pseudomonas spp., Staphylococcus spp. and Aspergillus niger.” J. of Biol. Environ. Sci., 4(12), 97-108.
25. Durga Devi, B., Thatheyus, A.J., and Ramya, D. (2012). “Bioremeoval of hexavalent chromium, using Pseudomonas Fluorescens.” J. of Microbiol. Biotech. Res., 2(5), 727-735.
26. Srivastava, J., Chandra, H., Tripathi, K., Naraian, R., and Sahu, R.K. (2008). “Removal of chromium (VI) through biosorption by the Pseudomonas spp. isolated from tannery effluent.” J. of Basic Microbiol.,
27. Sadeeshkumar, R., Saranraj, P., and Annadurai, D. (2012). ”Bioadsorption of the toxic heavy metal chromium by using Pseudomonas putida.” Int. J. of Res. in Pure and Applied Microbiol., 2(4), 32-36.
28. Xiao-xi, Z., Jian-xin, T., Xue-duan, L., and Pei, J. (2009). “Isolation, identification and characterization of cadmium-resistant Pseudomonas aeruginosa strain E1.” J. of Central South University, 16, 416-426.
29. Heshmatipour, Z. (2008). Practical Microbiology, Ketab Mir Pub., Tehran. (In Persian)