Home / Recent Researches / Bioremediation of Lead Contaminated Soil

Bioremediation of Lead Contaminated Soil


    Muhammad Faizan Ilyas*, Tahir Ilyas1 & Muhammad Asad Hameed.

    Department of Soil Science, University College of Agriculture, University of Sargodha, Pakistan.

    1University of Engineering and Technology, Kala Shah Kaku, Pakistan.


    Lead contamination is now becoming a global problem. The lead contamination occurs mainly through anthropogenic activities. Many of the developing countries have less availability of technologies required for dealing with the lead contamination. However removal of pollutants through bioremediation is cheap and reliable.  If lead is added to the soil, it ultimately becomes the part of food chain. High concentration of lead in environment is dangerous for plants, animals and humans. Methods used to remediate lead contamination in the soil are excavation, stabilization and bioremediation. Bioremediation is economical and environment friendly method. In bioremediation, microorganisms and plants are used for remediation. Soil microbes reduces the mobility and bioavailability of contaminants. Many Pb-resistant bacterial species e.g. Streptoverticillium cinnamoneum, Streptomyces rimosus, Pseudomonas putida and Bacillus sp. are capable of bioremediating the lead contaminated soil. Minimizing the release of lead into the environment is the best measure to control lead intoxication.


    *Corresponding Author: Muhammad Faizan Ilyas

    Department of Soil Science, University College of Agriculture, University of Sargodha, Pakistan.

    Email: faizanilyas007@gmail.com

    Key Words:

    Lead contamination, Pb-resistant bacteria, Bioremediation.


    Lead (Pb) is found in water, air and soil. It is distributed naturally in biologically inactive form. The use of lead in bearing metals, batteries, gasoline additives, cable covering, explosives, antifouling paints are major source of pollution. Increased number of vehicles caused to increase the use of lead containing fuels (Johnson, 1998).

    This metal is hazardous and highly poisonous to microbes, plants, animals and human s (Low et al., 2000). Bio-availability of lead can be hazardous for children and causes mental retardation. Lead may cause lethal effects on muscular, gastrointestinal, neurological and reproductive systems. It may enter into our body through ingestion of food and blood stream.  It disturbs the communication between cells and neuronal set up (Klassen and Watkins, 2003).  But extensive mining and smelting have resulted in soil contamination which poses risk to human and ecological health. Over 20 000 000 acres of farmland in China have been contaminated by Sn, Cr, Pb and Zn and other heavy metals, accounting for almost one fifth of the total arable farmland (Wang and Ma, 2008).

    Three methods are usually employed to remediate heavy metal contamination in the soil; Excavation-physical removal of the contaminated material, stabilization-amendment of the metals in the soil on site, and bioremediation including phytoremediation to uptake the metals from the soil (Usman and Mohamed, 2009). However, the application of first two methods is sometimes restricted due to technological or economical constrains (E. Plionsmits, 2005). It makes use of plants and their rhizospheric microbes to degrade or immobilize pollutants in soils (Wu et al., 2010). Soil microbes play significant roles in the process of bioremediation (Sheng et al., 2008).  They can absorb, transform, or degrade heavy metals and they also can reduce the mobility and bioavailability of contaminants (Wu et al., 2010). Microbes in rhizospheric soil can promote plants to accumulate extra heavy metals (Jiang et al., 2008).  Bacillus sp. has been identified as a possible candidate for metal sequestration.

    Many bacterial species are capable of bioremediating lead by biosoprtion like Streptoverticillium cinnamoneum, Streptomyces rimosus, Pseudomonas putida, Pseudomonas aeruginosa PU21 and Bacillus sp. (Chang et al., 1997; Uslu and Tanyol, 2006). The quantity of lead may be decreased by bacteria to producing complexes between acidic sites of cell wall and lead (Cabuk et al., 2006). The possible means comprise elimination by forming intra and extracellular sequestration, extracellular metal precipitation, a permeable barrier, active transport, dissolution of lead by acid production, enzymatic detoxification, precipitation of lead through the production of organic bases, and biotransformation reactions like volatilization, methylation, oxidation and reduction. Researchers have also found that Bacillus sp. L14 and Solanum nigrum L. could reduce the toxicity of metal by specifically uptaking up to 80.48% of Pb (II) within 24 h of incubation (Guo et al., 2010).

    Many coastal sites in the world are contaminated with toxic heavy metals due to anthropogenic activities (Dauvin, 2008). Biologically non-essential and toxic heavy metals viz. lead, cadmium and mercury released in aquatic and terrestrial environment persist indefinitely and eventually accumulate in the food chain and pose serious threat to the biota (Dauvin, 2008; Lombardi et al., 2010). Lead is mutagenic and teratogenic causing deleterious effects on biological systems viz. neurodegenerative impairment, renal failure, reproductive damage and cancer (Watt et al., 2000; Lam et al., 2007). Considering the severe toxic effect on humans, WHO has recommended <10 µg L-1 lead as safe permissible level in the drinking water (Watt et al., 2000). Heavy metal contaminated environments viz. soil, sediments and water create extreme conditions for microbial growth since they may adversely damage DNA, proteins and lipids and also replace essential metal ions from enzymes and proteins (Hartwig et al., 2002).

    Microbes possess various resistance mechanisms to withstand toxic levels of metals, which include efflux, reduction, oxidation, precipitation, extracellular sequestration and intracellular bioaccumulation (Borremans et al., 2001; De et al., 2008; Naik and Dubey, 2011). Intracellular metal bioaccumulation and homoeostasis in cell cytosol involves cysteine rich metallothionein proteins.

    Metallothioneins play an important role in immobilization of toxic heavy metals thereby protecting their enzyme catalyzed metabolic processes (Liu et al., 2003). Cyanobacterial and bacterial strains have been reported to possess metallothioneins e.g.  Synechococcus PCC 7942 (SmtA), Anabaena PCC 7120 and Pseudomonas putida (BmtA) to maintain cytosolic metal homoeostasis (Blindauer et al., 2002). Thus bacteria possessing metallothioneins are an ideal tool for bioremediation of heavy metal contaminated environmental sites.

    Minimizing the use of lead is the best measure to control lead intoxication therefore there is a need to develop and implement policies that facilitate the lead phase out at the earliest. Strong measures have been taken to control the use of lead in gasoline successfully in most of the developed countries during last 25 years (Needleman, 2000) and use of lead has been minimized in certain industries. However, strict measures have not yet been taken in most of the developing countries for minimizing the use of lead from industries (Loval and Magda, 1996).




    1. R. A. Usman and H. M. Mohamed, “Effect of Microbial inoculation and EDTA on the Uptake and Translocation of Heavy Metal by Corn and Sunflower,” Chemosphere, Vol. 76, August 2009, pp. 893-899.

    Blindauer, C.A., Harrison, M.D., Robinson, A.K., Parkinson, J.A., Bowness, P.W., Sadler, P.J., Robinson, N.J., 2002. Multiple bacteria encode metallothioneins and SmtA-like fingers. Mol. Microbiol. 45, 1421–1432.

    Borremans, B., Hobman, J.L., Provoost, A., Brown, N.L., van der Lelie, D., 2001. Cloning and functional analysis of thepbrlead resistance determinant of Ralstonia metallidurans CH34. J. Bacteriol. 183, 5651–5658.

    CABUK, A., AKAR, T., TUNALI, S. AND TABAK, O. 2006. Bio-sorption characteristics of Bacillus sp. ATS-2 immobilized in silica gel for removal of Pb.  Journal of Hazardous Materials, 136: 317-323.

    1. Y. Jiang, X.-F. Sheng, M.Qian and Q.-Y. Wang, “Iso-lation and Characterization of a Heavy Metal-Resistant Burkholderiasp. from Heavy Metal-Contaminated Paddy Field Soil and Its Potential in Promoting Plant Growth and Heavy Metal Accumulation in Metal polluted Soil,” Chemosphere, Vol. 72, No. 2, May 2008, pp. 157-164.

    CHANG, J.-S., LAW, R. AND CHANG, C.-C., 1997. Bio-sorption of lead, copper and cadmium by biomass of Pseudomonas aeruginosa PU21. Water Res., 31:1651– 8.

    Dauvin, J.-C., 2008. Effects of heavy metal contamination on the microbenthic fauna in estuaries: the case of the Seine estuary. Mar. Pollut. Bull. 57, 160–167.

    1. Plionsmits, “Phytoremediation,” Annual Review of Plant Physiology, May 2005, pp. 15-39.

    Fowler, B.A., 1998. Role of lead binding proteins in mediating lead bioavailability. Environ. Health Perspect. 106, 1585–1587.

    GUO, H., LUO, S., CHEN, L., XIAO, X., XI, Q., WEI, W., ZENG, G., LIU, C., WAN, Y., CHEN, J. AND HE, Y., 2010. Bioremediation of heavy metals by growing hyperaccumulaor endophytic bacterium Bacillus sp. L14. Bioresource Technology, 101: 8599–8605.

    Hartwig, A., Asmuss, M., Ehleben, I., Herzer, U., Kostelac, D., Pelzer, A., Schwerdtle, T., Burkle, A., 2002. Interference by toxic metal ions with DNA repair processes and cell cycle control: Molecular mechanisms. Environ. Health Perspect. 110, 797–799.

    JOHNSON, F.M., 1998. The genetic effects of environmental lead. Mutation Research, 410: 123 140.

    KLASSEN, C.D. AND WATKINS, J.B., 2003. Absorption, distribution and excretion of toxicants. Toxicology, 8:512-519.

    LIN, C.-C. AND LAI, Y.-T., 2006. Adsorption and recovery of lead (II) from aqueous solutions by immobilized Pseudomonas aeruginosa PU21 beads. J. Hazard. Mater., 137:99 – 105.

    Lombardi, P.E., Peri, S.I., Verrengia Guerrero, N.R., 2010. ALA-D and ALA-D reactivated as biomarkers of lead contamination in the fish Prochilodus lineatus. Ecotoxicol. Environ. Safety 73, 1704–1711.Loval, Magda, Phasing out Lead from Gasoline: WorldWide Experience and Policy Implementations, Environment Department, The World Bank, Washington, 1996.

    Loval, Magda, Phasing out Lead from Gasoline: World-Wide Experience and Policy Implementations, Environment Department, The World Bank, Washington, 1996.

    LOW, K.S., LEE, C.K. AND LIEW, S.C., 2000. Sorption of cadmium and lead from aqueous solution by spent grain. Process Biochemistry,36: 59-64.

    Needleman HL. The removal of lead from gasoline: historical and personal reflections.  Environ Res 2000;84(1):20-35.

    Naik, M., Dubey, S.K., 2011. Lead-enhanced siderophore production and alteration in cell morphology in a Pb-resistant Pseudomonas aeruginosa strain 4EA. Cur. Microbiol. 62, 409–414.

    Nies, D.H., 1999. Microbial heavy-metal resistance. Appl. Microbiol. Biotechnol. 51,730–750.

    1. L. Wang and X. Q. Ma, “Advance in the Research of Phytoremediation in Heavy Metal Contaminated Soils,” Subtrop Agricultural Research, Vol. 4, No. 1, February 2008, pp. 44-49.
    2. F. Sheng, J.-J. Xia, C.-Y. Jiang, L.-Y. He and M. Qian, “Characterization of Heavy Metal-Resistant Endophytic Bacteria from Rape (Brassica napus) Roots and Their Potential in Promoting the Growth and Pb Accumulation of Rape,” Environmental Pollution, Vol. 156, No. 3, December 2008, pp. 1164-1170.

    Tong, S., von Schirnding, Y.E., Prapamontol, T., 2000. Environmental lead exposure: a public health problem of global dimensions. Bullet. World Health Org. 78, 1068–1077.

    Watt, G.C.M., Britton, A., Gilmour, H.G., Moore, M.R., Murray, G.D., Robertson, S.J., 2000. Public health implications of new guidelines for lead in drinking water: a case study in an area with historically high water lead levels. Food Chem. Toxicol. 38, 73–79.


    About Staff

    This post is published by AgriHunt staff member. If you believe it should have your name please contact md@agrihunt.com

    Check Also


    Unserdstanding smog in Lahore

    Report Issue: * Suggest Edit Copyright Infringment Claim Article Invalid Contents Broken Links Your Name: …

    Leave a Reply

    Be the First to Comment!

    Notify of