Environmental Biotechnlogy
EJB Electronic Journal of Biotechnology ISSN: 0717-3458 Vol.2 No.1, Issue of April 15, 1999.
© 1999 by Universidad Católica de Valparaíso -- Chile
REVIEW ARTICLE

Feasible biotechnological and bioremediation strategies for serpentine soils and mine spoils

Majeti Narasimha Vara Prasad*
Departamento de Botânica, Faculdade de Ciências e Tecnologia da Universidade de Coimbra, 3000 Coimbra, Portugal
Permanent address: Department of Plant Sciences, School of Life Sciences
University of Hyderabad, Hyderabad 500046; Fax: +91-040-3010120/3010145

Email: mnvsl@uohyd.ernet.in

Helena Maria de Oliveira Freitas
Departamento de Botânica, Faculdade de Ciências e a Tecnologia da Universidade de Coimbra, 3000 Coimbra, Portugal
Fax: 351-039-820780, Tel: 351-039-822897
E-mail: hfreitas@cygnus.ci.uc.pt

* Corresponding author

Key words: Metalliferous soils, Rhizosphere, Mycorrhizae, Genetic engineering, Metal sequesteration, Metal hyperaccumulators, Metal tolerant plants

* MNVP is thankful to the Fundação para a Ciência e Tecnologia, Ministério da Ciencia de Tecnologia, Portugal for awarding visiting fellowship (December 1998 to February 1999).

Abstract Full Text

Reclamation of metalliferous areas is a priority field of biogeochemistry of trace elements. Ultramafic outcrops rich in heavy metals have been mapped in different parts of the world. Heavy metals are potentially cytotoxic, caricinogenic and mutagenic. Environment protection agencies and legislations insisting the mine operators to restore the mine spoils and tailings since the metal leachates have serious implications in production of healthy agricultural products. Hence, restoration of mine spoils, tailings and metalliferous soils is a challenging task for the well being of Humans. Synthetic and natural zeolites have been used as chelators for rapid mobility and uptake of metals from contaminated soils by plants. Use of synthetic chelators significantly increased Pb and Cd uptake and translocation from roots to shoots facilitating phytoextraction of the metals from low grade ores. Contrastingly, synthetic cross linked polyacrylates, hydrogels have protected plant roots from heavy metals toxicity and prevented the entry of metals into roots. However, application of these synthetics on large scale may not be a practical solution due to exorbitant costs. Therefore, introduction of metal tolerant wild plants to metalliferous soils, genetic engineering of plants for enhanced synthesis and exudation of natural chelators into the rhizosphere, improvement of the rhizosphere with the help of mycorrhiza and integrated management of the metalliferous ecosystem following the principles of phytoremediation are discussed in this paper.

 

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