Biological remediation of polychlorinated biphenyls (PCB) in the environment by microorganisms and plants
The environment is suffering severe contamination as a result of various uncontrolled activities of man and chemicals in the biosphere. This widespread contamination of air, soil and water by metals, chemicals and metalloids causes environmental concerns, which if left unchecked will be detrimental to man and other organisms. Biological methods for the cleaning of the environment especially our soil have been receiving increasing attention especially in the past two decades. Bacteria and fungi have been the natural detoxification agents for contaminants in the environment. Recently, research has shown that with the combination of plants and microorganism in the right proportions and technique, detoxification of environmental contaminants will produce a desirable and better result and most importantly our natural environment may not be affected as some of the processes are environmentally friendly. However, hydrophobic organic molecules such as polychlorinated biphenyls (PCBs) tend to be much less responsive to bioremediation strategies. The wide spread presence of this compounds and other persistent organic pollutants (POPs), that share common chemical, toxicological and environment properties continues to increase in the environment, even with the various measures taken to control its presence. This review focuses on the possible trends in the remediation of PCBs in the environment and the methodologies applied. It also compares plants remediation as well as microorganisms’ degradation as biological detoxification agents of the compound. This will highlight the possible improvement measures on the combination of plants and microorganisms in bioremediation, thereby filling the gap left by the conventional methods of remediation with its limitations and disadvantages.
Key words: Bioremediation, phytoremediation, (PCB), biodegradation, environmental pollution, rhyzodegradation, dechlorination, contaminated soil.