1. Bioremediation of hazardous pollutants

In the last two centuries, a series of technological advances provided significant benefits to human health, food production, housing, comfort, transport, and tourism. These human activities demand the development of new chemicals, materials and enormous quantities of energy, exploit natural resources and createlarge amounts of human made waste polluting the environment. Pollution of the soil, water, and air originates from a variety of sources and continues to be a major issue all around the world. Due to release of enormous quatities of organic and inorganic compounds as a result of the burning fossil fuels, mining activites, industrial and domestic wastes (sewage sludge/wastewater) and unhygienic approach of rapidly growing population, the environment has suffered multiple detrimental effects. Pollutants released from human activities are linked to ecological disasters such as acid rains and global warming. Contaminated ecosystems are causing impacts on plants, microorganisms, aquatic organisms and life support functions such as immobilization, mineralization and nitrification that is ultimately affecting human health as well as the health of the ecosystem. Therefore, the present situation demands urgent action to restore the proper functioning of biogeochemical cycles, which is the driving force behind life on our planet. Biogeochemical cycles are driven by the metabolic activity of microbial communities able to prevent pollutants from reaching the biosphere.

The remediation of a polluted environment can be attempted through conventional or biological measures. The selection and application of remedial procedures depend on the type and extend of the contamination. Scientists are reaching on a consensus to decrease the release of pollutants and to ameliorate their effects by bioremediation. The bioremediation methods are considered as efficient, environmental friendly and cost-effective alternatives to physicochemical treatment technologies for remediation of contaminated ecosystems. Advantagous features of bioremediation over conventional remediation methods include:

•    Elimination rather than transfer of the contaminants to another medium

•    Minimizing exposure of workers to the contaminants

•    Requiring low energy

•    Possible reduction in the duration of the remediation process

•    Lower cost

•    Less or no harm to ecosystem.