Crude oil spills in the environment, effects and some innovative clean-up biotechnologies

Crude oil, refined petroleum products, as well as polycyclic aromatic hydrocarbons are ubiquitous in various environmental compartments. They can bioaccumulate in food chains where they disrupt biochemical or physiological activities of many organisms, thus causing carcinogenesis of some organs, mutagenesis in the genetic material, impairment in reproductive capacity and / or causing hemorrhage in exposed population. The cause / effect of oil pollutant are usually quantified by using biological end point parameters referred to as biomarkers. Contamination of soil arising from spills is one of the most limiting factors to soil fertility and hence crop productivity These deleterious effects make it mandatory to have a counter measure for the petroleum hydrocarbon pollutant in the environment. Bioremediation of petroleum hydrocarbon-contaminated environment is, a potentially important application of Environmental Biotechnology. In this approach microorganisms are utilized under some specified conditions to ameliorate the negative effects in a cost-effective and environmentally friendly approach. The main strategies in bioremediation of oil spills, which include bio-stimulation, nutrient application, bio-augmentation, seeding with competent or adapted hydrocarbono-clastic bacteria or their consortium, and genetically engineered microbes, are reviewed. Although the promise of bioremediation is yet to be realized, innovative areas in Environmental Biotechnology for oil spill clean up are highlighted.