Bioremediation, hydrocarbon depletion and microbial genetic diversity of antarctic oil-polluted soil

Abstract

Natural environments have been affected by oil spills around the world for decades. In some cases, the attempt to cleanup can be made using physical and chemical methods. However, for the Antarctic environments this is not so simple. Displacement of the machinery necessary for the application of physical methods would be very expensive whereas the application of chemical methods would be dangerous considering the risks of additional environmental impacts. Oil contamination of soils of EACF was caused by a tank rupture in the mid eighties in addition to little spills and intense use of motor vehicles. In some sites the presence of oil can be visually detected, which leads us to believe that a monitored natural attenuation is not feasible. Bioremediation techniques are relatively more cost-effective and benign. These techniques are based on the ability of some microorganisms (especially some bacteria) to use the petroleum hydrocarbons as energy source. However, before any implementation of bioremediation action, it is important to perform studies for the chemical and biological characterization of the contaminated soil. We are performing physical-chemical and microbiological studies of soil samples of Brazilian Antarctic Station contaminated with diesel. The results show an absence of Nitrogen in soil, the presence of high content of petroleum hydrocarbons and a depletion effect of the microbial diversity in polluted soil.