Microorganisms are key organisms in the recycling of carbon in ecosystems. Not only do they recycle organic carbon produced from photosynthesis, but they are also responsible for the biodegradation of man-made organic pollutants which are introduced into the environment as a result of industrial and domestic wastewater discharges. An understanding of how microorganisms respond to pollutant stress is key to understanding how polluted environments function. While pollutants may affect an environment adversely by exerting toxic effects on the microbial population, those microorganisms capable of degrading the pollutant in question would be expected to increase in numbers as a result of pollutant discharges. DNA probe methodology will be used to address the dynamics of microbial adaptation to discharges organic pollutants, using polynuclear aromatic hydrocarbons (PAHs) as models. These relatively new methods permit the identification of and enumeration of microorganisms responsible for biodegradation of organic pollutants. By examining the genes which code for the underlying metabolic precesses. Knowledge of the numbers and activities of biodegrading microorganisms in the environment is key to designing effective bioremediation strategies. In this clean-up method, the natural capabilities of microorganisms are used to remove organic pollutants in an environmentally safe way with minimal physical disturbance to the environment.
