Chlorinated aromatics are among the most abundant pollutants world-wide. In the previous decades various microorganisms capable to transform or even mineralize a broad range of chloroaromatics have been isolated, however, metabolism in-situ is still poorly understood and bioremediation processes or strategies like natural attenuation, enhanced natural attenuation or bioaugmentation are still unpredictable. Taking into account the knowledge on aromatic degradation pathways accumulated in the last 50 years and the advancements in the development of molecular tools, it is clear that we are entering a new area, which will allow us to follow microbial communities and their relevant functions in diverse environments under in-situ conditions. Integrative knowledge from culture independent studies based on functional characters and assessment of the diversity and quantity of catabolic genes in response to pollution, will allow a deepened understanding of environmental processes.
We have now developed culture independent methods, specifically single stranded chain polymorphism analysis, to follow catabolic key genes and their diversity in environmental samples and will report on rieske-type non-heme iron oxygenases and ring-cleavage dioxygenase diversity in model communities and polluted environments.
However, all sequence based approaches are depending on knowledge accumulated from isolates and broad new information is still arising from isolates. We will report on a new chloroaromatic metabolic route, which, beside a key enzyme belonging to a thus far uncharacterized group of hydrolases, comprise enzymes only distantly related to enzymes of aromatic degradation.