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(48-02) Adaptation to toxicants and ecological functioning of communities of bacteria and algae. Boivin, Marie-Elene1, Massieux, Boris2, Van den Ende, Frank3, Breure, Anton*,1, Rutgers, Michiel1, 1 National Institute of Public Health and the Environment, Bilthoven, The Netherlands2 Netherlands Institute of Ecology, Maarssen, The Netherlands3 University of Amsterdam, Amsterdam, The Netherlands ABSTRACT- Due to human activities, the environment is exposed to a veil of contaminants spread over large areas. We investigate the effects of low concentrations of contaminants on the composition and functioning of microbial and algal communities. Bacteria are key organisms in aquatic ecosystems because they constitute a major part of the biomass and contribute to all nutrient cycles. Furthermore, microorganisms live in close contact with their environment and are therefore continuously exposed to contamination present. As bacterial communities live in close relation with algal communities the analysis of both trophic levels should shed a light on the consequences of bacterial community changes on the higher trophic algal level.This presentation focuses on the effect of contamination on the relationship between physiological and genetic adaptation and functioning of microbial communities in aquatic ecosystems as well as the relationship between the different trophic levels of bacteria and algae. We use different methods to analyse microbial communities. Physiological characterisation is performed using a community-level physiological profile (CLPP) and pollution induced community tolerance (PICT) approach, genetic changes are characterised using denaturing gradient gel electrophoresis (DGGE). PICT is also determined in algal communities.In this presentation the techniques and results will be discussed. Emphasis will be put on the relationship between different trophic levels, algae and bacteria, and also on the relationship between physiological and genetic characteristics of bacterial communities. The measurement of PICT at different trophic level and the further underpinning of the concept by other ecological parameters like community structure and ecosystem functioning will be discussed. Key words: metals, PICT, microbial community shifts, tolerance |
