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Keywords:

Pollutant degrading microbial biofilms, micropollutants

Abstract:

The worldwide use of organic xenobiotics ultimately leads to the contamination of a wide range of water bodies like rivers, lakes and aquifers with organic micropollutants. The concentrations at which these contaminants are detected in water bodies are in the µg to ng per liter range. Bacterial strains and consortia able to degrade xenobiotic compounds like pesticides have been isolated from various ecosystems and are considered catalysts of interest for pollutant removal from water. However the situation of the extremely low concentrations at which they occur has been suggested to pose a challenge for efficient biodegradation of the pollutant. In this study, we examined in which way the degradation activity of a multi-species microbial consortium, consisting of three bacterial strains which synergistically mineralize the phenylurea herbicide linuron and other linuron degrading bacterial strains, are affected when grown with linuron provided at micropollutant concentrations. The cultures were grown either in suspension or as a biofilm in continuous flow chambers. Linuron degrading strains and consortia showed in both systems the resilience to remove low concentrations of linuron. The linuron degrading consortium was able to form biofilms on low linuron concentrations down till 10 µg/L. From these results we conclude that the use of pollutant degrading microbial biofilm communities shows real promise in remediating micropollutants in polluted waters for example in biofilter systems.