ORGANISMS - Identification and characterisation of microbial cultures degrading low concentrations of organic micropollutants
WP1 will use new isolation techniques to enrich and isolate degradative bacteria adapted to degradation at low micropollutant concentrations. It is hypothesised that use of oligotrophic media for isolation will result in enrichment of currently unknown bacteria better adapted to degradation at the low contaminant concentrations found in groundwater and surface water. To improve reliability and stability of bioaugmentation in water treatment the strains and communities obtained will be identified and characterised addressing key features of their genetic and physiological adaptation to survive and sustain metabolic activity under relevant environmental conditions. Other relevant environmental parameters potentially affecting bioaugmentation will be dealt with by introducing new criteria in the isolation and enrichment procedure, for example the ability to colonise surfaces, carrier materials and other relevant matrices. In parallel to the new enrichment strategies, culture collections already available from the partner laboratories will be screened for the presence of strains showing promising degradative activity towards the model micropollutants being examined under BIOTREAT.
Furthermore, WP1 will immobilise and encapsulate degrading bacteria on specifically designed carriers that complement the physiological and environmental requirements of the strains and thereby ensure their survival and sustained degradative activity. The carriers will provide the microorganisms with a stable microenvironment with necessary nutrients, e.g. phosphorus, nitrogen or organic carbon. Four strategies for design of carriers will be pursued: (I) Protection of degraders from predation; (II) Microniches favouring degrader activity; (III) Concentration of the micropollutants near the degraders; (IV) Tailor-made consortia for degrading multiple contaminants. Carriers will be designed that intersect several strategies (figure 1).
|Figure 1. Principle of carrier technologies showing four strategies for immobilisation of degrading bacteria on carriers