Stable Isotope-based in-situ Labelling as a Reference for the Isolation of relevant Styrene Degraders from Biofilters

The enrichment of styrene degrading microorganisms from biofilters resulted in a broad range of degrading isolates with unkown in situ relevance. For this reason an in situ labeling of styrene degrading microorganisms using deuterated styrene and phospholipid fatty acids as biomarkers prior to the isolation approach was performed. By this method the fatty acid profiles of the primary styrene degraders in the biofilters were identified. The comparison of labeled fatty acids with a fatty acid database gave first evidences for a systematic position of the taxa of interest. The fatty acid profiles of several isolates were compared with the set of labeled fatty acids derived from the original filter material. The correspondence of these biomarkers is a central criterium for the in situ relevance of the isolates. Additionally, the quantitative relevance of the isolates in the filter material was examined by fluorescently labeled rRNA -targeted probes. The combination of isotope-based in situ-labeling, fluorescence in situ hybridisation and enrichment methods allows for an extensive characterization of the primary styrene degraders in the biofilters investigated.