bacteria communities degrading PCE

Precise characterisation of a contaminated site is essential to apply isotope enrichment factors for monitored natural attenuation to expect the grade of biodegradation. The aim of this study was to fortify site characterisation by compound specific isotope analysis of an anaerobic microcosm study to obtain isotope enrichment factors with 16S-rDNA analysis, degradation kinetic analysis and the influence of adsorption on the degradation process. The microcosm study comprised of eleven sediment samples taken from a geologically homogeneously looking site. Results showed two groups of isotope enrichment factors for PCE (-1.2‰, -6.4‰) and cis-DCE (-15.4‰, -28.2‰) besides one factor for TCE (-6.0‰) and VC (-27.8‰). Questioning the two groups suggested different microbial consortia consisting at least of Dehalogenimonas sp., Sedimentbacter sp., Desulfuromonas sp., Geobacter sp. and Pseudomonas sp., which were, as reported in literature, responsible for the partly complete degradation of PCE and its metabolites. In addition an increasing soil-water partitioning coefficient showed indication for enhancing the degradation of PCE.