Enrichment of MTBE degrading bacteria from gasoline contaminated subsurface soil

Biodegradation of methyl tert-butyl ether (MTBE) in aquifer material was studied during slurry enrichments (batch-systems) simulating in situ conditions. Soil samples taken at 4 different depths at a gasoline-contaminated site were used and the microbial population of each soil sample was separately enriched. The MTBE-degradation kinetics and the community dynamics as a response to different implemented in situ important parameters (e.g. additions of nutrients, addition of extra oxygen and presence of co-contaminants) were determined and compared between the different depths. In all enrichments the MTBE-biodegradation capacity was active for more than 600 days. PCR-DGGE fingerprints revealed that addition of extra nutrients or benzene did not lead to significant changes in the eubacterial population. No differences could also be observed between the community composition of the enrichment conditions after 1 year of incubation at different oxygen concentrations ( https://www.w3.org/1998/Math/MathML" display="inline"> 8 , 9.5 and https://www.w3.org/1998/Math/MathML" display="inline"> 11.5 m g / l D O ). In contrast, adding propane did induce differences in band intensity of the fingerprint. A different eubacterial community was observed at the 4 different examined depths.