Aerobic biodegradation of methyl tert-butyl ether by aquifer bacteria from leaking underground storage tank sites.
The potential for aerobic methyl tert-butyl ether (MTBE) degradation was investigated with microcosms containing aquifer sediment and groundwater from four MTBE-contaminated sites characterized by oxygen-limited in situ conditions. MTBE depletion was observed for sediments from two sites (e.g., 4.5 mg/liter degraded in 15 days after a 4-day lag period), whereas no consumption of MTBE was observed for sediments from the other sites after 75 days. For sediments in which MTBE was consumed, 43 to 54% of added [U-(14)C]MTBE was mineralized to (14)CO(2). Molecular phylogenetic analyses of these sediments indicated the enrichment of species closely related to a known MTBE-degrading bacterium, strain PM1. At only one site, the presence of water-soluble gasoline components significantly inhibited MTBE degradation and led to a more pronounced accumulation of the metabolite tert-butyl alcohol. Overall, these results suggest that the effects of oxygen and water-soluble gasoline components on in situ MTBE degradation will vary from site to site and that phylogenetic analysis may be a promising predictor of MTBE biodegradation potential.
Kane
S R
SR
Lawrence Livermore National Laboratory, Livermore, California 94550, USA. kane11@llnl.gov
Beller
H R
HR
Legler
T C
TC
Koester
C J
CJ
Pinkart
H C
HC
Halden
R U
RU
Happel
A M
AM
D000332:Aerobiosis; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D004269:DNA, Bacterial / Q000032:analysis; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D005618:Fresh Water / Q000382:microbiology*; D008738:Methyl Ethers / Q000378:metabolism*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D014881:Water Supply
D004269:DNA, Bacterial; D008738:Methyl Ethers; D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical; C043243:methyl tert-butyl ether