title: Molecular approach to evaluate biostimulation of 1,2-dibromoethane in contaminated groundwater.
abstract: This study investigated the effect of co-substrate amendments on EDB biodegradation under aerobic conditions. Microcosms were established using contaminated soil and groundwater samples and maintained under in situ conditions to determine EDB degradation rates, and the diversity and abundance of EDB degrading indigenous bacteria. After 100days of incubation, between 25% and 56% of the initial EDB was degraded in the microcosms, with added jet fuel providing highest degradation rates (2.97±0.49yr(-1)). In all microcosms, the quantity of dehalogenase genes did not change significantly, while the number of BTEX monooxygenase and phenol hydroxylase genes increased with jet fuel amendments. These results indicate that EDB was not degraded by prior dehalogenation, but rather by cometabolism with adapted indigenous microorganisms. This is also reflected in the history of the plume, which originated from an aviation gasoline pipeline leak. This study suggests that biostimulation of EDB is possible at aerobic groundwater sites.
authors.affiliation: Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: Kyunghwa
authors.initials: K
authors.lastname: Baek
authors.forename: Robert
authors.initials: R
authors.lastname: McKeever
authors.forename: Kahlil
authors.initials: K
authors.lastname: Rieber
authors.forename: Diane
authors.initials: D
authors.lastname: Sheppard
authors.forename: Chul
authors.initials: C
authors.lastname: Park
authors.forename: Sarina J
authors.initials: SJ
authors.lastname: Ergas
authors.forename: Klaus
authors.initials: K
authors.lastname: Nüsslein
mesh_terms: D001419:Bacteria / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D001483:Base Sequence; D001673:Biodegradation, Environmental; D058645:Denaturing Gradient Gel Electrophoresis; D015946:Ethylene Dibromide / Q000378:metabolism*; D005798:Genes, Bacterial / Q000235:genetics; D060587:Groundwater / Q000737:chemistry*; D006867:Hydrolases / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical; D015946:Ethylene Dibromide; D006899:Mixed Function Oxygenases; C022336:phenol 2-monooxygenase; D006867:Hydrolases; C046137:haloalkane dehalogenase