title: Enhancement of orimulsion biodegradation through the addition of natural marine carbon substrates.
abstract: Orimulsion is a bitumen-based heavy fuel that is a less expensive alternative to traditional fuel oils. However, because its density is intermediate between that of freshwater and seawater, in the event of a spill, the fuel could strand in the sediments. Previous work indicated that only 0.6-2.7% of the bitumen would degrade in long incubations of marine sediments. We added various natural carbon substrates to stimulate the degradation of bitumen by native populations of benthic bacteria. The concentration and carbon isotopic signature of the respired carbon dioxide was measured to partition the substrates that supported bacterial respiration. We found that the addition of seagrass and pinfish stimulated the degradation of bitumen by as much as 2-9-fold relative to incubations without these substrates. Biodegradation of bitumen may be enhanced by the addition of natural marine carbon substrates and may be a useful approach for bioremediation. Preadaptation of the bacteria to bitumen did not significantly enhance their ability to degrade it.
authors.affiliation: Department of Oceanography, Florida State University, Tallahassee 32306-4320, USA.
authors.forename: L M
authors.initials: LM
authors.lastname: Proctor
authors.forename: E
authors.initials: E
authors.lastname: Toy
authors.forename: L
authors.initials: L
authors.lastname: Lapham
authors.forename: J
authors.initials: J
authors.lastname: Cherrier
authors.forename: J P
authors.initials: JP
authors.lastname: Chanton
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D002244:Carbon / Q000378:metabolism*; D005399:Fishes; D005648:Fuel Oils / Q000032:analysis*; D019015:Geologic Sediments / Q000737:chemistry*; D006838:Hydrocarbons / Q000378:metabolism*; D010084:Oxidation-Reduction; D010944:Plants; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D005648:Fuel Oils; D006838:Hydrocarbons; D014874:Water Pollutants, Chemical; D002244:Carbon; C006647:asphalt