title: Chemical dispersants: Oil biodegradation friend or foe?
abstract: Chemical dispersants were used in response to the Deepwater Horizon oil spill in the Gulf of Mexico, both at the sea surface and the wellhead. Their effect on oil biodegradation is unclear, as studies showed both inhibition and enhancement. This study addresses the effect of Corexit on oil biodegradation by alkane and/or aromatic degrading bacterial culture in artificial seawater at different dispersant to oil ratios (DORs). Our results show that dispersant addition did not enhance oil biodegradation. At DOR 1:20, biodegradation was inhibited, especially when only the alkane degrading culture was present. With a combination of cultures, this inhibition was overcome after 10days. This indicates that initial inhibition of oil biodegradation can be overcome when different bacteria are present in the environment. We conclude that the observed inhibition is related to the enhanced dissolution of aromatic compounds into the water, inhibiting the alkane degrading bacteria.
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, Wageningen, The Netherlands. Electronic address: shokouh.rahsepar@wur.nl.
authors.forename: Shokouh
authors.initials: S
authors.lastname: Rahsepar
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, Wageningen, The Netherlands.
authors.forename: Martijn P J
authors.initials: MP
authors.lastname: Smit
authors.affiliation: Marine Animal Ecology Group, Wageningen University, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
authors.forename: Albertinka J
authors.initials: AJ
authors.lastname: Murk
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, Wageningen, The Netherlands.
authors.forename: Huub H M
authors.initials: HH
authors.lastname: Rijnaarts
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, Wageningen, The Netherlands.
authors.forename: Alette A M
authors.initials: AA
authors.lastname: Langenhoff
mesh_terms: D000473:Alkanes / Q000378:metabolism; D001673:Biodegradation, Environmental; D008800:Mexico; D008962:Models, Theoretical; D059392:Petroleum Pollution / Q000032:analysis*; D016958:Pseudomonas putida / Q000378:metabolism*; D012240:Rhodococcus / Q000378:metabolism*; D012623:Seawater / Q000737:chemistry* / Q000382:microbiology; D012995:Solubility; D013501:Surface-Active Agents / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000473:Alkanes; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical
keywords: Biodegradation; Dispersant; Enhanced dissolution; Oil spill