Oil photo-oxidation can transform crude oil compounds into oxygenated compounds on the sea surface after an oil spill. While it was believed that photo-oxidation had only a minimal effect on the fate of oil, new research in the aftermath of Deepwater Horizon has shown oxidized photo-products form a much larger proportion of the total oil mass than previously understood. Still, the fate of these photoproducts, particularly how they are biodegraded, is not well known. A series of experimental treatments were prepared to compare the rates of biodegradation in seawater between photo-oxidized and non-photo-oxidized oil to further understand how natural microbial communities respond to weathered oil. Photo-oxidized and evaporated treatments were prepared, including sterile controls and no-oil controls. Over the course of four weeks, samples were collected and analyzed through quantification of hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), bulk polar and non-polar fractions, and flow cytometry. The results provided evidence that both types of oil can support bacterial growth and can therefore be biodegraded. Saturated compounds degraded extensively and to a greater extent than aromatic compounds in both types of oil. Oxygenated products were formed, potentially indicating the presence of biodegradation products. Overall, while photo-oxidation does not inhibit biodegradation of saturated hydrocarbons, the observed increase in oxygenated compounds indicates that these products may not be as readily degraded.

Biodegradation of photo-oxidized oil products: Implications for the fate of marine weathered oil spills

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.