Responses of microbial community from northern Gulf of Mexico sandy sediments following exposure to deepwater horizon crude oil

• Published in: Environmental toxicology and chemistry 2012-05, Vol.31 (5), p.1004-1011
• Main Authors: Horel, Agota, Mortazavi, Behzad, Sobecky, Patricia A.
• Format: Article
• Language: English
• Subjects: Alabama; Alkanes - metabolism; Aromatic hydrocarbons; Bacteria - metabolism; Bathing Beaches; Beaches; Biodegradation; Biodegradation, Environmental; Carbon dioxide; Carbon Dioxide - metabolism; Crude oil; Deepwater Horizon; Diesel fuels; Gasoline - microbiology; Geologic Sediments - microbiology; Gulf of Mexico; Hydrocarbons; Hydrocarbons - metabolism; Macondo; Microbiology; Mineralization; Nitrogen - metabolism; Nutrients; Oil spill; Petroleum - metabolism; Petroleum - microbiology; Phosphorus - metabolism; Polycyclic aromatic hydrocarbons; Polycyclic Aromatic Hydrocarbons - metabolism; Seawater; Silicon Dioxide - chemistry; Water Microbiology
• ISSN: 0730-7268; 1552-8618
• DOI: 10.1002/etc.1770

In the present study, microbial community responses to exposure to unweathered Macondo Well crude oil and conventional diesel in a sandy beach environment were determined. Biodegradation was assessed in mesocosm experiments with differing fuel amounts (2,000 and 4,000 mg/kg) and with or without inorganic nutrient amendment. Carbon dioxide production was measured daily for 42 d. Aerobic alkane, total hydrocarbon, and polycyclic aromatic hydrocarbon (PAH) degraders were enumerated in treated and control mesocosms and changes in their abundances were measured weekly. Hydrocarbon mineralization occurred in all treatments. In the inorganic nutrient‐amended treatments, the degradation rates were 2.31 and 2.00 times greater in the 2,000 mg/kg diesel and crude oil treatments, respectively, and 3.52 (diesel) and 4.14 (crude) times higher for the fuel types at the 4,000 mg/kg fuel concentrations compared to unamended treatments. Microbial lag phases were short (