Hydrocarbon-degrading bacteria and the bacterial community response in Gulf of Mexico beach sands impacted by the Deepwater Horizon oil spill.. Contaminated Sand

This study was performed to identify and characterize predominant oil-degrading taxa that may be employed as model hydrocarbon-degraders or as microbial indicators of contamination, and to characterize the in situ response of indigenous bacterial communities to oil contamination in beach ecosystems. This study was conducted at municipal Pensacola Beach, Florida, where chemical analysis revealed petroleum hydrocarbon (C8-C40) concentrations ranging from 3.1 to 4500 mg kg-1 in beach sands. Bacterial community composition and structure was assessed in Pensacola Beach sands from multiple sampling time points, multiple depths and locations across the beach face, and with varying levels of oil contamination. Pyrotag sequencing of bacterial small subunit ribosomal RNAs (SSU rRNAs) and SSU rRNA genes was performed using multiplexed, bar-coded primers targeting the V1-V3 region of the bacterial SSU rRNA. These data were used to (a) track microbial community composition in association with oil contamination, (b) compare cultivation-independent results with cultivation of hydrocarbon-degrading bacteria from the same site, and (c) identify key microbial taxa correlating with the presence of oil contamination in beach sands.