Abstract
Indigenous bacterial populations play an important role in the restoration of crude oil-polluted marine environments. The identification and characterization of these bacteria are key in defining bioremediation strategies for the mitigation of possible future oil spills. In this work, we characterized Pseudomonas aeruginosa strain GOM1, which was isolated from the water column in the southwestern Gulf of Mexico. Phylogenetic analysis revealed that GOM1 strain was most closely related to P. aeruginosa WC55, a strain isolated from the northern Gulf of Mexico after the Deepwater Horizon oil spill. The hydrocarbon-degrading capacity of P. aeruginosa GOM1 was investigated using various approaches. This strain degraded 96% of the aliphatic fraction (C12-C38) of crude oil during a 30-day incubation period, exhibiting a high activity on long-chain alkanes, and expressing alkane hydroxylases AlkB1, AlkB2 and AlmA. Addition of nitrogen and phosphate to seawater culture medium enhanced hexadecane degradation by GOM1. Additionally, the strain exhibited high surfactant/rhamnolipid production and emulsifying activity when grown in a complex medium in the presence of hexadecane. Comparisons of growth kinetics, hydrocarbon degradation and gene expression between GOM1 and the closely related P. aeruginosa laboratory strain PAO1 revealed that the marine isolate is better adapted to degrade alkanes. Taken together, our results place P. aeruginosa GOM1 as a potentially effective candidate to be included in a consortium for use in the bioremediation of oil-polluted sites.
Highlights
Oil spills severely affect many different ecosystems due to the high toxicity and recalcitrance of crude oil in the environment
We reported the bacterial diversity from different sediments in the southwestern Gulf of Mexico (swGoM), and identified several specialized hydrocarbon-degrading genera at a basal level, whose population size could potentially increase during an oil spill (Godoy-Lozano et al, 2018)
We became interested in the isolation of bacterial consortia and species indigenous to the swGoM, to study their metabolic capabilities in hydrocarbon degradation
Summary
Oil spills severely affect many different ecosystems due to the high toxicity and recalcitrance of crude oil in the environment. Various strategies have been used for the restoration of crude oil-contaminated sites, among which bioremediation is considered a more efficient and ecofriendly alternative, compared to physical and chemical treatments (Mapelli et al, 2017). Hydrocarbon-Degrading Marine Pseudomonas aeruginosa bioremediation is usually done by endogenous microbial populations (fungi, microalgae, and bacteria) present in crude oil-polluted sites, playing an important role in the degradation of contaminants and contributing to the restoration of the environment. Marine environments hold hydrocarbon-degrading bacteria in low abundance (Godoy-Lozano et al, 2018), but oil spills trigger blooms of such populations, exhibiting a bacterial succession according to the type of hydrocarbons present. Colwellia and Cycloclasticus taxa were enriched at high concentrations of aromatic hydrocarbons, which occurred 43 days after the spill once the partial capture of oil and gas was performed (Dubinsky et al, 2013)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
