The association of bacteria with phytoplankton is ubiquitous and underlined by fundamentally important interactions that shape their ecology and impact on global biogeochemical processes. Phytoplankton have been shown to harbour a diversity of hydrocarbonoclastic bacteria (HCB), yet it is not understood how these phytoplankton-associated HCB would respond in the event of an oil spill at sea. Here, we assess the diversity and dynamics of the bacterial community associated with a natural population of marine phytoplankton under oil spill-simulated conditions, and compare it to that of the free-living (non phytoplankton-associated) bacterial community. Whilst the crude oil severely impacted the phytoplankton population and was likely conducive to marine oil snow (MOS) formation, analysis of the MiSeq-derived 16S rRNA data revealed dramatic and differential shifts in the oil-amended communities that included blooms of HCB (Thalassospira, Cycloclasticus, Colwelliaceae, Methylophaga and other Piscirickettsiaceae, Marinomonas), including putative novel phyla, as well as other groups with previously unqualified oil-degrading potential (Olleya, Winogradskyella, and members of the inconspicuous BD7-3 phylum). Notably, the oil biodegradation potential of the phytoplankton-associated community exceeded that of the free-living community in its capacity to degrade a wider diversity of hydrocarbon crude oil constituents, particularly substituted and non-substituted polycyclic aromatic hydrocarbons. Our study provides evidence of compartmentalization of hydrocarbon-degrading capacity in the marine water column, wherein HCB associated with phytoplankton are better tuned to degrading crude oil hydrocarbons than that by the community of planktonic free-living bacteria. Hence, the influence of HCB associated with phytoplankton should be considered in future studies examining the microbial response and biodegradation of crude oil in marine environments.
- School of Engineering & Physical Sciences - Associate Professor
- School of Engineering & Physical Sciences, Institute of Mechanical, Process & Energy Engineering - Associate Professor
- Research Centres and Themes, Centre for Marine Biology and Biodiversity - Associate Professor
- Research Centres and Themes, Energy Academy - Associate Professor
Person: Academic (Research & Teaching)