@article {7488,
	title = {Dynamics of Heterocapsa sp. and the associated attached and free-living bacteria under the influence of dispersed and undispersed crude oil},
	journal = {Letters in Applied Microbiology},
	volume = {63},
	number = {6},
	year = {2016},
	month = {Aug 2016},
	pages = {419-425},
	abstract = {While many studies have examined the impact of oil on phytoplankton or bacteria, very few considered the effects on the biological complex formed by phytoplankton and their associated phytoplankton-attached (PA) and free-living (FL) bacteria. However, associated bacteria can affect the physiology of phytoplankton and influence their stress responses. In this study, we monitored the growth of\&nbsp;Heterocapsa\&nbsp;sp., an armoured dinoflagellate, exposed to crude oil, Corexit dispersant, or both. Growth of\&nbsp;Heterocapsa\&nbsp;sp. is unaffected by crude oil up to 25\&nbsp;ppm, a concentration similar to the lower range measured on Florida beaches after the Deepwater Horizon oil spill. The PA bacteria community was resistant to exposure, whereas the FL community shifted towards oil degraders; both responses could contribute to\&nbsp;Heterocapsa\&nbsp;sp. oil resistance. The growth rate of\&nbsp;Heterocapsa\&nbsp;sp. decreased significantly only when exposed to dispersed oil at 25\&nbsp;ppm, indicating a synergistic effect of dispersant on oil toxicity in this organism. For the first time, we demonstrated the decoupling of the responses of the PA and FL bacteria communities after exposure to an environmental stress, in this case oil and dispersant. Our findings suggest new directions to explore in the understanding of interactions between unicellular eukaryotes and prokaryotes.
Significance and Impact of the Study
In the environment, oil spills have the capacity to modify phytoplankton communities, with important consequences on the food web and the carbon cycle. We are just beginning to understand the oil resistance of phytoplankton species, making it difficult to predict community response. In this study we highlighted the strong resistance of\&nbsp;Heterocapsa\&nbsp;sp. to oil, which could be associated with its resilient attached bacteria and oil degradation by the free-living bacteria. This finding suggests new directions to explore in the understanding of oil impacts and interactions between eukaryotic and prokaryotic microbes.},
	url = {http://onlinelibrary.wiley.com/doi/10.1111/lam.12661/full},
	author = {Severin, T. and Bacosa, HP and Sato, A. and Erdner, DL}
}
