Current Projects

Ecology and Evolution of Microbial Interactions in a Changing Ocean

Prochlorococcus is the most abundant photosynthetic organism on earth, but it has an Achilles heel- it can't get rid of the reactive oxygen products like hydrogen peroxide that are produced from photosynthesis. Prochlorococcus relies on 'helper' bacteria such as Alteromonas to clean up hydrogen peroxide.


However in an experiment in the lab we found that under ocean acidification predicted for 2100, Alteromonas decreased it's expression of a gene, catalase, that cleans up hydrogen peroxide. (Hennon et al. 2018)

These results led us to wonder if something similar would happen in a complex natural community.

Ambient CO2
Ambient CO2

Elevated CO2
Elevated CO2

Ambient CO2
Ambient CO2


(Hennon et al. 2018 ISME Journal)

Leaving Bermuda
CTD deployment
On deck incubations

We are studying how many potential 'helper' bacteria are in the natural community around Bermuda and whether they have similar responses to ocean acidification as Alteromonas in culture. We will also investigate whether there are wild pre-adapted Prochlorococcus strains that can handle predicted changes in dissolved carbon dioxide without experiencing  oxidative stress or whether there are other phytoplankton groups such as Synechococcus that are likely to increase in abundance.

This work is supported by the National Science Foundation (NSF) and made possible by collaboration with researchers at the Bermuda Institute of Ocean Sciences (BIOS) and the captain and crew of the R.V. Atlantic Explorer.