Nitrogen is an essential component of all cells. It is used to make the amino acid building blocks of proteins, and is also required in the nucleic acids of DNA and RNA. Although nitrogen extremely abundant in the open ocean, it is mostly found in dissolved N2 molecules that cannot be used by most phytoplankton, who require nitrogen in its reduced, or “fixed” forms, such as nitrate or ammonium.
In this study, Fanny Monteiro, Stephanie Dutkiewicz and Mick Follows, interpret the environmental controls on the global ocean diazotroph biogeography in the context of a three-dimensional global model with a self-organizing phytoplankton community.
Monteiro, F., S. Dutkiewicz, and M.J. Follows (2011), Biogeographical controls on the marine nitrogen fixers, Global Biogeochemical Cycles, 25, GB2003, doi:10.1029/2010GB003902
Iron is an essential nutrient for living things, but is scarce in the ocean. Darwin Project researchers Stephanie Dutkiewisz, Mick Follows and Fanny Monteiro, collaborating with a team from WHOI led by Mak Saito are reporting they have found that a key marine bacterium, Crocosphaera watsonii, may have evolved a remarkable biochemical way to recycle iron for dual metabolic activities. You can read more about this work in the following WHOI News Office release or in Saito et al (2011), a recent paper in PNAS.
Saito, M. A., E . M. Bertrand, S. Dutkiewicz, V. V. Bulygin, D. M. Moran, F. M. Monteiro, M. J. Follows, F. W. Valois, and J. B. Waterbury (2011), Iron conservation by reduction of metalloenzyme inventories in the marine diazotroph Crocosphaera watsonii.
Proc. Nat. Acad. Sci. doi: 10.1073/pnas.1006943108
Monteiro, F., M. J. Follows and S. Dutkiewicz (2010), Distribution of diverse nitrogen fixers in the global ocean, Global Biogeochemical Cycles, 24, GB3017, doi:10.1029/2009GB003731
Monteiro, F. and M. Follows (2009), On the interannual variability of nitrogen fixation in the subtropical gyres, Journal of Marine Research, 67, 1-20, doi: 10.1357/002224009788597944