Category Archives: Nitrogen Fixation


Ecology of nitrogen fixers in the Pacific Ocean

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.

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Monteiro, F., S. Dutkiewicz, and M.J. Follows (2011), Biogeographical controls on the marine nitrogen fixersGlobal Biogeochemical Cycles, 25, GB2003, doi:10.1029/2010GB003902



Hot-Bunking’ Bacterium Recycles Iron to Boost Ocean Metabolism

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