By catalyzing biological transformations as cofactors of key enzymes, trace metals like iron and zinc play a critical role in the global cycles of major nutrients such as carbon, nitrogen and phosphorus. In some cases metals also inhibit these transformations. The principal long-term research theme of our group is the elucidation, at both the molecular and the global level, of the linkages between the cycles of trace metals and those of C, N and P. Human activities, such as the burning of fossil fuel and the production of fertilizers, have profoundly modified these cycles. One of our research goals is to understand how trace metals modulate the responses of ecosystems to these global changes.
A large part of our work deals with the oceans, focusing on the grand question of what physical and chemical factors control the growth and activity of phytoplankton in the sea. Marine phytoplankton are responsible for about half of global primary production and, by exporting organic matter to the deep sea, they maintain a low concentration of CO2 in surface waters and in the atmosphere. As detailed below, the elements of most interest to us in this part of our work (besides C, N & P) are cationic metals from the first and second row of the periodic table –manganese, iron, cobalt, copper, nickel, zinc and cadmium. A newer research activity in our group concerns the role of metals in the cycling of nitrogen in soils; there the focus is on metals found principally as oxoanions: molybdenum, vanadium and tungsten. The biogeochemical cycling of mercury, one of the most toxic elements in aquatic systems, is the subject of one of our long-standing research activities. Our main present interest is the formation of methylmercury, an organometallic compound that accumulates in aquatic food-chains.
We approach our work with a mix of laboratory and field experiments using a variety of chemical, microbiological, biochemical and genetic tools, as appropriate. Our work is also informed by theoretical considerations from a number of disciplines ranging from bioinorganic chemistry to geology and ecology.
Selected Recent Publications
- Xu Y., C.T. Supuran and F.M.M. Morel, Cadmium-carbonic anhydrase. In Handbook of Metalloproteins (Online Edition), Edited by A. Messerschmidt, John Wiley & Sons. (In press).
- Xu, Y., J. M. Boucher and F. M. M., Morel. Expression and diversity of alkaline phosphatase EHAP1 in Emiliania huxleyi (Prymnesiophyceae). Journal of Phycology . 46 : 85-92 (2010) DOI: 10.1111/j.1529-8817.2009.00788.x
- Egleston, E.S., C. L. Sabine and F. M. M. Morel. Revelle Revisited: Buffer factors that quantify the response of ocean chemistry to changes in DIC and alkalinity. Global Biogeochemical Cycles Vol. 24, GB1002, (2010) DOI: 10.1029/2008GB003407
- Shi, D., Y. Xu, B.M. Hopkinson, and F.M.M. Morel. Effect of ocean acidification on iron availability to marine phytoplankton. Science 327: 676-679 (2010) (10.1126/science.1183517)
- Shi, D*., Y. Xu* and F. M. M. Morel. Effects of the pH/pCO2 control method in the growth medium of phytoplankton. Biogeosciences 6: 1199-1207 (2009) (the asterisk indicates equal contributions)
- Hopkinson, B. and F. M. M. Morel. The role of siderophorres in iron acquisition by phtosynthetic marine microorganisms. Biometals. 22:659-669 (2009). DOI: 10:1007/s10534-009-9235-2
- Kraepiel, A.M.L., J.P. Bellenger, T. Wichard and F. M. M.Morel. Multiple roles of siderophores in free-living nitrogen-fixing bacteria. Biometals. 22:573-581 (2009). DOI: 10.1007/s10534-009-9222-7
- Wichard, T., J.P. Bellenger, F. M. M. Morel and A.M.L. Kraepiel. Role of the siderophore azotobactin in the bacterial acquisition of nitrogenase metal cofactors. Environmental Science & Technology. 43: 7218-7224 (2009) DOI:10.1021/es8037214
- Milligan A.J., C. E. Mioni and F. M. M. Morel. Response of cell surface pH to pCO2 and iron limitation in
the marine diatom Thalassiosira weissflogii. Marine Chemistry. 114: 31-36 (2009) DOI: 10.1016/j.marchem.2009.03.003
- Schaefer, J.K., and F. M. M. Morel. High methylation rates of mercury bound to cysteine by Geobacter sulfurreducens. Nature Geoscience. (2009)
- Castruita, M., Y. Shaked, L.A. Elmegreen, E.I. Stiefel and F.M.M. Morel, Availability of iron from iron storage proteins to marine phytoplankton. Limnology & Oceanograpy, 53(3): 890-899 (2008).
- Egleston, E., F.M.M. Morel, Interactions between metals in urea-grown diatoms. Limnology & Oceanography, 53(6): 2462-2471 (2008).
- Ekstrom, E. and F.M.M. Morel, Cobalt limitation of growth and mercury methylation in sulfate reducing bacteria. Environmental Science & Technology, 42(1): 93-99 (2008). DOI: 10.1021/es0705644
- McGinn, P.J. and F.M.M. Morel, Expression and inhibition of the carboxylating and decarboxylating enzymes in the photosynthetic C4 pathway of marine diatoms. Plant Physiology,146: 1-10 (2008). DOI: 10.1104/pp.107.110569
- McGinn, P.J. and F.M.M. Morel, Expression and regulation of carbonic anhydrases in the marine diatom thalassiosira pseudonana and in natural phytoplankton assemblages from Great Bay, New Jersey. Physiologia Plantarum, 133: 78-91 (2008). DOI: 10.1111/j.1399-3054.2007.01039.x
- Morel, F.M.M., A.B. Kustka, and Y. Shaked, The role of unchelated Fe in the iron nutrition of phytoplankton. Limnology & Oceanography, 53(1): 400-404 (2008).
- Morel, F.M.M. The co-evolution of phytoplankton and trace element cycles in the oceans. Geobiology, 6(3): 318-324 (2008). DOI: 10.1111/j.1472-4669.2008.00144.x
- Park, H., P.J. McGinn and F.M.M. Morel, Expression of the Cadmium Carbonic Anhydrase of Diatoms in Seawater. Aquatic Microbial Ecology, 51: 183-193 (2008). DOI: 10.3354/ame01192
- Xu Y., L.Feng, P.D. Jeffrey, Y.G. Shi and F.M.M Morel, Structure and metal exchange in the cadmium carbonic anhydrase of marine diatoms. Nature, 452: 56-61 (2008) . DOI: 10.1038/nature06636