Maria T. (Maite) Maldonado
Tier 2 Canada Research Chair/ Assistant Professor

B.Sc. 1991. Biology/Marine Sciences. Smith College, Northampton, MA
Ph.D. 1999. Biology, McGill University, Montreal, Canada
Postdoctoral: University of California at Santa Cruz, Princeton University, University of Maine (Orono)

Faculty Member: UBC 2003 -

Telephone: (604) 822-4198

mmaldonado
@eos.ubc.ca

- Physiological mechanisms and regulation of trace metal acquisition by marine phytoplankton;
- The role of trace metal availability in controlling the ecology and evolution of marine phytoplankton and bacteria;
- Interactive effects of N metabolism and Fe acquisition in microorganisms;
- The role of the biota in controlling biogeochemical cycles of trace elements in the ocean;
- Trace elements regulation of harmful algal blooms;
- Substitution of trace metals in Fe-limited marine phytoplankton and bacteria;
- Elucidating the mechanistic link between variations in glacial-interglacial oceanic Fe bioavailability & phytoplankton assemblages, and the potential impact of phytoplankton productivity/assemblages in past and present climate.

Marine phytoplankton play an important role in the global C cycle by contributing to the export of C from surface waters to the deep ocean. Over the last decade, it has become clear that insufficient Fe inputs limit phytoplankton growth and C export in 30% of the world’s ocean. To improve our understanding of the C cycle and its effect on the climate, it is thus critical to investigate the metabolic pathways that control uptake and utilization of Fe by marine microorganisms. My research aims to addresses fundamental questions in microbial physiology and trace metal biogeochemical distribution and cycling. In particular, my research investigates the physiological mechanisms and regulation of Fe acquisition by marine phytoplankton and bacteria, as well as trace metal nutrition of Fe-limited microorganisms. My research approach is multidisciplinary, combining cell physiology, ecology, and ocean biochemistry, and applying state-of-the -art analytical techniques to the study of marine microbial/algal processes. Laboratory physiological investigations of trace metal nutrition and acquisition mechanisms by marine phytoplankton and bacteria are complemented with field research in Fe-limited regions, such as in the Subarctic Pacific and the Southern Ocean, in order to elucidate the occurrence of these physiological mechanisms in the ocean.

Maldonado, M.T., M.P. Hughes, E.L. Rue, & M.L. Wells. 2002. The effect of Fe and Cu on growth and domoic acid production by Pseudo-nitzschia multiseries and Pseudo-nitzschia australis. Limnology and Oceanography, 47: 515-526.

Maldonado, M.T., P.W. Boyd, R. Strzepek, J.L. LaRoche, A. Waite, P.L. Croot, & N.M. Price. 2001. Phytoplankton physiological responses to changing iron chemistry during a mesoscale Southern Ocean iron-enrichment. Limnology and Oceanography, 46: 1802-1808

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Maldonado, M.T., & N.M. Price. 2001. Reduction and transport of organically bound iron by Thalassiosira oceanica (Bacillariophyceae). Journal of Phycology, 37: 298-310.

Bowie, A.R., M.T. Maldonado, R.D. Frew, P.L. Croot, E.P. Achterberg, R.F.C. Mantoura, P.J. Worsfold, C.S. Law, & P.W. Boyd. 2001. The fate of added iron during a mesoscale fertilisation experiment in the polar Southern Ocean. Deep-Sea Research II, 48: 2703-2743.

Abraham, E.R., C.S. Law, P.W. Boyd, S.J. Lavender, & M.T. Maldonado, A. R. Bowie. 2000. The horizontal stirring of an iron-fertilized phytoplankton bloom. Nature 407: 727-730.

Boyd, P.W. et al. 2000. Phytoplankton bloom upon mesoscale iron fertilization of polar Southern Ocean waters. Nature 407: 695-702.

Maldonado, M.T., & N.M. Price. 2000. Nitrate regulation of iron reduction and transport in Fe-limited Thalassiosira oceanica. Limnology and Oceanography 45: 815-826.

Maldonado, M.T., & N.M. Price. 1999. Utilization of iron bound to strong organic ligands by plankton communities in the subarctic Pacific Ocean. Deep-Sea Research II 46: 2447-2473.

Tortell, P.D., M.T. Maldonado, J. Granger, & N.M. Price. 1999. Heterotrophic bacteria and Fe cycling in the oceans (Invited review). FEMS Microbiology Ecology 29: 1-11.

Maldonado, M.T., & N.M. Price. 1996. Influence of N substrate on Fe requirements of marine centric diatoms. Marine Ecology Progress Series 141: 161-172.

Tortell, P.D., M.T. Maldonado, & N.M. Price. 1996. The role of heterotrophic bacteria in iron-limited ocean ecosystems. Nature 383: 330-332.

Invited Presentations at Conferences

Maldonado MT (2002) Fe acquisition strategies in marine microorganisms.
Gordon Research Conference, Chemical Oceanography, Ocean chemistry
interactions with biological systems, Oxford, UK.

Maldonado MT, and Price NM (2000) The role of ferric chelate reductases in
Fe acquisition by a marine diatom. Ocean Sciences Meeting, San Antonio, TX,
USA.

Maldonado MT (1999) Reduction and transport of Fe bound to siderophores by
marine diatoms. Center for Environmental Bioinorganic Chemistry Workshop,
Princeton University, NJ, USA.

Price NM, Maldonado MT , and Granger J (1997) Utilization of complexed Fe by
eukaryotic marine phytoplankton. Gordon Conference, NH, USA.

Maldonado MT (1997) The bioavailable Fe pool: a new paradigm. La Relève en
océanographie au Québec, Rimouski, PQ, Canada.

Price NM and Maldonado MT (1994) Iron acquisition by marine diatoms
consuming different nitrogen substrates. Iron Speciation & its Biological
Availability in Seawater: A Workshop. Bermuda.

Abstracts and Presentations

Maldonado MT , H. Hughes H, Rue E, and Wells ML (2000) The role of
trace-metals on toxigenic Pseudo-nitzschia blooms. International Conference
on Harmful Algal Blooms, Hobart, Tasmania, Australia.

Rue E, Maldonado MT , and Bruland K(2000) Domoic acid binds iron: a possible
role for the toxin? International Conference on Harmful Algal Blooms,
Hobart, Tasmania, Australia.

Maldonado MT, Strzepeck R, Gall M, Boyd P, and Price NM (2000) Physiological
response of Southern Ocean phytoplankton to a mesoscale Fe enrichment. Ocean
Sciences Meeting, San Antonio, TX, USA.

Maldonado MT, and Price NM (1996) Iron acquisition by phytoplankton:
Laboratory and field results. Ocean Sciences Meeting, San Diego, CA, USA.

last updated December 3, 2003