Alexandra Z. Worden, Ph.D.

Population regulation of photoautotrophic microbes and carbon cycling


​Alexandra leads a microbial ecology research group at Monterey Bay Aquarium Research Institute, a non-profit organization focused on the intersection of oceanographic science and technology development.

Alexandra Z. Worden, Ph.D.

Research Description

I lead a microbial ecology research group at Monterey Bay Aquarium Research Institute, a non-profit organization focused on the intersection of oceanographic science and technology development.

My lab’s research is interdisciplinary, integrating genomics and evolutionary biology to explore microbial roles in carbon dioxide fixation. We develop novel approaches for genomic analysis of cultured and uncultured unicellular eukaryotes (microbes that have a nucleus) and quantifying their contributions to photosynthesis. The cultured strains used in the lab are widespread marine green algae related to land plants. Hence, the lab studies the ecology of these organisms in the field and also uses them to develop a better understanding of plants and the plant ancestor. Tiny (pico)eukaryotes in the stramenopile and haptophyte algal lineages are also being investigated with a focus purely on marine ecology. We are especially interested in organisms that can live by photosynthesis and by consuming other microbes, because these two growth modes have very different influences on the ecosystem.

Overall, we are trying to elucidate the molecular underpinnings - or mechanisms - of microbe-microbe interactions. An underlying principle for my research is that microbes must be studied at habitat scales relevant to their adaptive strategies to determine how their metabolism influences larger-scale ecosystem dynamics. I consider this principle essential for understanding how microbial communities and global carbon dioxide uptake by algae will transition during climate change.

Research Impact

In collaboration with scientists working on other organisms and ocean processes we hope to provide the knowledge necessary to develop more predictive ecosystem and carbon cycle models.

Media Press

EurekAlert! - Marine algae can sense the rainbow

Good Times Weekly - Mini Microbes Make A Big Splash

AAAS Member Central - Member Spotlight: Alexandra Worden and the eukaryote tree of life


related links

Marine Microbiology Initiative Science Monterey Bay Aquarium Research Institute Back


Ph.D., Ecology
University of Georgia, 2000

B.A., History
Wellesley College, 1992
(Concentration, Earth, Atmospheric and Planetary Sciences, MIT)


Senior Fellow, Integrated Microbial Biodiversity Program, Canadian Institute for Advanced Research (CIFAR), 2011- present

Scholar, CIFAR Integrated Microbial Biodiversity Program, 2009 - 2010

Young Investigator in Marine Science Award, Gordon & Betty Moore Foundation, 2004 - 2008

AAAS Women’s International Science Collaboration Award, 2003

NSF Post-doctoral Fellowship in Microbial Biology, 2000 - 2002

NASA Earth Systems Science Graduate Student Fellowship, 1996 - 1999


Rockwell, N. C., D. Duanmu, S. S. Martin, C. Bachy, D. C. Price, D. Bhattacharya, A. Z. Worden, & J. C. Lagarias. (2014). Eukaryotic algal phytochromes span the visible spectrum. Proc Natl Acad Sci U S A, 111(10), 3871-3876. doi: 10.1073/pnas.1401871111

McRose, D., J. Guo, A. Monier, S. Sudek, S. Wilken, S. Yan, T. Mock, J. M. Archibald, T. P. Begley, A. Reyes-Prieto, & A. Z. Worden. (2014). Alternatives to vitamin B uptake revealed with discovery of riboswitches in multiple marine eukaryotic lineages.ISME Jdoi: 10.1038/ismej.2014.146

Keeling, P. J., F. Burki, H. M. Wilcox, B. Allam, E. E. Allen, L. A. Amaral-Zettler, E. V. Armbrust, J. M. Archibald, A. K. Bharti, C. J. Bell, B. Beszteri, K. D. Bidle, C. T. Cameron, L. Campbell, D. A. Caron, R. A. Cattolico, J. L. Collier, K. Coyne, S. K. Davy, P. Deschamps, S. T. Dyhrman, B. Edvardsen, R. D. Gates, C. J. Gobler, S. J. Greenwood, S. M. Guida, J. L. Jacobi, K. S. Jakobsen, E. R. James, B. Jenkins, U. John, M. D. Johnson, A. R. Juhl, A. Kamp, L. A. Katz, R. Kiene, A. Kudryavtsev, B. S. Leander, S. Lin, C. Lovejoy, D. Lynn, A. Marchetti, G. McManus, A. M. Nedelcu, S. Menden-Deuer, C. Miceli, T. Mock, M. Montresor, M. A. Moran, S. Murray, G. Nadathur, S. Nagai, P. B. Ngam, B. Palenik, J. Pawlowski, G. Petroni, G. Piganeau, M. C. Posewitz, K. Rengefors, G. Romano, M. E. Rumpho, T. Rynearson, K. B. Schilling, D. C. Schroeder, A. G. Simpson, C. H. Slamovits, D. R. Smith, G. J. Smith, S. R. Smith, H. M. Sosik, P. Stief, E. Theriot, S. N. Twary, P. E. Umale, D. Vaulot, B. Wawrik, G. L. Wheeler, W. H. Wilson, Y. Xu, A. Zingone, & A. Z. Worden. (2014). The Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP): illuminating the functional diversity of eukaryotic life in the oceans through transcriptome sequencing. PLoS Biol, 12(6), e1001889. doi: 10.1371/journal.pbio.1001889

Bachy, C., & A. Z. Worden. (2014). Microbial Ecology: Finding Structure in the Rare Biosphere. Curr Biol, 24, R315-R317. doi: 10.1016/j.cub.2014.03.029

Monier, A., S. Sudek, N. M. Fast, & A. Z. Worden. (2013). Gene invasion in distant eukaryotic lineages: discovery of mutually exclusive genetic elements reveals marine biodiversity. ISME J, 7(9), 1764-1774. doi: 10.1038/ismej.2013.70

Affiliated Investigators