Professor Dr Alexandra Zoe Worden

Research Priorities: Ocean photosynthesis, plankton ecology, climate change, biogeochemical cycling, microbial interactions
Alexandra Zoe Worden is an American oceanographer, marine biologist and genome scientist. She researches the function and productivity of marine algae, microbial biogeochemical cycling, and microbial interactions in ocean ecosystems. Her core aim is understanding photosynthetic processes and fate of microbial cells (carbon) in the marine environment. She seeks to discover the effects of climate change on marine microbes – and the biochemical services they provide and to enable activity-based studies in the challenging ocean environment develops innovative methodologies and technologies. Her studies are contextualized within the background of earth history, evolutionary biology, and the molecular biology underpinning cell-to cell interactions.
Worden’s research has focused on ocean algae, a diverse group of organisms that are collectively responsible for approximately half of the global uptake of atmospheric carbon dioxide. These organisms also form the base of marine food chains. Climate change is expected to have a major impact on marine algae and therefore it is essential that knowledge of the mechanisms and controls of microbial dynamics in marine ecosystems is rapidly advanced – with attention to carbon transfer – and photosynthetic processes. She develops methods for investigating uncultivated marine microbes in the wild, and their role in the carbon cycle. In addition, she continues to develop a genetic model system that speaks both to developments in modern ocean algae as well as the evolution of land plants.
Worden’s team therefore is highly interdisciplinary, combining microbial ecology with studies of algal evolution, the interaction between microbes and ecosystems, and molecular acclimation mechanisms. From a methodological perspective her research spans genetics, microbiology, ecology, oceanography, and biochemistry. More broadly, research in her lab is approached from an evolutionary perspective and with a focus on cell-to-cell interactions and host-virus dynamics.
Worden has led and regularly participates in international expeditions. These field programs examine, for example, carbon processing in deep sea sediments and photosynthetic and export processes that occur in overlying sunlight regions of the water column. To this end, she also performs research in the Caribbean Sea, the Bay of Bengal, the Mediterranean Sea, the North Atlantic and other global sites, including Antarctica. Her studies further extend to microbial communities in corals, mangroves and extreme environments.