Small cells and big questions
In April 2006 Professor Birgitta Bergman, Department of Botany, Stockholm University received a STINT Institutional Grant for long-term cooperation with Luisa Falcon, Department of Molecular Ecology and Evolution, UNAM in Mexico and other partners, for research on marine cyanobacteria: small cells and big questions. The four-year grant amounts to 2.4 million SEK.
This STINT/IG research program has enabled an intensive exchange of students and senior scientists between Stockholm University, Universidad Autónoma de México (UNAM) in México City, University of Dar es Salaam in Tanzania, and the J. Craig Venter Institute in USA. The collaborators of the program together hold world-leading expertise on cyanobacteria, genome research and expertise on some unique and understudied marine geographical regions. Through these combined and targeted efforts, we have been able to start unveiling biogeographical patterns in populations of marine cyanobacteria and identify key organisms in ecologically important biological systems such as stromatolites, seagrass meadows, mangroves and coral reefs, including also whole-metagenome sequencing information of planktonic (free-floating) cyanobacteria in tropical Atlantic and Indian Oceans.
The atmosphere of the early Earth contained virtually no oxygen and was not suitable for most present day life forms. Thanks to ancient prokaryotic organisms the oxygen levels gradually increased, paving the way for life as we know it. These evolutionary imperative organisms were the ancestors of contemporary cyanobacteria, the major photosynthetic organisms in marine environments. Fossil evidence has suggested the presence of cyanobacteria already in calcified, stratified microbial consortia known as stromatolites. Modern day stromatolites harbor diverse cyanobacteria and form ‘hot spots’ for evolutionary and biogeochemical studies.
One such ‘hot spot’ is the valley Cuatro Cienegas an isolated ancient water system located in the desserts of northern Mexico, a system that probably once was connected to the Gulf of Mexico, and an important study sites in this STINT/IG program. Cyanobacteria have the unique capacity to acquire the two major nutrients, carbon (C) and nitrogen (N) from the atmosphere, being able to fix CO2 via oxygenic photosynthesis and to scavenge atmospheric dinitrogen (N2) in the nitrogen fixation process. These capacities make cyanobacteria extremely well adapted to highly nutrient-stressed marine environments. Cyanobacteria are now appreciated as important nitrogen-fixers in oceans world-wide.
However, our knowledge of sources and rates of marine nitrogen fixation is still limited. To date such environments have not been thoroughly analyzed and we lack information on the molecular diversity, biogeochemistry and physiological activities of these prokaryotes, as on their ultimate role as key players in the marine environment. Our STINT/IG program will therefore provide a much better understanding of cyanobacterial diversity, population dynamics and ecological significance by examining the carefully selected, highly exciting, but understudied sites mentioned above.
After an initial planning workshop with the senior partners in the STINT/IG exchange project, a second workshop was arranged in Mexico in 2007 and a third workshop is scheduled for the summer of 2008 in Tanzania. Field studies have been conducted in Mexico by members from the collaborating partners. Several Master and PhD students from Mexico and Sweden have conducted short-term (1- 2 months) exchanges to participate in courses or to learn new techniques, and two long-term (3-5 months) fellowships have been awarded a postdoctoral fellow and a senior scientist. These exchanges and combined research efforts have greatly stimulated and improved the quality of our research activities.
Professor Birgitta Bergman
Dr Karolina Bauer
Department of Botany
Senast uppdaterad: 08-04-02 10:46