Abstract
Unicellular planktonic cyanobacteria have in the last decade been discovered as highly important actors in the marine environments and as some are able to fix atmospheric nitrogen they also contribute significantly to the nitrogen economy in these vast ecosystems. Recent data indicates that unicellular, pico- and nanoplanktonic cyanobacteria, may be abundant during summer months in the Baltic Sea, co-developed with larger bloom forming cyanobacteria such as Nodularia, and may be responsible for nitrogen fixation rates observed in the dark in the southern Baltic Proper. I am applying for funding to apply genetic approaches such as denaturing gradient gel electrophoresis (DGGE), fluorescence in situ hybridization and real time-RT-PCR, based on conserved genes such as 16S rDNA and nifH genes, to conduct phylogenetic identification and study the ecological function that marine unicellular cyanobacteria play in biogeochemical cycles in the Baltic Sea. Because special attention will be focused on nitrogen fixers, gas chromatography/acetylene reduction and mass spectrophotometry 15N2-tracer assays will also be used to determine nitrogen fixation activities. All these data will enable us to understand the way these microbial communities function, allowing for the resolution of their differential response to changes in the environmental conditions, as a function of time, space, and abiotic and biotic variations, as well as relationships with other organisms in the system they share.
Sweden