Scientists investigate marine photosynthesis

The project, funded by the Natural Environment Research Council, will involve growing two different species of cyanobacteria – photosynthetic algae that are able to fix nitrogen from the atmosphere – under different conditions. Dr Tracy Lawson and Professors Richard Geider and David Nedwell will study how reductions in phosphorous and iron affect the ability of the cyanobacteria to fix nitrogen and carry out photosynthesis.

Dr Lawson, who is leading the project, explained: ‘Photosynthesis by marine algae is important as the ocean can act as a sink for carbon dioxide from the atmosphere. So, by increasing photosynthesis in the ocean, we may be able to reduce carbon dioxide in the atmosphere that is produced by man and counteract global warming.’

The reduction of phosphorus and iron is expected to affect the photosynthetic structure and function in different ways: iron is required for certain parts of the photosynthetic electron transport chain while phosphorous is required for the production of energy and as the building blocks of nucleic acids and protein.

Because photosynthesis also requires light and carbon dioxide, the researchers will also alter the light environment and carbon dioxide concentration that the algae will be grown under. By growing the cultures in such controlled conditions the researchers will be able to closely mimic the natural environment. This will be the first time some of these cultures have been grown in this way.

Dr Lawson added: ‘This work will give us information that is vital for use in mechanistic models that will predict marine responses to climatic change under different nutrient, light and carbon dioxide regimes.’