Professor Tom Bibby - University of Southampton

Professor Tom Bibby

Oxygenic photosynthesis transforms light into chemical energy through a suite of light-dependent reactions. This process sustains the biosphere and catalyses biogeochemical cycles that regulate climate. Photosynthesis is typically considered in terms of the amount of carbon that is reduced or ‘fixed’ into organic compounds. However, our research on phytoplankton communities in nutrient-limited oceans systems demonstrates that electrons generated from photosynthesis are often considerably in excess of those needed for carbon fixation. Or, put another way, the energy generated from the light reactions of photosynthesis is uncoupled from carbon fixation. As such, the carbon-centred perspective neglects as much as half of the photosynthetic energy and electron flux in the oceans. This not only impacts on how we understand oceanic production but also suggests that photosynthetic molecular pathways could be manipulated to power an array of chemical processes sustainably using light. In this talk we review both our recent understanding of photosynthesis under nutrient limitation in oceanic systems and also demonstrate how some of these alternative photosynthetic pathways can be tapped to power useful chemical reactions beyond carbon fixation.