Stress response and synthetic biology of photosynthetic microorganisms

The main purpose of our research is to improve primary photosynthetic productivity –and consequently CO₂ sequestration– under stress conditions in cyanobacteria and microalgae.

One of the research lines of our group focuses on understanding how cyanobacteria balance photosynthesis in response to changes in metal availability. In cyanobacteria the heme-protein cytochrome c₆ and the copper protein plastocyanin act as alternative electron carriers between the photosynthetic cytochrome b₆f and photosystem I complexes, as well as in respiration. Recently, the system regulating the cytochrome c₆/plastocyanin switch has been described as composed by a transcription factor (PetR) and a protease (PetP), the latter regulating the transcription factor levels in response to the presence of copper. We are carrying out an in-depth characterization of the system regulating the cytochrome c₆/plastocyanin exchange in the cyanobacteria Synechocystis and Anabaena, trying to identify the mechanisms for copper detection and signal transduction and the regulation of metal metabolism. In addition, this work addresses the design of new genetic tools in cyanobacteria, which will allow the development of genomic engineering and synthetic biology techniques in these organisms. This knowledge will facilitate the use of cyanobacteria as bio-factories.

Our group is also working on a second line of research, aimed at improving the primary productivity of microalgae under conditions of stress induced by high light or temperature. Microalgae are not only fundamental constituents of oceanic phytoplankton, contributing decisively to the fixation of CO₂, but also have applications as a source of biomass, biofuels and chemical products of high value, animal feed and as a source of phytoplankton in aquaculture. However, stress conditions limit the photosynthetic efficiency and primary productivity of microalgae. We use the model diatom Phaeodactylum and the green algae Chlamydomonas with the aim of generating new stress resistant strains under high light or temperature conditions. Our work would result in an increase in the biotechnological capacities of these microalgae, both in the usual climatic conditions in Spain that limit their commercial production, and in the upcoming conditions of global warming.

Research lines:

– Alternative redox proteins in photosynthesis

– Synthetic biology in cyanobacteria

– Improvement of primary productivity of microalgae under limiting conditions