Why does CO2 inhibit photosynthetic microbes?
Photosynthetic organisms usually struggle to get enough CO2 for photosynthesis, but too much CO2 appears to choke the organisms for unknown reasons that we wish to explore
Project type:
BSc, MSc, PUK
Keywords:
Microbiology; Biochemistry; Biology; Biotechnology
Project description:
The significant release of CO2 from human activities into the environment poses a critical challenge in the transition to a sustainable society. A successful green transformation therefore necessitates lowering CO2 emissions and enhancing efficient CO2-to-biomass conversion technologies. Photosynthetic microbes offer a solution by producing valuable biomass and bioproducts from CO2 sourced from industrial exhaust gases, such as those from incineration, fermentation, and biogas upgrading. Despite their need for CO2, photosynthetic organisms are not naturally adapted to high CO2 concentrations, and are typically inhibited when the gas phase content exceed 5% CO2. This behavior presents a limitation in industrial applications of many microalgae and cyanobacteria in commercial-scale photobioreactors. If these microbes could be made more resistant to high CO2 concentrations, industrial applications could become more productive.
This project aims to identify biological explanations and solutions to the problem of sensitivity to high CO2 concentrations. We use various model organisms of cyanobacteria and microalgae and cultivate these in specialized setups where the composition of the gas phase and the liquid phase can be manipulated. We characterize growth and biomass, use DNA and RNA sequencing, and chemical as well as DNA/RNA-engineered targeted mutagenesis strategies to understand the physiological and genetic factors underlying CO2 sensitivity and resistance. Ultimately, this research aims to deliver microbial strains with enhanced resistance to high CO2, thus advancing their potential for biotechnological applications.
Contact:
Niels-Ulrik Frigaard (nuf@bio.ku.dk). This project is part of the CO2CAPTURE project funded by the Independent Research Fund Denmark and takes place at the laboratories at the Section for Marine Biology in Helsingør.
Read more:
Project link: Capture of CO2 from exhaust gases using photosynthetic microorganisms
Zhou et al. (2017) Bio-mitigation of carbon dioxide using microalgal systems: Advances and perspectives. Renewable and Sustainable Energy Reviews 76: 1163–1175
Salih (2011) Microalgae Tolerance to High Concentrations of Carbon Dioxide: A Review. Journal of Environmental Protection 2: 648–654