Understanding the molecular mechanisms that drive global CO2 fixation to improve photosynthesis

Photosynthetic algae fix approximately 50% of global CO2, yet our understanding of the molecular mechanisms driving this process are limited. Deep knowledge of algal CO2 fixation at the genetic level has great potential for enhancing photosynthesis to improve biological carbon capture to drive a future carbon neutral economy and to enhance crop yields to ensure food security. This multidisciplinary project will use cutting edge methods in microscopy, robotics and synthetic biology to give rapid advances in our understanding of CO2 fixation in algae and supply the knowledge and tools for future engineering efforts to increase crop yields and biological based carbon capture systems.

Nearly all algae have evolved a photosynthetic turbocharger called a CO2 concentrating mechanism (CCM) that increases the efficiency of the primary carbon fixing enzyme, Rubisco, by increasing levels of its substrate CO2 in its proximity. The engineering of a CCM into crop plants that have failed to evolve CCMs, such as rice and wheat, is predicted to increase yields by up to 60%. The data generated in this project will give us an unprecedented insight into CO2 fixation in prokaryotic and eukaryotic algae. The data will subsequently guide the assembly of the first test tube CO2 concentrating system that will act as a platform for testing different components (i.e. proteins) and optimising component combinations to enable the engineering of CCMs into plants.

To attain our goal, we will systematically identify the CCM components and regulatory mechanisms of two evolutionary distinct algae that are fundamental for global CO2 fixation, eukaryotic diatoms and prokaryotic cyanobacteria. We will use this data to identify the underlying principles for efficient CO2 fixation and provide the knowledge and molecular toolkit to engineer a synthetic CCM. To achieve this the project has three core objectives:

1) Generate the first complete cell protein map for a photosynthetic organism to give novel insights into cyanobacterial CO2 fixation.

2) Identify the core components of the poorly understood diatom CCM using high-throughput gene editing and protein localisation methods.

3) Build a synthetic CO2 fixation system to guide the engineering of enhanced photosynthesis in plants.

Together, I anticipate the data will pave the way for future engineering efforts of CCMs to enhance photosynthesis.

Who will benefit from this research? In the short- to medium- term, the research will benefit academics and researchers across nearly all areas of algal research within the UK and internationally. The techniques, data and strains developed will be of particular interest to biologists working in all aspects of cyanobacterial and diatom biology. It will be of interest to biotechnologists and synthetic biologists working on algal strain engineering to enhance biomass and high-value products. This group will include UK based companies in this field such as Algenuity. The work will be of particular interest to researchers working on enhancing food security through photosynthesis engineering, this includes the international C4-Rice project and RIPE consortia. Medium- to long-term, agricultural biotechnology companies such as Syngenta and Bayer Crop Science, and charitable foundations such as the Bill and Melinda Gates Foundation may directly benefit from this research by building on it to generate photosynthesis based crop improvements. In addition, Government and Multinational Agencies can use results to strategize future funding in areas of high potential impact (e.g. GCRF). During the research, the PDRAs and undergraduates working on the project will benefit considerably from training. The general public will also benefit from planned outreach activities.

How will they benefit from the research? Academics and researchers will receive comprehensive new information about the CCM of diatoms and cyanobacteria and the components needed for a functional CCM. The field will have access to newly developed protocols, strains and plasmids once published. The algal industrial biotechnology industry will have data and methods to accelerate strain engineering and to enhance photosynthetic performance. The agro-industry and charitable organisations will have access to data to guide photosynthesis engineering and enable rapid testing of CCM designs. The PDRAs will receive a wide range of training in molecular biology, synthetic biology, biophysics, microfluidics and automated data analysis. They will develop a broad range of professional skills, with opportunities to attend training courses and interact closely with world leaders across multiple fields. Our research findings relate to issues of public interest including climate change, carbon cycling, sustainable crop production and global food security. The research also has a broad educational value, at both schools and universities.

How will we ensure they benefit from the research? I will ensure results are published as soon as feasible in high-impact open access journals. We will present research results at international meetings and invited seminars and promote new findings ahead of publications using the lab website (www.mackinderlab.com) and social media (i.e. Twitter). We will submit strains, plasmids, data and code to relevant depositories. When we are in a position to exploit our findings I will make informal contacts with biotechnologists once IP is protected. I will ensure that PDRAs are made aware of relevant training schemes and conferences and have regular progress reviews and career development plans. We will ensure that non-academic audiences have access to our findings through the University of York Outreach via the University website and press releases, through social media, talks by the fellow at local events including the Pints of Science public debate and interactions with secondary school students through the Future First network. I will seek opportunities to inform the work of charitable bodies by existing contacts, and I will involve undergraduate students by providing laboratory summer secondments.