About This Project

Plants capture CO2 from air to build sugars, which allows them to grow through a process called photosynthesis. While nature has slowly refined photosynthesis over 3.2 billion years, the key enzyme (a molecular machine) responsible for capturing CO2 is slow and makes mistakes. Here, we develop new methods to improve the CO2 capture efficiency and selectivity, which will lay the foundation for plant-based climate correction strategies.

Ask the Scientists

What is the context of this research?

Our planet is under treat by anthropogenic CO2 release, which must be captured to reverse climate change. While photosynthesis is been responsible for >90% of global CO2 capture [1], the key enzyme catalyzing this capture – called RuBisCO – is too slow to keep up with our increased CO2 output [2].

Given the need for sustainable approaches for climate correction, RuBisCO is considered to be one of the most important targets for protein bioengineering [3,4]. However, traditional bioengineering strategies have failed to improve RuBisCO's activity [3].

Why? Researchers have some ideas: some posit that this reflects biochemical tradeoffs in RuBisCO catalysis [2], but new data suggests that the issue may be connected to RuBisCO’s inability to adapt quickly through natural evolution [5].

What is the significance of this project?

Protein evolution is constrained by function and expression in nature [6], resulting in only 1-100 mutations every 10,000,000 years [7]. However, laboratory directed evolution can proceed at 1-5 mutations per week to improve bioactivity [8].

While RuBisCO has been subjected to directed evolution [9], traditional strategies can be slow and laborious to carry out, resulting in only modest gains to date. Further, these evolutionary methods have a high false-positive discovery rate and rely on existing genes or canonical amino acids found in nature.

New strategies are needed. Developing solutions to these issues would catalyze a paradigm shift in methods to improve RuBisCO-catalyzed CO2 capture, laying the foundation for sustainable climate correction using photosynthesis.

What are the goals of the project?

Starting in Nov 2023, we will develop an innovative strategy to evolve RuBisCOs with improved activities while simultaneously addressing all prior issues.

Our approach will integrate autonomous and continuous directed evolution that allows RuBisCO to explore hundreds of mutations every minute, a roughly 100-fold improvement as compared to traditional approaches. Our strategy will overcome false-positive bottlenecks, and be compatible with novel genes or amino acids to uncover new-to-nature enzymes altogether.

We will apply these state-of-the-art resources to improve RuBisCO CO2 capture kinetics by up to 300% (state-of-the-art to date = 60%). Findings from our work will lead to engineered plants with optimized RuBisCOs to capture CO2 with improved efficiency.