Pictured: (Back; L to R) - Justin A. North, Kyuha Lee, Cathleen Fry, Vishnu Baba Sundaresan, Sriram Satagopan; Front (L to R) – Bhavik Bakshi, Jon R. Parquette
Not pictured: Bob Tabita
Carbon dioxide (CO2) and methane (CH4) are the two most abundant greenhouse gases, trapping thermal radiation close to the earth’s atmosphere and contributing to global warming and climate change. These two gases contributed to 94% of all the greenhouse gas emissions in 2010. CO2 emissions are expected to increase by more than 40% by 2035, unless major worldwide policies are soon implemented. While CH4 emissions have remained fairly stable over the past 20 years, they are expected to rise significantly in the next decades, largely as a consequence of the increased use of natural gas and hydraulic fracturing, which results in major releases of CH4 to the atmosphere. From an industrial perspective, CO2 and CH4 provide very abundant sources of carbon for the synthesis of a large range of chemicals. While plants and microbes are efficient at converting CO2 into sugars and other compounds, the sophisticated chains of enzymatic reactions that usually accomplish these processes are difficult to replicate in an industrial context. Existing industrial methods to convert CH4 into methanol are also very energy consuming.
Biology-inspired catalysts derived from bacteria and plants, such as ribulose-1,5-bisphosphate carboxylase oxygenase (RubisCO) and methane monooxygenase (MMO), extract CO2 or methane, respectively, and convert them to energy-rich compounds like glucose, by the sequential action of multiple enzymes. However, the use of free or cell-based enzymes as biocatalysts for large-scale industrial processes pose significant drawbacks due to their incompatibility with reaction conditions that often depart from their physiological states. The challenge is to construct catalytic systems that mimic the cellular environment but are scalable and sufficiently robust to withstand harsher conditions and be separated from the product.
This CAPS project aims to develop methods (1) to encapsulate CO2 reducing enzymes within synthetic nanostructures to mimic natural carboxysomes found in nature, (2) to create a catalytic RNA molecule for methane oxidation, (3) to develop supramolecular catalysts for the conversion of CH4 into commodity chemicals and (4) to develop strategies to deploy these catalysts in real-world environments.
Jon Parquette (ASC) will develop methods to encapsulate and co-encapsulate catalytic CO2-reducing enzymes.
Jovica Badjic (ASC) will prepare artificial receptors for the binding and catalytic oxidation of methane.
Venkat Gopalan (ASC) will be involved in the development and selection of catalytic RNA aptamers for methane oxidation.
Christopher Jaroniec (ASC) will perform solid-state NMR structural studies of encapsulated enzymes.
T. V. RajanBabu (ASC) will design novel ligands for transition metal catalysis for methane oxidation.
Vish Subramaniam (COE) will develop specific pigment molecules for harnessing energy from the solar spectrum for the conversion processes.
Vishnu Sundaresan (COE) will use SECM to characterize the organic nanotubes, RNA catalysts immobilized on surfaces and the nanoconstructs formed from encapsulating various biomolecules.
F. Robert Tabita (ASC, CFAES) will evaluate the catalytic activity of encapsulated enzymes and will be responsible for developing strategies to encapsulate multi-protein biocatalysts for product formation.
- Photosynthesis and Carbon Fixation