From Plastics to Plastics
Society faces a monumental crisis as plastics infiltrate every ecosystem on the planet and pile up in landfills worldwide. There is a dire need to address this pollution, but plastics are and will remain a key material for many use cases and often cannot be replaced with other materials without compromising performance or drawing on resources to the detriment of the environment. Our goal is thus to find new ways to turn the products of plastic degradation into polymers that are biodegradable using engineered microbes.
We combine plastic degradation processes that are natural (e.g. those catalysed by PETases) and/or industrial with engineered polymer-producing metabolic pathways to create new processes which convert existing plastic waste into new plastic materials that are biodegradable. In this way, we can eventually achieve a plastic economy that is not only circular, but which is also minimally impactful on the environment. We collaborate with Prof. Yilan Liu (linked) at the University of Waterloo on elements of this research theme.
PUBLICATIONS
Publication #3
Publication #1
Hybrid Artificial Photosynthesis
Today, most chemical products are produced from oil. This practice not only has severe negative environmental impacts including climate change, but also irreversibly uses up a finite resource. The only sustainable source of carbon on the planet is the carbon in the atmosphere – CO2. Though photosynthesis naturally converts CO2 to biomass which can be used to make some chemical products, it does so with very low efficiency (1-5%).
In Hybrid Artificial Photosynthesis (HAP), CO2 is instead electrocatalytically converted into a feedstock that is then fermented into chemical products such as polymers and solvents by engineered microbes. HAP does not rely on plant biomass as a carbon middleman, so it is a potentially much more efficient carbon utilization route. Our goal is to predict how the two “halves” of HAP – electrocatalysis and fermentation – can be optimally integrated using flux balance analysis (FBA) and kinetic modelling, chemical process modelling, and techno-economic assessment (TEA). We work with a group at the University of Western Australia in Perth to support model-driven process integration.
PUBLICATIONS
Publication #2
Thermodynamics of Autocatalysis/Anabolism
Living organisms are open systems that operate very far from equilibrium. A core function of metabolism is the maintenance of the out-of-equilibrium states required for life, but how it is organized to achieve this and the associated emergent constraints on its function are not well understood. Uncovering these constraints would not only represent a fundamental advance in understanding how metabolism works, but would also allow for better predictions of both natural phenomena, such as overflow metabolism, and the performance of engineered and economically valuable, new-to-nature pathways.
We use metabolic reconstruction and constraint-based and kinetic modelling to understand how the structure and thermodynamic properties of metabolism determine its stability. In particular, we focus on autocatalytic structures and anabolic pathways to understand how these can be optimized to support the other research themes at The LAB. Our goal is to develop a computationally tractable, non-equilibrium thermodynamic, constraint-based approach that accurately reflects observed metabolic phenomena and can be used to evaluate engineered pathways with novel functionality.