Design and Assembly of a Multi-enzyme CO2 Fixation System
Biochemistry
Bioinformatics and Theoretical Biology
Metabolism, Biochemistry and Genetics of Microorganisms
Final Report Abstract
For the past many years, fossil fuel exploitation had a significant effect to our climate. This environmental shift has proven to distort human health and welfare, whilst diminishing biodiversity, wild fauna and flora worldwide. In recent times, CO2 conversion to high value-added molecules has been a great interest to the scientific community worldwide. In this context, this project aims to elucidate a novel route for the transformation of carbon dioxide into dihydroxyacetone through a multi enzymatic cascade reaction. Enzymes involved in this cascade system are carbonic anhydrase (previously engineered), formate dehydrogenase, formaldeyde dehydrogenase and formolase. A set of three different formate dehydrogenases were characterised to better understand this system. Optimisation of process parameters was done by design of experiments (DOE). Optimised conditions obtained from DOE were used to perform the cascade. This resulted in the production of 0.65 mM dihydroxyacetone, thus establishing proof of concept. Additional kinetic and stability insights led to the optimization of this cascade, resulting in a 3-fold improvement. Carbonic anhydrase (TaCa) enzyme in the cascade, plays a crucial role in the dissolution of CO2 and improved the DHA production to 2.57 Mm. This marks as the first approach to be able to go from C1 to C3 chemicals in one pot reactions.
