Sustainable Bioconversion of CO2 to Polyhydroxyalkanoates Biopolymer by Anaerobic Mixed Bacteria in a Single-Stage Gas Fermentation (CO2BIOPOL)

The increasing carbon dioxide (CO2) emissions are a significant contribution to global warming and climate change. The carbon capture and utilisation (CCU) strategy has emerged to convert the CO2 to carbon-based chemicals through gas fermentation to move towards a low-carbon economy. An interesting case for CCU is to produce intracellular biopolymers such as polyhydroxyalkanoates (PHA) from CO2 feedstock by anaerobic microorganisms. PHA holds several industrial and bulk applications, and it has been recognised as long-term sustainable green alternatives to petrochemical plastics since they are entirely biodegradable and biocompatible. This project is developing the concept of a novel biotech process for the sustainable bioconversion of CO2 into PHA by anaerobic mixed microbial cultures (MMC) via single-stage gas fermentation using novel high-rate gas transfer reactors. First, the project aims to investigate the appropriate anaerobic microbial communities for PHA synthesis. Secondly, intensification of PHA production conditions by selecting and controlling operating parameters along with PHA chain length elongation and medium-chain-length PHA synthesis by anaerobic MMC. Thirdly, optimised PHA production conditions will be evaluated under pilot-scale level along with cost-benefit analysis to demonstrate the sustainable long-term PHA production via single-stage gas fermentation. The proposed project is significant in terms of PHA production from renewable feedstocks (CO2) and would be an asset in the development of the bioeconomy within UK and European biotech industries. PHA production from CO2 would be an example of sustainable future clean technologies to save natural resources and energy.