James specialises in biological conversion of gaseous waste carbon to valuable products.
We are currently investigating biological processes that valorise waste carbon, typically gaseous compounds such as CO2, CO, or CH4. Microbial biotechnology is our focus due to its scalability, efficiency, and stability - being capable of utilising typical catalysis contaminants such as NOx and H2S. Further, certain hydrogenotrophs and methanotrophs (H2 and CH4 utilising organisms) have metabolic properties that make them attractive for use in the circular carbon economy (e.g. co-uptake of CO2 and CH4 as sole carbon and energy sources). A wide-range of products can also be made, from short-chain alcohols to polymers and animal feeds. To better understand their ability for real-world application, we characterise their metabolism using multi-omics analysis methodologies and then optimise it through data-driven hypotheses and testing.
James recently submitted his PhD, where he was also working in the Marcellin Group. Prior to this, he studied for a BE(Hons.) in Chemical and Process Engineering at the University of Canterbury (NZ) and undertook a summer research internship with Prof. Renwick Dobson before coming to UQ. His PhD research employed systems biology and phenomics principles to build datasets that expand our understanding of gas fermentation in an industrially relevant manner. The Marcellin Group has and continues to focus on analysis of the model acetogen Clostridium autoethanogenum, which LanzaTech utilises at industrial scale. Current interests in reducing global CO2 levels and high efficiencies encouraged us to investigate this biological system as a potential CO2 recycling platform. His other research interests include identifying genes that are essential for desirable phenotypes, and methods for manipulation of those genes to enhance the phenotype.
Key Publications
Heffernan J. K., Valgepea K., Souza R. De, Lemgruber P., Casini I., Plan M., et al. (2020). Enhancing CO₂-valorization using Clostridium autoethanogenum for sustainable fuel and chemicals production. Front. Bioeng. Biotechnol. 8, 1–10. doi:10.3389/fbioe.2020.00204.
Heffernan J. K., Mahamkali M., Valgepea K., Marcellin E., Nielsen L. K. (2022). Analytical tools for unravelling the metabolism of gas-fermenting Clostridia. Cur. Oppin. Biotechnol. 75, 102700. doi:10.1016/j.copbio.2022.102700
Heffernan J. K., Lai C.-Y., Gonzalez-Garcia R. A., Nielsen L. K., Guo J., Marcellin E. (2023). Biogas upgrading using Clostridium autoethanogenum for value-added products. Chem. Eng. Jour. 452, 138950. doi: 10.1016/j.cej.2022.138950