Anthropogenic climate change demands new ways to capture and use atmospheric CO₂. In this dissertation, Lisa Kaußler explores two distinct biological approaches to convert CO₂ into useful products. The first investigates whether an enzyme from a thermophilic acetogen can be run in reverse, turning CO₂ into oxalate - a chemical with potential applications in carbon-neutral cement. The second develops a system in which microorganisms directly consume CO₂ from solid capture materials, producing methane and acetate without the energy-intensive step of first releasing the gas. Together, these projects represent early steps toward integrating CO₂ capture with biological conversion, contributing to a growing toolkit for addressing CO₂ emissions.

The PhD study was completed at the Interdisciplinary Nanoscience Center (iNANO) and the Novo Nordisk Foundation CO₂ Research Center (CORC), Faculty of Natural Sciences, Aarhus University.

This summary was prepared by the PhD student.

Date: 22.06.26, 13h
Place: 3130-303
Title of PhD thesis: Enzymatic and Microbial CO₂ Conversions: Towards Novel Biological Platforms.
Contact information: Lisa Kaussler, e-mail: lk@corc.au.dk, tel.: +45 22 11 66 76 
Members of the assessment committee:
Professor Bastian Molitor, Microbial Metabolic Biochemistry, Institute of Biochemistry, University of Leipzig, Germany
Professor Peter Westh, Department of Biotechnology and Biomedicine, Section for Protein Chemistry and Enzyme Technology, Technical University of Denmark, Denmark
Professor Niels Christian Nielsen (chair), Department of Chemistry, Aarhus University, Denmark
Main supervisor: Professor Alfred Michael Spormann, Interdisciplinary Nanoscience Center (iNANO) and Novo Nordisk Foundation CO₂ Research Center (CORC), Aarhus University, Denmark
Co-supervisor: Professor Ross Dean Milton, Department of Inorganic and Analytical Chemistry, University of Geneva, Switzerland
Language: The PhD dissertation will be defended in English

The defense is public.
The PhD thesis is available for reading at the Graduate School of Natural Sciences/GSNS, Ny Munkegade 120, building 1521, 8000 Aarhus C