Photo: Emma Heinonen
In his doctoral dissertation, Yu Sun explored electro-fermentation, using electrodes to steer microbial metabolism and improve traditional fermentation performance. He discovered that a polarised electrode can push the oxygen-dependent industrial workhorse Bacillus subtilis to switch from making lactic acid to making acetoin. With bioengineering, the microbe could even 'exhale' electricity while producing mostly 2,3-butanediol. Meanwhile, in systems inoculated with wastewater-sourced microbes, a polarised electrode helped convert a plant sugar found in wood and agricultural residues into valuable chemicals linked to gut health. Together, these results point to practical ways to cut oxygen dependence and ease energy bottlenecks in fermentation. This could lower costs and emissions in industrial biotechnology and expand sustainable chemical production from a wider range of plant-based raw materials.
The doctoral dissertation of MSc (Tech) Yu Sun, in the field of Environmental Engineering, titled Electro-fermentation Enhanced Biochemical Production, will be publicly examined at the Faculty of Engineering and Natural Sciences at Tampere University on 13 March 2026.
The Opponent will be Professor Dirk Holtmann from Karlsruhe Institute of Technology, Germany. The Custos will be Professor Marika Kokko from the Faculty of Engineering and Natural Sciences, Tampere University.