Abstract:
Electrofermentation is known to mitigate redox imbalance in anaerobic growth, thus increasing growth and key metabolite production in yeast. In the first part of this work, I investigated growth, biofilm formation, and oil degradation under electrofermentation conditions of Yarrowia lipolytica through laboratory-scale bioelectrochemical cells. Two commonly used redox mediators, 2-hydroxy-1,4-naphthoquinone (2-HNQ) and potassium ferricyanide (K3[Fe(CN)6]) were tested to enhance the bio-electrochemical process. Results show that K3[Fe(CN)6] leads to better planktonic growth and biofilm formation compared to 2-HNQ. In the second part of the thesis, I investigated the possibility of using sunflower oil as an additional carbon source in a laboratory-scale electrofermentation process, to stimulate lipase production, a key group of enzymes used in the biofuel production and upcycling of waste oil. While I could not directly measure lipase expression, the electrofermentation experiments resulted in approximately 47 % higher cumulative charge output in presence of 5% of sunflower oil, suggesting that electrofermentation increases lipase production and oil metabolism. This work lay the basis for the development of an efficient waste oil degradation process under electrofermentation conditions.