Lactate-based chain elongation: Poduction and separation of medium-chain carboxylates from complex organic residues

The transition to a circular economy needs the development of technologies to make efficient use of alternative energy and materials sources in order to reduce our dependency on fossil resources. Alternative resources such as renewable and residual materials can be converted to valuable products using mixed cultures of bacteria. Through a process called microbial chain elongation medium- chain carboxylates (MCC) are produced, platform chemicals with diverse applications in the energy, agri-food and chemical industries. This thesis studies the production of MCC through lactate as an important intermediate of organic waste fermentation with mixed cultures. Alternative MCC separation schemes are also explored. Food waste and lactate were successfully used as substrates to produce carboxylates with varied chemical structures and up to 8 carbon units long. Lactate-based chain elongation is envisioned as a relevant biotechnology in the upcycling of organic materials to valuable biobased products such as novel feed additives or aviation fuels.