3.3.1. Targeted VFA production from (waste) waters

Biorefineries are set to become an important agent in the shift towards a circular economy due to their potential to valorize organic wastes into marketable products. Anaerobic fermentations yielding volatile fatty acids (VFA) are a key process in this biorefinery paradigm as VFA act as intermediates between the organic wastes and the final biorefinery products. However, the development of a new bioprocess based on mixed-culture fermentation is an extremely challenging task. Targeting the desired product requires finding a certain region in a very large operational space, which includes different pH, retention time, operation mode and substrate composition (including the possibility of using a defined mixture several substrates). This research line is a joint venture between mathematical model development and experimental research, aiming at providing an integral method for model-aided design of a novel bioprocess using mixed-culture fermentation.

Projects

• Engineering microbial communities for the conversión of lignocellulose into médium-chain carboxylates (Cell4Chem). ERACoBioTech (grant 722361). Ministry of Science and Innovation (PCI2021-121989). (2021-2024)

• Model-based design of a biorefinery platform to valorise agrifood organic waste into odd-chain volatile fatty acids integrating technical and environmental criteria (ODDITY) . NextGeneration EU, Strategic Projects Oriented to the Ecological and Digital Transition (2022-2024)

Completed Projects

• Management, coordination and valorization strategies of sludge and organic waste in the SUDOE region (ECOVAL) . Interreg Sudoe 2014-2020 Program (SOE4/P1/E1104) (2020-2023)

• Recovery of by-products and waste water from the canning industry in the POCTEP space (CONSERVAL) . Interreg Spain-Portugal, POCTEP, co-financed by the ERDF (European Regional Development Fund). (2019-2022)

The main aim of Biochem project, coordinated by the University of Santiago de Compostela, is to provide an integral method for model-aided design of a novel bioprocess using mixed-culture fermentation. In particular, BIOCHEM focuses on two essential aspects when designing a novel bioprocess: to reach a high selectivity of the desired product(s) and to achieve high productivity so that the process is economically feasible. As a demonstration, in BIOCHEM project, a process for the viable production of volatile fatty acids (VFA), i.e. acetic, propionic, butyric and valeric acids from low grade biomass (food wastes) by anaerobic (co-)fermentation will be developed. The selected case study is especially interesting because acetic acid global demand is approximately 10.3 million tonnes with wide applications in paints, adhesives, protective coatings and polymers; and propionic, butyric and valeric acid are produced in smaller quantities but have a higher added value and are used in animal feed and food preservation.
The consortium is formed by research groups form: Technical University Hamburg-Harburg (Germany), VTT Technical Research Centre of Finland Ltd (Finland) and University of Santiago de Compostela (Spain).