Sustainable Bioproduction of Volatile Fatty Acids Through Fermentation of Organic Wastes

Résumé

The current envirorunental situation led to an increase in public and political awareness of the importance of recovering resources from waste. This work addresses the study of the valorization of different organic wastes through acidogenic ferrnentation to produce volatile fatty acids (VFA). VFA are compounds with high added value in the market with many applications in the biotechnology industry. For the present thesis organic wastes from different agro-industrial and urban origins, generated in big quantities in Galicia, were selected. The acidogenic potential ofthese wastes was evaluated both in discontinuous mode (batch experiments) and in semi-continuous mode in laboratory-scale reactors. In addition, the effect of different parameters, such as pH, temperature, and hydraulic retention time, among others, on VF A production was studied. Studies were also carried out to evaluate the effect of co-digestion between wastes from different source on the VF A production. Moreover, the microbial populations involved in the acidogenic fennentation process were determined using next generation sequencing techniques.