From organic wastes to value: yeast-based bioconversion of waste-derived feedstocks into valuable compounds

: Environmental concerns are escalating as global waste accumulation and resource depletion reach critical levels. This highlights the urgent need to repurpose waste into valuable resources. The continued dependence on petroleum-based approaches is becoming unsustainable due to their significant environmental footprint. In light of this, biotechnology using yeast-based approaches, particularly the emerging exploitation of non- Saccharomyces yeasts, is a powerful tool offering sustainable solutions across multiple sectors such as food production, waste valorisation and environmental protection. By converting diverse organic wastes – including municipal, food, agricultural and industrial-derived residues – into feedstocks for microbial bioprocesses, these strategies promote resource efficiency and waste minimisation. In addition, they enable the creation of high-value compounds from otherwise discarded materials. The transition from a linear to a circular economy aligns with the goals outlined in the 2030 Agenda for Sustainable Development, highlighting the importance of creating value through bio-based solutions. This review focuses on the contribution of yeasts to long-term economic growth, innovation and sustainability, enabling the production of single cell oils, single cell proteins, bioethanol, biofertilisers/biopesticides and bioplastics, among others. Moreover, the integration of machine learning and automation-based systems in biotechnological processes further enhances the scalability and sustainability of yeast waste valorisation.