BBNet conference - Anaerobic Fermentation WG

This video is a version of an invited talk by Dr Yue Zhang on EBNet's Anaerobic Fermentation Working Group, and the role of Anaerobic Fermentation in the circular bio-economy. The talk was given at the 4th BBNet conference The Future Prospects for Biorefining: Feedstocks, Technologies & Products held on 15-17 Oct 2025 in Sheffield, UK.

Mixed-culture anaerobic fermentation (AF) is an enabling bioprocess with significant potential to valorise a wide range of unavoidable, heterogeneous organic wastes and residues. Its strength lies in the metabolic versatility of the microbial community, which can convert diverse substrates into a single major product group: volatile fatty acids, which represent an under-explored yet promising platform for biorefinery development. In parallel, essential plant nutrients locked within the biomass are released into the fermentation broth, offering opportunities for nutrient recovery and the creation of an additional value stream.

This approach can therefore be regarded as a 'dirty' biorefinery, where mixed organic waste streams can be processed without the need for pre-sterilisation, due to the robustness and resilience of the microbial consortia. This operational flexibility, however, introduces complexity in process control and optimisation. The performance of AF is very dependent on microbial ecology, the dynamic interactions between the microbiome and its engineered environment, substrate characteristics, and the integration of production with downstream extraction processes. These factors collectively influence process efficiency and whole-system optimisation.

The Working Group’s aim is to accelerate the implementation of AF-based systems for value recovery from diverse putrescible waste streams, including agro-industrial residues, food waste, wastewater biosolids, and residuals from existing biorefineries. This presentation will provide an overview of the working group’s recent activities and outline areas for future focus.

For more details on the EBNet AF Working Group see https://ebnet.ac.uk/wg-details/wg-af

And for EBNet’s sister NIBB the Biomass and Biorefinery Network (BBNet) see https://www.bbnet-nibb.co.uk