MYCO-CIRCLE: Circular valorization of industrial side-stream mycelium into bioleathers

The industrial production of bio-based chemicals via fermentation generates large volumes of fungal biomass as an unavoidable side stream. At present, this mycelium is often under-valorized, despite its rich biopolymeric composition. At the same time, there is increasing demand for sustainable alternatives to fossil-based and animal-derived leather, while many current mycelium-based material concepts remain limited by dedicated cultivation costs and scalability constraints.
MYCO-CIRCLE addresses this challenge by exploring whether industrial waste mycelium, originating as a side stream of citric acid fermentation at Citribel, can be transformed into a flexible, leather-like biomaterial using chemical-engineering and biochemical processing routes. The project does not aim to cultivate new mycelium for material production but instead focuses on the upcycling of an existing industrial fermentation residue that is produced on a multi-tonne scale. The project is practice-oriented and directly responds to questions from industrial partners active in fermentation (Citribel) and bio-based material development (BioVolo).
Within a 10-month period, the consortium aims to (i) establish a baseline understanding of the composition and variability of the industrial mycelium feedstock, (ii) explore and down-select processing strategies such as deproteinization and network stabilization, (iii) produce and iterate small-scale material sheets, and (iv) assess their mechanical and structural properties relevant for further application development towards robust sustainable leather fabrics. Throughout the project, all consortium partners are actively involved in defining requirements, executing experimental work, and evaluating results.
The main outcome of MYCO-CIRCLE will be a validated feasibility assessment of converting industrial fungal biomass into a bio-based, leather-like material, including a defined processing parameter window, prototype material, and practical recommendations for follow-up development. As such, the project contributes to circular chemistry by upgrading an unavoidable industrial side stream into a new material pathway and provides a concrete foundation for subsequent innovations and business development.