Development of a circulair sustainable culturing process for natural leather-like materials based on fungal mycelium

Development of a circulair sustainable culturing process for natural leather-like materials based on fungal mycelium


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Landbouw, Water, Voedsel>A. Kringlooplandbouw>A3. Hergebruik organische zij- en reststromen






Bolt Threads ( has developed a natural material called MYLO from fungal mycelium by engineering it to assemble into a supple and durable material that has the potential to biodegrade and be a sustainable, and cost competitive alternative to real and synthetic leather. Textile and Leather are among the industries with the highest environmental impact (besides the meat and oil/gas industries). The mycelium that is the basis of MYLO is grown on a substrate (MYSUB) based on a side stream (sawdust) supplemented with nutrients. After harvest of the mycelium the formed foamy material (called MYFOAM) is processed into “MYLO” to preserve it and to acquire the functional properties of “leather”. In 2020 the start-up (SME) company Mycelium Materials Europe (MME B.V.) started with the first production of MYFOAM. The MYFOAM produced is used to further develop the processing into MYLO on a small scale. Substrate, the mushroom strain, culturing conditions, and post-harvest processing each have a large impact on the characteristics and the properties of the MYFOAM, which impacts the quality and properties of the final product (MYLO). The small-scale process now used for the growing of the MYFOAM is still very laborious and costly. To produce the required volumes for MYLO to be a commercial success, further automation and (lower cost) substrates that are both sustainable and locally available are required (keeping in mind production in different countries). It is envisioned that the modular production system (known as Dutch shelf systems) as is used in the mushroom cultivation industry could serve as a blueprint to produce MYSUB and MYFOAM. Such a production system could then be easily implemented (inter)nationally. The Dutch are world-wide known for their know-how, and infra structure with respect to mushroom cultivation. For implementation of the process abroad, also the use of local mushroom species will be important. The MYLO produced is a natural vegan leather alternative and the process for the production should be sustainable. Production of MYLO does generate its own side streams. The spent substrate after harvest of MYFOAM and side streams from the MYLO process are potentially valuable natural resources, and finding applications would contribute to further circularity of the industry, as well as contribute to the chances of success of ‘vegan’ leather (better economic viability) to replace more polluting textiles.
In this project we want to develop a roadmap to an economically scalable circular process to produce natural leather-like materials based on fungal mycelium, that is suitable for use of local available side streams as raw materials, and that valorizes and re-uses occurring side streams.

a. Screen the ability of different fungi for the formation of MYFOAM on various types of biobased side streams as substrates
b. Characterize the properties of MYFOAM from different fungi grown on different substrates
c. Explore applications for the sustainable re-use of the spent substrate and MYLO side streams (compost/fertilizer/bio-stimulant/enzymes)

After 2 years, at the end of this feasibility study project, a route to a technically and economically viable process of MYLO based will be mapped.

Doel van het project

Biobased side streams are used for the development and production of new materials (non-food) that substitute leather and leather like materials. The worldwide market demand for natural high-quality sustainable (vegan) leather alternatives is huge. The European market for leather represents 48 billion €. (Eurostat:
This is a strong driver for the actual implementation of this technology. Using spent substrates and side streams of the process for additional different and new material applications will make this system exceptionally circular in nature. Principally the production takes place in existing (mushroom) farms and as such a whole new industry can be rapidly developed (invigorating a traditional industry currently under pressure by Eastern European and Asian competition). Production facilities are already largely in place and investments to adapt to producing the new materials are limited, enabling fast implementation. Growers have the know-how and craftmanship to grow mushrooms and a transition to growing mycelium should be relatively easy.

Relatie met missie (Motivatie)

This process is using side streams from agricultural crops, growing mycelium, and by re-using the spent substrate either in agriculture or as new sustainable materials. Hence, the whole production chain will basically be circular and sustainable. Mushroom growers in the Netherlands and Western-Europe (priority 47 Internationalization) can adapt the process to grow mycelium in their systems, use local side streams and gain a sustainable income by producing a non-food biobased leather alternative. The mycelium has a long(er) shelf life than mushrooms and does not need to be manually picked. The spent substrate can be valorized into new food and non-food applications. It could grow into a whole new agricultural non-food production line in countries where there is mushroom cultivation. Both mushroom production and the supply of substrate as well as complete cultivation systems for mushroom industry are key industries in the Netherlands and the Dutch are recognized throughout the world for this expertise ( total mushroom production value of 300M€, which must at least be doubled when including substrate and equipment production).

Geplande acties

The aim of this project is to develop an economically feasible agricultural circular sustainable culturing process for natural leather-like material based on fungal mycelium.
The following results are envisioned:
a. Selection of fungal strains able to produce mycelium on various agricultural side streams.
b. insight into the characteristics (functional properties) of mycelium and material produced by different selected fungal strains on various substrates.
c. technically feasible application routes for spent substrate and material side stream(s)
After 2 years, at the end of this feasibility study project, a route to a technically and economically viable process of material based will be mapped. Choice can be made with respect to the most promising strains and/or substrate and processing route.

Naam projectleider

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