Raw material scarcity and the pollution of the environment caused by plastic-based materials is advancing continuously, making it one of the biggest problems of the 21st century. This issue is moving into the focus of society which creates an increasing attention to circular economy approaches whose success is not based on the consumption of fossil raw materials. It supports the transformation of the petroleum-based economy to a sustainable, post-fossil economy that renounces fossil fuels and raw materials such as coal, oil and natural gas, and is thus an important pillar of the bioeconomy.

In Germany alone, around 20.7 million tons of the petroleum-based plastic "expanded polystyrene" (EPS) were produced in 2010, of which only a fraction is recycled.1 In addition to the main problem of very energy- and cost-intensive recycling, very high and specific transport costs are also incurred due to the low bulk density of the material.2 Thus, alternative materials, such as mycelium composites produced from regional raw materials, provide benefits not only from an environmental, but also from an economic perspective. Fungtion, a young biotechnological startup from Berlin, has set itself the goal of replacing petroleum-based plastics, first and foremost EPS, by upcycling residual materials from agriculture.

Agricultural by-products, such as rapeseed straw, plant residues left on the field after harvesting rapeseed, or hemp hurds, wood-like particles left over from the mechanical deforestation of plant stalks, serve as a source of nutrients for the mycelium, the root and communication network of fungi. For quite some time, research has been conducted into so-called fungal composites with the aim to establish them as an alternative to plastics in the packaging industry, but also as insulation or construction materials. The fungus is able to use lignin, a hydrocarbon compound embedded in the cell wall of grasses, shrubs and trees, and cellulose, the main component of plant cell walls that is normally difficult to degrade, as a carbon source. It grows through the loose substrate, connecting the individual particles and filling the interstices with its whitish microfilaments, the mycelium.

The mycelium is the totality of a fungus's innumerable filamentous cells, a fine, white meshwork located at the end of the stem and hidden in the soil or, in the case of tree fungi, in the wood. Although the mycelium makes up the largest part of the fungus, it is usually only the fruiting bodies, the reproductive organs of the fungi, that are associated with them because the meshwork grows underground and is thus hardly noticed.

In recent years, mycelial materials have received increasing attention. Especially in the U.S., the first companies have begun to use their application possibilities. The implementation of mycelium-based materials in technical applications also offers great potential. At the end of the manufacturing process, the fungus has produced a kind of biological foam from the loose substrate pile with comparable and in some cases even better properties than classic EPS.

For this purpose, tree fungi, collected once from the forest, are brought into pure culture and then used to produce biomaterials. An absolutely harmless fungus is used, which is not genetically modified and is killed by drying at the end of the manufacturing process. With fungtion, there is now a German start-up that has dedicated itself to the material. The team is convinced of its vision to replace petroleum-based foams step by step. The main focus is on the shock-absorbing properties. The material will be used to make helmet inner shells, classically consisting of EPS.

By using agricultural residues as substrate, they are put to a positive intermediate use before they are finally composted. In addition, farmers are saving costs because they do not have to pay for the disposal of the residual materials. Designing future production processes, especially in urban waste management, in terms of a circular economy is essential for sustainable social change. Fungal composites not only allow this in the manufacturing process itself, but can also be integrated into other production streams to serve as a source of nutrients and carbon. Fungtion aims to address current challenges with this innovative solution approach and initiates the transformation to a more sustainable, post-fossil economy.

Utilizing the mycelia of fungi and agricultural by-products such as rapeseed straw and hemp hurds is an example of the transformation of residual materials into valuable materials that LEROMA aims to stimulate in order to reduce the waste of valuable raw materials and harmful CO2 emissions generated by their disposal.