When mushrooms go in the lab: growing design

Few years ago, materials from mushroom mycelium were successfully introduced as a green alternative to synthetic plastic packaging, foams and construction materials. Today unique properties of mycelium-based materials excite and inspire scientists, artists and designers to use them for production of incredible environment friendly solutions for fashion and everyday life.

Are you ready to discover mushroom potential and grow materials?

Mushrooms are part of the fungi kingdom that is more closely related to us than it might be expected. Fungi are one of the oldest complex land-based life ever found on Earth and can be found as single-celled organisms, like yeast, and as multiple-celled organisms, like mushrooms.

The actual mushroom itself is a reproductive system that produces spores. Long thin cylindrical structures called hyphae are expanded from the spores, branch out and form tree-like network structure, — mycelium — the vegetative part and the root-like structure of mushrooms and other fungi.

Mycelium is mainly composed of natural polymers as chitin, cellulose, glucans, proteins, etc., so it is a biopolymer which branching density, network and properties, are strongly controlled by nutrition and environment conditions.

Schematic illustration of mycelium at different scales. A) Structure of mushroom: fruiting body (the part seen above ground, reproductive structure) and mycelium. B) Mycelium microstructure: branched network of micro-filaments (hyphae). C) Schematic overview of a hypha that is formed by several cells. D) Structure and composition of the single hyphae cell wall. One of the most important components of mycelium cell walls is chitin which is also found in the outer skeleton of insects and arthropods. Chitin is inelastic, very strong and provides rigidity and structural support of the thin cells of the mycelium (Sourced and adapted from Haneef M., 2017)

Mushrooms are the great members of “decomposers” community which allow the ecosystem to have energy and nutrient input back into it. Mycelium releases digestive enzymes that are used to breaking down complex organic compounds from dead organisms and waste materials into soluble nutrients, such as simple sugars, nitrates and phosphates. Fungi digest food outside of their “bodies” and then absorb the nutrients into their cells. Hyphae cells then begin to grow around the feeding substrate and waste, binding it together to form a shape… Due to unique structure and composition such shapes inspire scientists and designers to create huge amount of different mycelium-based materials.

Model of plant cell degradation and mycelium network formation. A) Mycelium colonises and degrades organic substrate (i.e. plant cell). B) Mycelium network formation. Degradation products (i.e. sugars, nitrates, phosphates) are used as nutrients for hyphae growth and its branching

Mycelium-based materials are produced by two alternative approaches: either using the ability of mycelium to bind other substances within its network to form a material (mycelium-based composites) or collecting a liquid culture of mycelium (pure mycelium).

Mycelium-based composite (left) and pure mycelium (right) (Sourced: Karana E., 2018)

Pure mycelium materials usually look like leather, paper or plastic with different visual, mechanical and functional properties. Mainly, such materials obtain in static or machine-shaken containers, when mycelium liquid culture grows, forms a mat of hyphae at the surface of liquid and dried.

Generally, mycelium-based materials are composites and produced in four steps. i) Substrate choice and preparation. The substrate should provide necessary nutrients and any specific needs for the growing mycelium (i.e. any cellulose-rich materials). Important: substrate significantly influences on the resulting material function and properties! ii) Substrate inoculation with mycelium. During colonization process and mycelium growth the optimal conditions of light, temperature, gas concentration, pH and moisture should be controlled because they can dramatically change properties and quality of the resulting mycelium composite. iii) After 2 or 3 weeks the growth of the mycelium is stopped by heating. iv) Treatment of the mycelium composite material with a surface finishing, etc., if needed.

Scheme of the mycelium composite materials fabrication process

Mycelium-based materials have very well controlled structural and mechanical properties, achieved by exploiting different factors and nutrient substances. All chemical, physical or biological variations allow to create palette of materials with numerous properties and its combinations.

A range of chemical, physical and biological parameters which can influence on the mycelium material resulting properties (Sourced and adapted from Karana E., 2018)

The possibilities are endless. Mycelium based materials could be very hard, soft, porous, weightless, could look like leather, plastic or paper, could have any texture, patterns and colors, could demonstrate high-temperature performance, corrosion resistance or conductivity, covering the requirements of a number of potential applications in architecture, design and fashion, for example.

Key benefits

Technology allows to produce sustainable polymeric materials that will not be a source of pollution to our planet.

Mycelium-based materials manufacturing process is carbon-negative, non-toxic, animal-free, low cost, scalable and requires minimum energy for production (materials are self-growing).

Mycelium-based materials are durable, versatile, engineerable and customizable, it could be grown to nearly any size, shape, tick, density and patterns.

Transformation of mycelium physical statement during fabrication process allows to create advanced biomaterials like leather, soft-foams, building materials and biopolymers with absolutely different properties for apparel, aerospace, automobile industries, architecture and design.

And more than attractive… Mycelium could grow on the low quality agricultural waste streams such as straw, sawdust, wood chips, etc. and transform it to the unique nature materials for everyday life. Inspiring power of nature! Amazing!

Are you ready to wear mushrooms and build a better world?

Companies

Ecovative Design (USA, 2007) is a leading expert in the research and development of mycelium-based materials. Company aims to remake the way the world makes materials and products by engaging the natural actions of mycelium. Company develops technologies allowing to produce home-compostable bio-materials based on mycelium to replace plastics, foams, and other harmful materials. In 2018 biomaterials company Bolt Threads using technology licensed from the Company and adapted it, launched the first bag from leather-like material Mylo™.

Founded in 2013 USA-based company Mycoworks focuses on the developing of natural alternatives to leather, engineered wood, and plastics. Company’s pioneer technology allows to transform agricultural waste into a new material that can compete with leather using the rapid, sustainable, animal-free and carbon negative manufacturing process. Obtaining materials are soft, hydrophobic, breathable and fully biodegradable. In the same time, it has durable, versatile, engineerable and customizable properties (any desirable thickness, patterns, density and 3D features). Product can be tanned, dyed, embossed and formed using the same process as animal leathers, to achieve the same finish.

Italy based company Mogu (2015) develops and promotes the mycelium-based technology allowing to transform agricultural by-products into strong naturally-grown functional biomaterials for the architecture, fashion, automotive, construction, packaging and other applications.

Mycotech (Indonesia, 2012) is a materials science company that creates sustainable building and structural materials based on mycelium. In the summer 2018 Company announced the limited edition of watches made entirely from organic materials — wood and mycelium veneer.

MycoTEX project (The Netherlands, 2016) aims to create lab-grown custom-made clothes from biodegradable material based on mycelium. Combining science and fashion and using 3D-based moulding, MycoTEX produced in 2018 the first wearable garment and shopper prototypes.

Instead of final words…

References:

Haneef M., Ceseracciu L., Canale C., Bayer I., Heredia-Guerrero J.A., Athanassiou A., Mycelium: fabrication and tuning of physical properties. Sci Rep. 2017; 7: 41292 (DOI: 10.1038/srep41292)

Jones M., Huynh T., Dekiwadia C., Daver F., John S. Mycelium Composites: A review of engineering characteristics and growth kinetics. Journal of Bionanoscience. 2017; 11(4):241–257 (DOI: 10.1166/jbns.2017.1440)

Islam M.R., Tudryn G., Bucinell R., Schadler L., Picu R.C. Morphology and mechanics of fungal mycelium. Sci Rep. 2017; 7: 13070 (DOI: 10.1038/s41598–017–13295–2)

Appels F.W., Dijksterhuis J., Lukasiewic E., Jansen K.M.B., Wösten H.A.B., Krijgsheld P. Hydrophobin gene deletion and environmental growth conditions impact mechanical properties of mycelium by affecting the density of the material. Sci Rep. 2018; 8: 4703 (DOI: 10.1038/s41598–018–23171–2)

Grimm D. and Wösten H.A.B. Mushroom cultivation in the circular economy. Appl Microbiol Biotechnol. 2018; 102: 7795–7803 (DOI: 10.1007/s00253–018–9226–8)

Karana E., Blauwhoff D., Hultink E.-J., Camere S. When the material grows: a case study on designing (with) mycelium-based materials. Int J Design; 2018; 12(2): 119–136