Fungi-based materials
Fungi-based materials

Fungi-based materials

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TL;DR

You will be hard-pressed to find another bio-based material source with as many potential applications as fungi. New processing techniques allow for greater customization, and producers can make everything from consumer goods like leather and paper to construction materials like insolation and bricks. Plus, the pun possibilities are almost endless.

What are fungi?

Fungi are an entire kingdom of organisms (in the way that plants and animals are also kingdoms), including yeasts, molds, and mushrooms. The mushrooms that we all know and love are actually just the fruiting body of many species of fungi (see below). The bulk of a mushroom-producing fungus is actually made up of its mycelium, or root-like structure.

More than 146,000 species of fungi have been identified, but there may be as many as 1.5 to 12 million yet to be discovered.

Source:
Source: Undecided (2021)

Depending on the species, fungi can be beneficial or harmful. Certain species help plants fix nutrients to grow and provide food for animals and people. Other types of fungi are “aggressive pathogens” that attract insects, can cause disease in plants, extinction of animal species, and allergies or even death in humans. Certain mycotoxins can even penetrate the skin of humans.

Common types of fungi

Mycorrhizal

Grow underground and around the roots of plants, forming a symbiotic relationship that enhances plant growth.

Saprophytic

Source:
Source: Fungimap

Feed on decomposing plant and animal material. Responsible for many of the mushrooms you see when walking through the forest.

Parasitic

Attack and feed off of plants, animals, and other mushrooms. Parasitic fungi can kill their hosts.

Fungi-based materials

This is just a snapshot of some of the alternatives available. It is not intended to be comprehensive or a list of suggested solutions. If you've encountered any great uses that aren't listed here, please feel free to get in touch.

Mycelium products

When creating products from mycelium, the root network is allowed to grow but never to produce fruit (the mushroom). Cultivating mycelium requires tightly controlled and sterile conditions (light, airflow, temperature, humidity, etc.) in either a bio-reactor or industrial fermenter (solid-state fermenter). There are two primary processes:

  • Composite mycelium materials (CMM): An organic material (hemp, woodchips, agricultural waste, etc.) is pressed into a mould, and mycelium is allowed to grow through it, filling in the gaps and essentially glueing the material together. The growing process is stopped through dehydration (either by heating or compressing the material).
    • Results in a rigid and foam-like product. Characteristics are dependent on the filler material.
    • Biodegradable, often in a matter of weeks.
  • Pure mycelium materials (PMM): Mycelium is grown without a substrate but is still connected to a nutrient source. This process can be combined with further processing techniques and offers more control over the resulting product.
    • Customizable and flexible. Characteristics depend on the type of fungi used to grow the mycelium.
    • Can be coated in chemicals to make them longer-lasting, but this means they will not biodegrade naturally.

Mushroom products

There are 35 species of mushrooms being commercially cultivated, but only 10 have reached industrial cultivation. These mushrooms are mainly used for food and medicine, but also have value as raw material.

  • Mushroom waste: When mushrooms are harvested, a portion of the stalk is left behind and up to 20% of the volume produces will not meet commercial standards. The wasted and leftover mushroom parts can be processed into many different kinds of material.

Material types

Looking beyond food, there are many different types of materials that can be made from fungi.

  • Textiles: A patent on the use of fungi to produce a wide variety of textiles expired in 2018, allowing more companies to develop the technology.
    • Leather: Mycelium leather can actually outcompete synthetic leather in terms of tensile strength and resistance to tearing. However, it does break down quickly when exposed to water if it has not been treated (treatment typically means coating it in plastic which can result in the material not being biodegradable).
      • Source:
      Source: Gandia et al., 2021
    • Woven fabric: This seems to be in development, but possible. MycoWorks has patented a method to orient mycelium growth patterns replicating woven fabric (Reishi). Being able to direct the structure means they can theoretically create stronger materials.
  • Absorbents: Can be used to produce animal bedding, cat litter, and even material to clean up oil spills.
  • Electronics: Mycelium combined with metal salts can be (theoretically) grown into wiring patterns for circuit boards.
  • Packaging: Ecovative makes an alternative to styrofoam from hemp and mycelium that biodegrades within weeks. It can be grown into any desired shape and is currently being used by Ikea and Dell.
  • Construction: Mycelium is fire resistant, water repellant, and has high thermal insulation performance but still allows airflow. It is currently used to create carbon-negative acoustic wall panels, building insulation, bricks, and paste. Some are even looking to grow entire buildings from mycelium.
  • Paper: Paper-like material can either be grown directly or produced by growing pellets of fungi that are then agitated into a pulp. The pellet process is faster but very sensitive to contamination.
  • Cosmetics: The chitin in mushroom waste can be used to produce a preservative for cosmetics, replacing fossil-fuel-based antioxidants. Other extracts are known to have moisturizing, anti-inflammatory, antimicrobial, anti-aging, and even sun protecting qualities.

Other fun(gi) applications

  • Environmental decontamination: When grown on contaminated soils or water sources, fungi can remove pollutants like dye, pesticides, herbicides, heavy metals, and pharmaceuticals. The process is called mycoremediation.
  • Waste processing: Multiple strains of fungi have been shown to break down roofing shingles, disposable face masks, and plastic products.
  • Boosting forest growth: The vast underground networks formed by mycorrhizal fungi play a symbiotic role with other plants in an ecosystem by transporting nutrients and protecting roots from toxins and pathogens. Boosting these fungal networks can enhance tree growth, make forests more resilient to climate change, and increase carbon sequestration.

Important considerations

Risk assessment is an important step for those working with fungi cultivation, especially during the development process for new species.

Source:
Source: van den Brandhof & Wösten, 2022
  • Preventing the spreading of spores: A single mushroom can produce a billion spores within one day. If those spores end up on clothing, they can easily be introduced into new environments.
  • Source of nutrients and growth substrate: Larger production volumes = more material needed. Ideally, this material should be locally sourced, otherwise, the carbon footprint increases.
    • ⚠️
    Peat is a popular growing medium for mushrooms, but peatlands are an incredibly important carbon reservoir. The amount of peat used by UK mushroom growers alone is enough to release 11,000 tonnes of CO2 each year—equivalent to about 2,600 cars. The UK is considering banning peat in horticulture by 2028.
  • Cultivation and processing methods: Some species of fungi will only die (thus ending the growing process) when exposed to temperatures >100C.
  • Waste: Growing mushrooms produces a lot of waste. Every 1 kg of mushrooms grown results in 5-6 kg of byproducts and waste—most of which ends up in a landfill.
  • Materials used to treat the products: This is especially important when looking at fungi-based textiles. Even if no plastics are involved in the production process for a material itself, once it is in the hand of the fashion brand, the standard practice is to apply a plastic coating that makes the product resistant to water, wear, and tear.

The market

  • The mycelium market was valued at $2.95 billion in 2021 and is predicted to be worth $5.49 billion by 2030. The wider mushroom market will likely hit $115.8 billion by 2030.
  • A patent survey found 47 patents and patent applications related to fungi-based biomaterials between 2009 and 2018, mostly in the US (28) and China (14). A more recent survey found over 70 published between 2018 and 2021.
    • A major patent related to fungi-based textiles expired in 2018, and this may be the reason why there are so many (20+) companies working on textiles at the moment.

Comparison to other bio-materials

Source
Products
Upsides
Downsides
Fungi
Textiles, packaging, construction, electronics, absorbents, medicine, paper
Can be grown to fit almost any need
Potential for invasive species, cultivation process can be costly
Cactus
Textiles, plastic, cosmetics
Not cut down to harvest, uses little water, no fertilizers or pesticides, promotes biodiversity
Can become invasive
Algae
Textiles, plastic, dyes, cosmetics
Traps CO2, cleans water, protects coasts
Potential for invasive species, too much in one place can be a CO2 source
Cork
Textiles, construction,
Not cut down to harvest, promotes biodiversity, traps CO2, prevents soil erosion, naturally waterproof
Requires skilled labour, which can make it more expensive than alternatives
Fruit (apples & pineapples)
Textiles
Reduces food waste (uses parts typically discarded)
Composite of around 50% synthetic materials
Starch (corn, potatoes, cassava)
Plastic, packaging,
Widely available, inexpensive
Needs separate waste processing (will contaminate plastic recycling); redirecting land that would have been used for food
Bamboo
Textiles, construction materials, plastic-alternative, paper
Fast-growing, strong, low-weight, no fertilizers or pesticides, traps CO2,
Will shrink, textiles require chemical processing, construction materials need preservation
💡
Biodegradable ≠ Sustainable. Petroleum-based plastic can be compostable, but that doesn’t make it sustainable.

Resources

Last updated: Nov 2022