How mushrooms could replace materials like plastic and leather

Scientists at McMaster University have unlocked new possibilities in sustainable material design using fungi. Specifically, the common split gill mushroom (Schizophyllum commune) shows immense potential. It contains over 23,000 mating types, making it a genetic goldmine for innovation.

These mushrooms form mycelium, a dense network of fibers. This structure, once processed, can become biodegradable replacements for plastics, leather, and foams. But even when grown identically, the resulting materials vary. Strength, flexibility, and water resistance often differ.

To address this, researchers studied 16 strains – four monokaryons and 12 of their dikaryotic offspring. These strains were carefully bred and tested for material yield and quality. They revealed that both nuclear and mitochondrial DNA influence the traits of resulting films.

Mushrooms, biodegradable leather, and plastic 

The team used a liquid fermentation method to grow mats of mycelium over 12 days. They applied two chemical crosslinkers: polyethylene glycol (PEG) and glycerol. These helped turn the fluffy mats into solid films.

“It’s possible to use natural genetic variation that already exists in nature and to make combinations that will potentially fit into all kinds of materials, not just one,” said Jianping Xu, a professor of biology at McMaster University.

Each film showed distinct features. Glycerol made soft, pliable sheets. PEG made films that were stiffer and stronger, but also more brittle. For instance, the αδ strain treated with PEG had a ductility over 41%, while others broke quickly.

Statistical analysis revealed something key: mitochondrial and nuclear genotypes interact with crosslinkers in complex ways. Some combinations absorbed water better, others yielded higher strength or elasticity. No single strain or treatment outperformed all others.

Some mushroom films were stronger

The researchers used electron microscopes to study the films’ fiber structure. PEG-treated films preserved more aerial hyphae and had rougher surfaces.

Glycerol-treated films were smooth and gelatinous. This roughness may influence where and how the film breaks.

When they tested tensile strength, PEG films often reached higher stresses but lacked flexibility. Glycerol films stretched more before breaking. Some films from the γ family had excellent energy absorption, especially βγ and βδ combinations.

Water behavior differed between treatments. PEG films became highly absorbent, rapidly soaking up water through superwicking properties.

Glycerol films showed consistent water attraction with 77-degree contact angles, making them ideal for packaging applications and wearable material uses due to their predictable moisture interaction.

Eco-friendly mushroom materials

This study is not just a lab exercise. It presents a real strategy for producing environmentally friendly materials using biology. Rather than engineer every trait from scratch, scientists can mix and match natural genetics.

The work also emphasizes scalability. Liquid-state surface fermentation is easier to replicate and scale than older methods. The researchers propose using protoplast fusion or selective mating to further expand material options.

Crosslinker selection adds another layer. PEG boosts stiffness but at the cost of flexibility. Glycerol preserves stretchiness but lowers strength.

The future lies in customizing the process for different industrial needs – fabrics, construction, or biodegradable wraps.

Sustainable materials from mushrooms

The study does have limitations. The untreated control films disintegrated, making them impossible to test. Also, the team couldn’t explore every genetic combination possible, which opens the door for more research.

Standardizing how strains are selected and linking genetic traits to material qualities still pose major hurdles. But despite these gaps, the work lays a strong foundation for future advances.

It proves that material properties can be shaped not only through processing or chemical treatments, but also by selecting specific mushroom genes.

This approach could shift how we think about designing sustainable materials. Instead of forcing nature to adapt to our needs, we can now search within nature’s own library of genetic variation.

The split gill mushroom, with its wide diversity, gives scientists a rich resource to explore. The message is simple: nature already provides the recipes.

The study is published in the Journal of Bioresources and Bioproducts.

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