Japanese researchers develop new mycelium-based packaging technology

09 Jan 2024 --- Researchers from Shinshu University, Japan, have found a simple way of obtaining mycelial fibers, the cells found in fruiting mushroom bodies, by bleaching them under sunlight to keep their mycelial structures intact. 

The “mycelial pulp” can be used as an environmentally friendly material for making leather and packaging owing to its “excellent” formability. A recent ACS Sustainable Chemistry & Engineering paper, published in November, provides a simple and effective way of obtaining mycelial pulp and fibers from mushrooms without destroying their structure. 

“Mushrooms, previously known primarily as a food resource, will now be utilized in everyday household items, allowing people to choose products that are safe, reliable and environmentally friendly,” says assistant professor Satomi Tagawa from the Faculty of Engineering at Shinshu University, who led the study. 

Dr. Tagawa conducted the study with her team members, Dr. Hiroya Nakauchi, recipient of the Research Fellowship for Young Scientists of Japan Society for the Promotion of Science (JSPS) and Dr. Yoshihiko Amano, professor at the Faculty of Engineering at Shinshu University.

Solution to plastic pollution 
Every year, humans generate millions of tons of waste, and a reported 38% of that waste ends up in landfill, stress the scientists. A significant portion of this waste consists of plastic or petroleum-based materials that can neither decompose nor degrade. This issue led the Japanese scientists to develop effective and environmentally friendly materials.

The researchers obtained bleached white mycelium fibers from reishi and enoki mushrooms while preserving their microscale mycelial structures (Image credit: Shinshu University).The mycelium fibers from the fruiting body contain proteins, chitin and polysaccharides, suitable for making various packaging materials, soundproofing and textiles. 

The researchers explain that the fibers are versatile, have low environmental impact, are biodegradable and have a low production cost. However, conventional chemical or mechanical treatments used to obtain mycelium fibers have notable shortcomings. Many extraction processes tend to give the materials an unwanted color and often destroy their intricate mycelial structures, limiting their nanoscale applications.

Upcycling by-products 
The team treated the fruiting bodies of enoki mushrooms and the inedible reishi mushrooms with sodium hydroxide and hydrogen peroxide. They then bleached (or decolorized) the obtained substances by exposing them to sunlight. 

The now-white material was subjected to ultrasonic treatment to defibrillate the pulp at a mycelial level. This process produced a dispersion containing micrometer-sized mycelium fibers with intact mycelial structures, as verified by Fourier-transform infrared spectroscopy.

The fibers obtained via this process showed “excellent” deformability and could be used for designing products like 3D porous sponges, 2D films and 1D yarns.

The researchers stress that besides obtaining a versatile mushroom-based material, the approach makes a valuable addition to the scrap-and-build approach for fabricating mushroom materials, which can complement the existing bottom-up approaches. 

“This technology has opened possibilities for upcycling unwanted by-products generated by the mushroom industry and making mushroom materials more circular and easier to reuse. We believe that further research on such sustainable materials and methods could create new industries, provide employment opportunities and revitalize local communities,” remarks Dr. Tagawa.

“We hope this research will help reduce waste on our planet and promote the bioeconomy.”

Edited by Natalie Schwertheim