You Could be Wearing Leather Clothing Made Out Of Mushrooms Soon

You Could be Wearing Leather Clothing Made Out Of Mushrooms Soon

CU Denver researcher advances bio-fabricated materials made from roots of fungi to introduce a scalable, economical, and sustainable alternative to animal-made garments.

June 20, 2024

Red leather is one of the hottest fashion trends for 2024, and CU Denver Assistant Professor Assia Crawford, PhD, is working hard to give the fashion industry and consumers a scalable, economical, and sustainable alternative by turning to mushrooms instead of animals. 

Crawford has been growing mycelium to create a fungi-based leather substitute that uses a new paste media she and her team developed in a CU Denver lab.

Her research findings, recently published in the Cambridge University Press journal Research Directions: Biotechnology Design show great potential because mycelium materials offer a low-cost and environmentally sustainable alternative to some petroleum-based materials. They are also a more sustainable and ethical alternative to animal-derived leather and can be grown on a wide variety of agricultural and industrial organic waste or side streams.  

“As researchers, we have a responsibility to continue developing better materials in response to the climate crisis, which is what the study aims to do,” said Crawford, who serves as an assistant professor in technology in CU Denver’s College of Architecture and Planning. “Bio-design methods like the ones explored in our study contribute to developing high-quality, scalable, biodegradable material alternatives.” 

With greater uptake and scaling of production, these products have the potential to become more economically viable than established traditional materials. They can also be optimized to meet consumer demands, she said. 

The researchers examined mushroom compatibility for the purposes of leather mat development by using two fungal species: Ganoderma lucidum (reishi), a medicinal mushroom widely used within bio-design; and Pleurotus djamor (pink oyster), a gourmet mushroom that has the tendency to quickly colonize the substrate and enter the fruiting stage, which means it produces mushroom fruit bodies quickly.  

By carefully formulating a new paste substrate for the mushrooms to grow in, the researchers sought to enhance nutrient availability from the mushrooms; enable their scalability; and streamline their cultivation processes.  

The Growing Process

Different species of mushrooms have their own preferences for substrates, which means that an important part of growing mushrooms—and mycelium leather—involves matching one’s mushrooms with the best available substrate. Common substrates include straw, coffee grounds, and manure.  

Mycelium leather is produced by growing the fungus as a biological tissue or mat on top of a liquid or solid substrate, or as fungal biomass in submerged liquid fermentation. Solid-state fermentation offers superior growth conditions. However, liquid-state surface fermentation allows mycelium mats to be harvested more easily, although growth rates are slower due to lower oxygen levels. Lastly, liquid-state fermentation gives improved yields, yet the product must be further manipulated to produce a mycelium mat. 

As a response to these challenges, the researchers developed a new method for cultivation based on a paste consistency substrate that offers the benefits of high-nutrient content as well as small nutrient particle size, which aids the uptake of nutrients. 

The researchers found that by using this specific paste, they were able to grow thicker mycelial mats over a shorter period of time in comparison to growth on nutrient-enriched agar or liquid culture. Moreover, further benefits of this growth method became apparent during the harvesting stage, as the mats had grown strong enough that it was possible to peel them off the growing surface in bigger pieces without needing to cut the sheet.

About Assia Crawford

Crawford teaches in CU Denver’s College of Architecture and Planning, and her research focuses on the development of biological material alternatives and digital fabrication practices. Her work lives at the intersection of architecture, science, and critical theory and employs experimental and speculative design to address ecological challenges. Crawford holds a doctoral degree in architecture from Newcastle University, where she specialized in bio design and experimental fabrication. She also recently published a book: Designer’s Guide to Lab Practice. An ARB registered architect, Crawford previously held positions as the architect for the Hub for Biotechnology in the Built Environment (HBBE) and artist-in-residence at the Wellcome (sic) Trust Centre for Mitochondrial Research. She has published multiple papers in peer-reviewed journals and was the site chair for the prestigious ACADIA conference, hosted by CU Denver in 2023. She joined CU Denver in 2022 and set up the Wild Futures Lab on campus. The experimental wet lab is dedicated to the development and fabrication of biological materials. Since its inception, the lab has hosted numerous bio-design classes to introduce the discipline to graduate and undergraduate students. 

Co-authors on the study are research assistant and alum Sarah Ruthanna Miller, Assistant Professor of Integrated Biology Sara Branco, post doc Jessica Fletcher of CU Denver, and Associate Professor of Biomedical Engineering Dimitar Stefanov of Middlesex University in the United Kingdom.