Researchers Develop Biodegradable Fungal Coating to Replace Plastic in Packaging and Textiles
- Gauri Khanna
- 6 hours ago
- 3 min read
Too long to read? Go for the highlights below.
• Scientists at the University of Maine created waterproof coatings using Trametes versicolor mycelium combined with cellulose nanofibrils, demonstrating resistance to water, oil, and grease
• The coating forms after 3-4 days of fungal growth at paint-layer thickness, requiring only heat treatment to inactivate biological activity whilst maintaining barrier properties
• The technology addresses plastic pollution from food packaging and textiles using food-safe, biodegradable materials accessible for industrial scaling
The ubiquity of single-use plastics in packaging and textiles represents one of modern industry's most intractable environmental challenges. Conventional plastic coatings contribute substantially to landfill accumulation and marine pollution, persisting in ecosystems for decades. Research published in ACS's Langmuir demonstrates a potential alternative: waterproof coatings cultivated from edible fungi that render paper, denim, and polyester felt resistant to liquids.
Mycelial Networks as Barrier Materials
Led by Caitlin Howell at the University of Maine, the research team focused on Trametes versicolor—commonly known as turkey tail—a polypore fungus possessing extensive underground mycelial networks. These networks, composed of fine thread-like structures called hyphae, exhibit inherent water-repelling properties. Rather than extracting or processing these properties, researchers cultivated the fungal material directly onto target substrates.
The methodology combined T. versicolor mycelia with cellulose nanofibrils (CNFs)—ultrafine fibres derived from wood pulp recognised for their strength and impermeability to gases and liquids. Materials including denim fabric, polyester felt, birch veneer, and paper were immersed in nutrient solutions containing fungal spores and CNFs. Over several days, mycelium grew sustained layers on these substrates.
The coating achieves paint-layer thickness after merely 3-4 days of incubation in controlled warm environments. Water droplets placed on treated surfaces formed spheres, indicating repulsion rather than absorption—a stark contrast to untreated materials where water spreads or soaks immediately. The composite film demonstrated barriers against n-heptane, toluene, and castor oil, suggesting resistance to broad chemical exposures beyond aqueous liquids.
Processing and Performance Characteristics
Following mycelial growth, samples underwent heat treatment for one day. This process inactivated the fungus, ensuring coating stability without continued biological activity, whilst enabling the film to dry and solidify. The treatment transformed living material into an inert barrier layer comparable to synthetic coatings in functional performance.
Visual modifications were notable: the coatings produced mottled patterns with hues ranging from yellow and orange to tan. Whilst these aesthetic characteristics might limit applications requiring uniform appearances, they offer distinctive natural aesthetics potentially appealing for product lines emphasising environmental credentials.
The underlying mechanism exploits complementary properties: mycelium contributes natural water-repellent chemistry and structural complexity, whilst CNFs provide mechanical strength and enhance impermeability to oils and oxygen. This combination yields coatings functionally competitive with conventional synthetic polymers.
Industrial Viability and Broader Applications
The technology arrives as global awareness of plastic-related environmental damage intensifies. Current proof-of-concept results suggest promising industrial scaling potential, given that core ingredients such as fungal spores, cellulose fibres, and common textiles or papers are widely accessible. The process utilises food-safe fungi, offering biodegradable solutions potentially integrable into existing manufacturing workflows without toxic chemicals or complex synthetic modifications.
Future research directions include optimising growth conditions, improving coating uniformity, and expanding durability under real-world conditions. Investigation of additional fungal species and nanomaterials may enable coatings with tailored properties for specialised applications spanning luxury textiles to food-grade packaging.
The research intersects with broader biofabrication efforts wherein living organisms and their products generate materials with enhanced environmental and mechanical properties. Mycelium-based products have recently attracted interest as biodegradable alternatives in leather-like fabrics, insulation panels, and acoustic absorption materials.
Environmental Implications
The fundamental proposition centres on nature's capacity to provide sustainable solutions to material science challenges. By replacing plastic coatings on ubiquitous consumer goods, fungal films might reduce pollution at source, aligning industrial materials with ecological cycles. Howell's work characterises how fungal biology integrated with nanocellulose technology forms functional coatings with minimal environmental impact.
As research advances, these naturally derived coatings could disrupt markets reliant on single-use plastics and synthetic polymers. The demonstrated resistance to water, grease, and oils positions the technology as a practical alternative aligned with sustainability goals and consumer demand for environmentally responsible alternatives. Whether the approach achieves commercial scale remains contingent on resolving uniformity challenges and demonstrating long-term durability across diverse applications.