Comparison of novel fungal mycelia strains and sustainable growth substrates to produce humidity-resistant biocomposites

Zeynep Tacer-Caba,Jutta J Varis,Pauliina Lankinen,Kirsi S Mikkonen

doi:10.1016/j.matdes.2020.108728

Abstract

Fungal mycelia are versatile, highly productive and sustainable sources for biocomposites to replace conventional plastics. However, with only very few fungal strains that have been characterized, numerous strains still remain unexplored as potential competitors against traditional non-biodegradable materials. Moreover, the functionality of mycelium composites at commonly occurring, challenging ambient conditions such as changing humidity and temperature is not well characterized. Here we evaluated the properties of the fungal composite material produced by novel fungal strains, including Trichoderma asperellum and Agaricus bisporus, grown on oat husk and rapeseed cake after oil pressing. The results showed that the mycelium composites were hydrophobic and strong, particularly when grown on rapeseed cake. A. bisporus grown on rapeseed cake exhibited increased stiffness after humidity was successively increased and decreased. The moisture-resistance of these novel mycelium composites is encouraging for novel sustainable material solutions.

Highlights

Use of numerous types of materials in commodities such as plastics and polymers is an essential aspect of modern living
Trichoderma asperellum (TA), Agaricus bisporus (AB), P. ostreatus (PO), and Ganoderma lucidum (GL) were selected for detailed characterization, since these strains grew rapidly and formed intact, homogeneous and rigid mycelium composite structures
TA and AB are previously unexplored strains in mycelium composites, and they were compared with the known strains of PO and GL to examine the unknown potential for bio-based composites and reveal any differences compared to the known strains

Summary

Introduction

Use of numerous types of materials in commodities such as plastics and polymers is an essential aspect of modern living. The substrates used to grow mycelium composites may be retrieved from industrial or agricultural waste streams, such as cereal straws, wood sawdust or other fibers, such as flax and cotton [11], or corn stove particles [12] These by-products enable fungal mycelial growth, as they have moderate amounts of carbohydrates, lipids, proteins, inorganic compounds, and water [13]. The present work aimed to 1) compare the growth and physical properties of mycelium composites from novel fungal strains grown on previously unused substrates, namely oat husk and rapeseed cake, and 2) characterize the novel mycelium composites at changing temperature and humidity, to thoroughly assess their material properties and evaluate the potential for their use at challenging conditions

Methods

Results

Conclusion