Mycelium-based composite (MBC) is being developed and researched in multiple commercial markets as an alternative sustainable material. MBC utilizes the mycelium ability to create a web-like structure in lignocellulosic structures. However, producing the material in a natural environment and subjecting it to various tests; the study aims to examine the distress of the southern Swedish climate on MBC grown in different substrates. The selection of substrates are based on their compatibility to fungal growth, the substrates are also locally sourced and grown. This is to explore MBC material production with a focus on circular economy as biodegradable material in architecture could help develop a reuse and recycle system. Various tests were done on the different substrate MBC to determine its characteristics, limitations and opportunities. The tests were developed with a focus on architectural construction and the southern Swedish climate; meaning experiments including MBC reaction to fire, water and temperatures. The results are based on the different MBC materials reaction, this ends with a description on how the materials could be used and developed in the future.

The current anthropogenic practices of generating single-use waste streams in agriculture, forestry and manufacturing industries have created a host of environmental health problems. Humankind's reliance on non-renewable resources for the production of food and materials, and its current approach to product design and development, are clearly unsustainable. One mitigation strategy to reducing industrial and municipal solid waste, as well as environmental pollution, can be found in using white rot fungi to valorize our planet's most abundant and regenerative natural resource – plant biomass containing lignocellulose. From residual dry plant matter, white rot fungi can be employed through a solid-state fermentation process to produce a variety of edible, nutrient-dense saprotrophic mushrooms in addition to biologically augmented composite materials. Under the framework of the circular economy, agricultural and forestry byproducts with fibers containing lignin, cellulose and hemicellulose may be used as a feedstock for the production of both food and biomaterials – keeping plant biomass revolving through multiple cycles of use and reuse for a variety of product outputs that are biodegradable and help to sequester carbon. In this study, mushrooms were grown on a variety of lignocellulosic substrates derived from agricultural and forestry residues. Hemp-based substrates performed the best of the feedstocks with regard to mushroom yield and mycelium colonization time. Additionally, a number of mycelium composite products were designed and fabricated in this study using residual lignocellulosic plant biomass, including: insulation bricks, acoustical panels, and biodegradable planter pots. In particular, spent mushroom substrate containing hemp hurd and other agricultural and forestry residues showed significant potential in upcycling lignocellulosic plant biomass for the production of both mushrooms and mycelium materials. Regenerative design practices demonstrated how food and materials can be generated from the same lignocellulosic feedstock; therefore, reducing waste, circulating products and materials, and ultimately regenerating nature. / Master of Science / Environmental pollution and natural resource scarcity have encouraged exploration into using biologically based materials for the production of more ecologically friendly products. By valorizing the Earth's most abundant, renewable natural resource for the production of food and materials– dry plant matter containing lignocellulose – waste is reduced, carbon is stored, and materials can remain upcycled through multiple generations of production. Lignocellulosic residues – natural fibers containing the biopolymers lignin, cellulose and hemicellulose – have recently been given increased attention due to their ability to be aggregated and grown into low-cost, lightweight materials using white rot fungi. Mushroom farming has historically valorized lignocellulosic agricultural and forestry residues to grow an edible, nutrient-dense food crop. This thesis investigates the potential of various agricultural and forestry residues for the production of mushrooms and mycelium-based lignocellulosic composites. Furthermore, this study explores the utilization of spent mushroom substrate for the production of several mycelium-based composite products within the framework of the circular economy. Hemp-based substrates demonstrated significant potential in both mushroom production and mycelium composite fabrication, outperforming other agricultural residues in this study with regard to mushroom yield and speed of mycelial growth of Pleurotus ostreatus. More research into the tunable lignocellulosic substrate compositions will continue to help advance mushroom production and mycelium-based composite generation as environmentally friendly materials and production practices continue to gain interest.