Current state and future prospects of pure mycelium materials

Understanding the Role of Controlled Environments for Producing Mycelium-bound Composites: Advancing Circular Practices for Integrating Biotechnology into the Construction Industry

The architecture, engineering, and construction industry is undergoing a significant shift, steering buildings away from resource-intensive processes toward becoming instruments for climate mitigation. In this transformative landscape, integrating circular bio-based alternatives and reducing emissions through biotechnological and enzymatic processes have significant potential. Specifically, mycelium-bound composites have emerged as renewable alternatives for new materials and added-value wood products. Despite their numerous advantages, integrating these materials into current engineering practices presents challenges deriving from the complex nature of the material´s production process and the transfer from the laboratory to the industrial scale. In this regard, the design and engineering of novel controlled environments are fundamental in maintaining optimal growth conditions during material production. This, in turn, influences the overall material performance and potential use in construction.

A Review Delving into the Factors Influencing Mycelium-Based Green Composites (MBCs) Production and Their Properties for Long-Term Sustainability Targets

Mycelium-based green composites (MBCs) represent an eco-friendly material innovation with vast potential across diverse applications. This paper provides a thorough review of the factors influencing the production and properties of MBCs, with a particular focus on interdisciplinary collaboration and long-term sustainability goals. It delves into critical aspects such as fungal species selection, substrate type selection, substrate preparation, optimal conditions, dehydrating methods, post-processing techniques, mold design, sterilization processes, cost comparison, key recommendations, and other necessary factors. Regarding fungal species selection, the paper highlights the significance of considering factors like mycelium species, decay type, hyphal network systems, growth rate, and bonding properties in ensuring the safety and suitability of MBCs fabrication. Substrate type selection is discussed, emphasizing the importance of chemical characteristics such as cellulose, hemicellulose, lignin content, pH, organic carbon, total nitrogen, and the C: N ratio in determining mycelium growth and MBC properties. Substrate preparation methods, optimal growth conditions, and post-processing techniques are thoroughly examined, along with their impacts on MBCs quality and performance. Moreover, the paper discusses the importance of designing molds and implementing effective sterilization processes to ensure clean environments for mycelium growth. It also evaluates the costs associated with MBCs production compared to traditional materials, highlighting potential cost savings and economic advantages. Additionally, the paper provides key recommendations and precautions for improving MBC properties, including addressing fungal strain degeneration, encouraging research collaboration, establishing biosecurity protocols, ensuring regulatory compliance, optimizing storage conditions, implementing waste management practices, conducting life cycle assessments, and suggesting parameters for desirable MBC properties. Overall, this review offers valuable insights into the complex interplay of factors influencing MBCs production and provides guidance for optimizing processes to achieve sustainable, high-quality composites for diverse applications.

Integrating microfluidics and synthetic biology: advancements and diverse applications across organisms

Synthetic biology is the design and modification of biological systems for specific functions, integrating several disciplines like engineering, genetics, and computer science. The field of synthetic biology is to understand biological processes within host organisms through the manipulation and regulation of their genetic pathways and the addition of biocontrol circuits to enhance their production capabilities. This pursuit serves to address global challenges spanning diverse domains that are difficult to tackle through conventional routes of production. Despite its impact, achieving precise, dynamic, and high-throughput manipulation of biological processes is still challenging. Microfluidics offers a solution to those challenges, enabling controlled fluid handling at the microscale, offering lower reagent consumption, faster analysis of biochemical reactions, automation, and high throughput screening. In this review, we diverge from conventional focus on automating the synthetic biology design-build-test-learn cycle, and instead, focus on microfluidic platforms and their role in advancing synthetic biology through its integration with host organisms - bacterial cells, yeast, fungi, animal cells - and cell-free systems. The review illustrates how microfluidic devices have been instrumental in understanding biological systems by showcasing microfluidics as an essential tool to create synthetic genetic circuits, pathways, and organisms within controlled environments. In conclusion, we show how microfluidics expedite synthetic biology applications across diverse domains including but not limited to personalized medicine, bioenergy, and agriculture.

Robust myco-composites: a biocomposite platform for versatile hybrid-living materials

Fungal mycelium, a living network of filamentous threads, thrives on lignocellulosic waste and exhibits rapid growth, hydrophobicity, and intrinsic regeneration, offering a potential means to create next-generation sustainable and functional composites. However, existing hybrid-living mycelium composites (myco-composites) are tremendously constrained by conventional mold-based manufacturing processes, which are only compatible with simple geometries and coarse biomass substrates that enable gas exchange. Here we introduce a class of structural myco-composites manufactured with a novel platform that harnesses high-resolution biocomposite additive manufacturing and robust mycelium colonization with indirect inoculation. We leverage principles of hierarchical composite design and selective nutritional provision to create a robust myco-composite that is scalable, tunable, and compatible with complex geometries. To illustrate the versatility of this platform, we characterize the impact of mycelium colonization on mechanical and surface properties of the composite. We found that our method yields the strongest mycelium composite reported to date with a modulus of 160 MPa and tensile strength of 0.72 MPa, which represents over a 15-fold improvement over typical mycelium composites, and further demonstrate unique applications with fabrication of foldable bio-welded containers and flexible mycelium textiles. This study bridges the gap between biocomposite and hybrid-living materials research, opening the door to advanced structural mycelium applications and demonstrating a novel platform for development of diverse hybrid-living materials.

Heavy Metal Remediation by Dry Mycelium Membranes: Approaches to Sustainable Lead Remediation in Water

Lead contamination poses significant and lasting health risks, particularly in children. This study explores the efficacy of dried mycelium membranes, distinct from live fungal biomass, for the remediation of lead (Pb(II)) in water. Dried mycelium offers unique advantages, including environmental resilience, ease of handling, biodegradability, and mechanical reliability. The study explores Pb(II) removal mechanisms through sorption and mineralization by dried mycelium hyphae in aqueous solutions. The sorption isotherm studies reveal a high Pb(II) removal efficiency, exceeding 95% for concentrations below 1000 ppm and ∼63% above 1500 ppm, primarily driven by electrostatic interactions. The measured infrared peak shifts and the pseudo-second-order kinetics for sorption suggests a correlation between sorption capacity and the density of interacting functional groups. The study also explores novel surface functionalization of the mycelium network with phosphate to enhance Pb(II) removal, which enables remediation efficiencies >95% for concentrations above 1500 ppm. Scanning electron microscopy images show a pH-dependent formation of Pb-based crystals uniformly deposited throughout the entire mycelium network. Continuous cross-flow filtration tests employing a dried mycelium membrane demonstrate its efficacy as a microporous membrane for Pb(II) removal, reaching remediation efficiency of 85-90% at the highest Pb(II) concentrations. These findings suggest that dried mycelium membranes can be a viable alternative to synthetic membranes in heavy metal remediation, with potential environmental and water treatment applications.

Porous Waterborne Polyurethane Films Templated from Pickering Foams for Fabrication of Synthetic Leather

Waterborne polyurethane (WPU) latex nanoparticles with proven interfacial activity were utilized to stabilize air-water interfaces of Pickering foams through interfacial interaction with hydrophobic fumed silica particles (SPs). The rheological properties of the Pickering foam were tailored through adjustment of their SP content, which influenced their formability and stability. A Pickering foam stabilized with WPU and SPs was used as a template to prepare a WPU-SP composite porous film. The as-prepared film had intact open-cell porous structures, which increased its water absorption and water-vapor permeability. The porous film was used as a middle layer in the preparation of synthetic leather via a four-step "drying method". Compared with commercial synthetic leather, the lab-made synthetic leather with a middle layer made of the WPU-SP composite porous film exhibited a richer porous structure, acceptable wetting on a fabric substrate, a thicker porous layer, and higher water-vapor permeability. This work provides a novel and facile approach for preparing WPU-SP Pickering foams. Furthermore, the foams have the potential to function as a sustainable material for creating a porous-structured synthetic leather made from WPU, which may be utilized as an alternative to solvent-based synthetic leather.

Mycelium-Based Composites as a Sustainable Solution for Waste Management and Circular Economy

The global population is expected to increase by nearly 2 billion individuals over the next three decades, leading to a significant surge in waste generation and environmental challenges. To mitigate these challenges, there is a need to develop sustainable solutions that can effectively manage waste generation and promote a circular economy. Mycelium-based composites (MBCs) are being developed for various applications, including packaging, architectural designs, sound absorption, and insulation. MBCs are made by combining fungal mycelium with organic substrates, using the mycelium as a natural adhesive. Mycelium, the vegetative part of fungi, can be grown on various organic feedstocks and functionalized into a range of diverse material types that are biobased and thus more sustainable in their production, use, and recycling. This work aims to obtain mycelium-based composites with acoustic absorption properties, using coffee grounds and agricultural waste as raw materials. The topic approached presents a new method of recovering spent coffee grounds that does not involve high production costs and reduces two current environmental problems: noise pollution and abundant waste. Measurements of the normal-incidence sound absorption coefficient were presented and analyzed. Mycelium-based composites offer an innovative, sustainable approach to developing bio-composite sound-absorbing surfaces for interior fittings. The material by Ganoderma lucidum exhibits exceptional sound-absorbing properties at frequencies below 700 Hz, which is a crucial aspect of creating sound-absorbing materials that effectively absorb low-frequency sound waves. The modular construction system allows for a high degree of flexibility to adapt to short-term changes in the workplace.

Mechanical, physical and thermal properties of composite materials produced with the basidiomycete Fomes fomentarius

BACKGROUND

To achieve climate neutrality, fundamentally new concepts of circularity need to be implemented by the building sector as it contributes to 40% of anthropogenic CO2 emission. Fungal biotechnology can make a significant contribution here and help eliminate fossil dependency for building material production. Recently, we have shown that the medicinal polypore Fomes fomentarius feeds well on renewable lignocellulosic biomass and produces composite materials that could potentially replace fossil fuel-based expanded polystyrene as insulation material.

RESULTS

In this study, we explored the mechanical, physical, and thermal properties of F. fomentarius-based composite materials in more detail and determined key performance parameters that are important to evaluate the usability of F. fomentarius-based composite materials in the construction sector. These parameters were determined according to European standards and included compressive strength, modulus of elasticity, thermal conductivity, water vapour permeability, and flammability of uncompressed composites as well as flexural strength, transverse tensile strength, and water absorption capacity of heat-pressed composites, among others. We could show that uncompressed composites obtained from F. fomentarius and hemp shives display a thermal conductivity of 0.044 W (m K)-1 which is in the range of natural organic fibres. A water vapour permeability of 1.72 and classification into flammability class B1 clearly surpasses fossil-based insulation materials including expanded polystyrene and polyurethane. We could furthermore show that heat-pressing can be used to reliably generate stiff and firm particleboards that have the potential to replace current wood-based particleboards that contain synthetic additives. X-ray microcomputed tomography finally visualized for the first time the growth of hyphae of F. fomentarius on and into the hemp shive substrates and generated high-resolution images of the microstructure of F. fomentarius-based composites.

CONCLUSION

This study demonstrates that fungal-based composites produced with F. fomentarius partially meet or even exceed key performance parameters of currently used fossil fuel-based insulation materials and can also be used to replace particleboards.

Impact of malt concentration in solid substrate on mycelial growth and network connectivity in Ganoderma species

With its distinctive material properties, fungal mycelium has emerged as an innovative material with a diverse array of applications across various industries. This study focuses on how the growth strategies of wood fungi adapt to nutrient availability. The effect of malt extract concentration in the growth medium on radial growth kinetics, morphology, mycelium network connectivity, and mechanical characteristics of mycelium from two Ganoderma species were investigated. While an evident pattern of radial growth rate enhancement with malt concentrations was not apparent, there was a discernible trend towards denser mycelium network characteristics as revealed by spectrophotometry. Increased malt extract contents corresponded to elevated optical density measurements and were visually confirmed by denser mycelium networks in photographic images. Investigating the mechanical characteristics of mycelium cultivated on varying solid substrate concentrations, the Young's modulus exhibited a substantial difference between mycelium grown on 5 wt% malt substrate and samples cultivated on 2 wt% and 0.4 wt% malt substrates. The obtained results represent a new understanding of how malt availability influences mycelial growth of two Ganoderma species, a crucial insight for potentially refining mycelium cultivation across diverse applications, including meat alternatives, smart building materials, and alternative leather.

A layered solid-state culture system for investigating the fungal growth and decay behaviour on the cellulosic substrate

Mycelium-based materials have attracted growing interest, facilitating their development for various new applications. Finding for suitable fungal species and strains enables further technical breakthroughs in their development and quality control. Here, we developed a model solid-state culture system to screen fungal strains efficiently for mycelium-based materials production. A piece of silicone-coated paper set on the general agar plate allows for isolation of the mycelial mat from the substrate. The mycelial growth and density can be evaluated by weighing the mycelial mat. We used the paper substrate after fungal incubation to investigate the relationship between substrate degradation and the contact time with hyphae. It yielded further insights into the fungal decay. Ten basidiomycetes were assessed for their fungal growth and degradation behaviour of the substrate using this method. Pleurotus floridanus FBCC375 showed a dense and elastic mycelial mat and mild degradation of the substrate. A unique decay behaviour was found in Hypsizygus ulmarius FBCC573 and Trametes versicolor FBCC564. They indicated a positional imbalance in the decay activity within the colony. This simple method is helpful for screening fungal strains and facilitates the further development of mycelium-based materials.

From purposeless residues to biocomposites: A hyphae made connection

Biocomposites create attractive alternatives to match packing needs with available agricultural residues. Growing native fungal strains developed a mycelium biocomposite over a mixture of Peach Palm Fruit Peel Flour and Sugar Cane Bagasse Wet Dust. A methodology was proposed to analyze their main characteristics: 1) morphological, 2) chemical, and 3) biodegradability. 1) SEM analysis evidenced the structural change of the dried vs pressed material and mycelium morphology for both species. 2) The ratio lignin:carbohydrate showed that P. ostreatus degrades the cellulose-hemicellulose fraction of the substrate at a higher rate than T. elegans, and 3) the curve BMP indicated that these materials are readily biodegradable with a maximum yield of 362,50 mL biogas/g VS. An innovative tangible valorization strategy based on mass balances is also presented: from just 50 kg of peel flour, up to 1840 units can be manufactured, which could pave the way for a more sustainable future.

Mycelium-based biomaterials as smart devices for skin wound healing

Introduction: Recently, mycelia of Ganoderma lucidum and Pleurotus ostreatus, edible fungi, have been characterized in vitro as self-growing biomaterials for tissue engineering since they are constituted of interconnected fibrous networks resembling the dermal collagen structure. Aim: This work aims to investigate the biopharmaceutical properties of G. lucidum and P. ostreatus mycelia to prove their safety and effectiveness in tissue engineering as dermal substitutes. Methods: The mycelial materials were characterized using a multidisciplinary approach, including physicochemical properties (morphology, thermal behavior, surface charge, and isoelectric point). Moreover, preclinical properties such as gene expression and in vitro wound healing assay have been evaluated using fibroblasts. Finally, these naturally-grown substrates were applied in vivo using a murine burn/excisional wound model. Conclusions: Both G. lucidum and P. ostreatus mycelia are biocompatible and able to safely and effectively enhance tissue repair in vivo in our preclinical model.

Recent technological innovations in mycelium materials as leather substitutes: a patent review

Leathery mycelium materials, made from the vegetative part of filamentous fungi, have garnered significant interest in recent years due to their great potential of providing environmentally sustainable alternatives to animal- and plastic-based leathers. In this systematic patent review, we provide an in-depth overview of the fabrication methods for mycelium materials as leather substitutes recently described in patents. This overview includes strategies for fungal biomass generation and industrial developments in the sector. We discuss the use of various fungal species, plasticizers, crosslinking agents, and post-processing techniques, thereby highlighting potential gaps in scientific knowledge and identifying opportunities, challenges, and concerns in the field. Our analysis suggests that mycelium materials have significant potential for commercialization, with a growing number of companies betting on this new class of biomaterials. However, we also reveal the need for further scientific research to fully understand the properties of these materials and to unlock potential applications. Overall, this patent review delineates the current state of the art in leathery mycelium materials.

Wood-Decaying Fungi: From Timber Degradation to Sustainable Insulating Biomaterials Production

Addressing the impacts of climate change and global warming has become an urgent priority for the planet's well-being. In recent decades the great potential of fungal-based products with characteristics equal to, or even outperforming, classic petroleum-derived products has been acknowledged. These new materials present the added advantage of having a reduced carbon footprint, less environmental impact and contributing to the shift away from a fossil-based economy. This study focused on the production of insulation panels using fungal mycelium and lignocellulosic materials as substrates. The process was optimized, starting with the selection of Trametes versicolor, Pleurotus ostreatus, P. eryngii, Ganoderma carnosum and Fomitopsis pinicola isolates, followed by the evaluation of three grain spawn substrates (millet, wheat and a 1:1 mix of millet and wheat grains) for mycelium propagation, and finishing with the production of various mycelium-based composites using five wood by-products and waste materials (pine sawdust, oak shavings, tree of heaven wood chips, wheat straw and shredded beech wood). The obtained biomaterials were characterized for internal structure by X-ray micro-CT, thermal transmittance using a thermoflowmeter and moisture absorption. The results showed that using a wheat and millet 1:1 (w/w) mix is the best option for spawn production regardless of the fungal isolate. In addition, the performance of the final composites was influenced both by the fungal isolate and the substrate used, with the latter having a stronger effect on the measured properties. The study shows that the most promising sustainable insulating biomaterial was created using T. versicolor grown on wheat straw.

Engineered Living Materials For Sustainability

Recent advances in synthetic biology and materials science have given rise to a new form of materials, namely engineered living materials (ELMs), which are composed of living matter or cell communities embedded in self-regenerating matrices of their own or artificial scaffolds. Like natural materials such as bone, wood, and skin, ELMs, which possess the functional capabilities of living organisms, can grow, self-organize, and self-repair when needed. They also spontaneously perform programmed biological functions upon sensing external cues. Currently, ELMs show promise for green energy production, bioremediation, disease treatment, and fabricating advanced smart materials. This review first introduces the dynamic features of natural living systems and their potential for developing novel materials. We then summarize the recent research progress on living materials and emerging design strategies from both synthetic biology and materials science perspectives. Finally, we discuss the positive impacts of living materials on promoting sustainability and key future research directions.

The complex structure of Fomes fomentarius represents an architectural design for high-performance ultralightweight materials

High strength, hardness, and fracture toughness are mechanical properties that are not commonly associated with the fleshy body of a fungus. Here, we show with detailed structural, chemical, and mechanical characterization that Fomes fomentarius is an exception, and its architectural design is a source of inspiration for an emerging class of ultralightweight high-performance materials. Our findings reveal that F. fomentarius is a functionally graded material with three distinct layers that undergo multiscale hierarchical self-assembly. Mycelium is the primary component in all layers. However, in each layer, mycelium exhibits a very distinct microstructure with unique preferential orientation, aspect ratio, density, and branch length. We also show that an extracellular matrix acts as a reinforcing adhesive that differs in each layer in terms of quantity, polymeric content, and interconnectivity. These findings demonstrate how the synergistic interplay of the aforementioned features results in distinct mechanical properties for each layer.

Mycelium-Composite Materials-A Promising Alternative to Plastics?

Plastic waste inefficiently recycled poses a major environmental concern attracting attention from both civil society and decision makers. Counteracting the phenomenon is an important challenge today. New possibilities are being explored to find alternatives to plastics, and one of them refers to mycelium-composite materials (MCM). Our study aimed at investigating the possibility of using wood and litter inhabiting basidiomycetes, an underexplored group of fungi that grow fast and create strong mycelial mats, to produce biodegradable materials with valuable properties, using cheap by-products as a substrate for growth. Seventy-five strains have been tested for their ability to grow on low-nutrient media and to form compact mycelial mats. Eight strains were selected further for evaluation on several raw substrates for producing in vitro myco-composites. The physico-mechanical properties of these materials, such as firmness, elasticity and impermeability, were analyzed. Abortiporus biennis RECOSOL73 was selected to obtain, at the laboratory scale, a real biodegradable product. Our results suggest that the strain used is a promising candidate with real possibilities for scalability. Finally, corroborating our results with scientific available data, discussions are being made over the feasibility of such technology, cost-effectiveness, scalability, availability of raw materials and, not least, where future studies should be directed to.

Microbial foods for improving human and planetary health

The current food production system is negatively impacting planetary and human health. A transition to a sustainable and fair food system is urgently needed. Microorganisms are likely enablers of this process, as they can produce delicious and healthy microbial foods with low environmental footprints. We review traditional and current approaches to microbial foods, such as fermented foods, microbial biomass, and food ingredients derived from microbial fermentations. We discuss how future advances in science-driven fermentation, synthetic biology, and sustainable feedstocks enable a new generation of microbial foods, potentially impacting the sustainability, resilience, and health effects of our food system.

Unlocking the magic in mycelium: Using synthetic biology to optimize filamentous fungi for biomanufacturing and sustainability

Filamentous fungi drive carbon and nutrient cycling across our global ecosystems, through its interactions with growing and decaying flora and their constituent microbiomes. The remarkable metabolic diversity, secretion ability, and fiber-like mycelial structure that have evolved in filamentous fungi have been increasingly exploited in commercial operations. The industrial potential of mycelial fermentation ranges from the discovery and bioproduction of enzymes and bioactive compounds, the decarbonization of food and material production, to environmental remediation and enhanced agricultural production. Despite its fundamental impact in ecology and biotechnology, molds and mushrooms have not, to-date, significantly intersected with synthetic biology in ways comparable to other industrial cell factories (e.g. Escherichia coli,Saccharomyces cerevisiae, and Komagataella phaffii). In this review, we summarize a suite of synthetic biology and computational tools for the mining, engineering and optimization of filamentous fungi as a bioproduction chassis. A combination of methods across genetic engineering, mutagenesis, experimental evolution, and computational modeling can be used to address strain development bottlenecks in established and emerging industries. These include slow mycelium growth rate, low production yields, non-optimal growth in alternative feedstocks, and difficulties in downstream purification. In the scope of biomanufacturing, we then detail previous efforts in improving key bottlenecks by targeting protein processing and secretion pathways, hyphae morphogenesis, and transcriptional control. Bringing synthetic biology practices into the hidden world of molds and mushrooms will serve to expand the limited panel of host organisms that allow for commercially-feasible and environmentally-sustainable bioproduction of enzymes, chemicals, therapeutics, foods, and materials of the future.

Nanomaterials in the future biotextile industry: A new cosmovision to obtain smart biotextiles

For centuries, man has dominated the development of fibers and textiles to make clothing that protects them against environmental adversities, and gradually dissimilar cultural and ethnic identity traits have been created. Our garments are composed of natural elements such as animal leather, vegetable fibers, and synthetic textiles that result in ultra-resistant and durable materials. However, the textile industry has a non-sustainable character mainly because population growth will limit the use of natural resources, such as land and water, exclusively for food. At the same time, petrochemical-derived materials will gradually be replaced by more biodegradable alternatives due to their toxic accumulation in the local environment and their contribution to global climate change. The vast inventiveness of human-being is opening the possibility of replacing our clothes by mimicking, reproducing, and scaling up nature’s biosynthetic machinery through cutting-edge biotechnological approaches. Nevertheless, the new cosmovision of biotextiles must meet two requirements: 1) the appearance and performance of the clothes should be preserved to join the current textile market demand, and at the same time, 2) new functionalities should be incorporated into our clothes to embrace the impressive technological advances occurring day to day. In this regard, nanotechnological developments will be able to provide the desired properties so that the textile industry can provide bio-based materials enhanced with nanotechnology-based intelligent functionalities. This perspective article discloses nano-biotechnological approaches to address the challenge of dressing up future societies and new material consciousness.

Ten decadal advances in fungal biology leading towards human well-being

Fungi are an understudied resource possessing huge potential for developing products that can greatly improve human well-being. In the current paper, we highlight some important discoveries and developments in applied mycology and interdisciplinary Life Science research. These examples concern recently introduced drugs for the treatment of infections and neurological diseases; application of -OMICS techniques and genetic tools in medical mycology and the regulation of mycotoxin production; as well as some highlights of mushroom cultivaton in Asia. Examples for new diagnostic tools in medical mycology and the exploitation of new candidates for therapeutic drugs, are also given. In addition, two entries illustrating the latest developments in the use of fungi for biodegradation and fungal biomaterial production are provided. Some other areas where there have been and/or will be significant developments are also included. It is our hope that this paper will help realise the importance of fungi as a potential industrial resource and see the next two decades bring forward many new fungal and fungus-derived products.

Fungi in Mycelium-Based Composites: Usage and Recommendations

Mycelium-Based Composites (MBCs) are innovative engineering materials made from lignocellulosic by-products bonded with fungal mycelium. While some performance characteristics of MBCs are inferior to those of currently used engineering materials, these composites nevertheless prove to be superior in ecological aspects. Improving the properties of MBCs may be achieved using an adequate substrate type, fungus species, and manufacturing technology. This article presents scientifically verified guiding principles for choosing a fungus species to obtain the desired effect. This aim was realized based on analyses of scientific articles concerning MBCs, mycological literature, and patent documents. Based on these analyses, over 70 fungi species used to manufacture MBC have been identified and the most commonly used combinations of fungi species-substrate-manufacturing technology are presented. The main result of this review was to demonstrate the characteristics of the fungi considered optimal in terms of the resulting engineering material properties. Thus, a list of the 11 main fungus characteristics that increase the effectiveness in the engineering material formation include: rapid hyphae growth, high virulence, dimitic or trimitic hyphal system, white rot decay type, high versatility in nutrition, high tolerance to a substrate, environmental parameters, susceptibility to readily controlled factors, easy to deactivate, saprophytic, non-mycotoxic, and capability to biosynthesize natural active substances. An additional analysis result is a list of the names of fungus species, the types of substrates used, the applications of the material produced, and the main findings reported in the scientific literature.

Challenges and Opportunities in Scaling up Architectural Applications of Mycelium-Based Materials with Digital Fabrication

In an increasing effort to address the environmental challenges caused by the currently linear economic paradigm of “produce, use, and discard”, the construction industry has been shifting towards a more circular model. A circular economy requires closing of the loops, where the end-of-life of a building is considered more carefully, and waste is used as a resource. In comparison to traditional building materials such as timber, steel and concrete, mycelium-based materials are renewable alternatives that use organic agricultural and industrial waste as a key ingredient for production, and do not rely on mass extraction or exploitation of valuable finite or non-finite resources. Mycelium-based materials have shown their potential as a more circular and economically competitive alternative to conventional synthetic materials in numerous industries ranging from packaging, electronic prototyping, furniture, fashion to architecture. However, application of mycelium-based materials in the construction industry has been limited to small-scale prototypes and architectural installations due to low mechanical properties, lack of standardisation in production methods and material characterisation. This paper aims to review the current state of the art in research and applications of mycelium-based materials across disciplines, with a particular focus on digital methods of fabrication, production, and design. The information gathered from this review will be synthesised to identify key challenges in scaling up applications of mycelium-based materials as load-bearing structural elements in architecture and suggest opportunities and directions for future research.

Connecting materials sciences with fungal biology: a sea of possibilities

The Special Issue "Connecting materials science with fungal biology" celebrates recent breakthroughs in the fabrication of fungal-based materials, all of which have been made possible by the interdisciplinary and transdisciplinary collaboration of fungal biologists and biotechnologists with artists, designers, materials scientists, and architects. It features conceptual considerations and latest developments of these joint research efforts and the paradigm shift that is involved. The aim of this collection of twelve papers is to highlight the infinite possibilities for the development of innovative fungal-based materials which can be realized through integrating the knowledge and methods from different disciplines.

Establishment of the basidiomycete Fomes fomentarius for the production of composite materials

Background

Filamentous fungi of the phylum Basidiomycota are considered as an attractive source for the biotechnological production of composite materials. The ability of many basidiomycetes to accept residual lignocellulosic plant biomass from agriculture and forestry such as straw, shives and sawdust as substrates and to bind and glue together these otherwise loose but reinforcing substrate particles into their mycelial network, makes them ideal candidates to produce biological composites to replace petroleum-based synthetic plastics and foams in the near future.

Results

Here, we describe for the first time the application potential of the tinder fungus Fomes fomentarius for lab-scale production of mycelium composites. We used fine, medium and coarse particle fractions of hemp shives and rapeseed straw to produce a set of diverse composite materials and show that the mechanical materials properties are dependent on the nature and particle size of the substrates. Compression tests and scanning electron microscopy were used to characterize composite material properties and to model their compression behaviour by numerical simulations. Their properties were compared amongst each other and with the benchmark expanded polystyrene (EPS), a petroleum-based foam used for thermal isolation in the construction industry. Our analyses uncovered that EPS shows an elastic modulus of 2.37 ± 0.17 MPa which is 4-times higher compared to the F. fomentarius composite materials whereas the compressive strength of 0.09 ± 0.003 MPa is in the range of the fungal composite material. However, when comparing the ability to take up compressive forces at higher strain values, the fungal composites performed better than EPS. Hemp-shive based composites were able to resist a compressive force of 0.2 MPa at 50% compression, rapeseed composites 0.3 MPa but EPS only 0.15 MPa.

Conclusion

The data obtained in this study suggest that F. fomentarius constitutes a promising cell factory for the future production of fungal composite materials with similar mechanical behaviour as synthetic foams such as EPS. Future work will focus on designing materials characteristics through optimizing substrate properties, cultivation conditions and by modulating growth and cell wall composition of F. fomentarius, i.e. factors that contribute on the meso- and microscale level to the composite behaviour.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40694-022-00133-y.

BioMateriOME: To understand microbe-material interactions within sustainable, living architectures

BioMateriOME evolved from a prototyping process which was informed from discussions between a team of designers, architects and microbiologists, when considering constructing with biomaterials or human cohabitation with novel living materials in the built environment. The prototype has two elements (i) BioMateriOME-Public (BMP), an interactive public materials library, and (ii) BioMateriOME-eXperimental (BMX), a replicated materials library for rigorous microbiome experimentation. The prototype was installed into the OME, a unique experimental living house, in order to (1) gain insights into society's perceptions of living materials, and (2) perform a comparative analysis of indoor surface microbiome development on novel biomaterials in contrast to conventional indoor surfaces, respectively. This review summarizes the BioMateriOME prototype and its use as a tool in combining microbiology, design, architecture and social science. The use of microbiology and biological components in the fabrication of biomaterials is provided, together with an appreciation of the microbial communities common to conventional indoor surfaces, and how these communities may change in response to the implementation of living materials in our homes. Societal perceptions of microbiomes and biomaterials, are considered within the framework of healthy architecture. Finally, features of architectural design with microbes in mind are introduced, with the possibility of codifying microbial surveillance into design and construction benchmarks, standards and regulations toward healthier buildings and their occupants.