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Leather-like material biofabrication using fungi
Abstract
Fungi-derived leather substitutes are an emerging class of ethically and environmentally responsible fabrics that are increasingly meeting consumer aesthetic and functional expectations and winning favour as an alternative to bovine and synthetic
leathers. While traditional leather and its alternatives are sourced from animals and synthetic polymers, these renewable sustainable leather substitutes are obtained through the upcycling of low-cost agricultural and forestry by-products into chitinous
polymers and other polysaccharides using a natural and carbon-neutral biological fungal growth process. Following physical
and chemical treatment, these sheets of fungal biomass visually resemble leather and exhibit comparable material and tactile
properties.
... The resulting structures of grown natural materials are intended to be an alternative for the fibrous structure of animal skin [11,24,25]. A typical representative is the fungusbased material Muskin ® taken from Phellinus ellipsoideus. ...
... The final layer on top is composed of very thin and tight collagen fibers. The grown skin tissue shows a very high mechanical stability (tensile strength, tear strength), which is by 100 to 1000 times higher than that of the microorganism-based materials [5,10,11,25,26,28]. The strength of leather can be related to the stability of the collagen fibers themselves and to the weaving and crosslinks between the fibers. ...
... In contrast, the tissue-like structures of microorganisms appear as parenchymatous materials, based on fiber networks, which primarily offer active cells a matrix for metabolism (bacteria, fungi) and transportation of nutrients (hyphae). Therefore, they appear at the bottom of Figure 4. To overcome these mechanical deficiencies, it was proposed to stabilize the fiber network of Muskin ® by crosslinking agents [25,26], or to adjust the softness of Kombucha materials by the addition of plasticizing agents [10]. However, this contradicts the multiscale idea, the variation of the density and the orientation of the fibers along their load direction, which would presumably better help to overcome the observed limitations. ...
The market for biogenic and synthetic alternatives to leather is increasing aiming to replace animal-based materials with vegan alternatives. In parallel, bio-based raw materials should be used instead of fossil-based synthetic raw materials. In this study, a shoe upper leather and an artificial leather, and nine alternative materials (Desserto®, Kombucha, Pinatex®, Noani®, Appleskin®, Vegea®, SnapPap®, Teak Leaf®, and Muskin®) were investigated. We aimed to compare the structure and technical performance of the materials, which allows an estimation of possible application areas. Structure and composition were characterized by microscopy and FTIR spectroscopy, the surface properties, mechanical performance, water vapor permeability, and water absorption by standardized physical tests. None of the leather alternatives showed the universal performance of leather. Nevertheless, some materials achieved high values in selected properties. It is speculated that the grown multilayer structure of leather with a very tight surface and a gradient of the structural density over the cross-section causes this universal performance. To date, this structure could neither be achieved with synthetic nor with bio-based materials.
... As a highly flexible manufacturing platform, fungi can be used to produce replacements for products such as bovine leather and its substitutes, synthetic foams for packaging, insulation, and textiles, and high-performance paper-like materials from a range of different fungal biomass sources and fermentation pathways (Figure 1, Key Figure). Leather-like materials and foams derived from fungi are now the focus of recent and rapid commercialization efforts in North America, Europe, and Asia, and advanced fungal materials for applications ranging from bioprinting to wound treatment and water purification have captured the imagination of the academic community in recent years [14][15][16][17][18][19][20][21][22]. This review details and contrasts the production techniques, material characteristics, and functionalities of various pure fungal flexible materials (FFMs) and discusses challenges hindering their widespread adoption. ...
... Mycelium-derived leather-like FFMs comprise nonwoven fungal mats harvested from the top surface of SSF substrates or static liquid-state fermentation (LSF) trays (liquid-state surface fermentation, LSSF), which are then physically and chemically treated to mimic bovine leather in mechanical performance, texture, and appearance (Boxes 2 and 3). These treatments range from micro-or nanoscale tuning of mechanical properties using deacetylation and crosslinking of chitin, denaturing of proteins, material densification, and control of moisture content to macroscopic modification of aesthetics, such as by mechanical imprinting, texturing, and dyeing of mats [16,18,[38][39][40][41][42] (Figure 2B,C). ...
... In addition, the resistance of Reishi™ to color fading when exposed to perspiration, water spotting, solvent wicking, crocking, UV exposure, or distilled and salt water is comparable with bovine leather. A more comprehensive review on Box 2. Solid-State Fermentation for Foams and Leather-like Materials SSF is the most popular approach for producing fungal foams and leather-like materials [18,46,53,75] on precolonized lignocellulosic substrate, for example, sawdust or corn stover with additives such as mineral elements and carbohydrates [18,38,39,46,51,53], although LSSF tray fermenters can also be used. Yield is affected by inoculum type and volume, substrate, particle size, pH, nutrient content, moisture and water activity, gas exchange, aeration, and agitation [76]. ...
Fungi are a revolutionary, smart, and sustainable manufacturing platform that can be used to upcycle byproducts and wastes into flexible fungal materials (FFMs) such as chitin- and β-glucan-based foams, paper, and textiles. With highly adaptable manufacturing pathways, the efficiency and properties of these materials depend on the biomass source and fermentation method. Liquid substrates provide fast, upscalable, and compact production processes but are susceptible to contamination and are limited to paper-like materials for printing, wound dressings, and membranes. Solid-state fermentation is cheaper but struggles to deliver homogeneous fungal growth and is used to produce fungal foams for packaging, insulation, textiles, and leather substitutes. The broad range of applications and uses of biological organisms in materials hallmarks fungi as forerunners in improving environmental sustainability globally.
... Fungi could, however, make a feasible alternative to the slime mould for the following reasons. Fungal materials -grow substrates colonised with mycelium of filamentous fungi -are emerging to be robust, reliable and ecologically friendly replacement for conventional building materials and fabrics [24,25,26,27,28,29,30,31,32,33]. Fungi "possess almost all the senses used by humans" [34]. ...
... Second direction is in development of a large scale fabric made purely from mycelium -fungal skin (Fig. 4) and tailoring the fabric into wearables. Such mycelial tissue can be prepared using trimitic polypore fungal cultures, which are apparently preferred for the production of sturdy fungal skins, such as fungal leather or mycoleather [33]. More specifically, a fungal fabric can be prepared by pouring a homogenised slurry of a liquid culture of Ganoderma resinaceum into a static fermentation tray and incubated for two weeks to allow the fungal hyphae to intermesh, forming a floating mat or skin [42]. ...
Smart wearables sense and process information from the user's body and environment and report results of their analysis as electrical signals. Conventional electronic sensors and controllers are commonly, sometimes augmented by recent advances in soft electronics. Organic electronics and bioelectronics, especially with living substrates, offer a great opportunity to incorporate parallel sensing and information processing capabilities of natural systems into future and emerging wearables. Nowadays, fungi are emerging as a promising candidate to produce sustainable textiles to be used as eco-friendly bio wearables. To assess the sensing potential of fungal wearables, we undertook laboratory experiments on the electrical response of a hemp fabric colonised by oyster fungi Pleurotus ostreatus to mechanical stretching and stimulation with attractants and repellents. We have shown that it is possible to discern a nature of stimuli from the fungi electrical responses. The results paved a way towards the future design of intelligent sensing patches to be used in reactive fungal wearables.
... Mycelium-based biomaterials offer an alternative fabrication paradigm based on the growth of materials, rather than their extraction. Agricultural residue fibers are inoculated with fungal mycelia, which form an interwoven three-dimensional filamentous network that binds the feedstock into a lightweight material [16]. Most Polyporales have shiny surfaces of a woody nature, owing to the pigmentation on the surface, and they are highly suitable for the development of mushroom-based biomaterials [10]. ...
... According to Chang et al. (1995), sawdust and rice bran substrates are suitable for Polyporale mycelial growth and fruiting body development [13]. MBL can be produced using agro-waste substrates, sawdust, rice straw, husk, bran, and other lignocellulosic materials [16,33]. This approach is low-cost, ecofriendly, and free of hazardous reagents and chemicals [33]. ...
Sustainable substitutes for leather can be made from mushroom mycelium, which is an environmentally friendly alternative to animal and synthetic leather. Mycelium-based leather is derived from Polyporales, in which lignocellulosic material is used as the substrate. The plasticizing and crosslinking of mycelial mats with various reagents might affect the leather properties and mycelial architecture. This study investigated the physicochemical and mechanical properties of mycelium-based leather (MBL) samples, including the hygroscopic nature, thermal stability, cell wall chemistry, density, micromorphology, tensile strength, elongation rate, and Young’s modulus. Micromorphological observations confirmed the mycelial networks and their binding performance, verifying their efficacy as a substitute leather. The most significant effects were observed after treatment with 20% polyethylene glycol, which resulted in an increase in Young’s modulus and tensile strength. Furthermore, the samples generally exhibited a high density (1.35, 1.46 g/cm3) and tensile strength (7.21 ± 0.93, 8.49 ± 0.90 MPa), resembling leather. The tear strength reached as low as 0.5–0.8 N/mm. However, the tensile and tear strength may be affected by leather processing and the tuning of mycelial growth. Nevertheless, high-density mycelia are shown to be suitable for the production of MBL, while mycofabrication and strain selection are sustainable for novel industrial applications of MBL.
... Thus, the whole animal farm industry can be regarded as an environmental threat in the future. Considering the downsides of the leather industry and the growing demand for leather as a luxury material, alternative and sustainable leather-like materials are highly demanded (Jones et al., 2021). ...
... Thus, natural leather shows tightness gradient throughout the cross-section which makes it hard for leather substitutes to compete with. Nonetheless, when it comes to biofabrication of leather-like materials that are environmentally friendly in both production and decomposition, fungal products can have a promising future perspective (Jones et al., 2021). ...
Food waste and fashion pollution are two of the most prominent global environmental issues. To alleviate the problems associated with food waste, while simultaneously contributing to sustainable fashion, the feasibility of making an alternative textile material with leather-like properties from fungal biomass cultivated on bread waste was investigated. The filamentous fungus, Rhizopus delemar, was successfully grown on waste bread in a submerged cultivation process, and fungal biomass was treated with vegetable tannin of chestnut wood. NMR and FTIR confirmed interactions between tannin and fungal biomass, while OM, SEM and AFM visualised the changes in the hyphae upon the tannin treatment. Thermal stability was assessed using TGA analysis. The wet-laid technique commonly utilised for paper-making was used to prepare sheets of hyphae. Some of the sheets were treated with glycerol and/or a biobased binder as post-treatment. Overall, three of the produced materials exhibited leather-like properties comparable to that of natural leather. Sheets from untreated biomass with only glycerol post-treatment showed a tensile strength of 7.7 MPa and an elongation at break of 5%. Whereas sheets from untreated biomass and tannin treated biomass with both glycerol and binder treatments led to tensile strengths of 7.1 MPa and 6.9 MPa, and the elongation at break of 12% and 17%, respectively. The enhancement of hydrophobicity after the binder treatment, helped to preserve the absorbed glycerol within the sheet and thereby the flexibility was retained when in contact with moisture. These findings demonstrate that bread waste-derived fungal sheets have great potential as environmentally friendly materials with leather-like properties.
... For example, the use of leather from both animal hides and synthetic-laminated materials (such as polyurethane (PU) and polyvinyl chloride (PVC)) in the production of footwear products exist as old processing technologies for several decades (Nam and Lee 2019). However, the increasing environmental hazards of such materials over recent years has gradually awakened major concerns toward the issue of sustainability (Mitchell et al. 2020). This has rendered the global footwear market a no stranger to the issue of sustainability thereby slowly drifting the shoe market toward eco-friendly products. ...
... Therefore, the shift toward natural materials derived from plants to produce shoe components and other related products makes the system more sustainable and eco-friendlier. Compared to conventional synthetic laminated leather materials from PU or PVC that have raised concern as regards to their environmental effect such as low biodegradability and are not easily recyclable by any major recycling technique (Mitchell et al. 2020;Nam and Lee 2019a). ...
This paper outlines an overview of recent research advances in different production technologies toward sustainable development of nonwoven naturally sourced materials as alternatives to conventional synthetic laminated and bovine leather in the footwear industry. The current state of the footwear industry as a major stakeholder in the fashion sector is discussed, its footprints on the environment, and key developments from nonwoven natural fibrous materials for different footwear components are highlighted. Lastly, the review discusses recent research innovations of naturally sourced fibrous materials as leather alternatives in the footwear sector with special focus on sustainability and material performance. In addition, challenges and limitations in terms of industrial scalability and market potential are outlined. In conclusion, featuring promising nonwoven natural fibrous leather alternatives obtained via up-cycling of agro-wastes using microbes and fungi may be used in the textile and shoe industries. Since the prepared sheets through simple and cost-effective processes visually resemble conventional leather and demonstrate comparable material and tactile properties.
... Pure fungal materials mainly consist of mycelium [20]. These materials are either the result of the complete degradation of the substrate or can be obtained by removing the fungal mat from the surface of a liquid or solid substrate [22]. ...
... In recent years, the textile and fashion design industries have placed a great deal of emphasis on the development of new sustainable and compostable materials that are able to be obtained using environmentally friendly, non-pollutant processes. The production of fungal mats for textile applications promises more sustainable and compostable alternatives to the soft materials that are currently on the market, especially those from the leather sector [22,23]. ...
Wood decay fungi (WDF) seem to be particularly suitable for developing myco-materials due to their mycelial texture, ease of cultivation, and lack of sporification. This study focused on a collection of WDF strains that were later used to develop mycelium mats of leather-like materials. Twenty-one WDF strains were chosen based on the color, homogeneity, and consistency of the mycelia. The growth rate of each strain was measured. To improve the consistency and thickness of the mats, an exclusive method (newly patented) was developed. The obtained materials and the corresponding pure mycelia grown in liquid culture were analyzed by both thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) to evaluate the principal components and texture. TGA provided a semi-quantitative indication on the mycelia and mat composition, but it was hardly able to discriminate differences in the production process (liquid culture versus patented method). SEM provided keen insight on the mycelial microstructure as well as that of the mat without considering the composition; however, it was able to determine the hyphae and porosity dimensions. Although not exhaustive, TGA and SEM are complementary methods that can be used to characterize fungal strains based on their desirable features for various applications in bio-based materials. Taking all of the results into account, the Fomitopsis iberica strain seems to be the most suitable for the development of leather-like materials.
... Mycelium bound composites -masses of organic substrates colonised by fungi -are considered to be future environmentally sustainable growing bio-materials ( Karana et al., 2018 ;Cerimi et al., 2019 ;Jones et al., 2020 ). The fungal materials are used in acoustic insulation panels ( Pelletier et al., 2013 ;Elsacker et al., 2020 ;Robertson et al., 2020 ), thermal insulation wall cladding ( Wang et al., 2016 ;Yang et al., 2017 ;Xing et al., 2018 ;Girometta et al., 2019 ;Cárdenas-R, 2020 ;Dias et al., 2021 ), packaging materials ( Holt et al., 2012 ;Mojumdar et al., 2021 ;Sivaprasad et al., 2021 ) and wearables ( Karana et al., 2018 ;Silverman et al., 2020 ;Appels, 2020 ;Jones et al., 2021 ;Adamatzky et al., 2021c ). In Adamatzky et al. (2019) , we proposed to develop a structural substrate by using live fungal mycelium, functionalise the substrate with nanoparticles and polymers to make mycelium-based electronics ( Beasley et al., 2020a ;2020b ;2020c ), implement sensorial fusion and decision making in the mycelium networks ( Adamatzky et al., 2020 ). ...
Fungal construction materials—substrates colonised by mycelium—are getting increased recognition as viable ecologically friendly alternatives to conventional building materials. A functionality of the constructions made from fungal materials would be enriched if blocks with living mycelium, known for their ability to respond to chemical, optical and tactile stimuli, were inserted. We investigated how large blocks of substrates colonised with mycelium of Ganoderma resinaceum responded to stimulation with heavy weights. We analysed details of the electrical responses to the stimulation with weights and show that ON and OFF stimuli can be discriminated by the living mycelium composites and that a habituation to the stimulation occurs. Novelty of the results cast in the reporting on changes in electrical spiking activity of mycelium bound composites in response to a heavy loads.
... Fungi are demonstrated to be at the forefront of environmentally sustainable biomaterials (Karana et al., 2018;Jones et al., 2020b;Cerimi et al., 2019) used in manufacturing of acoustic (Pelletier et al., 2013;Elsacker et al., 2020;Robertson et al., 2020) and thermal (Yang et al., 2017;Xing et al., 2018;Girometta et al., 2019;Dias et al., 2021;Wang et al., 2016;Juan Pablo, 2020) insulation panels, packaging materials (Holt et al., 2012;Sivaprasad et al., 2021;Mojumdar et al., 2021) and adaptive wearables (Adamatzky et al., 2021;Silverman et al., 2020;Karana et al., 2018;Appels, 2020;Jones et al., 2020a). In our project 'Fungal architectures' (Adamatzky et al., 2019) we proposed to grow mycelium bound composites into monolithic building elements (Adamatzky et al., 2021b). ...
Mycelium networks are promising substrates for designing unconventional computing devices providing rich topologies and geometries where signals propagate and interact. Fulfilling our long-term objectives of prototyping electrical analog computers from living mycelium networks, including networks hybridised with nanoparticles, we explore the possibility of implementing Boolean logical gates based on electrical properties of fungal colonies. We converted a 3D image-data stack of Aspergillus niger fungal colony to an Euclidean graph and modelled the colony as resistive and capacitive (RC) networks, where electrical parameters of edges were functions of the edges’ lengths. We found that and, or and and-not gates are implementable in RC networks derived from the geometrical structure of the real fungal colony.
... The mycelium bound composites are seen as future environmentally sustainable growing biomaterials [26,25,10,1]. They are already used in acoustic [40,15,41] and thermal [52,51,19,14,49,8] insulation panels and cladding, materials for packaging [21,45,36] and wearables [2,44,26,4,24]. The currently used fungal materials are passive and inert because the fungi in the composites are dead and treated to prevent decay. To make the fungal materials adaptive and intelligent we must either (1) leave part of the fungal materials alive, or (2) dope the materials with functional nanoparticles and polymers. ...
Living substrates are capable for nontrivial mappings of electrical signals due to the substrate nonlinear electrical characteristics. This property can be used to realise Boolean functions. Input logical values are represented by amplitude or frequency of electrical stimuli. Output logical values are decoded from electrical responses of living substrates. We demonstrate how logical circuits can be implemented in mycelium bound composites. The mycelium bound composites (fungal materials) are getting growing recognition as building, packaging, decoration and clothing materials. Presently the fungal materials are passive. To make the fungal materials adaptive, i.e. sensing and computing, we should embed logical circuits into them. We demonstrate experimental laboratory prototypes of many-input Boolean functions implemented in fungal materials from oyster fungi \emph{P. ostreatus}. We characterise complexity of the functions discovered via complexity of the space-time configurations of one-dimensional cellular automata governed by the functions. We show that the mycelium bound composites can implement representative functions from all classes of cellular automata complexity including the computationally universal. The results presented will make an impact in the field of unconventional computing, experimental demonstration of purposeful computing with fungi, and in the field of intelligent materials, as the prototypes of computing mycelium bound composites.
... Mycelium bound composites -masses of organic substrates colonised by fungi -are considered to be future environmentally sustainable growing biomaterials [1,2,3]. The fungal materials are used in acoustic insulation panels [4,5,6], thermal insulation wall cladding [7,8,9,10,11,12], packaging materials [13,14,15] and wearables [16,17,1,18,19]. ...
Fungal construction materials -- substrates colonised by mycelium -- are getting increased recognition as viable ecologically friendly alternatives to conventional building materials. A functionality of the constructions made from fungal materials would be enriched if blocks with living mycelium, known for their ability to respond to chemical, optical and tactile stimuli, were inserted. We investigate how large blocks of substrates colonised with mycelium of \emph{Ganoderma resinaceum} respond to stimulation with heavy weights. We analyse details of the electrical responses to the stimulation with weights and show that ON and OFF stimuli can be discriminated by the living mycelium composites and that a habituation to the stimulation occurs.
... Leather is a kind of durable and flexible material closely related to people's daily lives given its wide applications in making various articles, including footwear, automobile seats, clothing, bags, upholstery, and fashion accessories [1,2]. Leather is created by tanning animal rawhide and skins, which are generally the byproducts from meat processing [3]. ...
An amino-terminated waterborne polyurethane-based polymeric dye (AWPUD) was synthesized for the high-performance dyeing of chrome-free leather tanned by biomass-derived aldehyde (BAT). Fourier transform infrared spectroscopy (FTIR) and ¹H NMR spectra illustrated the successful synthesis of AWPUD via incorporating small-molecule dyes (SMDs) (C.I. Acid Red 14) and sodium 2,4-diaminobenzenesulfonate into the polyurethane skeleton. The amino group content of AWPUD was tested to be 1.34 wt% (based on dry weight), which included 0.65 wt% of terminal amino groups. The characteristic absorption peaks of AWPUD were observed at 538 nm and 573 nm, similar to those of SMDs. AWPUD-dyed crust leathers exhibited better dyeing performances than SMD-dyed crust leather in terms of comparable dye penetration degree, lower chroma of wastewater, and higher filler-dye uptake ratio. In addition, AWPUD-dyed crust leathers had higher dyeing uniformity, dry-wet rubbing resistance, and thermal stability. Meanwhile, AWPUD-dyed crust leathers had better comprehensive physical properties in terms of higher mechanical strengths, comparable softness, and smooth grain surface. These results suggest that AWPUD has the great potential to be used in the high-performance dyeing of BAT-tanned leather.
... Fungi are demonstrated to be at the forefront of environmentally sustainable biomaterials [31,30,16] used in manufacturing of acoustic [41,21,42] and thermal [55,54,23,20,53,15] insulation panels, packaging materials [26,47,39] and adaptive wearables [5,46,31,8,29]. In our project 'Fungal architectures' [2] we proposed to grow mycelium bound composites into monolithic building elements [4]. The composite would combine living mycelium, capable of sensing light, chemicals, gases, gravity and electric fields [10,50,33,22,9,28,27], with dead mycelium functionalised using nanoparticles and polymers. ...
Mycelium networks are promising substrates for designing unconventional computing devices providing rich topologies and geometries where signals propagate and interact. Fulfilling our long-term objectives of prototyping electrical analog computers from living mycelium networks, including networks hybridised with nanoparticles, we explore the possibility of implementing Boolean logical gates based on electrical properties of fungal colonies. We converted a 3D image-data stack of Aspergillus niger fungal colony to an Euclidean graph and modelled the colony as resistive and capacitive (RC) networks, where electrical parameters of edges were functions of the edges' lengths. We found that and, or and and-not gates are implementable in RC networks derived from the geometrical structure of the real fungal colony.
... Fungi are explored to grow leather-like material (Jones et al., 2021) or to make wearables reactive (Adamatzky et al., 2021). Plants are explored to grow textiles from roots (Zhou et al., 2020), as a dynamic material for textile design (Keune, 2018) and to explore ways of living between the inside and the outside (Keune, 2019). ...
The emergence of biodesign opens new ways for textile design and production processes by e.g. using living organisms directly for growing or dyeing textiles. Researchers and designers who engage in such practices often describe their processes as a collaboration with the living. Since maintenance or acts of caring are often fundamental for a successful result, supportive environments for the living are created. However, most of the organisms are only used to carry out a specific task given by the designers’ intention, e.g., excreting pigments to dye a piece of silk, and are killed after the successful completion of the “collaborative” project, which is one of the reasons why the anthropocentric perspective remains an integral part of the textile design process.
This research aims to challenge the anthropocentrism inherent in textile design methodologies. Drawing from the work of Donna Haraway, in this exploratory paper, I advocate for exploring more than anthropocentric and multispecies perspectives to textile design by understanding the textile design practice as a way of being-with and staying-with, rather than as a solution-driven practice. Therefore, I revisit and reflect on three stories that derived from encounters between humans and insects in shared textile contexts. The stories on multispecies cohabitation resulted from the autobiographic research ‘Textile Farming’. Weaving connections between contemporary approaches to design, this paper proposes a conceptual framework of the levels that designers can engage with the living e.g., designing with, for, or together with living organisms up to living-with and becoming-with. I found these reflections to offer valuable perspectives to reflect on, analyze, and discuss processes in which living organisms play a role. Consequently, the paper contributes to reflective practice and opens up the textile design practice towards open-ended events as a more than anthropocentric approach to designing textiles.
... In an effort to replace fossil fuel-based materials, attempts to employ fungal mycelia in the fabrication of eco-friendly composite materials have emerged recently. Particularly, basidiomycetes, such as Daedaleopsis confragosa, A. bisporus, P. ostreatus, and G. lucidum, have been sought for the industrial application in coatings, papers, membranes, packaging materials, composite materials, and leathers due to their physical strength and growth characteristics [17,18]. Accordingly in this study, screening of 64 strains of Polyporales in terms of growth rate and the capability to form mycelial mat was performed, resulting in the finding of G. lucidum LBS5496GL as a potential candidate for further industrial application. ...
Mushroom strains of Polyporales from the genera Coriolus, Trametes, Pycnoporus, Ganoderma, and Formitella were explored in terms of mycelial growth characteristics for the application of mushroom mycelia as alternative sources of materials replacing fossil fuel-based materials. Among the 64 strains of Polyporales, G. lucidum LBS5496GL was selected as the best candidate because it showed fast mycelial growth with high mycelial strength in both the sawdust-based solid medium and the potato dextrose liquid plate medium. Some of the Polyporales in this study have shown good mycelial growth, however, they mostly formed mycelial mat of weak physical strength. The higher physical strength of mycelial mat by G. lucidum LBS5496GL was attributed to its thick hyphae with the diameter of 13 µm as revealed by scanning electron microscopic analysis whereas the hyphae of others exhibited less than 2 µm. Glycerol and skim milk supported the best mycelial growth of LBS5496GL as a carbon and a nitrogen source, respectively.
... Para ello, sus hifas contienen proteínas morfogenéticas que responden al ambiente aéreo colonizando la superficie del sustrato creando una capa esponjosa o compacta. La capa de micelio también se conoce como "fungal skin" 66 , considerada una alternativa al cuero animal por sus propiedades de maleabilidad, inducción de crecimiento aéreo homogéneo, sin procesos de curtido o reactivos contaminantes, y sobre todo es biodegradable y libres de la crueldad animal 78 . ...
http://revistabionatura.com/2021.06.01.29.html
RESUMEN
El biodiseño y biofabricación de biomateriales a partir de residuos vegetales lignocelulósicos y auto-generados por el micelio de hongos es un campo de investigación emergente desde las últimas dos décadas. Surge una nueva cultura material que se basa en los nuevos paradigmas de la fabricación alternativa partiendo de la lógica “de hacer crecer los nuevos materiales en lugar de extraerlos” e integrando los principios básicos de la economía circular y de la Biotecnología Material, asegurando la susceptibilidad de los mismos a ser biodegradados y volver a su estado original en la naturaleza. Su implementación a nivel industrial en distintas áreas de la manufactura comienza a competir con el cuero de origen animal, materiales y productos de origen petroquímico, a la vez que promueve nuevas alternativas de alimentos proteicos sustentables que contribuyan al cambio de los patrones de consumo humano de alto impacto ambiental arraigados a nivel global. La presente revisión, aborda una mirada particular que va desde lo molecular a lo global sobre la nueva cultura micelial, considerando aspectos generales del reino Fungi, la morfogénesis, composición química e integridad celular del micelio, los sistemas multienzimáticos extracelulares de degradación de lignocelulosa que poseen los hongos, pasando por los principales sustratos empleados, los biomateriales desarrollados a partir de micelio a nivel industrial, destacando los biotextiles, materiales y productos para el empaquetamiento y aislamiento, nuevas fuentes alimentarias basadas en el micelio, el arte y el diseño arquitectónico. Finalmente, se presenta el estado del arte actual de las empresas o laboratorios vanguardistas que suscitan una economía circular basada en el micelio de hongos a nivel mundial, al reemplazar recursos y productos de origen fósil por materiales amigables con el entorno, generando alternativas sostenibles y ciclos de producción con una baja demanda de energía y sin repercusiones al medio ambiente, es decir, promoviendo una nueva conciencia material.
Palabras clave. Hongos, micelio, lignocelulosa, biomateriales, biofabricación, materiales compuestos, biotextiles, economía circular.
ABSTRACT
The biodesign and biofabrication of self-generated biomaterials based on lignocellulosic plant residues and by fungal mycelium is an emerging field of research for the last two decades. A new material culture emerges based on the new paradigms of alternative manufacturing founded on the logic “of growing new materials instead of extracting them” that integrates the basic principles of the circular economy and Material Biotechnology, ensuring susceptibility of them to be biodegraded and returned to their original state in nature. Its implementation at an industrial level in different manufacturing areas begins to compete with animal origin-leather, materials, and petrochemical products while promoting new alternatives of sustainable protein foods that contribute to changing high human consumption patterns globally entrenched environmental impact. This review addresses a detailed overview from the molecular to the global of the new mycelial culture, considering general features about Fungi kingdom, the morphogenesis, chemical composition, and cellular integrity of the mycelium, the extracellular multi-enzymatic systems for the lignocellulose degradation, passing through the primary substrates used, the biomaterials developed from fungal mycelium at the industrial level; highlighting biotextiles, materials and products for packaging and insulation, new mycelium-based food sources, art, and architectural design. Finally, a current state-of-the-art of frontlines companies or laboratories promoting a circular economy based on fungal mycelium is addressed by replacing resources and fossil origin products with environmentally friendly materials, generating sustainable alternatives and production cycles with low energy demand and without environmental repercussions, that is to say, promoting a new material consciousness.
Keywords. Fungi, mycelium, lignocellulose, biomaterials, biofabrication, composite materials, biotextiles, circular economy.
... Spent mushroom compost is rich in both lignocellulosic plant materials and fungal compounds, such as the antimicrobial polysaccharide chitosan, and is thus particularly apt for circular economy (311). Beyond fruiting body production, mycelia of Agaricomycetes have promising applications as insulating or building materials or as animal-free leather alternatives (312). Leveraging evo-devo knowledge for improving the biotechnological application of mushroom-forming fungi is becoming feasible as we gain more and more information on how fruiting bodies develop. ...
The development of sexual fruiting bodies is one of the most complex morphogenetic processes in fungi. Mycologists have long been fascinated by the morphological and developmental diversity of fruiting bodies; however, evolutionary developmental biology of fungi still lags significantly behind that of animals or plants. Here, we summarize the current state of knowledge on fruiting bodies of mushroom-forming Basidiomycota, focusing on phylogenetic and developmental biology. Phylogenetic approaches have revealed a complex history of morphological transformations and convergence in fruiting body morphologies. Frequent transformations and convergence is characteristic of fruiting bodies in contrast to animals or plants, where main body plans are highly conserved. At the same time, insights into the genetic bases of fruiting body development have been achieved using forward and reverse genetic approaches in selected model systems. Phylogenetic and developmental studies of fruiting bodies have each yielded major advances, but they have produced largely disjunct bodies of knowledge. An integrative approach, combining phylogenetic, developmental, and functional biology, is needed to achieve a true fungal evolutionary developmental biology (evo-devo) synthesis for fungal fruiting bodies.
... In contrast, for PMM, flexibility is preferred over rigidity for applications such as fabrics and flexible foams [33]. For this, different chemical treatments can be applied to the fungal tissue ( Fig. 4) and also provide pliable or absorbent properties, durability and a protective coating [16,17,22,[34][35][36]. So far it is unclear which exact formulation of post-growth processing elements and steps yield the best results as the combinations are numerous and this research field is ongoing, but we tried to regroup Table 1 Influence of varying airflow rates and relative humidities on the dry density and tensile strength of mycological biopolymers from Ganoderma sp. at 5% CO 2 and ± 30 °C in a customized incubator [26,31] the most relevant steps and elements in Fig. 4 to provide a simplified general overview. ...
In the context of the ongoing transition from a linear to a circular economy, ecologically friendly renewable solutions are put in place. Filamentous fungi can be grown on various organic feedstocks and functionalized into a range of diverse material types which are biobased and thus more sustainable in terms of their production, use and recycling. Pure mycelium materials, consisting only of mycelial biomass, can adopt versatile properties and appear promising as a substitute for current petrochemically produced polymeric materials or, in the case of myco-leather, as a substitute for animal-based leather. In recent years, a handful of private companies have been innovating to bring products based on pure mycelium materials to the market while scientific interest in these promising biomaterials is now starting to gain momentum. In this primer, we introduce pure mycelium materials, frame different production methods, review existing and potential future applications, thereby offering a vision on future advances for this emerging fungi-based technology.
... These are soft, paper-like materials that can also be obtained by separating fungal skin from substrates (Appels et al. 2019). Synthetic leathers and biodegradable papers are among the most common products generated with pure mycelium (Jones et al. 2020a;Vandelook et al. 2021). The other group of mycelium-based materials, which is the focus of this paper, are mycelium-based composites (MBC). ...
Mycelium-based composites (MBC) are biomaterials presenting renewable and bio-degradable alternatives for a wide range of design and manufacturing processes, including the building industry. MBC result from the incomplete growth of mycelium, fibrous root systems of fungi. They can turn urban and agricultural waste into high-end products. Existing research shows that MBC can reduce fossil fuels’ reliance and embodied energy and decrease building waste. Architects recently designed and built a wide range of experimental projects with MBC. In parallel, there is a growing body of work on MBC by scholars from different disciplines, such as mycology, material science, and mechanical engineering, focusing on assessing and enhancing the material properties of MBC for various applications.
In this paper, we first provide essential knowledge on the cultivation of MBC for architectural applications. Next, we analyze some of the prominent architectural prototypes with MBC to exemplify the architectural potentials of MBC and uncover the constraints and affordances of this biomaterial when used in an architectural context. Finally, we review and synthesize the existing literature on MBC from different disciplines providing a guide for architects to cultivate and enhance the material properties of MBC for architectural goals.
... Leather products with durability and longevity have been used for centuries by human beings. They have occupied an important position in modern people's daily lives in footwear, automobile seats, clothing, bags, upholstery and fashion accessories (Jones et al., 2021). Leather is generally made by tanning the sustainable animal rawhide/skin obtained as a by-product in the meat processing industry (Joseph and Nithya, 2009). ...
The traditional chrome-based leather industry is facing several restrictions due to potential risks to the environment, especially for the formation and release of hazardous and carcinogenic Cr (VI). However, the leather produced from alternative organic tanning agents generally does not meet the market requirements due to the poor fixation of some of the conventional anionic post-tanning materials. Herein, we report on a pioneering, Cr-free strategy to produce high-quality leather. It comprises the use of a carbon-neutral, biomass-based aldehyde (BAT) tanning agent, efficiently fixed in the leather by means of novel terminal aluminum tanning treatment (TAT). In this treatment, Al (III) bonded with the excess oxygen-containing functional groups present in the BAT, post-tanning materials and collagen fibers. As a result, these connections created a robust crosslinking network, leading to leather production with similar (and in some cases superior) properties to those produced with the conventional Cr tanning procedure. For example, the tensile and tear strengths (19.78 N/mm², 101.47 N/mm) were much higher than those of the Cr leather (7.13 N/mm² and 43.12 N/mm). Therefore, these outstanding results, along with the carbon-neutral and environmentally-friendly features of our BAT-TAT strategy, are a step-change toward chrome-free leather production, which paves the wave to ensuring the viable and sustainable development of the leather industry.
... However, fungi can also be used not only to decompose but also to compose new structures. Mycelium is the vegetative growth of filamentous fungi that bonds organic matter through a network of hyphal microfilaments and it is currently a competitor of several synthetic materials [32]. There are two main types of mycelium-based materials: pure mycelium materials and mycelium-based composites. ...
The perceptions and definitions of healthy indoor environments have changed significantly throughout architectural history. Today, molecular biology teaches us that microbes play important roles in human health, and that isolation from them puts not only us but also other inhabitants of urban landscapes, at risk. In order to provide an environment that makes honeybees more resilient to environmental changes, we aim for combining the thermal insulation functionality of mycelium materials with bioactive therapeutic properties within beehive constructions. By identifying mycelial fungi’s interactions with nest-related materials, using digital methods to design a hive structure, and engaging in additive manufacturing, we were able to develop a set of methods for designing and fabricating a fully grown hive. We propose two digital methods for modelling 3D scaffolds for micro-super organism co-occupation scenarios: “variable-offset” and “iterative-subtraction”, followed by two inoculation methods for the biofabrication of scaffolded fungal composites. The HIVEOPOLIS project aims to diversify and complexify urban ecological niches to make them more resilient to future game changers such as climate change. The combined functions of mycelium materials have the potential to provide a therapeutic environment for honeybees and, potentially, humans in the future.
... These non-food by-products, which are often by-products of meat production, would need to be replaced by alternatives such as synthetic leather, synthetic fertilizer or plant-based fats, causing additional GHG emissions and other environmental impacts that are not considered in our assessment. Partly, non-food by-products could be replaced in the future by fermentation-enabled alternatives such as fungi-based leather 42 . However, in analogy to MP this could result in higher energy-related GHG emissions, depending on the sustainability of energy production. ...
Ruminant meat provides valuable protein to humans, but livestock production has many negative environmental impacts, especially in terms of deforestation, greenhouse gas emissions, water use and eutrophication1. In addition to a dietary shift towards plant-based diets2, imitation products, including plant-based meat, cultured meat and fermentation-derived microbial protein (MP), have been proposed as means to reduce the externalities of livestock production3–7. Life cycle assessment (LCA) studies have estimated substantial environmental benefits of MP, produced in bioreactors using sugar as feedstock, especially compared to ruminant meat3,7. Here we present an analysis of MP as substitute for ruminant meat in forward-looking global land-use scenarios towards 2050. Our study complements LCA studies by estimating the environmental benefits of MP within a future socio-economic pathway. Our model projections show that substituting 20% of per-capita ruminant meat consumption with MP globally by 2050 (on a protein basis) offsets future increases in global pasture area, cutting annual deforestation and related CO2 emissions roughly in half, while also lowering methane emissions. However, further upscaling of MP, under the assumption of given consumer acceptance, results in a non-linear saturation effect on reduced deforestation and related CO2 emissions—an effect that cannot be captured with the method of static LCA. Replacing 20% of per-capita ruminant consumption with microbial protein can offset future increases in global pasture area, cut annual deforestation and related CO2 emissions in half, and lower methane emissions.
... Within the last 5 years, the ability of fungal mycelium not only to digest but also to bind and connect loose plant-based particles into firmer composite materials has thus led to a substantial increase in publications that pioneered the manufacturing process and that described some characteristics of mycelium-based materials [6][7][8][9][10][11][12]. Potential applications for fungal composite materials that have been discussed so far are as diverse as disruptivesoon packaging material, thermal insulation, acoustic insulation, construction material as well as leather could be produced by filamentous fungi of the phylum Basidiomycota [2][3][4][13][14][15]. ...
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.
... Mycelium-based composites have been successfully tested for combinations with cellulose-based waste products, such paper and cardboard (Jones, 2021) but also combinations with mineral substrates including clay (Jauk et al. 2021). ...
A sustainable, circular, post-carbon economy of the future will take waste material from one part of the economy and give it new value. This will reduce energy and material leakage from the economy and create new opportunities for innovation in materials. Myco-materials provide an opportunity to transform ligno-cellulosic matter, such as waste cardboard and sawdust, into useful materials. This is achieved by using a fungus to bind together these substrates into useful forms. This paper explores how computational design parameters can be informed from the mycelia growth process. We created several prototype forms that show behaviour of myco-materials through the growing and drying process. These show how inclusion of cardboard substructures may improve the performance of the resulting material by increasing its stability during the drying process. We also demonstrate limits to the size of myco-materials through computational design. Myco-materials will likely be part of a sustainable post-carbon economy, by bringing new value to waste material, and this paper shows how computational design can be informed by mycelial growth.
... Fungal mycelium is exceptionally promising because it can be produced on the basis of a wide variety of organic substrates, such as agricultural residues, it is fully biodegradable and has low density, low production cost, and low processing energy input [1,2]. This makes fungal mycelium a sustainable option for the production of various materials, including materials for packaging [3], construction [4], sound absorption [5][6][7], flame-retardation [8], medication [9], filtration [10], and as a substitute for leather [11,12]. The ability to degrade lignocellulosic plant biomass by the fungal division Basidiomycota including white-and brown-rot fungi, combined with their flexible but strong cell walls make them ideal ...
Background
Recent efforts in fungal biotechnology aim to develop new concepts and technologies that convert renewable plant biomass into innovative biomaterials. Hereby, plant substrates become metabolized by filamentous fungi to transform them into new fungal-based materials. Current research is thus focused on both understanding and optimizing the biology and genetics underlying filamentous fungal growth and on the development of new technologies to produce customized fungal-based materials.
Results
This manuscript reports the production of stable pastes, composed of Fomes fomentarius mycelium, alginate and water with 71 wt.% mycelium in the solid content, for additive manufacturing of fungal-based composite materials. After printing complex shapes, such as hollow stars with up to 39 mm in height, a combination of freeze-drying and calcium-crosslinking processes allowed the printed shapes to remain stable even in the presence of water. The printed objects show low bulk densities of 0.12 ± 0.01 g/cm ³ with interconnected macropores.
Conclusions
This work reports for the first time the application of mycelium obtained from the tinder fungus F. fomentarius for an extrusion-based additive manufacturing approach to fabricate customized light-weight 3D objects. The process holds great promise for developing light-weight, stable, and porous fungal-based materials that could replace expanded polystyrene produced from fossil resources.
... Mycelium-based composites have been successfully tested for combinations with cellulose-based waste products, such paper and cardboard (Jones, 2021) but also combinations with mineral substrates including clay (Jauk et al. 2021). ...
A sustainable, circular, post-carbon economy of the future will take waste material from one part of the economy and give it new value. This will reduce energy and material leakage from the economy and create new opportunities for innovation in materials. Myco-materials provide an opportunity to transform ligno-cellulosic matter, such as waste cardboard and sawdust, into useful materials. This is achieved by using a fungus to bind together these substrates into useful forms. This paper explores how computational design parameters can be informed from the mycelia growth process. We created several prototype forms that show behaviour of myco-materials through the growing and drying process. These show how inclusion of cardboard substructures may improve the performance of the resulting material by increasing its stability during the drying process. We also demonstrate limits to the size of myco-materials through computational design. Myco-materials will likely be part of a sustainable post-carbon economy, by bringing new value to waste material, and this paper shows how computational design can be informed by mycelial growth.
Mycelium composites are a class biopolymeric composites, consisting of cost-effective and environmentally sustainable materials. Globally, this class of composites is currently experiencing burgeoning research interest. With increasing pressure on cheaper materials with sustainable and ‘green’ credentials, mycelium composites hold some promise in this space, particularly in the construction industry, where the cost-performance indicator is a critical consideration. This material type uses the biological phenomenon of fungal growth to transition agri-waste materials to low-cost and low energy-embodied construction materials. Mycelium composites are inherently lossy in constitution and hence, have natural thermal and acoustic insulating properties. They have also shown impressive fire-resistant properties. These lossy properties, however, do not attribute good mechanical properties to mycelium composites, which are further compounded by its low hydrophobicity. However, some recent developments in the processing of the mycelium composites using 3D printing technologies by chemical manipulation of its constituents and self-healing mycelium structures, point this class of composites towards more flexural, robust, and strength-based semi-structural applications.
Scholars and industries are studying the use of fungi-based materials as sustainable alternatives for materials in the several industries. Fungi are the decomposers of nature. They secrete enzymes through their vegetative root that is called mycelium and break down biopolymers of organic matter to simpler structures of carbon-based nutrients. Mycelium-based composites (MBC) are the most widely used form of fungi-based materials. These are foam-like, light-weight, and biodegradable composite materials. Since MBC do not depend on fossil fuels during production, are renewable, and create no waste throughout their life cycle, their use in architectural applications are being increasingly explored. In this chapter, we review the ongoing efforts to explore and enhance material properties of MBC to render them more suitable for the architecture, engineering, and construction (AEC) industry. In the AEC industry, MBC are currently used as insulation panels, load-bearing masonry components, and cores for sandwich structures. In this chapter, we review the methods used to enhance the material properties of MBC. Since material properties of MBC depend on various cultivation and post-processing factors, the effect of the growth factors on the final material outcome are reviewed from scholarly papers written and published from 2012 to 2021 related to MBCs and their use in design, architecture, and construction industry.
Efficient hemostasis is a great challenge for treating the inaccessible hemorrhage wounds. A novel shape-memory chitin-glucan hemostatic sponge (ATC-Sponge) is constructed via sequentially in-situ removal of protein and glucan from Pleurotus eryngii fruiting body, TEMPO oxidation and Ca²⁺ crosslinking. The sponge displays interconnected microporous structure with high water absorption and robust mechanical properties. The sponge at dry state shows rapid blood-triggered shape-memory, allowing easy insertion into the puncture wound in a compressed fixed-shape and the subsequent quick volume expansion to conform wound shape to stop bleeding. Compared with standard medical gauze and gelatin sponge, ATC-Sponge demonstrates superior hemostatic performance in the rat femoral artery and non-compressive liver puncture injury models. Additionally, ATC-Sponge can effectively accelerate wound healing. This multi-functional shape-memory ATC-Sponge shows high potential in controlling the bleeding of inaccessible traumas.
Mycelium-based composites (MBC) are biomaterials presenting renewable and bio-degradable alternatives for a wide range of design and manufacturing processes, including the building industry. MBC result from the incomplete growth of mycelium, fibrous root systems of fungi. They can turn urban and agricultural waste into high-end products. Existing research shows that MBC can reduce fossil fuels’ reliance and embodied energy and decrease building waste. Architects recently designed and built a wide range of experimental projects with MBC. In parallel, there is a growing body of work on MBC by scholars from different disciplines, such as mycology, material science, and mechanical engineering, focusing on assessing and enhancing the material properties of MBC for various applications.
In this paper, we first provide essential knowledge on the cultivation of MBC for architectural applications. Next, we analyze some of the prominent architectural prototypes with MBC to exemplify the architectural potentials of MBC and uncover the constraints and affordances of this biomaterial when used in an architectural context. Finally, we review and synthesize the existing literature on MBC from different disciplines providing a guide for architects to cultivate and enhance the material properties of MBC for architectural goals.
We hybridised lignocellulose microfibres with a fungal derived nanoscale chitin-β-glucan network produce hydrophobic papers with improved tensile properties.
Panorama das pesquisas relacionadas ao câncer de mama e a contribuição do design
The most recent strategies available for upcycling agri-food losses and waste (FLW) into functional bioplastics and advanced materials are reviewed and the valorization of food residuals are put in perspective, adding to the water–food–energy nexus. Low value or underutilized biomass, biocolloids, water-soluble biopolymers, polymerizable monomers, and nutrients are introduced as feasible building blocks for biotechnological conversion into bioplastics. The latter are demonstrated for their incorporation in multifunctional packaging, biomedical devices, sensors, actuators, and energy conversion and storage devices, contributing to the valorization efforts within the future circular bioeconomy. Strategies are introduced to effectively synthesize, deconstruct and reassemble or engineer FLW-derived monomeric, polymeric, and colloidal building blocks. Multifunctional bioplastics are introduced considering the structural, chemical, physical as well as the accessibility of FLW precursors. Processing techniques are analyzed within the fields of polymer chemistry and physics. The prospects of FLW streams and biomass surplus, considering their availability, interactions with water and thermal stability, are critically discussed in a near-future scenario that is expected to lead to next-generation bioplastics and advanced materials.
This research explores the carbon removal of a novel bio-insulation composite, here called MycoBamboo, based on the combination of bamboo particles and mycelium as binder. First, an attributional life cycle assessment (LCA) was performed to define the carbon footprint of a European bamboo plantation and a bio-insulation composite, as well as its ability to remove CO2 along its lifecycle at a laboratory scale. Secondly, the Global Worming Potential (GWP) was estimated through a dynamic LCA with selected end-of-life and technical replacement scenarios. Finally, a building wall application was analyzed to measure the carbon saving potential of the MycoBamboo when compared with alternative insulation materials applied as an exterior thermal insulation composite system. The results demonstrate that despite the negative GWP values of the biogenic CO2, the final
Net-GWP was positive. The technical replacement scenarios had an influence on the final Net-GWP values, and a longer storage period is preferred to more frequent insulation substitution. The type of energy source and the deactivation phase play important roles in the mitigation of climate change. Therefore, to make the MycoBamboo competitive as an insulation system at the industrial scale, it is fundamental to identify alternative low-energy deactivation modes and shift all energy-intensity activities during the production phase to renewable energy.
Materials on the nanoscale, for instance carbon nanotubes or polymer nanofibers, both well-known for high strength and modulus, have become focal points of research in material science. In the quest for sustainable materials exhibiting those characteristics, nano-sized materials based on renewable resources would be a major leap forward. Natural nanofibrils are thus an attractive development to combine advantages of the nanoscale with renewable raw materials. Specifically, nanocellulose has attracted great attention in this regard, in particular nanocellulose sheets, i.e. nanopapers, have shown huge potential both in composite and water treatment applications. This is based on nanoscale fibrils having high specific surface areas resulting in remarkable mechanical properties, together with the possibility to establish specific chemical and surface properties enabled by a plethora of functional groups attachable. Even though chitin was identified prior to cellulose as load-bearing component in natural structures, research into nanocellulose has already seen a significant rise over the course of the past two decades, whereas chitin nanofibrils have slightly lagged behind this trend. However, extraction of chitin nanofibrils from fungi has initiated a new direction of research. Fungal chitin nanofibrils are natively already present in nanoscale and thus can be isolated with very little energy demand and effort compared to nanocellulose. These nanofibrils can be directly employed in water treatment but nanopapers utilizable in structural applications are also facilitated. Furthermore, utilization of mycelium, that is the vegetative part of fungi, could allow for an even more sustainable approach to attain renewable nanofibrils, as there is no competition with an edible food product present.
The utilization of biological systems has been receiving considerable attention in the past couple of decades in the development of bio-based functional materials. This has been largely inspired by the use of green, biodegradable, and environmentally sustainable materials for the development of new functional biomaterials. The utilization of renewable resources for the production of materials introduces fast-growing and biodegradable fungal mycelium-derived materials for various applications. Mycelium secretes enzymes and decomposes the substrate to take nutrients for growth and make an interwoven three-dimensional network. The elastic, porous, stiff, and dense mycelia are rich in antioxidants, antiviral, and anti-inflammatory compounds. The properties of mycelium-derived materials are greatly dependent upon the feeding substrate, fungus type, and processing conditions. Both pure mycelial materials and their composites secure an important position in the race of utilization of renewable resources for material synthesis. This chapter summarizes the utilization of mycelium-based materials for numerous applications like cosmetics, medicine, textile, construction, packaging, and the food industry. It also describes the potential of mycelial-derived materials as an alternative to the traditional insulators, packaging materials, and bovine leather. It further explains the importance of mycelium-based functional foods, cosmetics, and medicines.
This study aims to identify and compare the key social, economic and environmental sustainability practices in the leather industry. Content analysis was used to analyse extracted sustainability information from either the website, annual report, sustainability report or corporate social responsibility report of six leather-related companies. Review of existing literature assisted in categorising different practices under social, economic and environmental sustainability, while an identification of patterns among practices followed. Findings reveal that companies are observing a good practice of either dedicating a section of their website to revealing their sustainability activities or utilising their sustainability reports or annual reports. Energy efficiency, waste management and reduction of greenhouse gases emission were the most occurring environmental sustainability practices. Health and safety occurred as the dominant social sustainability practice, while economic sustainability practices have not been well defined, providing an opportunity for future research. The study provides a useful resource for managers and companies in the leather supply chain to learn from brands that have been embarking on sustainability efforts and assist them to a better understanding of the concept, in readiness for strategy formulation, implementation and reporting.
Chitin and its derivative chitosan are popular constituents in wound-treatment technologies due to their nanoscale fibrous morphology and attractive biomedical properties that accelerate healing and reduce scarring. These abundant natural polymers found in arthropod exoskeletons and fungal cell walls affect almost every phase of the healing process, acting as hemostatic and antibacterial agents that also support cell proliferation and attachment. However, key differences exist in the structure, properties, processing, and associated polymers of fungal and arthropod chitin, affecting their respective application to wound treatment. High purity crustacean-derived chitin and chitosan have been widely investigated for wound-treatment applications, with research incorporating chemically modified chitosan derivatives and advanced nanocomposite dressings utilizing biocompatible additives, such as natural polysaccharides, mineral clays, and metal nanoparticles used to achieve excellent mechanical and biomedical properties. Conversely, fungi-derived chitin is covalently decorated with β-glucan and has received less research interest despite its mass production potential, simple extraction process, variations in chitin and associated polymer content, and the established healing properties of fungal exopolysaccharides. This review investigates the proven biomedical properties of both fungal-and crustacean-derived chitin and chitosan, their healing mechanisms, and their potential to advance modern wound-treatment methods through further research and practical application.
Mycelium composites are an emerging class of cheap and environmentally sustainable materials experiencing increasing research interest and commercialisation in Europe and the United States for construction applications. These materials utilise natural fungal growth as a low energy bio-fabrication method to upcycle abundant agricultural by-products and wastes into more sustainable alternatives to energy intensive synthetic construction materials. Mycelium composites have customisable material properties based on their composition and manufacturing process and can replace foams, timber and plastics for applications, such as insulation, door cores, panelling, flooring, cabinetry and other furnishings. Due to their low thermal conductivity, high acoustic absorption and fire safety properties outperforming traditional construction materials, such as synthetic foams and engineered woods, they show particular promise as thermal and acoustic insulation foams. However, limitations stemming from their typically foam-like mechanical properties, high water absorption and many gaps in material property documentation necessitate the use of mycelium composites as non- or semi-structural supplements to traditional construction materials for specific, suitable applications, including insulation, panelling and furnishings. Nonetheless, useful material properties in addition to the low costs, simplicity of manufacture and environmental sustainability of these materials suggest that they will play a significant role in the future of green construction.
Greener alternatives to synthetic polymers are constantly being investigated and sought after. Chitin is a natural polysaccharide that gives structural support to crustacean shells, insect exoskeletons, and fungal cell walls. Like cellulose, chitin resides in nanosized structural elements that can be isolated as nanofibers and nanocrystals by various top-down approaches, targeted at disintegrating the native construct. Chitin has, however, been largely overshadowed by cellulose when discussing the materials aspects of the nanosized components. This perspective presents a thorough overview of chitin-related materials research with an analytical focus on nanocomposites and nanopapers. The red line running through the text emphasizes the use of fungal chitin that represents several advantages over the more popular crustacean sources, particularly in terms of nanofiber isolation from the native matrix. In addition, many β-glucans are preserved in with chitin upon its isolation from the fungal matrix, enabling new horizons for various engineering solutions.
Global warming is an important phenomenon responsible for global climate change. The rise in mean air temperature is attributed to the enhanced concentration of greenhouse gases in the atmosphere. Carbon dioxide (CO2), methane, nitrous oxide, and chlorofluorocarbons are the abundant greenhouses gases in the atmosphere. CO2 is the main greenhouse gas accounting for 76% of the total greenhouse effect. Both human activities and natural phenomena are responsible for the rise in atmospheric CO2 concentration. Soil respiration and soil carbon sequestration are considered as the source and sink, respectively, for CO2 gas. The net balance of respiration and sequestration in the soil are responsible for carbon concentration dynamics in the atmosphere. Higher CO2 concentration in the atmosphere is a major culprit behind global threat known as global warming. The CO2 concentration in the atmosphere may be reduced by soil carbon sequestration. Microorganisms including soil fungi enhance the rate of soil carbon sequestration through carbon assimilation from the atmosphere. In soil, fungi assimilate carbon in its hyphae. The amount and rate of carbon sequestration with the help of soil fungi are also affected by age and resilience of hyphae. The higher rate of carbon sequestration in soil may help in mitigating climate change
Cellulose and chitin, the most abundant natural polymers in the world, are used in applications ranging from construction and paper to cosmetics, pharmaceuticals and water treatment. Traditionally these polymers have been sourced from finite resources such as forests and crustacean exoskeletons, however they can be sourced more sustainably and at lower cost through waste upcycling. This study investigated nanocellulose-chitin hybrid materials derived from sugarcane by-products; cellulose from bagasse and fungal chitin from mycelial biomass grown on molasses. Hybrid physical properties such as mechanical performance and wettability were then tuned using varying ratios of nanocellulose and Trametes versicolor and Allomyces arbuscular fungal chitins. The natural polymers were isolated via mild chemical extraction and hot-pressed to produce hybrid materials, utilising more hydrophobic A. arbuscular and more hydrophilic T. versicolor fungal chitin, reinforced with nanocellulose. The resulting homogenous materials constituted cheap, environmentally sustainable thin films with tunable physical properties, potentially suitable for applications including coatings, membranes and paper.
Fungi are an understudied, biotechnologically valuable group of organisms. Due to the immense range of habitats that
fungi inhabit, and the consequent need to compete against a diverse array of other fungi, bacteria, and animals, fungi have
developed numerous survival mechanisms. The unique attributes of fungi thus herald great promise for their application in
biotechnology and industry. Moreover, fungi can be grown with relative ease, making production at scale viable. The
search for fungal biodiversity, and the construction of a living fungi collection, both have incredible economic potential in
locating organisms with novel industrial uses that will lead to novel products. This manuscript reviews fifty ways in which
fungi can potentially be utilized as biotechnology. We provide notes and examples for each potential exploitation and give
examples from our own work and the work of other notable researchers. We also provide a flow chart that can be used to
convince funding bodies of the importance of fungi for biotechnological research and as potential products. Fungi have
provided the world with penicillin, lovastatin, and other globally significant medicines, and they remain an untapped
resource with enormous industrial potential.
Keywords Biocontrol · Biodiversity · Biotechnology · Food · Fungi · Mushrooms
The current physical goods economy produces materials by extracting finite valuable resources without taking their end of the life and environmental impact into account. Mycelium-based materials offer an alternative fabrication paradigm, based on the growth of materials rather than on extraction. Agricultural residue fibres are inoculated with fungal mycelium, which form an interwoven three-dimensional filamentous network binding the feedstock into a lightweight material. The mycelium-based material is heat-killed after the growing process. In this paper, we investigate the production process, the mechanical, physical and chemical properties of mycelium-based composites made with different types of lignocellulosic reinforcement fibres combined with a white rot fungus, Trametes versicolor. This is the first study reporting the dry density, the Young's modulus, the compressive stiffness, the stress-strain curves, the thermal conductivity, the water absorption rate and a FTIR analyse of mycelium-based composites by making use of a fully disclosed protocol with T. versicolor and five different type of fibres (hemp, flax, flax waste, softwood, straw) and fibre processings (loose, chopped, dust, pre-compressed and tow). The thermal conductivity and water absorption coefficient of the mycelium composites with flax, hemp, and straw have an overall good insulation behaviour in all the aspects compared to conventional materials such as rock wool, glass wool and extruded polystyrene. The conducted tests reveal that the mechanical performance of the mycelium-based composites depends more on the fibre processing (loose, chopped, pre-compressed, and tow), and size than on the chemical composition of the fibres. These experimental results show that mycelium-composites can fulfil the requirements of thermal insulation and have the potential to replace fosile-based composites. The methology used to evaluate the suitability and selection of organic waste-streams proved to be effective for the mycelium-material manufacturing applications.
Living fungal mycelium with abolished ability to form fruiting bodies is a self-healing substance, which is particularly valuable for further engineering and development as materials sensing environmental changes and secreting signals. Suppression of fruiting body formation is also a useful tool for maintaining the stability of a mycelium-based material with ease and lower cost. The objective of this study was to provide a biochemical solution to regulate the fruiting body formation, which may replace heat killing of mycelium in practice. The concentrations of glycogen synthase kinase-3 (GSK-3) inhibitors, such as lithium chloride or CHIR99021 trihydrochloride, were found to directly correlate with the development of fruiting bodies in the mushroom forming fungi such as Coprinopsis cinerea and Pleurotus djamor. Sensitive windows to these inhibitors throughout the fungal life cycle were also identified. We suggest the inclusion of GSK-3 inhibitors in the cultivation recipes for inhibiting fruiting body formation and regulating mycelium growth. This is the first report of using a GSK-3 inhibitor to suppress fruiting body formation in living fungal mycelium-based materials. It provides an innovative strategy for easy, reliable, and low cost maintenance of materials containing living fungal mycelium.
Mycelium and mycelium-biomass composites are emerging as new sustainable materials with useful flame-retardant potentials. Here we report a detailed characterisation of the thermal degradation and fire properties of fungal mycelium and mycelium-biomass composites. Measurements and analyses are carried out on key parameters such as decomposition temperatures, residual char, and gases evolved during pyrolysis. Pyrolysis flow combustion calorimetry (PCFC) evaluations reveal that the corresponding combustion propensity of mycelium is significantly lower compared to poly(methyl methacrylate) (PMMA) and polylactic acid (PLA), indicating that they are noticeably less prone to ignition and flaming combustion, and therefore safer to use. The hyphal diameters of mycelium decrease following pyrolysis. Cone calorimetry testing results show that the presence of mycelium has a positive influence on the fire reaction properties of wheat grains. This improvement is attributable to the relatively higher charring tendency of mycelium compared to wheat grain, which reduces the heat release rate (HRR) by acting as a thermal insulator and by limiting the supply of combustible gases to
the flame front. The mycelium growth time has been found to yield no significant improvements in the fire properties of mycelium-wheat grain composites.
Shoe patterns and a sole made of BC, baby shoe made of BC and, on the right BC material dyed in red. (prototype made by www.patent-shoes.com).
Filamentous fungi colonize substrates by forming a mycelium. This network of hyphae can be used as
a bio-based material. Here, we assessed the impact of environmental growth conditions and deletion
of the hydrophobin gene sc3 on material properties of the mycelium of the mushroom forming fungus
Schizophyllum commune. Thermogravimetric analysis showed that Δsc3 mycelium retained more
water with increasing temperature when compared to the wild type. The Young’s modulus (E) of the
mycelium ranged between 438 and 913MPa when the wild type strain was grown in the dark or in the
light at low or high CO2 levels. This was accompanied by a maximum tensile strength (σ) of 5.1–9.6MPa.
In contrast, E and σ of the Δsc3 strain were 3–4- fold higher with values of 1237–2727MPa and 15.6–
40.4MPa, respectively. These values correlated with mycelium density, while no diferences in chemical
composition of the mycelia were observed as shown by ATR-FTIR. Together, genetic modifcation
and environmental growth conditions impact mechanical properties of the mycelium by afecting the
density of the mycelium. As a result, mechanical properties of wild type mycelium were similar to those
of natural materials, while those of Δsc3 were more similar to thermoplastics.
We study a unique biomaterial developed from fungal mycelium, the vegetative part and the root structure of fungi. Mycelium has a filamentous network structure with mechanics largely controlled by filament elasticity and branching, and network density. We report the morphological and mechanical characterization of mycelium through an integrated experimental and computational approach. The monotonic mechanical behavior of the mycelium is non-linear both in tension and compression. The material exhibits considerable strain hardening before rupture under tension, it mimics the open cell foam behavior under compression and exhibits hysteresis and the Mullins effect when subjected to cyclic loading. Based on our morphological characterization and experimental observations, we develop and validate a multiscale fiber network-based model for the mycelium which reproduces the tensile and compressive behavior of the material.
Mycelium bio-composites are emerging as a safer and more fire-resistant alternative to commercially available thermoplastics intended for non-structural and semi-structural applications in the building and construction industry. In this paper, the fire reaction and thermal degradation properties of a mycelium bio-composite grown from rice hulls are evaluated and compared with commercially available extruded polystyrene (XPS) foam. The fire reaction properties of these materials are measured under cone calorimeter heating conditions that can generate correlations for a well-developed room fire (e.g. an incident heat flux of 50 kW/m2). Despite having similar time-to-ignition, the heat release rates (including the peak values), carbon dioxide release, carbon monoxide release and smoke density of the mycelium composite is significantly lower than those of the XPS foam. Thermo-gravimetric analysis (TGA) revealed that the superior fire-retardant characteristics of mycelium composites can be attributed to significant char formation driven by the presence of aromatic compounds (i.e. lignin) in the rice hulls, and phosphorus in the mycelium. The high silica content of rice hulls (15-20 wt%) also contributed to the better fire reaction properties of the mycelium composite. This array of fire retardant mechanisms reduced the amount of heat and toxic fumes released during combustion, thereby making mycelium bio-composites safer for use in construction applications requiring resistance to thermal shock.
Mushrooms are the most conspicuous fungal structures. Transcription factors (TFs) Bri1 and Hom1 of the model fungus Schizophyllum commune are involved in late stages of mushroom development, while Wc-2, Hom2, and Fst4 function early in development. Here, it is shown that Bri1 and Hom1 also stimulate vegetative growth, while biomass formation is repressed by Wc-2, Hom2, and Fst4. The Δbri1Δbri1 and the Δhom1Δhom1 strains formed up to 0.6 fold less biomass when compared to wild-type, while Δwc-2Δwc-2, Δhom2Δhom2, and Δfst4Δfst4 strains formed up to 2.8 fold more biomass. Inactivation of TF gene tea1, which was downregulated in the Δwc-2Δwc-2, Δhom2Δhom2, and Δfst4Δfst4 strains, resulted in a strain that was severely affected in mushroom development and that produced 1.3 fold more biomass than the wild-type. In contrast, introducing a constitutive active version of hom2 that had 4 predicted phosphorylation motifs eliminated resulted in radial growth inhibition and prompt fructification in both Δhom2 and wild-type strains, even in sterile monokaryons. Together, it is concluded that TFs involved in mushroom formation also modulate vegetative growth. Among these TFs is the homeodomain protein Hom2, being the first time that this class of regulatory proteins is implicated in repression of vegetative growth in a eukaryote.
Adipic acid, an abundant and nontoxic compound, was used to dissolve and cross-link chitosan. After the preparation of chitosan films through casting technique, the in situ amidation reaction was performed at 80–100 °C as verified by Fourier transform infrared (FT-IR). The reaction was accompanied by the release of water which was employed to investigate the reaction kinetics. Accordingly, the reaction rate followed the first-order model and Arrhenius equation, and the activation energy was calculated to be 18 kJ/mol. Furthermore, the mechanical properties of the chitosan films were comprehensively studied. First, optimal curing conditions (84 °C, 93 min) were introduced through a central composite design. In order to evaluate the effects of adipic acid, the mechanical properties of physically cross-linked (uncured), chemically cross-linked (cured), and uncross-linked (prepared by acetic acid) films were compared. The use of adipic acid improved the tensile strength of uncured and chemically cross-linked films more than 60% and 113%, respectively. Finally, the effect of cellulose nanofibrils (CNFs) on the mechanical performance of cured films, in the presence of glycerol as a plasticizer, was investigated. The plasticized chitosan films reinforced by 5 wt % CNFs showed superior properties as a promising material for the development of chitosan-based biomaterials.
In this work is presented a new category of self-growing, fibrous, natural composite materials with
controlled physical properties that can be produced in large quantities and over wide areas, based
on mycelium, the main body of fungi. Mycelia from two types of edible, medicinal fungi, Ganoderma
lucidum and Pleurotus ostreatus, have been carefully cultivated, being fed by two bio-substrates:
cellulose and cellulose/potato-dextrose, the second being easier to digest by mycelium due to presence
of simple sugars in its composition. After specific growing times the mycelia have been processed in
order to cease their growth. Depending on their feeding substrate, the final fibrous structures showed
different relative concentrations in polysaccharides, lipids, proteins and chitin. Such differences are
reflected as alterations in morphology and mechanical properties. The materials grown on cellulose
contained more chitin and showed higher Young’s modulus and lower elongation than those grown on
dextrose-containing substrates, indicating that the mycelium materials get stiffer when their feeding
substrate is harder to digest. All the developed fibrous materials were hydrophobic with water contact
angles higher than 120°. The possibility of tailoring mycelium materials’ properties by properly choosing
their nutrient substrates paves the way for their use in various scale applications.
Over the past two decades there has been a rapid growth in tanning and leather manufacturing in developing countries, an undesirable by-product of this is an increase in waste associated with leather products. End-of-life management options for leather products are often limited to incineration or landfill; these carry a range of environmentally damaging impacts. This indicates a need for an urgent diversion towards material recycling in order to prevent further environmental degradation. This paper investigates a number of interdependent and complex challenges in implementation of a circular economy approach within leather industry. These challenges range from achieving economy of scale required for commercial viability and finding secondary markets for the recycled materials to developing ‘resource efficient recycling processes’ that are especially tailored to the specific needs of leather products.
Fungi: Biology and Applications is a comprehensive, balanced introduction of the biology, biotechnological applications and medical significance of fungi. With no prior knowledge of the subject assumed, the opening chapters offer a broad overview of the basics of fungal biology, in particular the physiology and genetics of fungi. Later chapters move on to include more detailed coverage of topics such as proteomics, bioinformatics, heterologous protein expression, medical mycology, anti-fungal drug development and function, fungal biotechnology and fungal pathogens of economically important plants. Carefully structured, each chapter contains self-assessment exercises with answers included at the end of the book to enhance student understanding. A comprehensive treatment of the medical and economic importance of fungi to everyday life. Chapters include revision sections and problems to reinforce key concepts. Invaluable for undergraduates taking a first course on fungal biology or mycology. Also of interest to those working within the field looking for an up-to-date introduction.
In Transylvania, part of Romania, fungi are
traditionally used in the human medicine, handicraft,
and several customs for a long time past. This study
aimed at systematic collecting of ethnomycological
and ethnomedicinal data of Fomes fomentarius (L.) Fr.
and Piptoporus betulinus (Bull.) P. Karst. in Corund in
south-eastern Transylvania. In addition, we aimed to
compare our data with earlier ethnomycological and
pharmacological records of the region and other
countries. The fieldwork was carried out in Corund in
2012–2013. The visited ‘‘topla´sz’’ people who work
with tinders were asked with semi-structured interviews
to list the harvesting method and time, storage
and preparations, as well as the ethnomycological and
ethnomedicinal use of the fruit body of tinder fungus
and birch polypore. Literature data were collected from
the major scientific databases. The ethnomycological
use of tinder fungus and birch polypore starts with the
traditional steps of collection, storage, and trimming
and involves the use for ethnomedicinal purposes and
preparation of unique handmade products. These
preparations are still available on national and international
markets nowadays. The ethnobotanical use of
these fungi resulted in a special local occupation in
Corund, which is a unique activity in the world.
Unfortunately, it seems to be a disappearing tradition
nowadays because of the lack of transmission. Therefore,
these living data should be urgently documented
and preserved for the maintenance of this valuable
local tradition and knowledge of Sze´kelys.
Skins and hides are perishable resources that can be damaged by parasitic diseases and human error, which result in downgrading or rejection. This study was conducted to identify defect types and to determine their prevalence in pickled sheep and wet blue goat skins and wet blue hides. Each selected skin or hide was examined for defects in natural light and the defects were graded according to established quality criteria in Ethiopian standard manuals. Major defects were captured by digital photography. The major pre-slaughter defects included scratches (64.2%), cockle (ekek) (32.8%), wounds or scars (12.6%), lesions from pox or lumpy skin disease (6.1%), poor substance (5%), branding marks (2.3%) and tick bites (1.5%). The presence of grain scratches in wet blue hides (76.3%) was significantly higher than in pickled sheep (67.2%) and wet blue goat (59.1%) skins. The major slaughter defects included flay cuts or scores, holes, poor pattern and vein marks, with a higher occurrence in wet blue goat skins (28.7%; P < 0.001) than in wet blue hides (22.8%) and pickled sheep skins (11.1%). The most prevalent postslaughter defects were grain cracks (14.9%), hide beetle damage (8%), damage caused by heat or putrefaction (3.7%) and machine-induced defects (0.5%). Grain cracks (27.04%) and hide beetle damage (13.9%) in wet blue goat skins were significantly more common than in wet blue hides and pickled sheep skins. These defects cause depreciation in the value of the hides and skins. Statistically significant (P < 0.001) higher rejection rates were recorded for wet blue hides (82.9%) than for pickled sheep skins (18.3%) and wet blue goat skins (8.5%). Improved animal health service delivery, effective disease control strategies and strong collaboration between stakeholders are suggested to enhance the quality of skins and hides.
Nutrient mining through removal by crops, soil erosion and leaching is a major challenge for sustaining the productivity of oilseeds. Besides external application of fertilisers, a major contribution of nitrogen for legumes is addressed by nitrogen-fixing bio-inoculants. In the scenario of climate change, efforts should also be made to identify climate-resilient microbes to address the issue in the future. Within the constraints of available resources, a large number of plant growth-promoting microorganisms including AM fungi have been identified and found to enhance growth and yield of many oilseed crops. However, effective strains tolerant to abiotic stresses like salinity, high temperature and moisture-deficit stress are scanty. The quality inoculum production of AM fungi and its application in oilseeds have been discussed with consideration of the soil edaphic factors for identifying potential AM fungi and their management for higher oilseed crop yields yet maintaining the agroecosystem sustainability.
Chrome tanning remains the most favourite technology in the leather industry worldwide due to its ability to produce leather with attributes desirable for high-quality leather such as excellent hydrothermal stability, better dyeing characteristics and softness. Nevertheless, the technology has been censured globally for its severe environmental pollution and adverse effects on human health and other organisms. Developing alternative eco-friendly tanning technologies capable of producing leather of high quality has remained a challenging scientific inquiry. This review article provides an assessment of various eco-friendly tanning attempts geared towards improving or replacing the chrome technology without compromising the quality of the produced leather. The reviewed publications have ascertained that, these attempts have been centred on recycling of spent liquors; chromium exhaustion enhancement and total replacement of chromium salts. The research gaps and levels of key environmental pollutants from the reviewed technologies are presented, and the qualities of the leather produced from these technologies are highlighted. Of all the examined alternative technologies, total replacement of chromium salts sounds ideal to elude adverse effects associated with chrome tanning. Combination tanning, which implies blending two tanning agents that individually cannot impart desired properties to the leather, is anticipated to be an alternative technology to chrome tanning. Apart from being an eco-friendly technology, combination tanning produces leather with similar features to those produced by chrome tanning. In this regard, blending vegetable tannins with aluminium sulphate provides a promising chrome-free tanning technology. However, further studies to optimize combination tanning technologies to suit industrial applications are highly recommended.
In this study, a novel fungal chitin was extracted from Hericium erinaceus residue using moderate chemical sequential extraction procedures. The effects of deproteinization conditions, including NaOH concentration, reaction temperature, and reaction time, on the chitin yield, purity, molecular weight (Mw), and degree of acetylation (DA) were investigated. Additionally, SEM, FTIR, XRD, NMR and TGA were applied to indicate the removal of non-chitin components from HER. Results suggested that the deproteinization processes meaningfully influence the chitin yield, purity, Mw, and DA. The chitin with most desirable parameters (yield of 16.30%, purity of 97.88%, Mw of 2.01 × 105 g/mol, and DA of 77.67%) was obtained at low NaOH concentration of 2%, reaction temperature of 85 °C, and reaction time of 3 h. In addition, non-chitin components such as minerals, proteins, and pigments were mostly removed after the extraction. The results demonstrated that the Hericium erinaceus residue can lead to a high-quality chitin, which is useful for a broad range of applications.
Peatlands are major carbon sinks globally, but it is still unclear what drives their shift from functioning as carbon sink to a source. Fungi rely on soil carbon inputs and play an active role in carbon mobilization and stabilization. Future climate change scenarios predict increases in temperature and lower water tables, which may lead to functional shifts in fungal communities growing in peatlands. Despite their abundance, the impact of fungi on carbon cycling in peatlands is still poorly understood. Therefore, it is crucial to study the dynamics and distribution of fungal communities in pristine peatlands in order to predict the potential changes in peatland ecosystems more accurately. Here, we review the current knowledge about fungal communities in peatlands, including the influence of peatland type, abiotic factors, and temporal and spatial dynamics on fungal diversity. Our overview shows that fungal diversity in peatlands of certain regions such as tropical areas is severely understudied. Furthermore, we examine the ecological roles and the relative contribution to carbon cycling of functional guilds of fungi in peatlands, showing that saprotrophs are the key guild in organic matter decomposition, and ericoid- and ectomycorrhizal fungi have the ability to act as decomposers and vectors of plant carbon input to soil. We suggest that the application of a combination of methodological approaches for taxonomic and functional characterisation of peatland fungal communities is needed to build better understanding about the diversity-functioning relationships in peatland ecosystems. Overall, this review shows that fungi must be considered as important drivers of mechanistic processes underlying biodiversity, plant nutrient uptake and carbon losses in peatlands.
Mycelium is a biopolymer that has the potential to be a sustainable replacement for petroleum based foams in some engineering applications. During a recent study, with the objectives to first relate the effects of growing conditions on material properties and second to develop a model to predict the bulk behavior of mycelium, it was found that a variety of standard test methods are being used for the tensile characterization of mycelium in the literature. In the current study, these test methods were found to cause stress concentrations that resulted in maximum loads away from the gauge section, griping conditions that crushed the test samples through the thickness, and gauge sections that were smaller than the level of heterogeneity typically observed in samples of mycelium biopolymer. A new tensile specimen configuration has been developed that mitigates the issues associated with other specimen configurations. This new specimen configuration is used to determine the tensile strength, tensile modulus, and Poisson’s ratio of mycelium biopolymer specimens.
Filamentous fungi have been used for more than a century as versatile and highly productive cell factories. They are used to produce enzymes and small molecule compounds such as antibiotics and organic acids. Filamentous fungi are now also being explored for the production of sustainable materials that can for instance replace plastics. Mutagenesis and genetic modification are used to improve performance of production strains. Single cell technologies and bulk sample analysis are novel strategies to identify genes that can be used for genetic modification of production strains. Such genes may for instance be involved in fungal reproduction and hyphal heterogeneity. These differentiation processes have recently been implicated to affect production of enzymes and small molecule compounds. Finally, use of mixed cultures instead of monocultures can be a strategy to improve production processes.
This study explores the broader questions and implications involved in selecting sustainable materials for designing everyday products for consumers, through a qualitative review of leather and new modern alternatives. Leather is a resilient material that has been used for thousands of years. However, the processes involved in producing the material on a mass scale create adverse environmental and social impact when not carefully managed and considered. Although the modern leather alternatives may have comparatively smaller environmental footprints, designing a sustainable product may not be as simple as replacing one material for another and involves complex value judgements amongst industry players and consumers. This, therefore, brings up questions about what is material or immaterial when it comes to sustainable design decisions, and emphasizes the need for systemic thinking across the value chain in order to have a truly meaningful attempt towards designing for environmental, social and economic sustainability.
This work addresses the application of Refuse Derived Fuel (RDF) char as a low-cost ad-sorbent for methylene blue (MB) in batch mode, as an approach to remediate pigment contaminated effluents and a model for the adsorption of cationic analytes. The RDF char was tested without pre-treatment and after a cold alkali treatment to enhance adsorption. The adsorbents were characterized for proximate and ultimate composition, pHpzc and N2 adsorption/desorption behavior. Operation parameters such as pH, adsorbent dose, contact time, dye concentration and temperature were varied. Kinetic studies revealed that adsorp-tion of methylene blue in the RDF chars followed a pseudo-second-order kinetic model. Adsorption isotherms showed differences in the possible adsorption mechanisms as a re-sult of char activation. This work highlighted that RDF chars that are not suitable for ener-gy conversion may be valorized as a low-cost adsorbents.
Mycelium, the vegetative growth of filamentous fungi, has attracted increasing commercial and academic interest in recent years due to its ability to upcycle agricultural and industrial wastes into low-cost, sustainable composite materials. However, mycelium composites typically exhibit foam-like mechanical properties, primarily originating from their weak organic filler constituents. Fungal growth can be alternatively utilised as a low-cost method for on-demand generation of natural nanofibrils, such as chitin and chitosan, which can be grown and isolated from liquid wastes and by-products in the form of fungal micro-filaments. This study characterised polymer extracts and nanopapers produced from a common mushroom reference and various species of fungal mycelium grown on the sugarcane by-product molasses. Polymer yields of ~10-26% were achieved, which is comparable to those of crustacean-derived chitin, and the nanopapers produced exhibited much higher tensile strengths than existing mycelium materials, with values of up to ~25 MPa (mycelium) and ~98 MPa (mushroom), in addition to useful hydrophobic surface properties resulting from the presence of organic lipid residues in the nanopapers. HCl or H2O2 treatments were used to remove these impurities facilitating tuning of mechanical, thermal and surface properties of the nanopapers produced. This potentially enables their use in a wide range of applications including coatings, membranes, packaging and paper.
Climate change being today’s major issue is concerned with the unprecedented increase in natural resource exploitation and uncontrolled population increase, reaching in an irreversible point. Greenhouse gases (GHGs) responsible for such changes are emitted by a variety of natural as well as anthropogenic sources. Agriculture sector shares a major proportion in total GHG emission. As the food demand is increasing with the rising population, the proportion of GHG emissions from agricultural sector is also increasing. The total amount of GHGs (in terms of carbon equivalent (C-eq)) emitted by the processes in agricultural sector is regarded as carbon footprint of agriculture. Various activities related to agriculture such as plowing, tilling, manuring, irrigation, variety of crops, rearing livestock, and related equipment emit a significant amount of GHGs that are categorized in three tiers of carbon footprinting, separated by hypothetical boundaries. The energy input through machinery, electricity, livestock management, and fossil fuel constitutes a major proportion of carbon emission through agriculture. Crop cultivation system mainly cereals produces higher GHGs than any other farming systems like vegetables and fruits. Beside this, land-use changes including conversion of natural ecosystem to agricultural, deforestation, and crop residue burning after harvest contribute significantly to higher carbon emission. This review article will focus on carbon footprint from agriculture including inputs for uses from energy, fertilizers, organic manure, pesticides, and processes that affect carbon emission from agriculture. The mitigation practices effective in reducing the carbon footprinting from various agricultural activities will also be reviewed. Efficient use of fossil fuel and other non-renewable energy sources in the agriculture system, diversified cropping system, enhancing soil carbon sequestration by straw return, plantation, etc., crop rotation system, and limiting deforestation will be discussed as measures which may help to reduce the GHG emissions from agriculture sector.
Tanneries boost the local economic development, but lead to severe environmental pollution; hence, improving the environmental assessment of this sector is essential. In this paper, the Life Cycle Assessment method was applied to estimate impacts on the environment and human health of retanning, fatliquoring and dyeing. The analysis was performed from a “gate to gate” perspective. Moreover, sulpho chlorinated paraffin and epoxidized vegetable oil have been evaluated as alternative fatliquoring agents.
The production of electricity required for the rotation of drums gives the main contribute to most of the impact categories, followed by the azo-dye production. Emissions of sulfur dioxide, nitrogen oxides, manganese, vanadium and nickel associated to power plants are the main sources of terrestrial acidification and particulate matter formation, as well as of human and marine toxicity (4.48·10-1 and 1.09·10-2 kg of 1,4-DBeq kg-1 crust leather, respectively). Nitrate loads from wastewater treatment and oxidative treatments affect heavily marine eutrophication (6.9·10-1 g N eq kg-1 crust leather). The use of epoxidized vegetable oil would affect human toxicity, ecosystem, metal and water resources depletion more than the use of sulpho chlorinated paraffin, mainly due to pesticides distribution and other cultivation practices. Phosphate and nitrate releases due to fertilization determine the high impact on the categories freshwater and marine eutrophication.
Progress in increasing the conversion efficiency is demanded, but overall focus must be made on the substitution of fossil fuels with cleaner alternatives. The transition towards a circular economy is encouraged; increasing rates of reduction, reuse, recycle and recover of solid waste and tannery effluents are recommended. Agricultural practices with a reduced consumption of phytosanitary products and mineral fertilizers, alternative to conventional farming, would strongly contribute to increase the sustainability of epoxidized vegetable oil as alternative fatliquoring agent.
An isolation method with mild mechanical agitation and no acidic extraction step from a mushroom substrate resulted in chitin nanofibres (ChNFs) with large shares of retained glucans (50-65%). The subsequent chitin nanopapers exhibited exceptionally high tensile strengths of >200 MPa and moduli of ca. 7 GPa which were largely attributed to the preserved glucans in the mixture, imparting a composite nature to the nanopapers. The isolation method for ChNFs is notably different from the conventional process with crustacean chitin sources that do not incorporate glucans and where an acidic extraction step for the removal of minerals must always be included.
Meat co-products are the non-meat components arising from meat processing/fabrication and are generated in large quantities on a daily basis. Co-products are considered as low added-value products, and in general it is difficult for industries to divert efforts into increasing their value. While many of these products can be edible those not used for human consumption or pet food is usually processed to be used as animal feed, fertilizer or fuel. However, to a large extent meat co-products are an excellent source of high nutritive value protein, minerals and vitamins and hence may be better diverted to contribute to alleviate the increasing global demand for protein. In this review the current uses, legislation and potential techniques for meat co-products processing are reviewed with the aim of showing a route to improve meat industry sustainability, profitability and better usage of available resources.
Mycelial growth attracts academic and commercial interest because of its ability to upcycle agricultural and industrial wastes into economical and environmentally sustainable composite materials using a natural, low-energy manufacturing process able to sequester carbon. This study aims to characterise the effect of varying ratios of high silica agricultural and industrial wastes on the flammability of mycelium composites , relative to typical synthetic construction materials. The results reveal that mycelium composites are safer than the traditional construction materials considered, producing much lower average and peak heat release rates and longer time to flash-over. They also release significantly less smoke and CO2 , although CO production fluctuated. Rice hulls yielded significant char and silica ash which improved fire performance , but composites containing glass fines exhibited the best fire performance because of their significantly higher silica concentrations and low combustible material content. Higher concentrations of glass fines increased volume-specific cost but reduced mass-specific and density-specific costs. The findings of this study show that mycelium composites are a very economical alternative to highly flammable petroleum derived and natural gas-derived synthetic polymers and engineered woods for applications including insulation, furniture, and panelling.
Methanogenic activity tests were used for the determination of anaerobic biodegradability of some concentrated wastes from the pharmaceutical industry - waste biomass from threonine production, mycelium after penicillium extraction, and excess activated sludge from the treatment of other pharmaceutical wastewaters. The tests were performed in 120 ml vials for each of the wastes ru1d for a mixture of the wastes in a real ratio. The mixture was tested at a wide range of initial biomass loading (1.15-8.8 gCOD/gVSS). The anaerobic biodegradability of the threonine biomass, the mycelium and the activated sludge was determined as 81.3%, 94.3% ru1d 44.4% respectively, and the average biodegradability of the mixture as 85.8%. Retention times needed for an 80% degradation efficiency were evaluated and used as a proposal for the starting-up biomass loading rate of the continuous reactor operation. An optimum substrate concentration without an inhibition effect was estimated and a specific methane yield for each waste; and for the mixture determined.
We report the mechanical strength of native chitin nanofibrils. Highly crystalline α-chitin nanofibrils were purified from filaments produced by a microalgae Phaeocystis globosa, and two types of β-chitin nanofibrils were purified from pens of a squid Loligo bleekeri and tubes of a tubeworm Lamellibrachia satsuma, with relatively low and high crystallinity, respectively. These chitin nanofibrils were fully dispersed in water. Strength of individualized nanofibrils was estimated using cavitation-induced tensile fracture of nanoscale filaments in a liquid medium. Both types of β-chitin nanofibrils exhibited similar strength values of approximately 3 GP; in contrast, the α-chitin nanofibrils exhibited a much lower strength value of 1.6 GPa. These strength estimates suggest that the tensile strength of chitin nanofibrils is governed by the molecular packing modes of chitin, rather than their crystallinity.
Mycelium composites comprise of networks of filamentous hyphae, utilising biological growth rather
than expensive energy intensive manufacturing processes to convert low-cost organic wastes into
economically viable and environmentally friendly materials. Although generally characterised as
polymer grade foams and used primarily for limited packaging and construction applications, the
mechanical performance of these materials varies significantly and is governed by hyphal architecture,
cell wall composition, composite constituents and growth kinetics which are in turn influenced
by inherent and exogenous factors. A range of potential applications have been proposed including
acoustic dampers, super absorbents, paper, textiles, structural and electronic parts. Limited
research, inconclusive data and the proposed applications and feasibility suggest that further investigation
is warranted.
At first some general considerations about specificity and characteristics of SSF, their advantages and disadvantages as compared to LSF, are presented. Microorganisms involved in solid substrate fermentations are identified, considering the better performances of filamentous fungi. The solid substrates and their basic macromolecular compounds are detailed in relation to this complex and heterogeneous system. Biomass measurement is examined in detail, as well as environmental factors, both essential for studying and optimising solid substrate fermentations.
In recent years, the growing attention to environmental challenges has shown that these issues are becoming of more and more interest to both research and industry. Companies are expected to ensure their products are fully traceable and more sustainable, which requires the involvement of all of the actors in the production network. According to this aim, this study proposes a structured approach that uses the traditional traceability concept as a means to identify the main information needed to assess environmental impacts along the whole supply chain (SC). The proposed approach is composed of four main steps: (i) SC modelling to identify all stakeholders and their inter-relations, (ii) data sharing to collect all relevant data, (iii) data elaboration to calculate performance at different levels of detail and (iv) result interpretation to optimise the SC. The distributed implementation of the approach at different SC steps represents a useful means to practically realise a sustainable SC management. A case study involving a leather shoe SC is used to demonstrate the effectiveness of the approach in identifying criticalities, supporting the selection of the most appropriate suppliers and correctly setting a management strategy towards the optimisation of internal and external traceability and environmental sustainability performances.
Because of its rigidity, the wall maintains the shape of the fungal hypha and various arguments have indicated chitin microfibrils embedded in an amorphous matrix as the major polymeric assemblage conferring rigidity to the wall (Bartnicki-Garcia 1973; Burnett 1979; Gooday and Trinci 1980; Wessels and Sietsma 1981). This rigidity contrasts with the need for expansion of the wall when growth occurs either apically, as in all vegetatively growing hyphae, or by diffuse extension, as in hyphae in some fruit bodies. To accommodate these contrasting needs, two basic hypotheses have been advanced. Either the wall as synthesized is inherently rigid and must be continuously loosened by lysins in order to expand and to allow for intercalation of new polymers. Alternatively, the newly synthesized wall is inherently visco-elastic and expandable and gradually develops rigidity to fulfill its role in the mature wall.
On the hydrological map of the world eutrophication has become the primary water quality issue. The excessive enrichment of waters with anthropogenic sources of nutrients especially nitrogen (N) and phosphorus (P) lead to the transformation of oligotrophic water bodies to mesotrophic, eutrophic, and finally hypertrophic. Mesotrophic and eutrophic phases exhibit intermediate and rich levels of nutrients and show increasing and serious water quality problems, respectively. Eutrophication restricts water use for fisheries, recreation, industry, and drinking because of increased growth of undesirable algae and aquatic weeds and the oxygen shortages caused by their death and decomposition. Associated periodic surface blooms of cyanobacteria (blue-green algae) occur in drinking water supplies and may pose a serious health hazard to animals and humans. Anthropogenic activities are the worst culprit of nutrient enrichment and root cause of eutrophication of water bodies. Excess nutrient inputs to water bodies usually come from sewage, industrial discharges, agricultural runoff, construction sites, and urban areas. Eutrophication can be minimized by regulating the nutrient sources, reducing the use of fertilizers, proper soil management practices, implementing mathematical models, phytoremediation etc. Among these, public awareness of eutrophication can play an important role in preventing the eutrophication of water bodies. © 2014 Springer Science+Business Media Dordrecht. All rights are reserved.