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Morphological features of mycelia. (a-d) "Re-growth" experiments with oven-dried and autoclaved mycelia (e-j) TEM images of mycelia as grown (e, f), dried in oven (g, h) and autoclaved (i, j), CW = cell wall. (k, n) SEM images of autoclaved mycelia; (o) distribution of hyphal diameters as calculated from the SEM images of the autoclaved mycelia.
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Mycelia, the vegetative part of fungi, are emerging as the avant-garde generation of natural, sustainable, and biodegradable materials for a wide range of applications. They are constituted of a self-growing and interconnected fibrous network of elongated cells, and their chemical and physical properties can be adjusted depending on the conditions...
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... halt its growth, constituted the first crucial step before testing it as a potential biomaterial scaffold. Mycelium inactivation is usually performed via heat treatment 53 . However, in a control experiment in which pieces of oven-dried mycelia (50 °C for 15 h) were placed back in contact with PDB, Ganoderma occasionally re-grew, unlike Pleurotus (Fig. 2a,c), suggesting that this weak treatment could be insufficient to achieve a stable configuration. This phenomenon was not completely unexpected since the heat-resistance of growing strains of Ganoderma lucidum has already been observed 54 , contrarily to Pleurotus ostreatus 55 . Therefore, the autoclave was chosen as post-growth treatment, ...
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... to achieve a stable configuration. This phenomenon was not completely unexpected since the heat-resistance of growing strains of Ganoderma lucidum has already been observed 54 , contrarily to Pleurotus ostreatus 55 . Therefore, the autoclave was chosen as post-growth treatment, since both strains appear inactive after being subjected to it (Fig. 2b,d). Transmission microscopy (TEM) investigation showed that after the oven treatment (Fig. 2g,h), the inner cell organization was comparable to the control (Fig. 2e,f). Instead, after autoclaving (Fig. 2i,j), the hyphal cells content drastically changed: large white areas appeared inside the cells, probably due to plasmolysis, and ...
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... the heat-resistance of growing strains of Ganoderma lucidum has already been observed 54 , contrarily to Pleurotus ostreatus 55 . Therefore, the autoclave was chosen as post-growth treatment, since both strains appear inactive after being subjected to it (Fig. 2b,d). Transmission microscopy (TEM) investigation showed that after the oven treatment (Fig. 2g,h), the inner cell organization was comparable to the control (Fig. 2e,f). Instead, after autoclaving (Fig. 2i,j), the hyphal cells content drastically changed: large white areas appeared inside the cells, probably due to plasmolysis, and vacuoles formed as a consequence of the heat and pressure shocks 56 . Importantly, the main ...
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... been observed 54 , contrarily to Pleurotus ostreatus 55 . Therefore, the autoclave was chosen as post-growth treatment, since both strains appear inactive after being subjected to it (Fig. 2b,d). Transmission microscopy (TEM) investigation showed that after the oven treatment (Fig. 2g,h), the inner cell organization was comparable to the control (Fig. 2e,f). Instead, after autoclaving (Fig. 2i,j), the hyphal cells content drastically changed: large white areas appeared inside the cells, probably due to plasmolysis, and vacuoles formed as a consequence of the heat and pressure shocks 56 . Importantly, the main structural component, the cell wall (CW), was still intact in both mycelia, even ...
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... ostreatus 55 . Therefore, the autoclave was chosen as post-growth treatment, since both strains appear inactive after being subjected to it (Fig. 2b,d). Transmission microscopy (TEM) investigation showed that after the oven treatment (Fig. 2g,h), the inner cell organization was comparable to the control (Fig. 2e,f). Instead, after autoclaving (Fig. 2i,j), the hyphal cells content drastically changed: large white areas appeared inside the cells, probably due to plasmolysis, and vacuoles formed as a consequence of the heat and pressure shocks 56 . Importantly, the main structural component, the cell wall (CW), was still intact in both mycelia, even if it slightly shrunk in Pleurotus. The ...
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... does not occur in this case 57 . Given these results, further analyses were only performed onto autoclaved samples. www.nature.com/scientificreports/ Morphological characterization. Scanning electron microscopy (SEM) investigation of post-autoclave mycelia allowed the observation of the hyphal structure and the calculation of their diameters (Fig. 2k-n), both essential features for a biomedical scaffold. Fibers were randomly oriented, and the strains presented the same morphological differences already observed by Haneef and colleagues with oven dried mycelia 46 . In Ganoderma lucidum two kinds of hyphal structures were noticeable, a tube-like short one, and a long smoother one, ...
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... and a long smoother one, defined as thread-like. Instead, Pleurotus ostreatus mycelia were only composed by the latter kind. Distribution of hyphal diameters was comparable to what previously reported for oven-dried mycelia: Pleurotus hyphae are larger, measuring on average 1.5 ± 0.4 μm, while Ganoderma thread-like ones average at 0.7 ± 0.2 μm (Fig. 2o). Such fibrous network arrangements and dimensions have been reported to be suitable for cell attachment 58-60 . Being able to greatly affect cell migration, oxygen regulation and nutrient exchange, porosity is a key parameter that should be considered during a scaffold design 61 . Usually, in tissue engineering applications, average ...
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... experiment revealed a significant amount of a Ganoderma metabolite even after two 24 h-washing steps with sterile PBS. This metabolite (Ganoderic acid V, a highly oxygenated lanostane-type triterpenoid, Figure S2) is known to have apoptotic and cytotoxic activities 94,95 . The toxic glucoside oleandrin was also detected in the extract, probably causing the fibroblasts death 96 . ...
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... These fungi are also valuable for primary biomass degradation for production of bioethanol [16], production of enzymes for industry [18], and bioaccumulation, bioremediation [19][20][21]. Notably, G.resinaceum may serve as biomaterial with various applications [22][23][24][25]. ...
Wood-decaying fungi are important study subjects for their ecological role as well as for their biotechnological applications. They break down lignin, cellulose, and hemicelluloses using enzymes that modify the chemical structure of these complex macromolecules. Due to their ability to degrade wood, these fungi can create structural damage to wooden structures and to trees, especially those with very low level of fitness. Previous studies on wood decay fungi in the Maltese Islands are limited to records and checklists described by a handful of authors. The aim of this study was to provide a comprehensive description of wood decay fungal diversity in the Maltese Islands including an updated checklist based on DNA barcoding, as well as to establish the first wood-decay fungal culture collection at the Biology Department Seed Bank of the University of Malta. Several surveys were carried out during the rainy season along wooded areas of the Maltese Islands as well as in historical gardens. Isolates were identified using macro- and micro-morphological features, dichotomous keys, as well as molecular data. Basidiomes were recorded growing on 14 different host plant species, 11 axenic cultures have been made and 9 species of wood decay fungi have been conclusively identified by DNA barcoding. The collection of the axenic isolates includes one of Aurificaria cf. euphoria, three of Ganoderma resinaceum sl., two of Laetiporus sulphureus, one of Inonotus sp., one of Inonotus rickii anamorph, one of Inocutis tamaricis, one of Stereum hirsutum, and one of Pleurotus eryngii. However, the mycelium of Coriolopsis gallica, though collected and identified, could not be isolated.
... A wide range of both conventional and avant-garde techniques has been applied to explore and utilize the potential of mycelial materials, from mold-based cultivation to additive manufacturing, 10 indirect cultivation, 12 and continuous filmmaking. 13 This versatility has also extended to more advanced applications, such as off-earth construction, 14 biomedical devices, 15 and sensors, 16 offering a clear insight into the extensive scope of their potential. ...
In transitioning toward a sustainable economy, mycelial materials are recognized for their adaptability, biocompatibility, and eco-friendliness. This paper updates the exploration of mycelial materials, defining their scope and emphasizing the need for precise terminology. It discusses the importance of mycelial type and characteristics, reviews existing and future research directions, and highlights the need for improved understanding, clarity, and standardization in this emerging field, aiming to foster and guide future research and development in sustainable material science.
... Researchers have created therapeutic wound dressings out of the filamentous growths of select species with some encouraging results [73,74]. To mimic the extracellular matrix with the hyphal structure of mycelia, novel biomedical scaffolds have been developed with excellent physiochemical properties, all while being tunable and self-growing [75,76]. With growing interest in creating natural and customized biomaterials, PMMs could potentially fill the current gaps in tissue engineering. ...
Modern efforts to influence materials science with principles of biology have allowed fungal mycelial materials to take a foothold and develop novel solutions for the circular bioeconomy of tomorrow. However, recent studies have shown that the value of tomorrow’s green materials is not determined simply by their environmental viability, but rather by their ability to make the polluting materials of today obsolete. With an inherently strong structure of chitin and β-glucan, the ever-adaptable mycelia of fungi can compete at the highest levels with a litany of materials from leather to polyurethane foam to paper to wood. There are significant efforts to optimize pure mycelial materials (PMMs) through the entire process of species and strain selection, mycelial growth, and fabrication. Indeed, the promising investigations of novel species demonstrate how the diversity of fungi can be leveraged to create uniquely specialized materials. This review aims to highlight PMMs’ current trajectory, evaluate the successes in technology, and explore how these new materials can help shape a better tomorrow.
... Biomass fermentation is used to grow large amounts of microorganisms that are themselves used as ingredients for alternative proteins. Biomass fermentation is also being explored to produce mycelium scaffolds for use in CM due to their biodegradability, affordability, and continuous growth capabilities (Antinori et al., 2021). Various agricultural inputs can be added to edible fungal species to simulate the growth conditions of mycelium and produce feedstock for fermentation (Ahlborn et al., 2019). ...
... According to the results from the screening, G. sessile was further selected for this study because of the observed promising mycelial growth features, which have also been noticed in the production of bio-composite materials and fungal skins 25,26 . In addition, G. lucidum was included as a recognized edible species within the same genus 27 (see Supporting Figure S1) and given its widespread presence in fungal biomaterial-related literature 2,21,28 , which allows for a side-to-side comparison of the findings aiming toward food-focused applications. ...
... 21 found that materials derived from Pleurotus ostreatus are stiffer than those from G. lucidum, which is attributed to the increased amount of polysaccharides in P. ostreatus-based materials. The measured moduli of the two studied Ganoderma species were lower than the values found in the literature 2,21,22,38 . For instance, Haneef et al. ...
With its distinctive material properties, fungal mycelium has emerged as an innovative material with a diverse array of applications across various industries. This study focuses on how the growth strategies of wood fungi adapt to nutrient availability. The effect of malt extract concentration in the growth medium on radial growth kinetics, morphology, mycelium network connectivity, and mechanical characteristics of mycelium from two Ganoderma species were investigated. While an evident pattern of radial growth rate enhancement with malt concentrations was not apparent, there was a discernible trend towards denser mycelium network characteristics as revealed by spectrophotometry. Increased malt extract contents corresponded to elevated optical density measurements and were visually confirmed by denser mycelium networks in photographic images. Investigating the mechanical characteristics of mycelium cultivated on varying solid substrate concentrations, the Young’s modulus exhibited a substantial difference between mycelium grown on 5 wt% malt substrate and samples cultivated on 2 wt% and 0.4 wt% malt substrates. The obtained results represent a new understanding of how malt availability influences mycelial growth of two Ganoderma species, a crucial insight for potentially refining mycelium cultivation across diverse applications, including meat alternatives, smart building materials, and alternative leather.
... Due to the large number of functional groups on the cell wall of hyphae, such as hydroxyl and amine, mycelial fibers are promising for the development of new functional biobased materials [8]. Nowadays, mycelium is a highly tunable, biodegradable, low-cost material with a broad spectrum of exploitation [9], including packaging [10-12], construction [13][14][15][16][17], and biomedical applications [18,19]. Considering the support for PCM composites, the mycelial hyphae have an order less fiber thickness compared to MFCs that should result in higher bulk density. ...
... Another type of mycelium-based substrate studied in this work was the mycelium hyphae, which were self-grown at the liquid/air interface under static conditions, employing liquid-state surface fermentation [18,30,31]. The resulting substrate was a mycelial mat with a high density of branched fungal hyphae. ...
... Additionally, the FTIR spectra of mycelium-based fibers demonstrated maximums of absorption that are not presented in the MFC spectrum. The most prominent ones are the bands at 1543, 1313, and 1245 cm −1 due to vibration of N-H and C-N bonds in chitin [18,30,36]. Since cellulose is not fully biotransformed, the intensity of these bands in the spectrum of MFC-MYC fibers is lower than those in the spectrum of the pure mycelium fibers. ...
Adsorption of organic phase-change materials (PCMs) by the porous matrix of microfibrillar cellulose (MFC) is a simple and versatile way to prepare shape-stable phase-change composites, which are promising as sustainable thermoregulating additives to construction materials. However, due to MFC inherent morphology, the resulting composites have relatively low poured density that complicates their introduction in sufficient amounts, for instance, into mortar mixes. Unlike MFC, fungal mycelium has, by an order, less fibrils thickness and, thus, possesses significantly higher poured density. Herein, we studied the feasibility of fungal mycelium-based matrices as alternative biopolymeric porous supports for preparation of sustainable and shape-stable phase-change composites. Two methods were employed to prepare the porous mycelium-based supports. The first one was the solid-state fermentation, which resulted in partial biotransformation of MFCs to mycelium hyphae, while the second one was the liquid-state surface fermentation, used to cultivate the reference matrix of Trametes hirsuta hyphae. The phase-change composites were prepared by adsorption of model organic PCMs on porous biopolymer matrices. The mass ratio of support/PCM was 40/60 wt%. The composites were studied with respect to their structure, composition, poured density, latent heat storage properties, and thermal and shape stability. The employment of the partially transformed to mycelium-hyphae MFC fibers was found to be a suitable way to prepare phase-change composites with improved poured density while preserving a reasonable latent heat capacity and shape stability as compared to the MFC/PCM composites.
... The plot displays the range of dominant hyphal radii, varying from the thinnest at 0.17 μm to the thickest at 1.2 μm within the mycelium network. These values are consistent with the previous studies 25,27 , which reported a distribution range of ~ 0.1-1.5 μm. In comparison, our study further resolves the discrete nature of the hyphal types and identifies network heterogeneity as a function of growth depth. ...
Gradient porous structures (GPS) are characterized by structural variations along a specific direction, leading to enhanced mechanical and functional properties compared to homogeneous structures. This study explores the potential of mycelium, the root part of a fungus, as a biomaterial for generating GPS. During the intentional growth of mycelium, the filamentous network undergoes structural changes as the hyphae grow away from the feed substrate. Through microstructural analysis of sections obtained from the mycelium tissue, systematic variations in fiber characteristics (such as fiber radii distribution, crosslink density, network density, segment length) and pore characteristics (including pore size, number, porosity) are observed. Furthermore, the mesoscale mechanical moduli of the mycelium networks exhibit a gradual variation in local elastic modulus, with a significant change of approximately 50% across a 30 mm thick mycelium tissue. The structure-property analysis reveals a direct correlation between the local mechanical moduli and the network crosslink density of the mycelium. This study presents the potential of controlling growth conditions to generate mycelium-based GPS with desired functional properties. This approach, which is both sustainable and economically viable, expands the applications of mycelium-based GPS to include filtration membranes, bio-scaffolds, tissue regeneration platforms, and more.
... During early stages of growth, Ganoderma lucidum produces thick and septate generative hyphae that thrive on substrate and fully settle on. Afterwards, skeletal filaments are produced, as a way to strengthen the network [16,37]. They are long, non-septate, unbranched, and continuously oriented along a specific direction (Fig. 2a). ...
Mycelium materials are an emerging class of natural, inexpensive, and environmentally sustainable materials. They are promising alternatives to petroleum-based polymeric ones, and they can also be used as substitutes for animal-based leather. This work investigates the water relation properties (equilibrium and transfer) of pure mycelium materials produced using Ganoderma lucidum fungal species in liquid-state fermentation. The dynamic gravimetric method was used to determine sorption isotherms at four temperatures (20 °C, 30 °C, 40 °C, and 50 °C) over a water activity (a w) range of 0 to 0.9. This material is highly hygroscopic and depicts a huge condensation phase at high water activity, with an equilibrium moisture content of 53% at 20 °C and 90% RH. Among the eight sorption models tested, the GAB model gives good results and was further used to analyze data. Thermodynamic properties (net isosteric heat of sorption, sorption entropy change, and the isokinetic temperature) were determined from the sorption isotherms to represent better the energy related to the sorption processes. Finally, the transient stages of sorption measurement were analyzed to extract mass transfer properties. Consistently with the morphology of this material, a dual-scale effect is evidenced, which turns into a representation by two independent parameters: the macroscopic and microscopic mass diffusivity values.
... In this context, mycelia materials are rapidly gaining interest in the biomedical field. Mycelium is the self-growing vegetative part of filamentous fungi and has been recently proposed as a potential novel platform for wound healing due to its interwoven three-dimensional, interconnected fibrous networks similar to the dermal collagen structure (Antinori et al., 2021). This network is made of hyphae, which grow in a thread-like architecture, resembling the dermal extracellular matrix (Haneef et al., 2017;Sayfutdinova et al., 2022). ...
... Afterwards, each 20-mg mycelium piece was incubated with 1 mL of a serum-free DMEM for 24 h, and the resulting stock solution (extracted medium) was used to prepare the tested dilutions (1:20, 1:200). These dilutions were selected from the results of an experimental screening previously conducted in our laboratory (Antinori et al., 2021). ...
... The fungal mycelia were grown with potato dextrose broth (PDB) in a climatic chamber (27°C, 78% R.H.) until a piece of 20 days-grown mycelium completely covered the surface of a 100 mm Petri dish, to be then collected and leaned from the substrate ( Figure 1A). After the harvest, the inactivation of the biological activity of the mycelium was achieved by steam sterilization since it has been previously demonstrated that this treatment led to mycelium complete inactivation (Antinori et al., 2021). ...
Introduction: Recently, mycelia of Ganoderma lucidum and Pleurotus ostreatus, edible fungi, have been characterized in vitro as self-growing biomaterials for tissue engineering since they are constituted of interconnected fibrous networks resembling the dermal collagen structure.
Aim: This work aims to investigate the biopharmaceutical properties of G. lucidum and P. ostreatus mycelia to prove their safety and effectiveness in tissue engineering as dermal substitutes.
Methods: The mycelial materials were characterized using a multidisciplinary approach, including physicochemical properties (morphology, thermal behavior, surface charge, and isoelectric point). Moreover, preclinical properties such as gene expression and in vitro wound healing assay have been evaluated using fibroblasts. Finally, these naturally-grown substrates were applied in vivo using a murine burn/excisional wound model.
Conclusions: Both G. lucidum and P. ostreatus mycelia are biocompatible and able to safely and effectively enhance tissue repair in vivo in our preclinical model.
... Therefore, this study explores the potential of mycelium, the root structure of fungi, as an economically viable and self-growing brous biomaterial with the ability to generate gradient porous structures. The GPS of mycelium possess inherent chemical activity and presents a possibility to tailor structures with desired functional properties 17 . ...
Gradient porous structures (GPS) are characterized by structural variations along a specific direction, leading to enhanced mechanical and functional properties compared to homogeneous structures. This study explores the potential of mycelium, the root part of a fungus, as a biomaterial for generating GPS. During the intentional growth of mycelium, the filamentous network undergoes structural changes as the hyphae grow away from the feed substrate. Through microstructural analysis of sections obtained from the mycelium tissue, systematic variations in fiber characteristics (such as fiber radii distribution, crosslink density, network density, segment length) and pore characteristics (including pore size, number, porosity) are observed. Furthermore, the mesoscale mechanical moduli of the mycelium networks exhibit a gradual variation in local elastic modulus, with a significant change of approximately 50% across a 1.2-inch-thick mycelium tissue. The structure-property analysis reveals a direct correlation between the local mechanical moduli and the network crosslink density of the mycelium. This study presents the potential of controlling growth conditions to generate mycelium-based GPS with desired functional properties. This approach, which is both sustainable and economically viable, expands the applications of mycelium-based GPS to include filtration membranes, bio-scaffolds, tissue regeneration platforms, and more.
