Enzymatic activities and analysis of a mycelium-based composite formation using peach palm (Bactris gasipaes) residues on Lentinula edodes

Incorporation of canola meal as a sustainable natural filler in PLA foams

The canola oil industry generates significant waste as canola meal (CM) which has limited scope and applications. This study demonstrates the possibility of valorization of CM as a sustainable natural filler in a biodegradable polymer composite of Poly(lactic acid) (PLA). Generally, interfacial bonding between natural fibers and the polymer matrix in the composite is weak and non-uniform. One possible solution is to derivatize natural fibre to introduce interfacial bond strength and compatibility with the PLA polymer matrix. Here, CM was succinylated in a reactive extrusion process using succinic anhydride at 30 wt% to get 14% derivatization with 0.02 g of -COOH density per g of CM. The CM or succinylated CM at 5 and 15 wt% was co-extruded with amorphous PLA to get composite fibers. CM-PLA and succinylated CM-PLA biocomposites were foamed using a mild and green microcellular foaming process, with CO2 as an impregnating agent without any addition of organic solvents. The properties of the foams were analyzed using differential scanning calorimetry (DSC), Dynamic mechanical thermal analysis (DMTA), shrinkage, and imaging. The addition of CM or succinylated CM as a natural filler did not significantly change the glass transition temperature, melting point, percent crystallization, stiffness, and thermal stability of PLA foams. This suggests succinylation (modification) of CM is not a mandatory step for improving interphase compatibility with the amorphous PLA. The new PLA-CM foams can be a good alternative in the packaging industry replacing the existing petroleum-based polymer foams.

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

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

Successful cultivation of edible fungi on textile waste offers a new avenue for bioremediation and potential food production

Textile waste contains both natural fibres such as cotton and bamboo viscose, and synthetic fibres such as elastane and polyester. As a complex mixture, textiles present a challenging pollution issue as breakdown in landfill results in microplastics entering water and soil environments, and incineration results in particulate air pollution. Here the use of edible fungi as bioremediation agents of waste textiles is described for the first time. Three species of filamentous fungi were shown to colonise and grow on mixed fibre textile waste (underpants made from 28% cotton: 68% bamboo viscose: 4% elastane). All three fungi were able to metabolise the common textile dye Reactive Black 5 to some extent. The metabolome was captured to elucidate the dye remediation pathway utilized and to characterise the volatiles released during bioremediation with a view to assessing the safety profile of this process for future industrial applications. The results suggest that edible fungi may be cultivated on textiles, and that some interesting and useful compounds may be produced in the process. This has great biotechnological potential. No mushrooms were produced in this study, suggesting that further work will be needed to optimise conditions for crop production from waste textiles.

Effects of Environmental and Nutritional Conditions on Mycelium Growth of Three Basidiomycota

In recent decades, an enormous potential of fungal-based products with characteristics equal to, or even outperforming, classic petroleum-derived products has been acknowledged. The production of these new materials uses mycelium, a root-like structure of fungi consisting of a mass of branching, thread-like hyphae. Optimizing the production of mycelium-based materials and fungal growth under technical conditions needs to be further investigated. The main objective of this study was to select fast-growing fungi and identify optimized incubation conditions to obtain a dense mycelium mat in a short time. Further, the influence of the initial substrate characteristics on hyphae expansion was determined. Fungal isolates of Ganoderma lucidum, Pleurotus ostreatus, and Trametes versicolor were cultivated for seven days on substrate mixtures consisting of various proportions of pine bark and cotton fibers. Furthermore, the substrates were mixed with 0, 2, and 5 wt.% calcium carbonate (CaCO3), and the incubator was flushed with 0, 5, and 10 vol.% carbon dioxide (CO2). All samples grew in the dark at 26 °C and a relative humidity of 80%. Evaluation of growth rate shows that cotton fiber-rich substrates performed best for all investigated fungi. Although Pleurotus ostreatus and Trametes versicolor showed comparatively high growth rates of up to 5.4 and 5.3 mm d-1, respectively, mycelium density was thin and transparent. Ganoderma lucidum showed a significantly denser mycelium at a maximum growth rate of 3.3 mm d-1 on a cotton fiber-rich substrate (75 wt.%) without CaCO3 but flushed with 5 vol.% CO2 during incubation.

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

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

Sustainable Innovation: Fabrication and Characterization of Mycelium-Based Green Composites for Modern Interior Materials Using Agro-Industrial Wastes and Different Species of Fungi

Mycelium-based bio-composites (MBCs) represent a sustainable and innovative material with high potential for contemporary applications, particularly in the field of modern interior design. This research investigates the fabrication of MBCs for modern interior materials using agro-industrial wastes (bamboo sawdust and corn pericarp) and different fungal species. The study focuses on determining physical properties, including moisture content, shrinkage, density, water absorption, volumetric swelling, thermal degradation, and mechanical properties (bending, compression, impact, and tensile strength). The results indicate variations in moisture content and shrinkage based on fungal species and substrate types, with bamboo sawdust exhibiting lower shrinkage. The obtained density values range from 212.31 to 282.09 kg/m3, comparable to traditional materials, suggesting MBCs potential in diverse fields, especially as modern interior elements. Water absorption and volumetric swelling demonstrate the influence of substrate and fungal species, although they do not significantly impact the characteristics of interior decoration materials. Thermal degradation analysis aligns with established patterns, showcasing the suitability of MBCs for various applications. Scanning electron microscope observations reveal the morphological features of MBCs, emphasizing the role of fungal mycelia in binding substrate particles. Mechanical properties exhibit variations in bending, compression, impact, and tensile strength, with MBCs demonstrating compatibility with traditional materials used in interior elements. Those produced from L. sajor-caju and G. fornicatum show especially promising characteristics in this context. Particularly noteworthy are their superior compression and impact strength, surpassing values observed in certain synthetic foams multiple times. Moreover, this study reveals the biodegradability of MBCs, reaching standards for environmentally friendly materials. A comprehensive comparison with traditional materials further supports the potential of MBCs in sustainable material. Challenges in standardization, production scalability, and market adoption are identified, emphasizing the need for ongoing research, material engineering advancements, and biotechnological innovations. These efforts aim to enhance MBC properties, promoting sustainability in modern interior applications, while also facilitating their expansion into mass production within the innovative construction materials market.

Preparation, characterization, and adsorption kinetics of graphene oxide/chitosan/carboxymethyl cellulose composites for the removal of environmentally relevant toxic metals

This study attempted to develop a low-cost and eco-friendly bio-based composite adsorbent that is highly efficient in capturing potential toxic metals. The bio-composite adsorbent was prepared using graphene oxide (GO), carboxymethyl cellulose (CMC) and chitosan (CS); and characterized using FTIR, SEM-EDX and WAXD techniques. Metal-ion concentration in an aqueous solution was measured by ICP-OES. This article reveals that the adsorption of heavy metal ions varied according to the adsorbent quantity, initial metal concentration, pH, and interaction time. The metal ions' adsorption capacity (mg/g) was observed to increase when the interaction time and metal concentration increased. Conversely, metal ions adsorption was decreased with an increase in adsorbent dosages. The effect of pH on metal ions' adsorption was ion-specific. The substantial adsorption by GO/CMC/CS composite for Co2+, CrO42-, Mn2+ and Cd2+, had the respective values of 43.55, 77.70, 57.78, and 91.38 mg/g under acidic conditions. The metal ions experimental data were best fitted with pseudo-second-order (PSO) kinetics, and Freundlich isotherm model (except Co2+). The separation factors (RL) value in the present investigation were found between 0 and 1, meaning that the metal ions adsorption onto GO/CS/CMC composite is favorable. The RL and sorption intensity (1/n) values fitted well to the adsorption isotherm.

Fungal mycelia: From innovative materials to promising products: Insights and challenges

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.

Brazilian Agro-industrial Wastes as Potential Textile and Other Raw Materials: a Sustainable Approach

The Brazilian agro-industrial chain generates about 291 million/tons/year of wastes, which, if inadequately destinated, could originate social and environmental risks. There is a growing need for the use of alternative raw materials to replace that originated from fossil resources in the Brazilian industry. Renewable materials play an important role on the sustainability of ecosystems and materials’ circularity. The issue has acquired importance in light of recent bio-based agro-fiber development potential applications. Considering sustainability guidelines, this study aimed to analyze the main Brazilian agro-industrial waste crops (temporary and permanent) as important sources of natural fibers and other raw materials. A systematic review of the literature (SRL) about Brazilian researches, based on concepts of industrial ecology, and the creation of a bibliometric analysis network were carried out. The agricultural biomass related to the main crops presents characteristics making them suitable to be applied for textiles, as natural fibers and polymers, in biosorbents for industrial effluents, and cellulose obtention and reinforcement material in composites. Thus, scientific investment in researches on materials and technology development are necessary to provide applications that could meet current and future demands and expand the scope of new materials for sustainability.

Full Exploitation of Peach Palm (Bactris gasipaes Kunth): State of the Art and Perspectives

The peach palm (Bactris gasipaes Kunth) is a palm tree native to the Amazon region, with plantations expanding to the Brazilian Southwest and South regions. This work is a critical review of historical, botanical, social, environmental, and nutritional aspects of edible and nonedible parts of the plant. In Brazil, the importance of the cultivation of B. gasipaes to produce palm heart has grown considerably, due to its advantages in relation to other palm species, such as precocity, rusticity and tillering. The last one is especially important, as it makes the exploitation of peach palm hearts, contrary to what happens with other palm tree species, a non-predatory practice. Of special interest are the recent efforts aiming at the valorization of the fruit as a source of carotenoids and starch. Further developments indicate that the B. gasipaes lignocellulosic wastes hold great potential for being upcycled into valuable biotechnological products such as prebiotics, enzymes, cellulose nanofibrils and high fiber flours. Clean technologies are protagonists of the recovery processes, ensuring the closure of the product's life cycle in a "green" way. Future research should focus on expanding and making the recovery processes economically viable, which would be of great importance for stimulating the peach palm production chain.

Mechanical, Physical, and Chemical Properties of Mycelium-Based Composites Produced from Various Lignocellulosic Residues and Fungal Species

Mycelium-based composites (MBCs) are characterized as biodegradable materials derived from fungal species. These composites can be employed across a range of industrial applications that involve the manufacturing of packaging materials as well as the manufacturing of buildings, furniture, and various other household items. However, different fungal species and substrates can directly affect the functional properties of MBCs, which ultimately vary their potential to be used in many applications. In this study, the mechanical, physical, and chemical properties of MBCs made from four different fungal species (Ganoderma fornicatum, Ganoderma williamsianum, Lentinus sajor-caju, and Schizophyllum commune) combined with three different types of lignocellulosic residues (sawdust, corn husk, and rice straw) were investigated. The results indicate that differences in both the type of lignocellulosic residues and the fungal species could affect the properties of the obtained MBCs. It was found that the MBCs obtained from sawdust had the highest degree of density. Moreover, MBCs obtained from S. commune with all three types of lignocellulosic residues exhibited the highest shrinkage value. The greatest degree of water absorption was observed in the MBCs obtained from rice straw, followed by those obtained from corn husk and sawdust. Additionally, the thermal degradation ability of the MBCs was observed to be within a range of 200 to 325 °C, which was in accordance with the thermal degradation ability of each type of lignocellulosic residue. The greatest degrees of compressive, flexural, impact, and tensile strength were observed in the MBCs of G. williamsianum and L. sajor-caju. The results indicate that the MBCs made from corn husk, combined with each fungal species, exhibited the highest values of flexural, impact, and tensile strength. Subsequently, an analysis of the chemical properties indicated that the pH value, nitrogen content, and organic matter content of the obtained MBCs were within the following ranges: 4.67−6.12, 1.05−1.37%, and 70.40−86.28%, respectively. The highest degree of electrical conductivity was observed in MBCs obtained from rice straw. Most of the physical and mechanical properties of the obtained MBCs were similar to those of polyimide and polystyrene foam. Therefore, these composites could be used to further develop relevant strategies that may allow manufacturers to effectively replace polyimide and polystyrene foams in the future.

Optimization of Conditions for Feather Waste Biodegradation by Geophilic Trichophyton ajelloi Fungal Strains towards Further Agricultural Use

The aim of the study was to optimize culture conditions and medium composition to accelerate the biodegradation of chicken feather waste by keratinolytic soil strains of Trichophyton ajelloi, which are poorly known in this respect, as well as to propose hitherto unconsidered culture conditions for these fungi in order to obtain a biopreparation with a high fertilization value. Different pH of the medium, incubation temperatures, amounts of chicken feathers, additional carbon sources, and culture methods were tested. The process of optimizing keratin biodegradation was evaluated in terms of measuring the activity of keratinase, protease, disulfide reductase, concentration of released soluble proteins and peptides, total pool of amino acids, ammonium and sulfate ions, changes in medium pH, and feather weight loss. It was found that the studied fungal strains were capable of decomposing and mineralizing keratin from feather waste. Regarding the fertilizer value of the obtained hydrolysates, it was shown that the release of sulfate and ammonium ions was highest in a stationary culture containing 2% feathers with an initial pH of 4.5 and a temperature of 28 °C. Days 14-21 of the culture were indicated as the optimal culture time for these fungi to obtain biopreparations of high fertilizing value.

White rot fungus Calocybe indica: Incredulous factory of lignocellulolytic enzymes and their potential applicability for mushroom cultivation

Cultivation of specialty mushrooms on lignocellulosic wastes represents one of the most economical organic recycling processes. Compared with other cultivated mushrooms, very little is known about the nature of the lignocellulolytic enzymes produced by the edible fungus Calocybe indica, its enzymatic activity profiles during submerged and solid state fermentation. The intracellular activity of laccase (7.67 U mg−1), manganese peroxidase (7.48 U mg−1), cellobiohydrolase (5.46 U mg−1), and endoxylanase (4.21 U mg−1) was best obtained in C. indica on 14th and 21st day of incubation. The extracellular activity of laccase (11.57 U mL−1), lignin peroxidase (8.45 U mL−1), and endoxylanases (6.22 U mL−1) were found to be highest on the 14th day. Ligninolytic enzyme activity was substantial during substrate colonisation but quickly dropped during fruiting body development. C. indica, on the other hand, showed relatively modest hydrolase activity during substrate colonisation. The activity of hydrolytic enzymes increased dramatically when primordia formed and peaked at the mature fruiting body stage. The yield of the crude enzyme-treated wheat straw utilised for mushroom production was 52.47%. These findings showed that the activities of lignocellulolytic enzymes were regulated in line with developmental phase of growth of C. indica.

Amazing Fungi for Eco-Friendly Composite Materials: A Comprehensive Review

The continually expanding use of plastic throughout our world, along with the considerable increase in agricultural productivity, has resulted in a worrying increase in global waste and related environmental problems. The reuse and replacement of plastic with biomaterials, as well as the recycling of agricultural waste, are key components of a strategy to reduce plastic waste. Agricultural waste is characterized as lignocellulosic materials that mainly consist of cellulose, hemicellulose, and lignin. Saprobe fungi are able to convert agricultural waste into nutrients for their own growth and to facilitate the creation of mycelium-based composites (MBC) through bio-fabrication processes. Remarkably, different fungal species, substrates, and pressing and drying methods have resulted in varying chemical, mechanical, physical, and biological properties of the resulting composites that ultimately vary the functional aspects of the finished MBC. Over the last two decades, several innovative designs have produced a variety of MBC that can be applied across a range of industrial uses including in packaging and in the manufacturing of household items, furniture, and building materials that can replace foams, plastics, and wood products. Materials developed from MBC can be considered highly functional materials that offer renewable and biodegradable benefits as promising alternatives. Therefore, a better understanding of the beneficial properties of MBC is crucial for their potential applications in a variety of fields. Here, we have conducted a brief review of the current findings of relevant studies through an overview of recently published literature on MBC production and the physical, mechanical, chemical, and biological properties of these composites for use in innovative architecture, construction, and product designs. The advantages and disadvantages of various applications of mycelium-based materials (MBM) in various fields have been summarized. Finally, patent trends involving the use of MBM as a new and sustainable biomaterial have also been reviewed. The resulting knowledge can be used by researchers to develop and apply MBC in the form of eco-friendly materials in the future.

Growth Characteristics of Polyporales Mushrooms for the Mycelial Mat Formation

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.