Mushroom cultivation in the circular economy

Transcriptomics reveals the regulation of the immune system of the mushroom-forming fungus Schizophyllum commune during interaction with four competitors

Mushroom-forming fungi frequently encounter competitors during their lifecycle, but their defense mechanisms remain largely unexplored. We studied the response of the mushroom-forming fungus Schizophyllum commune during interaction with the fungal competitors Trichoderma harzianum, Trichoderma aggressivum and Purpureocillium lilacinum and the bacterial competitor Serratia quinivorans. Transcriptomics revealed 632 up-regulated genes in the direct interaction zone, which were enriched in small secreted proteins and transporters. A set of 26 genes were up-regulated during all interactions, indicating a core transcriptomic defense response. In the non-interacting edge of the mycelium of S. commune, there were 154 up-regulated genes, suggesting that there is a systemic response due to a signal that reaches unaffected areas. The GATA zinc finger transcription factor gene gat1 was up-regulated during interaction and a Δgat1 strain displayed increased colonization by T. harzianum. Previously linked to mushroom development, this transcription factor apparently has a dual role. Moreover, 138 genes were up-regulated during both interaction and mushroom development, indicating priming of the defense response during development to prepare the fruiting body for future interactions. Overall, we unveiled a defensive response of S. commune during interaction with fungal and bacterial competitors and identified a regulator of this response.

Molecular Profiling of Rice Straw Degradability Discrepancy in Stropharia rugosoannulata Core Germplasm

The rice-S. rugosoannulata pattern is a rapidly growing agricultural practice for straw disposal and mushroom production in China. However, different S. rugosoannulata strains show a large variation in rice straw degradability. Here, we constructed a core collection of S. rugosoannulata containing 14 strains with rich genetic diversity. The molecular profiling of the lignocellulose degradability discrepancy of S. rugosoannulata strains was then explored using enzyme activity assays and transcriptome analysis. The results indicated that mycelial growth rate, lignocellulolytic enzyme activities, and rice straw degradability differed widely among the S. rugosoannulata core strains. The genes encoding lignin modifying and degrading auxiliary enzymes, oxidases, glycoside hydrolases, and detoxification proteins were differentially expressed between two representative S. rugosoannulata strains, resulting in differences in their lignocellulolytic enzyme activities and further causing differences in lignocellulose degradability. This study is useful to improve the production efficiency of S. rugosoannulata and promote the recycling of rice straw.

Research hotspots and emerging trends in growth and development of macrofungi: a bibliometric review based on CiteSpace analysis

Macrofungi (or mushrooms) are essential for agriculture, food, and ecology. Although research on the growth and development of macrofungi (GDM) can provide insights into their biological characteristics and metabolite synthesis mechanisms, further exploration is needed for a systematic and visual analysis of the current research progress on GDM. To comprehensively understand the research status and development trend of GDM, a total of 545 scientific literature related to GDM in the Web of Science Core Collection database from 2008 to 2024 were searched and selected as research objects. The general information (publication year, country, institution, and cited journal) and the specific information (co-authorship, keyword co-occurrence, and references with strong citation bursts) were mined and visualized in detail based on CiteSpace software. These analyses demonstrated that related research is still fashionable, and China is dominant and influential in this field. More frequent and in-depth cooperation among authors, institutions and regions is conducive to promoting the research on GDM. Additionally, the quantity and cluster analyses of keywords and references demonstrated that medicinal/edible macrofungi and sustainable development (e.g. mushroom substrate reuse) may be research hotspots and will remain popular in the coming years. This research aims to supply researchers with up-to-date knowledge and cutting-edge issues related to GDM by providing a visually appealing representations on quantitative GDM studies.

Metagenomic insights into the mechanism of sophorolipid in facilitating co-anaerobic digestion of mushroom residues and cattle manure: Functional microorganisms and metabolic pathway analysis

The present study aimed to enhance the co-anaerobic digestion system of mushroom residues and cattle manure by incorporating biosurfactant sophorolipid. Results demonstrated that the addition of 75 mg/L sophorolipid increased cumulative methane production by 33.68%, acetate content by 9-10 times, and the abundance of Methanosarcina by 69.22%. The electroactive microorganisms (Bacteroides, Petrimonas, etc.) were enriched, while the up-regulation of functional genes associated with carbohydrate metabolism and methane metabolism was observed. The metagenomic analysis revealed the significant involvement of inter-microbial communication and extracellular electron transfer in anaerobic digestion. Petrimonas was identified as the predominant host involved in cellular processes and environmental information processing. The supplementation of sophorolipid significantly enhanced its abundance during the late anaerobic digestion period (by 12.30%-64.84%). The results emphasize the crucial function of sophorolipid as biosurfactant in enhancing the efficiency of anaerobic digestion.

Biofortification of Mushrooms: A Promising Approach

Mushrooms exhibit a broad spectrum of pharmacological activities and are widely used for medical purposes and in nutrition. Numerous bioactive metabolites are responsible for these activities. Their distribution and biological effects differ depending on the fungal species and their chemical composition. Biofortification is a sustainable process that aims to improve the nutritional profile of food crops, as most of them are low in key nutrients. This review aims to delve into the process of fungal biofortification and review the most commonly used elements and species. Through biofortification, it is possible to combat hidden hunger, which affects as many as 2 billion people worldwide. "Hidden hunger" is a phenomenon in which the organism lacks the minerals and vitamins needed for development, growth, and good overall health. Mushrooms are increasingly being considered for biofortification due to their ability to accumulate various elements (both micro- and macroelements).

Genome Sequencing of Three Pathogenic Fungi Provides Insights into the Evolution and Pathogenic Mechanisms of the Cobweb Disease on Cultivated Mushrooms

Fungal diseases not only reduce the yield of edible mushrooms but also pose potential threats to the preservation and quality of harvested mushrooms. Cobweb disease, caused primarily by fungal pathogens from the Hypocreaceae family, is one of the most significant diseases affecting edible mushrooms. Deciphering the genomes of these pathogens will help unravel the molecular basis of their evolution and identify genes responsible for pathogenicity. Here, we present high-quality genome sequences of three cobweb disease fungi: Hypomyces aurantius Cb-Fv, Cladobotryum mycophilum CB-Ab, and Cladobotryum protrusum CB-Mi, isolated from Flammulina velutipes, Agaricus bisporus, and Morchella importuna, respectively. The assembled genomes of H. aurantius, C. mycophilum, and C. protrusum are 33.19 Mb, 39.83 Mb, and 38.10 Mb, respectively. This is the first report of the genome of H. aurantius. Phylogenetic analysis revealed that cobweb disease pathogens are closely related and diverged approximately 17.51 million years ago. CAZymes (mainly chitinases, glucan endo-1,3-beta-glucosidases, and secondary metabolite synthases), proteases, KP3 killer proteins, lipases, and hydrophobins were found to be conserved and strongly associated with pathogenicity, virulence, and adaptation in the three cobweb pathogens. This study provides insights into the genome structure, genome organization, and pathogenicity of these three cobweb disease fungi, which will be a valuable resource for comparative genomics studies of cobweb pathogens and will help control this disease, thereby enhancing mushroom quality.

Utilization of local agro-industrial by-products based substrates to enhance production and dietary value of mushroom (P. ostreatus) in Ethiopia

Food insecurity and malnutrition are serious problems in many developing countries, including Ethiopia. This situation warrants an urgent need for the diversification of food sources with enhanced productivity. This study was aimed at contributing to the food security in Ethiopia through cultivation of Pleurotus ostreatus mushrooms using sustainable and locally available agro-industrial byproduct-based substrates in parallel with pollution control. Ten substrates were prepared using sugarcane bagasse, filter cake, trash, cotton seed hull and animal waste, namely cow dung and horse and chicken manure. The effect of each substrate (treatment) on the yields, biological efficiency, nutritional composition, and mineral contents of Pleurotus ostreatus mushroom species was evaluated at the Ethiopian Forest Products Innovation Center, Addis Ababa, Ethiopia. The results obtained indicate that a significantly higher (p < 0.05) yield and biological efficiency were recorded from the mushroom cultivated on S2 substrate containing a mixture of 80% sugarcane bagasse, 12% cow dung, and 8% cotton seed hull. Moreover, substrate containing sugarcane bagasse mixed with cotton seed hull, cow dung, and chicken manure significantly (p < 0.05) increased the yields and biological efficiency of the mushroom. The content of protein, crude fat, fiber, and carbohydrates of the mushroom cultivated from all the utilized substrates were in the range of 17.30-21.5, 1.77-2.52, 31.03-34.38, and 28.02-39.74%, respectively. The critical macro-elements are abundant in the mushroom in the order of potassium, magnesium, calcium, and sodium. The mushrooms cultivated on all the substrates were rich in essential micro-elements in the order of iron and zinc. It was found that substrate preparation and formulation significantly (p < 0.05) improved the yields, biological efficiency, nutritive values, and mineral contents of the mushroom. The use of these by-products as substrates is sustainable and environmentally friendly and allows the production of mushroom with high nutritional value on a sustainable basis in order to enhance food security in the country.

Hydroalcoholic Extracts from Pleurotus ostreatus Spent Substrate with Nematocidal Activity against Nacobbus aberrans Phytonematode and the Non-Target Species Panagrellus redivivus

Pleurotus ostreatus, an edible mushroom widely consumed worldwide, generates a by-product known as spent mushroom substrate (SMS). This material has demonstrated biological activity against agricultural crop pathogens. In this study, we evaluated the nematocidal effectiveness of hydroalcoholic extracts (T5, T2, AT5, and AT2) derived from SMS of P. ostreatus against (J2) of the phytonematode Nacobbus aberrans and assessed their potential toxicity towards the non-target nematode Panagrellus redivivus. Among these extracts, AT5 exhibited the highest efficacy against N. aberrans and was the least toxic against P. redivivus. Liquid-liquid partitioning yielded the AQU fraction, which showed significant nematocidal activity against J2 (75.69% ± 8.99 mortality), comparable to chitosan. The GC-MS analysis revealed the presence of several compounds, including palmitic acid, linoleic acid, and 2,4-Di-tert-butylphenol. These findings are consistent with studies confirming the antagonistic effectiveness of these compounds against phytonematodes. Additionally, all extracts exhibited toxicity against P. redivivus, with T2 being the most toxic. Our findings demonstrate that while the AT5 extract displays antagonistic effectiveness against both N. aberrans and P. redivivus, it was the least toxic among the extracts tested. Thus, SMS of P. ostreatus holds potential as a source of nematocidal compounds, which could offer significant benefits for agricultural pest control.

Cascading social-ecological benefits of biodiversity for agriculture

Cultivated species diversity can provide numerous benefits to agricultural systems. Many ecological theories have been proposed to understand the relationships between plant species diversity and trophic interactions. However, extending such theories to socioeconomic systems has been rare for agriculture. Here, we establish ten hypotheses (e.g., the natural enemy hypothesis, resource concentration hypothesis, insurance hypothesis, and aggregation hypothesis) about the relationships between cultivated species diversity (i.e., crop diversification, co-cultures of crops and domestic animals, and co-cultures of crops and edible fungi) and trophic cascades of crops, invertebrate herbivores and natural enemies in cropping systems. We then explore the socioeconomic advantages (e.g., yield, economic and environmental performance) of these trophic cascades. Finally, we propose a multi-perspective framework to promote the cascading social-ecological benefits of species diversity for agricultural sustainability. Integrating the benefits of trophic cascades into agricultural socioeconomic systems requires policies and legislation that support multi-species co-culture practices and the willingness of consumers to pay for these practices through higher prices for agricultural products.

Mushroom oils: A review of their production, composition, and potential applications

This review delves into the world of mushroom oils, highlighting their production, composition, and versatile applications. Despite mushrooms' overall low lipid content, their fatty acid composition, rich in essential fatty acids like linoleic acid and oleic acid, proves nutritionally significant. Variations in fatty acid profiles across mushroom species and the prevalence of unsaturated fats contribute to their cardiovascular health benefits. The exploration extends to mushroom essential oils, revealing diverse volatile compounds through extraction methods like hydrodistillation and solvent-assisted flavor evaporation (SAFE). The identification of 1-octen-3-ol as a key contributor to the distinct "mushroom flavor" adds a nuanced perspective. The focus broadens to applications, encompassing culinary and industrial uses with techniques like cold pressing and supercritical fluid extraction (SFE). Mushroom oils, with their unique nutritional and flavor profiles, enhance gastronomic experiences. Non-food applications in cosmetics and biofuels underscore the oils' versatility. The nutritional composition, enriched with essential fatty acids, bioactive compositions, and trace elements, is explored for potential health benefits. Bioactive compounds such as phenolic compounds and terpenes contribute to antioxidant and anti-inflammatory properties, positioning mushroom oils as nutritional powerhouses. In short, this concise review synthesizes the intricate world of mushroom oils, emphasizing their nutritional significance, extraction methodologies, and potential health benefits. The comprehensive overview underscores mushroom oils as a promising area for further exploration and utilization. The characteristics of mushroom biomass oil for the use in various industries are influenced by the mushroom species, chemical composition, biochemical synthesis of mushroom, and downstream processes including extraction, purification and characterization. Therefore, further research and exploration need to be done to achieve a circular bioeconomy with the integration of SDGs, waste reduction, and economic stimulation, to fully utilize the benefits of mushroom, a valuable gift of nature.

Fabrication of Living Entangled Network Composites Enabled by Mycelium

Organic polymer-based composite materials with favorable mechanical performance and functionalities are keystones to various modern industries; however, the environmental pollution stemming from their processing poses a great challenge. In this study, by finding an autonomous phase separating ability of fungal mycelium, a new material fabrication approach is introduced that leverages such biological metabolism-driven, mycelial growth-induced phase separation to bypass high-energy cost and labor-intensive synthetic methods. The resulting self-regenerative composites, featuring an entangled network structure of mycelium and assembled organic polymers, exhibit remarkable self-healing properties, being capable of reversing complete separation and restoring ≈90% of the original strength. These composites further show exceptional mechanical strength, with a high specific strength of 8.15 MPa g.cm-3, and low water absorption properties (≈33% after 15 days of immersion). This approach spearheads the development of state-of-the-art living composites, which directly utilize bioactive materials to "self-grow" into materials endowed with exceptional mechanical and functional properties.

Nutritional and antioxidant potential of Pleurotus djamor (Rumph. ex Fr.) Boedijn produced on agronomic wastes banana leaves and sugarcane bagasse substrates

Global food production faces challenges concerning access to nutritious and sustainably produced food. Pleurotus djamor, however, is an edible mushroom that can be cultivated on agricultural waste. Considering that nutritional and functional potential of mushrooms can change based on cultivation conditions, we examined the influence of substrates with different compositions of banana leaf and sugarcane bagasse on the nutritional, mycochemical, and antioxidant properties of P. djamor. The mushrooms were grown for 120 days and dried in a circulating air oven at 45 °C for three days. We conducted bromatological analyses and mycochemical characterization (1H-NMR, total phenolics, and flavonoids) of the mushrooms and assayed the antioxidant activity of extracts from the dried mushrooms using an ethanol/water solution (70:30 v/v). In general, the substrates produced mushrooms with high protein (18.77 ± 0.24% to 17.80 ± 0.34%) and dietary fiber content (18.02 ± 0.05% to 19.32 ± 0.39%), and with low lipid (0.28 + 0.08% to 0.4 + 0.6%), and caloric content (maximum value: 258.42 + 8.49), with no significant differences between the groups (p ≥ 0.05). The mushrooms also exhibited high levels of total phenolics and flavonoids. The mushrooms cultivated on sugarcane bagasse substrates presented the highest values (p < 0.05). Analysis of the 1H-NMR spectra indicates an abundant presence of heteropolysaccharides, β-glucans, α-glucans, and oligosaccharides, and all the mushroom extracts exhibited high antioxidant activity. In conclusion, our study demonstrates that agricultural residues permit sustainable production of edible mushrooms while maintaining nutritional and functional properties.

Isolation and Evaluation of Erinacine A Contents in Mycelia of Hericium erinaceus Strains

Hericium erinaceus has long been favored for its remarkable nutritional and health-promoting benefits, and erinacine A is the key component responsible for the neuroprotective properties of H. erinaceus. Establishing an efficient method for separating erinacine A from H. erinaceus and screening the erinacine A-enriched strains is crucial to maximizing its benefits. Herein, we first reported that high-speed counter current chromatography (HSCCC) is an effective method for separating high-purity erinacine A. Using a two-phase solvent system composed of n-hexane/ethyl acetate/methanol/water (4.5:5:4.5:5, v/v/v/v), erinacine A with a purity of over 95% was separated. Then, we evaluated the content and yield of erinacine A in the liquid-fermented mycelia of Hericium germplasms. Both the content and yield of erinacine A varied greatly among the surveyed strains. The significant effect of the strain on the erinacine A content and yield was revealed by an analysis of variance. The highest erinacine A content and yield were observed in the mycelia of a wild strain HeG, reaching 42.16 mg/g and 358.78 mg/L, which is superior to the current highest outcomes achieved using submerged cultivation. The isolation method established and the strains screened in this study can be beneficial for the scaling up of erinacine A extraction and nutraceutical development to industrial levels.

Current Advances in the Functional Genes of Edible and Medicinal Fungi: Research Techniques, Functional Analysis, and Prospects

Functional genes encode various biological functions required for the life activities of organisms. By analyzing the functional genes of edible and medicinal fungi, varieties of edible and medicinal fungi can be improved to enhance their agronomic traits, growth rates, and ability to withstand adversity, thereby increasing yield and quality and promoting industrial development. With the rapid development of functional gene research technology and the publication of many whole-genome sequences of edible and medicinal fungi, genes related to important biological traits have been mined, located, and functionally analyzed. This paper summarizes the advantages and disadvantages of different functional gene research techniques and application examples for edible and medicinal fungi; systematically reviews the research progress of functional genes of edible and medicinal fungi in biological processes such as mating type, mycelium and fruit growth and development, substrate utilization and nutrient transport, environmental response, and the synthesis and regulation of important active substances; and proposes future research directions for functional gene research for edible and medicinal fungi. The overall aim of this study was to provide a valuable reference for further promoting the molecular breeding of edible and medicinal fungi with high yield and quality and to promote the wide application of edible and medicinal fungi products in food, medicine, and industry.

Mushrooms: a food-based solution to vitamin D deficiency to include in dietary guidelines

Vitamin D deficiency and insufficiency is a public health issue, with low dietary vitamin D intakes a contributing factor. Rates of vitamin D deficiency are 31% in Australia, and up to 72% in some regions globally. While supplementation is often prescribed as an alternative to additional sun exposure, complementary approaches including food-based solutions are needed. Yet, food-centric dietary guidelines are not always adequate for meeting vitamin D needs. Edible mushrooms such as Agaricus bisporus can produce over 100% of vitamin D recommendations (10 μg/day, Institute of Medicine) per 75 g serve (18 μg) on exposure to UV-light, with the vitamin D2 produced showing good stability during cooking and processing. However, mushrooms are overlooked as a vitamin D source in dietary guidelines. Our dietary modelling shows that four serves/week of UV-exposed button mushrooms can support most Australian adults in meeting vitamin D recommendations, and UV-exposed mushrooms have been found to increase vitamin D status in deficient individuals. While recent evidence suggests some differences between vitamin D2 and vitamin D3 in physiological activities, vitamin D2 from mushrooms can be part of a larger solution to increasing dietary vitamin D intakes, as well as an important focus for public health policy. Mushrooms exposed to UV represent an important tool in the strategic toolkit for addressing vitamin D deficiency in Australia and globally. Health authorities lead the recognition and promotion of mushrooms as a natural, vegan, safe, and sustainable vitamin D food source.

Pore size and organic carbon of biochar limit the carbon sequestration potential of Bacillus cereus SR

Carbon-fixing functional strain-loaded biochar may have significant potential in carbon sequestration given the global warming situation. The carbon-fixing functional strain Bacillus cereus SR was loaded onto rice straw biochar pyrolyzed at different temperatures with the anticipation of clarifying the carbon sequestration performance of this strain on biochar and the interaction effects with biochar. During the culture period, the content of dissolved organic carbon (DOC), easily oxidizable organic carbon, and microbial biomass carbon in biochar changed. This finding indicated that B. cereus SR utilized organic carbon for survival and enhanced carbon sequestration on biochar to increase organic carbon, manifested by changes in CO2 emissions and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) enzyme activity. Linear regression analysis showed that the strain was likely to consume DOC on 300 °C biochar, although the Rubisco enzyme activity was higher. In contrast, the strain had a higher carbon sequestration potential on 500 °C biochar. Correlation analysis showed that Rubisco enzyme activity was controlled by the physical structure of the biochar. Our results highlight the differences in the survival mode and carbon sequestration potential of B. cereus SR on biochar pyrolyzed at different temperatures.

Effects of an efficient straw decomposition system mediated by Stropharia rugosoannulata on soil properties and microbial communities in forestland

Cultivation of Stropharia rugosoannulata with straw in forestland is effective for straw biodegradation and can prevent the waste of straw resources and environmental pollution and generate economic benefits. However, there is a lack of systematic evaluation of spent mushroom substrate (SMS) input into forestland, such as soil properties and microbial succession. In this experiment, 0 (CK), 10 (SA), 20 (SB), 30 (SC), 40 (SD), and 50 (SE) kg/m2 straw were used to cultivate S. rugosoannulata, and two soil layers (0-10 cm, 10-20 cm) of the cultivated forestland were analyzed. The results indicated that SMS significantly promoted nutrient accumulation in forestland. The bacterial alpha diversity in the SC treatment group was greater than that in the control and gradually decreased to the control level with interannual changes, while the trend of fungal alpha diversity was opposite to that of bacterial alpha diversity. Furthermore, the SC treatment group positively affected soil nitrogen metabolism-related microorganisms for two consecutive years and significantly promoted tree growth. Habitat niche breadth and null model analysis revealed that bacterial communities were more sensitive than fungal communities after SMS input. Linear mixed model (LMM) analysis revealed that SMS supplementation significantly positively affected bacteria (Gammaproteobacteria and Bacteroidota) and significantly negatively affected fungi (Coniochaetales). The constructed fungal-bacterial co-occurrence networks exhibited modularity, and the five types of bacteria were significantly correlated with soil organic matter (SOM), soil organic carbon (SOC), available potassium (AK), available phosphorus (AAP) and available nitrogen (AN) levels. The structural equation model (SEM) showed that bacterial diversity responded more to changes in soil nutrients than did fungal diversity. Overall, 30 kg/m2 of straw decomposition and 2 years of continuous cultivation were beneficial to soil health. This study provides new insights into the rational decomposition of straw and maintenance of forestland ecological balance by S. rugosoannulata.

Nitrogen balance and supply in Australasian mushroom composts

Mushrooms are an important source of protein in the human diet. They are increasingly viewed as a sustainable meat replacement in an era of growing populations, with button mushrooms (Agaricus bisporus) the most popular and economically important mushroom in Europe, Australia and North America. Button mushrooms are cultivated on a defined, straw-derived compost, and the nitrogen (N) required to grow these high-protein foods is provided mainly by the addition of poultry manure and horse manure. Using the correct balance of carbon (C) and N sources to produce mushroom compost is critically important in achieving maximum mushroom yields. Changes in the amount and form of N added, the rate and timing of N addition and the other compost components used can dramatically change the proportion of added N recovered in the mushroom caps, the yield and quality of the mushrooms and the loss of N as ammonia and nitrogen oxide gases during composting. This review examines how N supply for mushroom production can be optimised by the use of a broad range of inorganic and organic N sources for mushroom composting, together with the use of recycled compost leachate, gypsum and protein-rich supplements. Integrating this knowledge into our current molecular understanding of mushroom compost biology will provide a pathway for the development of sustainable solutions in mushroom production that will contribute strongly to the circular economy. KEY POINTS: • Nitrogen for production of mushroom compost can be provided as a much wider range of organic feedstocks or inorganic compounds than currently used • Most of the nitrogen used in production of mushroom compost is not recovered as protein in the mushroom crop • The sustainability of mushroom cropping would be increased through alternative nitrogen management during composting and cropping.

Multiple potentially toxic elements in urban gardens from a Brazilian industrialized city

Urban agriculture should be promoted as long as the food produced is safe for consumption. Located in the metropolitan region of São Paulo-Brazil, Santo André has intense industrial activities and more recently an increasing stimulus to urban gardening. One of the potential risks associated to this activity is the presence of potentially toxic elements (PTEs). In this study, the concentration of PTEs (As, Ba, Cd, Co, Cu, Cr, Ni, Mo, Pb, Sb, Se, V and Zn) was evaluated by soil (n = 85) and soil amendments (n = 19) in urban gardens from this municipality. Only barium was above regulatory limits in agricultural soil ranging from 20 to 112 mg kg-1. Geochemical indexes (Igeo, Cf and Er) revealed moderate to severe pollution for As, Ba, Cr, Cu, Pb Se and Zn, especialy in Capuava petrochemical complex gardens. A multivariate statistical approach discriminated Capuava gardens from the others and correlated As, Cr and V as main factors of pollution. However, carcinogenic and non-carcinogenic risks were below the acceptable range for regulatory purposes of 10-6-10-4 for adults. Soil amendments were identified as a possible source of contamination for Ba, Zn and Pb which ranged from 37 to 4137 mg kg-1, 20 to 701 mg kg-1 and 0.7 to 73 mg kg-1, respectively. The results also indicated the presence of six pathogenic bacteria in these amendments. Besides that, the occurrence of antimicrobial resistance for Shigella, Enterobacter and Citrobacter isolates suggests that soil management practices improvement is necessary.

Environmental damages, cumulative exergy demand, and economic assessment of Panus giganteus farming with the application of solar technology

The use of photovoltaic (PV) technology in agricultural production can mitigate the environmental impacts of mushroom farming. However, changes in the environmental impacts and economic benefits of the application of PV technology are still unclear. Thus, we evaluated the environmental impacts, energy flow, and economic aspects of mushroom (Panus giganteus) farming systems without solar PV (WS) technology and with PV technology from the generation of substrate materials through harvesting. In addition to a 27 % increase in terrestrial ecotoxicity, P. giganteus farming with PV technology reduced all impact categories by 4-60 %, with a 60 % reduction in CO2 emissions and a 25 % reduction in land resources. These findings highlight the importance of combining PV technology with mushroom farming in agricultural carbon reduction and the efficient use of land resources. In terms of the climate change impact, the PV system reduced CO2 emissions by 2.94 kg CO2 eq./kg of mushrooms compared with the WS system, wherein the aspects of substrate transformation, spawn running, and cultivation were reduced by 78.27-89.91 %. The cumulative exergy demand (CExD) analysis showed that P. giganteus farming combined with PV technology reduced the total CExD by 48 %. With the application of PV technology, the top contributor to the total CExD of mushroom farming shifted from electricity to transportation throughout the supply chain. The PV system reduced costs by 22.09 % and increased the total revenue by 22 % and the cost-benefit ratio by 50 %. Halving the transportation distances of substrate materials and performing localized substitution of wood chips resulted in a 3-34 % reduction in the environmental impacts category and a 23-30 % reduction in nonrenewable fossil energy consumption. These results showed that improvements helped optimize the environmental performance in terms of carbon reduction and energy mixing. Thus, combining PV technology with greenhouse mushroom farming can improve trends in energy and environmental damage.

Nutraceutical Potential of Lentinula edodes' Spent Mushroom Substrate: A Comprehensive Study on Phenolic Composition, Antioxidant Activity, and Antibacterial Effects

Lentinula edodes, commonly known as shiitake mushroom, is renowned for its potential health advantages. This research delves into the often-overlooked by-product of shiitake cultivation, namely spent mushroom substrate (SMS), to explore its nutraceutical properties. The SMS samples were collected and subjected to different extraction methods, namely short or long agitation, and ultrasound-assisted extractions using different temperatures and distilled water or a 50% (v/v) ethanol as solvents. The extracts were tested for phenolic content (total phenols, ortho-diphenols, and flavonoids), antioxidant capacity (DPPH, 2,2-diphenyl-1 picrylhydrazyl; ABTS, 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid; and FRAP, ferric reducing antioxidant power), and antibacterial activity. The different extraction methods revealed substantial variations (p < 0.05) in phenolic composition and antioxidant capacity. The highest phenolic content and antioxidant capacity were achieved using 24 h extraction, agitation, 50 °C, and ethanol as the solvent. Furthermore, the extracted compounds displayed antibacterial activity in specific tested bacterial strains. This study highlights the nutraceutical potential of L. edodes' SMS, positioning it as a valuable dietary supplement for animal nutrition, with emphasis on its prebiotic properties. Hence, this research unveils the promising health benefits of SMS in both human and animal nutrition.

Sustainability assessment of waste and wastewater recovery for edible mushroom production through an integrated nexus. A case study in Lazio

With a global population of eight billion people, improving the sustainability and nutritional quality of diets has become critical. Mushrooms offer a promising solution because of their nutritional value and ability to be grown from agricultural residues, in line with the circular economy. This study, therefore, focuses on assessing the environmental compatibility of Agaricus bisporus mushroom production in Italy, the world's third largest per capita consumer, by using a Life Cycle Assessment (LCA) and an integrated Water-Energy-Nitrogen-Carbon-Food (WENCF) nexus analysis. The LCA results reveal that for a functional unit of 23,000 kg of the substrate, the production process emits 2.55 × 104 kg of CO2 eq. Sensitivity analysis shows that changing input quantities can reduce environmental impacts by about 5 %. In addition, one scenario evaluates the environmental effects of recycling resources by introducing water and ammonium sulfate from scratch instead of continuous recycling, along with water purification. The study shows that sustainable food production can mitigate resource depletion, climate-altering emissions, and intersectoral competition. Using agro residues for mushroom cultivation and optimizing resource management contribute to environmental sustainability. This approach could not only improve the resilience and efficiency of the food system but could also improve the sustainability of diets. In conclusion, this study highlights the importance of adopting sustainable and circular approaches in mushroom production to address global challenges related to food sustainability.

Chaga mushroom: a super-fungus with countless facets and untapped potential

Inonotus obliquus (Chaga mushroom) is an inexpensive fungus with a broad range of traditional and medicinal applications. These applications include therapy for breast, cervix, and skin cancers, as well as treating diabetes. However, its benefits are virtually untapped due to a limited understanding of its mycochemical composition and bioactivities. In this article, we explore the ethnobotany, mycochemistry, pharmacology, traditional therapeutic, cosmetic, and prospective agricultural uses. The review establishes that several secondary metabolites, such as steroids, terpenoids, and other compounds exist in chaga. Findings on its bioactivity have demonstrated its ability as an antioxidant, anti-inflammatory, antiviral, and antitumor agent. The study also demonstrates that Chaga powder has a long history of traditional use for medicinal purposes, pipe smoking rituals, and mystical future forecasts. The study further reveals that the applications of Chaga powder can be extended to industries such as pharmaceuticals, food, cosmetics, and agriculture. However numerous publications focused on the pharmaceutical benefits of Chaga with few publications on other applications. Overall, chaga is a promising natural resource with a wide range of potential applications and therefore the diverse array of therapeutic compounds makes it an attractive candidate for various applications such as plant biofertilizers and active ingredients in cosmetics and pharmaceutical products. Thus, further exploration of Chaga's potential benefits in agriculture and other industries could lead to exciting new developments and innovations.

Use of oyster mushrooms (Pleurotus ostreatus) for increased circularity and valorization of rapeseed residues

In Europe, rapeseed is a common oilseed crop, resulting in the production of 20 million tons of rapeseed press cake yearly. This press cake can be further upcycled and a protein fraction can be extracted for food purposes, leaving de-proteinized fiber-rich residues. This study examined the use of these residues in the production of oyster mushrooms (Pleurotus ostreatus) and of the spent substrate as feed, since mushroom cultivation may improve the feed properties of substrate. In terms of mushroom production, the addition of rapeseed press residues was beneficial, giving significantly higher biological efficiency (BE = 93.1 ± 11.0%) compared with the control, sugar beet pulp substrate (70.0 ± 6.6%). This increase in productivity can most likely be explained by higher energy content in the substrate supplemented with lipid-rich rapeseed residues. Despite differences in BE between the substrates, high similarity was observed in lipid composition of the fruiting bodies (lipid profile dominated by linoleic acid (18:2), palmitic acid (16:0), and oleic acid (18:1)), and in protein and moisture content. After mushroom harvest, approximately 70% of the initial dry weight of both substrates remained as a possible feed source. Both substrates had significantly lower levels of carbohydrates and unchanged neutral detergent fiber content after mushroom harvest, and both gave lower in vitro digestibility, total gas production, and methane production. However, protein concentration differed between the substrates, with the highest concentration (15.8% of dry weight) found in spent substrate containing rapeseed press residues. The result of the present study suggests that the de-proteinized rapeseed press residue is a resource well-suited for use in the production of mushrooms and feed.

Unlocking the Potential of Spent Mushroom Substrate (SMS) for Enhanced Agricultural Sustainability: From Environmental Benefits to Poultry Nutrition

In this comprehensive review, we delve into the myriad applications of spent mushroom substrate (SMS) in agricultural contexts, with a particular emphasis on its role in fostering sustainable poultry production. Our examination spans three key domains: the use of SMS in fertilizers, its impact on environmental factors and gas emissions, and its contribution to poultry nutrition. This review synthesizes findings from multiple studies that underscore the potential of composted SMS as a viable alternative to conventional inorganic fertilizers, effectively meeting crop nutrient needs while mitigating groundwater contamination risks. Moreover, we highlight the substantial environmental advantages associated with the utilization of SMS and poultry waste, including reductions in greenhouse gas emissions and the promotion of sustainable waste management practices. Additionally, we explore the promising outcomes of integrating SMS into animal feed formulations, which have demonstrated significant enhancements in livestock growth performance and overall health. In sum, this review underscores the versatility and untapped potential of SMS as a valuable agricultural resource, with a particular focus on its role in advancing sustainable practices, optimizing nutrient management, and harnessing the value of organic waste materials, especially in the context of poultry production.

A Further Step toward Sustainable Development: The Case of the Edible Mushroom Supply Chain

This study provides an accurate economic characterization of the supply of edible mushrooms throughout Italy within the European context to fill the relevant research gap and highlight barriers and opportunities that are consistent with the Sustainable Development Goals. Italian companies operating in this field were identified and economically characterized using the Chamber of Commerce's Register of Companies. A qualitative web content analysis was then conducted to extract information about the marketed products, mushroom species, and retail channels, as well as the adopted certifications. The obtained data were quantitatively analyzed through descriptive statistics and multiple correspondence analysis. The Italian market is concentrated in northern areas of the country, and the limited company size indicates fragmentation at the production level, which led to Italy not being competitive enough and, thus, heavily rely on imports. Production is limited to less than 10 species, and innovative mushroom-based products, such as burgers, have shown a limited presence on the market, although they are gaining market share online. The novelty of growing kits highlights the potential to use food production waste to create fungal substrates. Investments in training new mushroom growers and studying new formulations and new fungal species are needed; these investments could allow greater market differentiation and be a good opportunity to promote local economies and create new job opportunities, thus meeting the requirements for sustainable development.

Substrate Optimization for Shiitake (Lentinula edodes (Berk.) Pegler) Mushroom Production in Ethiopia

Edible mushrooms are seen as a way of increasing dietary diversity and achieving food security in Ethiopia. The aim of this study was to develop substrates using locally available agro-industrial by-products and animal manures to enhance the production of Shiitake (Lentinula edodes) mushrooms in Ethiopia. The hypothesis was L. edodes mushroom production on seven different substrates: 100% sugarcane bagasse (S1), 80% sugarcane bagasse, 20% cow dung (S2), horse manure (S3), chicken manure (S4), cottonseed hulls (S5), sugarcane filter cake (S6), and sugarcane trash (S7). Mushroom yield and biological efficiency were significantly affected by substrate type (p < 0.05). A significantly higher yield (434.33 g/500 g of substrate) and biological efficiency (86.83%) were obtained using substrate S4 while lower yield (120.33 g/500 g) and biological efficiency (24.33%) were obtained using substrate S7 than when using other substrates. The largest first flush of mushrooms was obtained on S4, and five flushes were produced on this substrate. S4 also had the highest biological efficiency, the highest nitrogen content, and the lowest C:N. Chicken manure is rich in nitrogen, magnesium, calcium, and potassium, which are crucial for Shiitake mushroom growth. Thus, substrate S4 would be a viable option for cultivating Shiitake mushrooms, particularly in regions where chicken manure is readily available. Substrate S2 also provided high yields and rapid fructification and would be a suitable alternative for Shiitake mushroom cultivation.

Mycoremediation with Agaricus bisporus and Pleurotus ostreatus growth substrates versus phytoremediation with Festuca rubra and Brassica sp. for the recovery of a Pb and γ-HCH contaminated soil

Mycoremediation with mushroom growth substrates can be used for the recovery of mixed contaminated soils due to the benefits derived from the physicochemical characteristics of the substrates, the activity of extracellular enzymes secreted by the fungi, and the presence of the fungal mycelia. The objective of this work was to assess the potential of Agaricus bisporus and Pleurotus ostreatus growth substrates (inoculated mushroom substrates vs. spent mushroom substrates) for the mycoremediation of soils co-contaminated with lead and lindane (γ-HCH). We compared the efficiency of these mycoremediation strategies with the phytoremediation with Brassica spp. Or Festuca rubra plants, in terms of both reduction in contaminant levels and enhancement of soil health. An enhanced soil health was achieved as a result of the application of mycoremediation treatments, compared to phytoremediation and control (untreated) treatments. The application of P. ostreatus inoculated substrate led to the most significant reduction in γ-HCH concentration (up to 88.9% compared to corresponding controls). In the presence of inoculated mushroom substrate, P. ostreatus fruiting bodies extracted more Pb than Brassica spp. Or F. rubra plants. Mycoremediation with P. ostreatus growth substrates appears a promising strategy for the recovery of the health of soils co-contaminated with Pb and γ-HCH.

Production of 17 strains of edible mushroom grown on corn stover and its effect on the chemical composition and ruminal in vitro digestibility of the residual substrate

The objective of this study was to evaluate the production (P) (g of fresh mushrooms /bag) and biological efficiency (BE) (g of fresh mushrooms per 100 g of dry substrate) of 17 fungal strains, namely Pleurotus ostreatus Po-IAP, Po-P38, Po-P14, Po-IE202, Po-Sfco, Po-JP, Po-Psma, and Po-POS, Pleurotus djamour Pd-PRO and Pd-UTMR, Pleurotus eryngii Pe-MB and Pe-PQ, Lentinula edodes L15, L9, L5, and LC, and Hericium erinaceus Heri, produced in corn stover (CS) and to assess the content of crude protein (CP), lignin (L), cellulose, hemicellulose, acid detergent fiber (ADF), and neutral detergent fiber (NDF) and in vitro digestibility of dry matter (IVDMD) of the residual substrate of CS, the so called spent mushroom substrate (SMS), in comparison to the non-inoculated substrate (C). The variables were analyzed as a completely randomized block design using R 4.0.3 software. Means were compared using Tukey's procedure. The Pleurotus spp. strains, compared to Lentinula spp. and Hericium spp., presented better BE and P. In comparison to C, the SMS increased the CP content (p < 0.05) from 10.8% (Po-JP) to 70.3% (LC), while NDF decreased (p < 0.05) from 11.5% (Pd-Pro) to 33.5% (L15) and IVDMD increased (p < 0.05) from 16.2% (Heri) to 47.7% (Pd-UTMR). In conclusion, of the 17 strains evaluated, the 3 strains of Lentinula edodes (L5, L15, and L9), one strain of Pleurotus djamour (Pd-UTMR), and one strain of Pleurotus ostreatus (Po-IAP) generated a SMS that, due to its nutritional improvement and increase in IVDMD, could be used as feed for ruminants. Our results also showed that corn stover is a suitable substrate to produce Pleurotus spp. fruiting bodies, with strain Po-IAP as the best yielding.

The degradation of single-use plastics and commercially viable bioplastics in the environment: A review

Plastics have become an integral part of human life. Single-use plastics (SUPs) are disposable plastics designed to be used once then promptly discarded or recycled. This SUPs range from packaging and takeaway containers to disposable razors and hotel toiletries. Synthetic plastics, which are made of non-renewable petroleum and natural gas resources, require decades to perpetually disintegrate in nature thus contribute to plastic pollution worldwide, especially in marine environments. In response to these problems, bioplastics or bio-based and biodegradable polymers from renewable sources has been considered as an alternative. Understanding the mechanisms behind the degradation of conventional SUPs and biodegradability of their greener counterpart, bioplastics, is crucial for appropriate material selection in the future. This review aims to provide insights into the degradation or disintegration of conventional single-use plastics and the biodegradability of the different types of greener-counterparts, bioplastics, their mechanisms, and conditions. This review highlights on the biodegradation in the environments including composting systems. Here, the various types of alternative biodegradable polymers, such as bacterially biosynthesised bioplastics, natural fibre-reinforced plastics, starch-, cellulose-, lignin-, and soy-based polymers were explored. Review of past literature revealed that although bioplastics are relatively eco-friendly, their natural compositions and properties are inconsistent. Furthermore, the global plastic market for biodegradable plastics remains relatively small and require further research and commercialization efforts, especially considering the urgency of plastic and microplastic pollution as currently critical global issue. Biodegradable plastics have potential to replace conventional plastics as they show biodegradation ability under real environments, and thus intensive research on the various biodegradable plastics is needed to inform stakeholders and policy makers on the appropriate response to the gradually emerging biodegradable plastics.

Vermicomposting of Pleurotus eryngii spent mushroom substrates and the possible mechanisms of vermicompost suppressing nematode disease caused by Meloidogyne incognita

The mushroom industry produces a large amount of spent mushroom substrate (SMS), which requires a large geographical footprint and causes pollution. Vermicomposting is a low-cost technology for its value in recycling of organic wastes and production of beneficial organic fertilizers. In this study, the changes of physicochemical properties was characterized during vermicomposting of Pleurotus eryngii SMS with cow dung (CD) as amendment. The efficiency and possible mechanisms of vermicompost suppressing disease induced by Meloidogyne incognita was also investigated. Six combinations with different ratios of SMS and cow dung (CD) was included in the vermicomposting using Eisenia fetida. Effect of vermicompost against disease induced by M. incognita on tobacco was conducted under greenhouse condition. And the possible mechanisms of vermicompost suppressing M. incognita was investigated by evaluated the species diversity of nematode-trapping fungi (NTF) in soil, and the defense response enzymes in tobacco. The combination of 65% SMS +35% CD was more suitable for vermicomposting, in which the highest vermicompost production (57%) and earthworm biomass increment (268%) were achieved. Additionally, the reduction in pH, total organic carbon, carbon: nitrogen ratio, and the pronounced elevation in four overall nutrient status were also observed. Soil amended with vermicompost (100:1 w/w) showed 61% control efficiency against nematode disease caused by M. incognita on tobacco, which significantly higher than that of the normal compost (24%). Comparing to the normal compost, the potential mechanism of vermicompost suppressing M. incognita could be rely on promoting species diversity of NTF in soil and enhancing the activities of the defense response enzymes in tobacco plant. Our findings indicate that vermicomposting is a promising technology for recycling of P. eryngii SMS, and the resulting vermicompost as organic fertilizer can be sued for management of the diseases caused by root-knot nematodes. This study establish a sustainable avenue for P. eryngii SMS disposal and a practical manner for controlling pathogens.

Biosorption of methylene blue by residue from Lentinus crinitus mushroom cultivation

Conventional textile effluent treatments cannot remove methylene blue, a mutagenic azo dye, and an endocrine disruptor, that remains in the drinking water after conventional water treatment. However, the spent substrate from Lentinus crinitus mushroom cultivation, a waste, could be an attractive alternative to remove persistent azo dyes in water. The objective of this study was to assess the methylene blue biosorption by spent substrate from L. crinitus mushroom cultivation. The spent substrate obtained after mushroom cultivation had been characterized by the point of zero charge, functional groups, thermogravimetric analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy. Moreover, the spent substrate biosorption capacity was determined in function of pH, time, and temperature. The spent substrate had a point of zero charge value of 4.3 and biosorbed 99% of methylene blue in pH from 3 to 9, with the highest biosorption in the kinetic assay of 15.92 mg g^- 1, and in the isothermal assay of 120.31 mg g^- 1. Biosorption reached equilibrium at 40 min after mixing and best fitted the pseudo-second-order model. Freundlich model best fitted the isothermal parameters and each 100 g spent substrate biosorbed 12 g dye in an aqueous solution. The spent substrate of L. crinitus cultivation is an effective biosorbent of methylene blue and an alternative to removing this dye from water, adding value to the mushroom production chain, and supporting the circular economy.

Spent Mushroom Substrate Hydrolysis and Utilization as Potential Alternative Feedstock for Anaerobic Co-Digestion

Valorization of lignocellulosic biomass, such as Spent Mushroom Substrate (SMS), as an alternative substrate for biogas production could meet the increasing demand for energy. In view of this, the present study aimed at the biotechnological valorization of SMS for biogas production. In the first part of the study, two SMS chemical pretreatment processes were investigated and subsequently combined with thermal treatment of the mentioned waste streams. The acidic chemical hydrolysate derived from the hydrothermal treatment, which yielded in the highest concentration of free sugars (≈36 g/100 g dry SMS, hydrolysis yield ≈75% w/w of holocellulose), was used as a potential feedstock for biomethane production in a laboratory bench-scale improvised digester, and 52 L biogas/kg of volatile solids (VS) containing 65% methane were produced in a 15-day trial of anaerobic digestion. As regards the alkaline hydrolysate, it was like a pulp due to the lignocellulosic matrix disruption, without releasing additional sugars, and the biogas production was delayed for several days. The biogas yield value was 37 L/kg VS, and the methane content was 62%. Based on these results, it can be concluded that SMS can be valorized as an alternative medium employed for anaerobic digestion when pretreated with both chemical and hydrothermal hydrolysis.

Increasing the production of the bioactive compounds in medicinal mushrooms: an omics perspective

Macroscopic fungi, mainly higher basidiomycetes and some ascomycetes, are considered medicinal mushrooms and have long been used in different areas due to their pharmaceutically/nutritionally valuable bioactive compounds. However, the low production of these bioactive metabolites considerably limits the utilization of medicinal mushrooms both in commerce and clinical trials. As a result, many attempts, ranging from conventional methods to novel approaches, have been made to improve their production. The novel strategies include conducting omics investigations, constructing genome-scale metabolic models, and metabolic engineering. So far, genomics and the combined use of different omics studies are the most utilized omics analyses in medicinal mushroom research (both with 31% contribution), while metabolomics (with 4% contribution) is the least. This article is the first attempt for reviewing omics investigations in medicinal mushrooms with the ultimate aim of bioactive compound overproduction. In this regard, the role of these studies and systems biology in elucidating biosynthetic pathways of bioactive compounds and their contribution to metabolic engineering will be highlighted. Also, limitations of omics investigations and strategies for overcoming them will be provided in order to facilitate the overproduction of valuable bioactive metabolites in these valuable organisms.

Extraction and utilization of active substances from edible fungi substrate and residue: A review

The expansion of the edible fungi industry has resulted in the production of large amounts of edible fungus residues, causing great pressure on environmental protection.Therefore, research on edible fungus residue utilization has become a controversial issue. Thus far, numerous efforts have been devoted to separate active substances from edible fungus substrates and residues for high application value utilization. Building upon this, the main methods for extracting active substances from edible mushroom residues are reviewed, and the mechanisms, influencing factors, and trade-offs of the various methods are analysed. Furthermore, the existing and possible directions of utilization of the extracted active substances are reviewed and discussed. Finally, challenges and prospects for the extraction and utilization of different substances in edible fungus residues are proposed. This review provides an effective strategy for protecting the ecological environment and promoting the sustainable development of human society.

Production of oyster mushroom (Pleurotus ostreatus) on sawdust supplemented with anaerobic digestate

Anaerobic digestion of organic waste results in production of biogas and a nutrient-rich digestate that has an established use as fertilizer in plant production. This study evaluated use of anaerobic digestate based on a high concentration of organic household waste as a fertilizer in sawdust-based production of oyster mushrooms (Pleurotus ostreatus). Inclusion of 0.5 L of anaerobic digestate (AD) per kg sawdust gave similar productivity in terms of biological efficiency (79.5 ± 5.4 %), and protein concentration (24.7 ± 2.4 % of dry weight (dw)) as standard mushroom substrate (78.1 ± 5.3 %, and 21.9 ± 3.0 % of dw, respectively). However, mushroom growth was impaired at the highest concentration of anaerobic digestate tested, 1 L digestate per kg dw sawdust. Comparison of the AD-fertilized substrate with a mushroom substrate with standard components (sawdust, wheat bran, calcium sulfate) and with similar C/N-ratio revealed some differences in elemental composition of the fruiting bodies, with an major increase in sodium concentration for the AD-fertilized substrate compared with the standard substrate (413.3 ± 28.9 and 226.7 ± 30.6 mg kg^-1 dw, respectively). This difference can be explained by high sodium concentration in the anaerobic digestate, most likely due to inclusion of food scraps from households and restaurants in the biodigester feedstock. Screening of both substrates for a total of 133 micropollutants revealed that total sum of micropollutants was significantly higher in the AD-fertilized substrate (258 ± 12 ng/g dw substrate) than in the standard substrate (191 ± 35 ng/g dw substrate). Nitrogen losses during preparation of the AD-fertilized substrate were negligible.

Mushroom Production in the Southern Cone of South America: Bioeconomy, Sustainable Development and Its Current Bloom

A Sustainable Development Goals (SDGs) based analysis is presented here for business development of the production of edible and medicinal mushrooms using agro-wastes in the Southern Cone of South America. This circular economy approach using edible and medicinal mushroom production on lignocellulosic residues is discussed by analysing both its advantages and drawbacks. Among its main benefits, it is notable that mushroom cultivation using lignocellulosic residues promotes innovation aimed at environmental sustainability, facilitating diversification of the labour supply and the transfer of science to the socio-cultural sphere, which also increases the availability of healthy foods. However, there are some bottlenecks in the process, such as the continuous supply chain of substrates for fungal growth, the lack of equipment and infrastructure for the implementation of cultivation systems in extreme habitats, as well as authorization requirements and other limitations related to a non-fungiphilic culture society. Therefore, this chapter tries to provide key tools for establishing sustainable guidelines for the procurement of local healthy food and other products derived from mushroom cultivation using agricultural residues in the region, which might bloom due to an SDGs-based circular economy approach.

Diversity and effects of competitive Trichoderma species in Ganoderma lucidum-cultivated soils

Ganoderma lucidum (GL) is a well-known medicinal mushroom that has been extensively cultivated. Our previous study has shown that abundant Trichoderma colonies grow on the casing soil surface, posing cultivation obstacles for GL. However, an understanding of species-level characteristics of Trichoderma strains and their adverse effects on GL growth is limited. This study aimed to investigate the diversity and potential effects of Trichoderma from GL-cultivated soils. Over 700 Trichoderma isolates were collected from two trails in Longquan Country, southeast China. Eight Trichoderma species, including T. atrioviride, T. guizhouense, T. hamatum, T. harzianum, T. koningiopsis, T. pleuroticola, T. sp. irale, and T. virens, were identified based on the combination alignment of tef-1α and rpb2 sequences. The number of Trichoderma colonies increased dramatically during GL cultivation, with an increase of 9.2-fold in the Lanju trail. T. virens accounted for the most colonies (33.33 and 32.50% in Lanju and Chengbei, respectively) at the end of GL cultivation. The Trichoderma species growth varied but was satisfactory under different temperature or pH conditions. Moreover, Trichoderma species showed different adverse effects on GL growth. The non-volatile metabolites from T. virens and volatile metabolites from T. atroviride displayed the strongest antagonistic activity. Furthermore, the volatile 6-pentyl-2H-pyran-2-one (6-PP) showed a significant inhibitory effect on GL growth with an 8.79 μl mL-1 headspace of 50% effective concentration. The different Trichoderma spp. produced different amounts of 6-PP. The most efficient 6-PP producer was T. atroviride. To the best of our knowledge, this study is the first to demonstrate the abundance of competitive Trichoderma species associated with GL cultivation. Our results would contribute to.

Metagenomics analysis of the effects of Agaricus bisporus mycelia on microbial diversity and CAZymes in compost

Agaricus bisporus growth alters the lignocellulosic composition and structure of compost. However, it is difficult to differentiate the enzyme activities of A. bisporus mycelia from the wider microbial community owing to the complication of completely speareting the mycelia from compost cultures. Macrogenomics analysis was employed in this study to examine the fermentation substrate of A. bisporus before and after mycelial growth, and the molecular mechanism of substrate utilization by A. bisporus mycelia was elucidated from the perspective of microbial communities and CAZymes in the substrate. The results showed that the relative abundance of A. bisporus mycelia increased by 77.57-fold after mycelial colonization, the laccase content was significantly increased and the lignin content was significantly decreased. Analysis of the CAZymes showed that AA10 family was extremely differentiated. Laccase-producing strains associated with AA10 family were mostly bacteria belonging to Thermobifida and Thermostaphylospora, suggesting that these bacteria may play a synergistic role in lignin decomposition along with A. bisporus mycelia. These findings provide preliminary evidence for the molecular mechanism of compost utilization by A. bisporus mycelia and offer a reference for the development and utilization of strains related to lignocellulose degradation.

Effect of microbial agents on maturity, humification, and stability and the bacterial succession of spent mushroom substrate composting

Two composting experiments were conducted to investigate the effects of commercial microbial agents on microbial succession and nutrient flow such as humification, maturation, and stability during the aerobic composting of the spent mushroom substrate (SMS). The cellulose degradation rate of T (added microbial agents at the initial stage) reached 41.8%, which was much significantly (p < 0.05) higher than that of CK (14.9%). The seed germination index (GI) in T (82.38%) was significantly (p < 0.05) higher than that in CK (74.74%) in the maturation phase. Moreover, the total organic carbon/total nitrogen ratio (C/N) and electrical conductivity (EC) value of T decreased to 10.5 and 2.37 mS/cm, respectively. Chemical detection and fluorescence excitation-emission region integration method (EEM-FRI) analysis showed that the microbial agents significantly accelerated the organic matter (OM) decomposition and promoted the quality of mature compost using SMS as a single raw material. The bacterial abundance of T was significantly richer than the CK due to the addition of microbial agents. The results could provide a comprehensive understanding of adding microbial agents into composting SMS and a scientific feasibility strategy to rational utilization of resources in the edible fungi industry, which was conducive to the waste management and sustainable development of the edible fungi industry.

Temporal characterization of biocycles of mycelium-bound composites made from bamboo and Pleurotus ostreatus for indoor usage

Mycelium-bound composites (MBCs) are materials obtained by growing fungi on a ligno-cellulosic substrate which have various applications in packaging, furniture, and construction industries. MBCs are particularly interesting as they are sustainable materials that can integrate into a circular economy model. Indeed, they can be subsequently grown, used, degraded, and re-grown. Integrating in a meaningful biocycle for our society therefore demands that MBCs fulfil antagonistic qualities which are to be at the same time durable and biodegradable. In this study, we conduct experiments using MBCs made from the fungus species Pleurotus ostreatus grown on bamboo microfibers substrate. By measuring the variations of the mechanical properties with time, we provide an experimental demonstration of a biocycle for such composites for in-door applications. We found that the biocycle can be as short as 5 months and that the use of sustainable coatings is critical to increase the durability of the composites while maintaining biodegradability. Although there are many scenarios of biocycles possible, this study shows a tangible proof-of-concept example and paves the way for optimization of the duration of each phase in the biocycle depending on the intended application and resource availability.

MycelioTronics: Fungal mycelium skin for sustainable electronics

Electronic devices are irrevocably integrated into our lives. Yet, their limited lifetime and often improvident disposal demands sustainable concepts to realize a green electronic future. Research must shift its focus on substituting nondegradable and difficult-to-recycle materials to allow either biodegradation or facile recycling of electronic devices. Here, we demonstrate a concept for growth and processing of fungal mycelium skins as biodegradable substrate material for sustainable electronics. The skins allow common electronic processing techniques including physical vapor deposition and laser patterning for electronic traces with conductivities as high as 9.75 ± 1.44 × 10⁴ S cm^-1. The conformal and flexible electronic mycelium skins withstand more than 2000 bending cycles and can be folded several times with only moderate resistance increase. We demonstrate mycelium batteries with capacities as high as ~3.8 mAh cm^-2 used to power autonomous sensing devices including a Bluetooth module and humidity and proximity sensor.

Valorization of spent mushroom substrate in combination with agro-residues to improve the nutrient and phytohormone contents of vermicompost

In recent years, enormous amounts of spent mushroom substrate (SMS) have been generated because of the rapid development of mushroom production. Since the conventional disposal methods of these residues can cause serious environmental problems, alternative waste management techniques are required to ensure sustainable agriculture. However, SMS might be not suitable for vermicomposting when used alone. Therefore, the primary purpose of this study was to investigate the effect of Azolla microphylla (Azolla) biomass, eggshells, fruit peels, and cassava pulp on the biodegradation process of SMS. The results showed the treatments supplemented with cassava pulp and fruit peel waste improved the growth of earthworms, while the carbon-to-nitrogen ratio of these vermicomposts decreased significantly (p < 0.05) due to the improved total nitrogen contents (7.64 g kg^-1 and 6.71 g kg^-1). Concerning the degradation process and the vermicompost quality, the addition of these agro-residues facilitated the enzyme activities (cellulase, urease, and alkaline phosphatase) and increased the total macronutrient (P, K, Mg, and Ca) and phytohormone (fruit peel waste: AA, GA3, and cytokinin; cassava pulp: cytokinin) contents of the final products compared to the control treatment. On the other hand, Azolla had no additional effect on the fecundity and growth of Eudrilus eugenia. Meanwhile, the treatment supplemented with eggshells was high in Mg (7.15 g kg^-1) and Ca (305.6 g kg^-1). Overall, the combined decomposition of SMS-based bedding material with Azolla, eggshells, fruit peel waste, and cassava pulp resulted in mature organic fertilizers with improved chemical properties.

Transcription factor FfMYB15 regulates the expression of cellulase gene FfCEL6B during mycelial growth of Flammulina filiformis

Background

Cellulose degradation can determine mycelial growth rate and affect yield during the growth of Flammulina filiformis. The degradation of cellulose requires the joint action of a variety of cellulases, and some cellulase-related genes have been detected in mushrooms. However, little is known about the transcriptional regulatory mechanisms of cellulose degradation.

Results

In this study, FfMYB15 that may regulate the expression of cellulase gene FfCEL6B in F. filiformis was identified. RNA interference (RNAi) showed that FfCEL6B positively regulated mycelial growth. Gene expression analyses indicated that the expression patterns of FfCEL6B and FfMYB15 in mycelia cultured on the 0.9% cellulose medium for different times were similar with a correlation coefficient of 0.953. Subcellular localization and transcriptional activity analyses implied that FfMYB15 was located in the nucleus and was a transcriptional activator. Electrophoretic mobility shift assay (EMSA) and dual-luciferase assays demonstrated that FfMYB15 could bind and activate FfCEL6B promoter by recognizing MYB cis-acting element.

Conclusions

This study indicated that FfCEL6B played an active role in mycelial growth of F. filiformis and was regulated by FfMYB15.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-022-01932-z.

Sustainability perspectives for future continuity of mushroom production: The bright and dark sides

Mushrooms are now well-known as healthy food ingredients that contain dietary fiber, vitamin D and compounds with numerous health benefits. Its procurement was initially based on the collection of naturally occurring wild mushrooms in the field, which depended on the region. Modern established cultivation techniques have contributed to environmental sustainability through the recycling of forestry and agricultural by-products and have successfully developed into a global industry. Such development of global mushroom production is the “bright” side as circular agriculture. However, the potential environmental and economic benefits in the sustainability of mushroom production have not yet been widely recognized, and its global production trend has stagnated in recent years. Therefore, dissemination activities through international mutual cooperation centered on education including ecology, cultivation science, and nutrition science of mushrooms are indispensable for the development of mushroom production in the future. On the other hand, we also need to urgently identify and address the challenges associated with negative sustainability impacts, or “dark” side, of mushroom production. The adverse effects of spores derived from cultivated mushrooms on the surrounding environment and disposal methods such as used heat-resistant bags and spent mushroom substrates are often neglected. Clarifying such the positive and negative aspects of sustainability in mushroom production and presenting their future prospects should contribute to improving international perceived value and the continuity of mushroom production.

Effects of Agricultural Management of Spent Mushroom Waste on Phytotoxicity and Microbiological Transformations of C, P, and S in Soil and Their Consequences for the Greenhouse Effect

The huge volumes of currently generated agricultural waste pose a challenge to the economy of the 21st century. One of the directions for their reuse may be as fertilizer. Spent mushroom substrate (SMS) could become an alternative to manure (M). A three-year field experiment was carried out, in which the purpose was to test and compare the effect of SMS alone, as well as in multiple variants with mineral fertilization, and in manure with a variety of soil quality indices-such as enzymatic activity, soil phytotoxicity, and greenhouse gas emissions, i.e., CO₂. The use of SMS resulted in significant stimulation of respiratory and dehydrogenase activity. Inhibition of acid phosphatase and arylsulfatase activity via SMS was recorded. SMS showed varying effects on soil phytotoxicity, dependent on time. A positive effect was noted for the growth index (GI), while inhibition of root growth was observed in the first two years of the experiment. The effect of M on soil respiratory and dehydrogenase activity was significantly weaker compared to SMS. Therefore, M is a safer fertilizer as it does not cause a significant persistent increase in CO₂ emissions. Changes in the phytotoxicity parameters of the soil fertilized with manure, however, showed a similar trend as in the soil fertilized with SMS.

Soil microbial diversity and functional capacity associated with the production of edible mushroom Stropharia rugosoannulata in croplands

In recent years, a rare edible mushroom Stropharia rugosoannulata has become popular. S. rugosoannulata has the characteristics of easy cultivation, low cost, high output value, and low labor requirement, making its economic benefits significantly superior to those of other planting industries. Accumulating research demonstrates that cultivating edible fungus is advantageous for farming soil. The present experiment used idle croplands in winter for S. rugosoannulata cultivation. We explored the effects of S. rugosoannulata cultivation on soil properties and soil microbial community structure in paddy and dry fields, respectively. We cultivated S. rugosoannulata in the fields after planting chili and rice, respectively. The results showed that Chili-S. rugosoannulata and Rice-S. rugosoannulata planting patterns increased the yield, quality and amino acid content of S. rugosoannulata. By analyzing the soil properties, we found that the Chili-S. rugosoannulata and Rice-S. rugosoannulata cropping patterns increased the total nitrogen, available phosphorus, soil organic carbon, and available potassium content of the soil. We used 16s amplicons for bacteria and internal transcribed spacer (ITS) region for fungi to analyze the microbial communities in rhizosphere soils. Notably, S. rugosoannulata cultivation significantly increased the abundance of beneficial microorganisms such as Chloroflexi, Cladosporium and Mortierella and reduce the abundance of Botryotrichumin and Archaeorhizomyces. We consider S. rugosoannulata cultivation in cropland can improve soil properties, regulate the community structure of soil microorganisms, increase the expression abundance of beneficial organisms and ultimately improve the S. rugosoannulata yield and lay a good foundation for a new round of crops after this edible mushroom cultivation.