Edible Fungi Industry Research Articles

Degradation of edible mushroom waste by Hermetia illucens L. and consequent adaptation of its gut microbiota

The edible fungus industry is one of the pillar industries in the Yunnan–Guizhou Plateau, China. The expansion of the planting scale has led to the release of various mushroom residues, such as mushroom feet, and other wastes, which are not treated adequately, resulting in environmental pollution. This study investigated the ability of black soldier fly (Hermetia illucens L.) larvae (BSFL) to degrade mushroom waste. Moreover, this study analyzed changes in the intestinal bacterial community and gene expression of BSFL after feeding on mushroom waste. Under identical feeding conditions, the remaining amount of mushroom waste in Pleurotus ostreatus treatment group was reduced by 18.66%, whereas that in Flammulina velutipes treatment group was increased by 31.08%. Regarding gut microbial diversity, compared with wheat bran-treated control group, Dysgonomonas, Providencia, Enterococcus, Pseudochrobactrum, Actinomyces, Morganella, Ochrobactrum, Raoultella, and Ignatzschineria were the most abundant bacteria in the midgut of BSFL in F. velutipes treatment group. Furthermore, Dysgonomonas, Campylobacter, Providencia, Ignatzschineria, Actinomyces, Enterococcus, Morganella, Raoultella, and Pseudochrobactrum were the most abundant bacteria in the midgut of BSFL in P. ostreatus treatment group. Compared with wheat bran-treated control group, 501 upregulated and 285 downregulated genes were identified in F. velutipes treatment group, whereas 211 upregulated and 43 downregulated genes were identified in P. ostreatus treatment group. Using Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment analyses, we identified 14 differentially expressed genes (DEGs) related to amino sugar and nucleotide sugar metabolism in F. velutipes treatment group, followed by 12 DEGs related to protein digestion and absorption. Moreover, in P. ostreatus treatment group, two DEGs were detected for fructose and mannose metabolism, and two were noted for fatty acid metabolism. These results indicate that feeding on edible mushroom waste can alter the intestinal microbial community structure of BSFL; moreover, the larval intestine can generate a corresponding feedback. These changes contribute to the degradation of edible mushroom waste by BSFL and provide a reference for treating edible mushroom waste using BSFL.

Overexpression of cat2 restores antioxidant properties and production traits in degenerated strains of Volvariella volvacea

Strain degeneration is an important factor hindering the development of the edible fungus industry. Strain degeneration is associated with the excessive accumulation of reactive oxygen species (ROS) in vivo. Catalase (CAT), an important antioxidant enzyme, can promote the clearance of ROS. In this study, the cat2 gene of Volvariella volvacea was first cloned into an overexpression plasmid via homologous recombination. Finally, through Agrobacterium-mediated transformation, this plasmid was inserted into degenerated strains of V. volvacea T19. The physiological properties, antioxidant properties, ROS content, matrix degradation activity, and cultivation properties of the transformants were tested. The results showed that the cloned cat2 gene was 99.94% similar to the reference sequence. Screening revealed that six positive transformants were successfully obtained. After the overexpression of cat2, the growth rate and biomass of the mycelium increased significantly in the transformant strains (versus the V. volvacea T19 degenerated strains). Moreover, the accumulation of superoxide radical (O2•-) and hydrogen peroxide (H2O2) was significantly reduced, and the activity of the enzymes CAT, superoxide dismutase (SOD), glutathione reductase (GR), and glutathione peroxidase (GPX) was significantly increased. Meanwhile, the expression of cat2, Mnsod1, Mnsod2, gpx, and gr was significantly upregulated, and the activity of eight matrix degradation-related enzymes was increased to varying degrees. More importantly, the overexpression of the cat2 gene promoted the regrowth of fruiting bodies in degenerated strains of V. volvacea T19. This study provides a new biotechnological strategy to control the degeneration of V. volvacea and other edible fungi.

Integrative analysis of genome and transcriptome reveal the genetic basis of high temperature tolerance in pleurotus giganteus (Berk. Karun & Hyde)

BackgroundPleurotus giganteus is a commonly cultivated mushroom with notable high temperature resistance, making it significant for the growth of the edible fungi industry in the tropics. Despite its practical importance,, the genetic mechanisms underlying its ability to withstand high temperature tolerance remain elusive.ResultsIn this study, we performed high-quality genome sequencing of a monokaryon isolated from a thermotolerant strain of P. giganteus. The genome size was found to be 40.11 Mb, comprising 17 contigs and 13,054 protein-coding genes. Notably, some genes related to abiotic stress were identified in genome, such as genes regulating heat shock protein, protein kinase activity and signal transduction. These findings provide valuable insights into the genetic basis of P. giganteus’ high temperature resistance. Furthermore, the phylogenetic tree showed that P. giganteus was more closely related to P. citrinopileatus than other Pleurotus species. The divergence time between Pleurotus and Lentinus was estimated as 153.9 Mya, and they have a divergence time with Panus at 168.3 Mya, which proved the taxonomic status of P. giganteus at the genome level. Additionally, a comparative transcriptome analysis was conducted between mycelia treated with 40 °C heat shock for 18 h (HS) and an untreated control group (CK). Among the 2,614 differentially expressed genes (DEGs), 1,303 genes were up-regulated and 1,311 were down-regulated in the HS group. The enrichment analysis showed that several genes related to abiotic stress, including heat shock protein, DnaJ protein homologue, ubiquitin protease, transcription factors, DNA mismatch repair proteins, and zinc finger proteins, were significantly up-regulated in the HS group. These genes may play important roles in the high temperature adaptation of P. giganteus. Six DEGs were selected according to fourfold expression changes and were validated by qRT-PCR, laying a good foundation for further gene function analysis.ConclusionOur study successfully reported a high-quality genome of P. giganteus and identified genes associated with high-temperature tolerance through an integrative analysis of the genome and transcriptome. This study lays a crucial foundation for understanding the high-temperature tolerance mechanism of P. giganteus, providing valuable insights for genetic modification of P. giganteus strains and the development of high-temperature strains for the edible fungus industry, particularly in tropical regions.

Antibacterial mechanism of rose essential oil against Pseudomonas putida isolated from white Hypsizygus marmoreus at cellular and metabolic levels

Pseudomonas putida (P. putida) is a common spoilage microorganism that can cause food contamination and various foodborne illnesses. Rose essential oil (REO) is regarded as a good natural antibacterial agent because of its broad spectrum and excellent antibacterial properties. This study aimed to reveal the mechanism of action of REO on P. putida at the cellular level and to investigate the regulatory role of REO on the metabolic pathway of P. putida for the first time using the metabolome. The results demonstrated that the integrity of bacterial cell walls and membranes was disrupted, leakage of cell contents (proteins, ATP, and nucleic acids) occurred after the bacterial cell is treated with REO. The severe disruptive effect of REO on cell morphology was observed under scanning electron microscopy and transmission electron microscopy, further confirming the damage of REO on the cell wall and cell membrane. A total of 200 differential metabolites were screened at the metabolic level, of which 130 differential metabolites were significantly up-regulated, and 70 differential metabolites were significantly down-regulated. These differential metabolites were mainly involved in the TCA cycle, amino acid metabolism, nucleotide metabolism, carbohydrate metabolism, lipid metabolism, biosynthesis of pantothenic acid and coenzyme A, and aminoacyl tRNA biosynthesis, among which amino acid metabolism was most severely disrupted. Finally, the application results showed that the color, smell, and tissue state of white Hypsizygus marmoreus did not change significantly 8 days after REO treatment, indicating that REO has a good bacterial inhibitory effect on white Hypsizygus marmoreus. In conclusion, REO can inhibit P. putida at multiple targets and pathways, destroying cell morphological structure and disrupting metabolic processes. These results would provide new theoretical basis for the inhibition mechanism of REO on P. putida, and REO may be used as an effective alternative to chemical additives in the edible fungi industry.

Recent Advances in Postharvest Irradiation Preservation Technology of Edible Fungi: A Review

Edible fungi have high edible, medicinal and economic value. Rapid development of the edible fungi industry can meet people's consumption demands. However, due to lack of suitable preservation technology after harvest, edible fungi are susceptible to mechanical damage, microbial infection, and discoloration, which could affect the quality and shelf life of fresh edible fungi. Many techniques have been developed to extend the postharvest storage time of fresh edible fungi and irradiation technology has been proven to be one of the potential technologies. This review summarizes the internal and external factors affecting the postharvest quality deterioration of edible fungi, introduces the types of irradiation preservation technology and describes comprehensive advances in the effects of irradiation on shelf life, microbiology, organoleptic qualities, nutritional qualities (proteins, fats, sugars and vitamins) and enzymatic activities of edible fungi from different regions and of different species worldwide. This review uncovers that the postharvest quality decay of edible fungi is a complex process. The irradiation preservation of edible fungi is affected not only by the edible fungus itself and the storage environment but also by the radiation type, radiation dose and radiation source conditions. Future studies need to consider the combined application of irradiation and other novel technologies to further improve the preservation effect of edible fungi, in particular in the area of irradiation's influence on the flavor of edible fungus.

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.

Metabolomics Analysis of Morchella sp. From Different Geographical Origins of China Using UPLC-Q-TOF-MS.

The morel mushroom (Morchella sp.) is reputed as one of the most highly-prized edible fungi with mounting cultivated area as well as commercial popularity in China. To date, optimized methods specific for quality evaluation and constituent analysis of Morchella sp. are still non-available, impeding the healthy and sustainable development of this industry. Herein, an untargeted UPLC-Q-TOF-MS-based metabolomics approach was performed to characterize the metabolite profiles of morel samples from four distinct geographical origins of China, viz. Gansu, Guizhou, Liaoning, and Henan province. A total of 32 significantly different metabolites assigned to lipids (19), organic acids (9), amino acids (3), and ketones (1) were identified to distinguish the geographic-segregation samples amenable to multivariate analysis. These metabolites may serve as molecular markers indicative of specific regions. More importantly, the lipid, protein and amino acid metabolism were responsible for geographic differences as revealed by KEGG pathway enrichment analysis. Collectively, this study not only pioneered high-throughput methodology to evaluate quality of Morchella sp. and distinguish geographical origins in a sensitive, rapid and efficient manner, but also shed light on the potential link between physiochemical variation and geological origins from a metabolic perspective, which may be conducive to the advancement of edible fungi industry and establishment of food traceability system.

Insoluble Dietary Fibers From By-Products of Edible Fungi Industry: Basic Structure, Physicochemical Properties, and Their Effects on Energy Intake.

With the rapid development of the edible fungi industry in the world, especially in China, the resource utilization of edible fungi by-products has become an urgent problem for the industry's sustainable development. The waste residue of edible fungi after polysaccharide extraction by water accounts for a large proportion, which contains a large amount of water-insoluble dietary fiber (IDF). At present, the extracted residue is generally treated as fertilizer or solid waste, which not only pollutes the environment, but wastes resources too. In order to develop these by-products, expand their potential utilization in the food industry, the structure characterization, physicochemical properties, and the influence of IDF on dietary energy intake were studied. The IDF from the residues of polysaccharides extracted from four edible fungi was extracted using the Association of Official Analytical Chemists (AOAC) method. The results showed that IDF in the four kinds of edible fungi residues was similar in composition but different in texture. Cellulose and hemicellulose are the main IDF extracted from four kinds of edible fungi. Among them, Hericium erinaceus is the softest without obvious granular texture, following Lentinus edodes, while Ganoderma lucidum and Grifola frondosa have a relatively hard texture. The yield of four kinds of IDF from high to low came from Ganoderma lucidum, Hericium erinaceus, Lentinus edodes, and Grifola frondosa. Fourier transform IR (FTIR) and X-ray diffraction (XRD) spectra showed that the four IDFs had similar functional groups and all of them contained a large amount of cellulose. Physical and chemical analysis showed that all the four IDFs had certain water holding capacity, water binding capacity, and oil holding capacity. In-vitro digestion experiments showed that the four IDFs could inhibit the digestion of starch and fat to a certain extent. By-products of edible fungi are an ideal material for the recovery of IDFs, which have the potential to be processed into functional food materials due to their physicochemical properties and physiological functions.

Maximizing the value of Korshinsk peashrub branches by the integration of Pleurotus tuoliensis cultivation and anaerobic digestion of spent mushroom substrate

Korshinsk peashrub branches (Korpb) are agroforestry byproducts that accumulate in millions of tons per year and need to be reasonably utilized. To maximate the utilization value of Korpb, an integrated process was proposed and conducted by using Korpb as the main substrate ingredient for Pleurotus tuoliensis cultivation and also performing anaerobic digestion (AD) of spent mushroom substrate (SMS) for biogas production. The results indicated that the cultivation substrate including Korpb could obtain higher mushroom yields than a conventional substrate, and AD of SMS added the value of Korpb. Preliminary calculation suggested that, for every t of P. tuoliensis production, 1.65 t Korpb was consumed and 314 m3 biogas was produced from corresponding amount of SMS, bringing a total economic profit of $906.1. In addition, this integrated strategy has positive ecological and social benefits. The maximization of Korpb value can not only promote the biological conversion of Korpb to circle economy, but also be beneficial for the development of environment, energy conservation and edible fungus industry.

Effect of the development of the edible fungus industry on the circular economy of the beautiful new countryside based on the var3D regional model

As China’s accession to the World Trade Organization takes longer and longer, it has gained a place in the international market. At present, in the international market, China ranks first in the trading volume of agricultural and sideline products, especially in the development of foreign trade in Southeast Asia, Europe, and Africa. The development momentum of the edible fungus industry continues to increase in China, becoming a leader in the emerging agricultural industry. Based on the influence of the edible fungus industry in rural areas, according to the survey and record of data valuation, the specific index data content from 2005 to 2019 was taken as an example, and a three-tier research system was proposed using var3D model. Respectively, it is the relationship between the three types of rural basic indicators, economic indicators, and industrial development indicators, verifying the role of the edible fungus industry in driving the development of beautiful new rural construction and enhancing economic development. Results show that the targeted distribution of edible fungi across the country and the construction of beautiful villages have a high degree of direct correlation, and its steep performance trend is obvious. In the analysis of the equilibrium degree of the edible fungi industry driving the local rural economic development, the edible fungi continues to strengthen the advantages of local industries have used its industrial power to further improve the intensity and integrity of local rural construction and promote the development of beautiful new rural areas. The development of the edible fungus industry has also led to the enthusiasm and source power of the construction of beautiful new villages. The development of beautiful new villages will help to enhance the gain effect of the edible fungus industry and form a new model of the beautiful new rural circular economy.

Improve spent mushroom substrate decomposition, bacterial community and mature compost quality by adding cellulase during composting

Three composting experiments were carried out to evaluate the effect of cellulase on the spent mushroom substrate (SMS) composting and develop a better disposal technology: added cellulase at the initial stage in T1, after the thermophilic stage in T2, while added no cellulase in the control experiments (CK). Results showed that cellulase accelerated SMS decomposition, improved bacterial community, promoted nitrate synthesis and improved mature compost quality. The total thermophilic stage of T2 reached 14 days, much longer than that of CK (8 days) and T1 (6 days). The cellulose degradation rate of T2 reached 41.22%, much higher than that of CK (19.86%) and T1 (29.72%). Total nutrient of mature compost increased by 13.13% in T2 and 3.28% in T1, compared with that of CK, respectively. Also, cellulase increased the humus content and the seed germination index (GI) of mature compost and decreased the electrical conductivity (EC) and the C/N ratio. The optimised cellulase adding time was after the thermophilic stage of composting. This study elucidated the role of cellulase in SMS composting, and provided an efficient disposal way for this organic residue, which was helpful for the cleaner production and sustainability of edible fungi industry.

Determination of nicotine in wild edible fungi by QuEChERS-ultra performance liquid chromatography-triple quadrupole mass spectrometry

Yunnan Province has many wild edible fungi resources, and of these, endogenous nicotine has received extensive attention in recent years. In this study, wild edible fungus was used as the research object, and the QuEChERS method was improved, including optimization of solvent extraction and purification conditions and optimization of the chromatographic behavior of nicotine under different mobile phase conditions for ultra performance liquid chromatography (UPLC). Combined with triple quadrupole mass spectrometry, a high-efficiency, rapid, and sensitive method for the determination of nicotine in wild edible fungi was established. The results showed that an ammonia:acetonitrile (6:94, v/v) mixed solution can completely extract nicotine from wild edible fungi, and the extraction solution was purified by graphitized carbon black (GCB) and N-propylethylenediamine (PSA) mixed filler. Then, a 0.1% (volume percentage) ammonia solution and acetonitrile were used as the mobile phases. The nicotine peak obtained in the positive ion multiple reaction monitoring (MRM) mode had a better peak shape and better response. The linear relationship of nicotine mass concentration with peak area in the range of 0.05-50.0 μg/L was good. The correlation coefficient (r2) was 0.9999. The limit of quantification was 0.2 μg/kg, and the limit of detection was 0.05 μg/kg. The average recovery rates at three spiked concentrations were in the range of 86.34%-96.4%, and the relative standard deviations varied from 4.44% to 6.3%. The sensitivity and recovery of this method are consistent with the rapid determination of nicotine in the edible fungus industry.

Study on three major effects and guarantee system for quality management of edible mushroom products

In order to provide consumers with more safe and edible fungus products and to create a faithful social environment of food quality, the edible fungus products quality safety events, as well as their evoked factors and effects on edible fungus industry were discussed in depth in this paper. The performance of edible fungus products quality management is a comprehensive reflection of technical effect, control effect and implementation effect. Among them, the implementation effect is the most important, which refers to the actual implementation effect of quality and safety rules by practitioners of edible fungus industry. Thus, the initiative implementation effect in quality management will be improved, and a quality assurance system in which practitioners are volunteered to participate and implement initiatively the quality standards and regulations so as to provide safe and high-quality products will be established, thereby achieving the best actual implementation effect in quality management.

Integrated economic and environmental analysis of agricultural straw reuse in edible fungi industry.

BackgroundChina currently faces severe environmental pollution caused by burning agricultural straw; thus, resource utilization of these straws has become an urgent policy and practical objective for the Chinese government.MethodsThis study develops a bio-economic model, namely, “straw resource utilization for fungi in China (SRUFIC),” on the basis of a field survey of an edible fungi plant in Zhejiang, China, to investigate an integrated economic and environmental performance of straw reuse in fungi production. Five scenarios, which cover changes in the production scale, wage level, and price fluctuations of the main product and inputs, are simulated.ResultsResults reveal that (1) the pilot plant potentially provides enhanced economic benefits and disposes added agricultural residues by adjusting its production strategy; (2) the economic performance is most sensitive to fungi price fluctuations, whereas the environmental performance is more sensitive to production scale and price of fungi than other factors; (3) expanding the production scale can be the most efficient means of improving the performance of a plant economically and environmentally.DiscussionOverall, agricultural straw reuse in the edible fungi industry can not only reduce the environmental risk derived from burning abandoned straws but also introduce economic benefits. Thus, the straw reuse in the fungi industry should be practiced in China, and specific economic incentive policies, such as price support or subsidies, must be implemented to promote the utilization of agricultural straws in the fungi industry.

加快玉林市食用菌产业转型升级发展的思路与对策

通过调查研究，阐述玉林食用菌产业发展成效，分析其产业形势，并提出加快食用菌产业转型升级发展的思路与对策，以推动玉林市食用菌产业发展。 Through the investigation and study, this paper expounds the development of edible fungus in-dustry in Yulin, analyzes its industry situation and puts forward the thoughts and countermeas-ures on accelerating the upgrading of edible fungus industry to promote the development of edi-ble fungus industry in Yulin city.

The Development and Demonstration of Edible Fungus Circular Agriculture Mode and its Standardization Production Technology

The circular agriculture mode of forest (fast-growing acacia trees) leftover material→ edible fungus cultivation→ fungus chaff fertilizer → forestry has been built by the project members for the study of more than three years. The high efficiency standardization cultivation techniques of edible fungi has been introduced, demonstrated and promoted. Also, the recycling technology of fungus chaff has been researched and promoted. All of these technologies have reduced the environment pollution of waste fungus chaff and promoted the sustained and healthy development of the edible fungus industry.

Study on the Intelligent Monitoring System for the Industrialized Producing Environment of Edible Fungus Based on the Internet of Things

The edible fungus industry has relatively high output rate and high added value. In the production of edible fungus, the environmental factors have great impacts. This paper studies the intelligent monitoring system for producing environment of the factory-farmed edible fungus based on the internet of things and aiming at online real-time management. The monitoring system can realize real-time surveillance and visual operation during production by dynamically regulating the environmental factors needed for growing edible fungus and early warning of the environmental parameters fluctuation with traceable history records at any time. When parameters like temperature and humidity are beyond reasonable range, warning will be sent via text messages and equipments such as air conditioners and warming devices will be automatically adjusted for on and off so as to raise management level, increase the output, improve the quality and lower the risks.

Income generation from wild mushrooms in marginal rural areas

Harvesting wild edible fungi for recreation, home consumption or to supply small local markets has traditionally been a popular activity in rural Finland. Yet some species, such as ceps ( Boletus edulis) and pine boletes ( Boletus pinophilus), which are well appreciated in Southern Europe, were not exploited commercially. In the past decade, international trade in previously unused mushroom resources has increasingly provided rural communities with additional earning opportunities. In this article we document the emergence in Eastern Finland of a wild edible fungi industry, describe its value chain, and assess its significance as a source of income for disadvantaged rural dwellers. The data for the analysis were collected through interviews with the management of Finland's largest wild mushroom business, and an extensive survey of the pickers who supply the company.

Indoor composting of vine by-products to produce substrates for mushroom cultivation

This paper describes a new technique for producing high quality, low cost organic substrates for use in the cultivation of the most widely consumed edible mushroom, Agaricus bisporus (Lange) Imbach. With production, economic and environmental concerns in mind, the aim of this work was to provide fresh impetus to the edible fungus industry by introducing alternative materials to those traditionally used in substrate production: in this case waste products from grape growing and wine making (vine shoots, grape stalks and grape pomace). These were composted under controlled conditions. While no more biologically efficient than traditional compost, the agronomic assessment of the alternative indoor substrates (performed using different proportions of grape stalks and vine shoots as base materials and using two varieties of Agaricus bisporus) showed them to be economically viable (their use reduces costs) and environmentally advantageous (their use reduces the emission of volatile compounds).