Fungus Pleurotus Research Articles

Isolation of bioactive beta-glucans from mycelium of <i>Pleurotus ostreatus</i> mushroom

Background: Beta-glucan, a compound found in higher fungi, possesses significant properties important for the human body, including immunomodulatory effects. Developing efficient extraction technology is crucial to ensure a high yield of beta-glucan component while preserving its bioactive properties. Context and purpose of this study: This study aimed to evaluate the extraction efficiency of beta-glucans from Pleurotus ostreatus mycelium powder using microwave-assisted extraction and to compare its performance with traditional extraction methods—specifically water and ethyl alcohol-based extractions. Objective: The aim of this study is to increase the yield of the aqueous extract of beta-glucan from the mycelium of the fungus Pleurotus ostreatus, while ensuring its biological activity is preserved for subsequent use in the fortifying food products. To achieve this, various extraction methods were employed. Results: Traditional methods of beta-glucan extraction, including water and ethyl alcohol-based processes, yielded the largest amount of beta-glucan of 1.45 ± 0.02 g of beta-glucan. The stimulation index, a measure of beta-glucans on the human phagocytosis system, reached 1.28 under optimal conditions — double treatment with ethanol followed by a double extraction with water, each extraction lasting three hours. When extracting beta-glucan using microwave radiation, 2.97 g of beta-glucan was obtained—2.05 times greater than traditional methods. The simulation index also improved by 13%, reaching 1.47% while reducing the extraction time. Conclusions: Based on the conducted research, it has been found that the extraction of beta-glucan from the mycelium of the Pleurotus ostreatus fungus is advisable to carry out using microwave processing, which significantly reduces the extraction time while maintaining the biological activity of beta-glucan. Keywords: Basidiomycetes, Pleurotus ostreatus, beta-glucan, water extraction, ethyl alcohol extraction, microwave radiation, immunomodulatory properties.

Disruption of the pkac2 gene in Pleurotus ostreatus alters cell wall structures and enables mycelial dispersion in liquid culture.

In this study, we developed a mycelial dispersion strain by disrupting the pkac2 gene in the white-rot fungus Pleurotus ostreatus. pkac2 is a catalytic subunit gene of protein kinase A, which regulates several transcription factors related to cell wall synthesis. Liquid cultures of the Δpkac2 strains showed very high mycelial dispersibility and were visibly different from the wild-type strain (WT). Although growth on agar medium was slower than that of WT, Δpkac2 strains grew faster in liquid culture and had approximately twice the mycelial dry weight of WT after 5 d of culture. Microscopic observations showed that the cell walls of the Δpkac2 strains were thinner compared to WT. The β-glucan content in the cell walls decreased in the pkac2 disruptants, although the transcription levels of β-glucan synthase genes increased. Furthermore, the Δpkac2 strains showed decreased hydrophobicity and stress tolerance compared to WT. These results indicate that disruption of the pkac2 gene in P. ostreatus alters the structure of the cell wall surface layer, resulting in high-density cultures due to mycelial dispersion.

Treatment of Cigarette Butts: Biodegradation of Cellulose Acetate by Rot Fungi and Bacteria.

This study demonstrated the biodegradation of two different brands of cigarette butts (CBs), which are primarily composed of cellulose acetate, by four distinct microorganisms. These included the white rot fungus Pleurotus ostreatus, the brown rot fungus Lentinus lepideus, and the bacteria Bacillus cereus and Pseudomonas putida. After 31 days of treatment, weight loss measurements revealed a mass loss of 24-34%, where B. cereus exhibited the greatest efficacy in terms of mass loss for both brands of CBs. Fourier-Transform Infrared Spectroscopy (FTIR), confocal microscopy, and scanning electron microscopy (SEM) confirmed changes in the surface of the CBs, attributable to structural wear and material breakdown, indicating effective biodegradation by the evaluated microorganisms. Furthermore, the analyses confirmed changes in the surface of the CBs, attributable to structural wear and material breakdown, indicating effective biodegradation by the evaluated microorganisms.

Purification and characterization of laccase from the white-rot fungus Pleurotus pulmonarius VAST02.42

Purification and characterization of laccase from the white-rot fungus Pleurotus pulmonarius VAST02.42

Reducing Plastic Waste and Generating Bioelectricity Simultaneously through Fuel Cells Using the Fungus Pleurotus ostreatus

Plastic waste, a persistent and escalating issue, and the high costs of installing electric power, particularly in remote areas, have become pressing concerns for governments. This research proposes a novel method for generating electric power from sugarcane bagasse waste and reducing plastic waste. The key to this method is the use of the fungus Pleurotus ostreatus in microbial fuel cells. Microbial fuel cells (MFCs) demonstrated their effectiveness by generating peaks of electric current (4.325 ± 0.261 mA) and voltage (0.427 ± 0.031 V) on day twenty-six, with a pH of 5.539 ± 0.278. The peak electrical conductivity of the substrate was 130.574 ± 4.981 mS/cm. The MFCs were able to reduce the chemical oxygen demand by 83%, showing a maximum power density of 86.316 ± 4.724 mW/cm2 and an internal resistance of 37.384 ± 62.522 Ω. The infrared spectra of the plastic samples showed a decrease in the peaks 2850–2920, 1470, and 720 cm−1, which are more characteristic of plastic, demonstrating the action of the Pleurotus ostreatus fungus on the plastic samples. Also, the micrographs taken by SEM showed the reduction in the thickness of the plastic film by 54.06 µm and the formation of microstructures on the surface, such as pores and raised layers of the sample used.

Production of milk-coagulating protease by fungus Pleurotus djamor through solid state fermentation using wheat bran as the low-cost substrate

Proteases are enzymes that hydrolyze peptide bonds present in proteins and peptides. They are widely used for various industrial applications, such as in the detergent, food, and dairy industries. Cheese is one of the most important products of the dairy industry, and the coagulation stage is crucial during the cheese-making process. Enzymatic coagulation is the most common technique utilized for this purpose. Microbial enzymes are frequently used for coagulation due to their advantages in terms of availability, sustainability, quality control, product variety, and compliance with dietary and cultural/religious requirements. In the present study, we identified and subsequently characterized milk coagulant activity from the fungus Pleurotus djamor PLO13, obtained during a solid-state fermentation process, using the agro-industrial residue, wheat bran, as the fermentation medium. Maximum enzyme production and caseinolytic activity occurred 120 h after cultivation. When the enzyme activity against various protease-specific synthetic substrates and inhibitors was analyzed, the enzyme was found to be a serine protease, similar to elastase 2. This elastase-2-like serine protease was able to coagulate pasteurized whole and reconstituted skim milk highly efficiently in the presence and absence of calcium, even at room temperature. The coagulation process was influenced by factors such as temperature, time, and calcium concentration. We demonstrate here, for the first time, an elastase-2-like enzyme in a microorganism and its potential application in the food industry for cheese production.

Mitochondrial targeted modification and anticancer mechanism of natural product ergosterol peroxide

Ergosterol peroxide (EP) isolated from the edible medicinal fungus Pleurotus ferulae has a wide range of anti-tumor activity, but poor water solubility and low bioavailability limit further application. In this study, EP was structurally modified using triphenylphosphine (TPP+), which combines mitochondrial targeting, amphiphilicity, and cytotoxicity. A series of TPP+-conjugated ergosterol peroxide derivatives (TEn) with different length linker arms were synthesized. The structure–activity relationship showed that the anticancer activity of TEn gradually decreased with the elongation of the linker arm. The compound TE3 has the optimal and broadest spectrum of antitumor effects. It mainly through targeting mitochondria, inducing ROS production, disrupting mitochondrial function, and activating mitochondria apoptosis pathway to exert anti-cervical cancer activity. Among them, TPP+ only acted as a mitochondrial targeting group, while EP containing peroxide bridge structure served as an active group to induce ROS. In vivo experiments have shown that TE3 has better anti-cervical cancer activity and safety than the first-line anticancer drug cisplatin, and can activate the immune response in mice. Although TE3 exhibits some acute toxicity, it is not significant at therapeutic doses. Therefore, TE3 has the potential for further development as an anti-cervical cancer drug.

Crystal Structure of the Native Chromoprotein from Pleurotus salmoneostramineus Provides Insights into the Pigmentation Mechanism.

The pink-colored protein from the fungus Pleurotus salmoneostramineus (PsPCP) possesses unusual primary sequences with little resemblance to those of known proteins and exhibits a red color in aqueous solution. To understand the pigmentation mechanism of PsPCP, we elucidated the X-ray crystal structure of the native PsPCP. We identified a highly conjugated polyene ligand 2-dehydro-3-deoxylaetiporic acid A as a chromophore ligand, whose solution exhibits yellow. The crystal structure of PsPCP indicated that the ligand is secured in the central cavity and anchored at both termini by hydrophilic interactions and that surrounding residues show CH-pi and C-H···O hydrogen bondings. Geometrical analyses of the bound ligand demonstrated that the conjugated C-C and C═C bonds exhibit similar bond distances. The result indicated enhanced electron delocalization within the conjugated CC bond system, resulting in a redshift of the chromophore ligand. The computational estimates of the UV-vis spectra support the view that the electron delocalization within the conjugated CC bonds system of the bound ligand, induced by the specific ligand geometry within a limited space of PsPCP cavity, is responsible for the red pigmentation of PsPCP. Thus, we propose that the coloring mechanism of PsPCP, which constrains the geometry of a highly conjugated polyene ligand, is a novel type of pigment chemistry.

Evidence of Cooperative Interactions between Rhizobacteria and Wood-Decaying Fungi and Their Effects on Maize Germination and Growth

Advances in soil microbial communities are driving agricultural practices towards ecological sustainability and productivity, with engineering microbial communities significantly contributing to sustainable agriculture. This study explored the combined effects of two white-rot fungi (Trametes sp. and Pleurotus sp.) and six rhizobacterial strains belonging to four genera (Acinetobacter sp., Enterobacter sp., Flavobacterium sp., and Pseudomonas sp.) on maize growth and soil enzymatic activity over a 14-day period. At the plant level, germination, fresh and dry mass of the aerial and root parts, length, and stage of development of the stem, as well as the chlorophyll content, were evaluated. Furthermore, soil dehydrogenase, acid and alkaline phosphatases, pH, and electrical conductivity were evaluated. Rot fungi induced distinct effects on maize germination, with Pleurotus sp. strongly suppressing maize germination by 40% relative to that of the control. The isolated bacterial strains, except Enterobacter sp. O8, and 8 of the 12 fungus + bacterial strain combinations induced germination rates higher than those of the control (≥40%). Combinations of Flavobacterium sp. I57 and Pseudomonas sp. O81 with the rot fungus Pleurotus sp. significantly improved plant shoot length (from 28.0 to 37.0 cm) and developmental stage (fourth leaf length increase from 10.0 to 16.8 cm), respectively, compared with the same bacteria alone or in combination with the rot fungus Trametes sp. In the soil, the presence of both fungi appeared to stabilize phosphatase activity compared to their activity when only bacteria were present, while also promoting overall dehydrogenase enzymatic activity in the soil. Integrating all parameters, Trametes sp. rot fungus + Enterobacter sp. O8 may be a potential combination to be explored in the context of agricultural production, and future studies should focus on the consistency of this combination’s performance over time and its effectiveness in the field.

Evaluation of agricultural waste, as a substrate for the artisanal production of the Oyster Mushroom (Pleurotus Ostreatus)

Pleurotus ostreatus is one of the most consumed edible mushrooms worldwide, in Ecuador, there is not much information on the use of agricultural residues that serve as optimal substrates, nor agroclimatic adaptations of the artisanal cultivation of this fungus. The objective of this work was to evaluate different agricultural residues, as a substrate for the artisanal production of the oyster mushroom (Pleurotus ostreatus) in the community of Carmen, Loja, Ecuador. For the development of this work, three treatments with five replicates for each treatment were evaluated, the treatments were evaluated on agricultural residues of: cane bagasse (T1), coffee husk (T2) and rice chaff (T3), the variables that were measured were: earliness, biological efficiency and production rate. The statistical design used was a completely randomized design statistically evaluated by means of an ANOVA with the statistical program R. The results indicated that for the treatment with sugar cane bagasse (T1) the earliness found was between 34 and 44 days, obtaining an average production of 25% and biological efficiency 15%. For the cultivation of the fungus in the coffee husk residues (T2), growth problems were observed; in the treatment with rice chaff (T3) it presented an earliness between 52 and 81 days with an average production rate of 3.2% and an average biological efficiency of 2%. Concluding that cane bagasse is the most recommended agricultural residue for the cultivation of the fungus Pleurotus ostreatus in the community of Carmen, Loja Ecuador.

Effect of mushroom crop residue on growth performance, carcass traits, nutrient digestibility, nitrogen balance, ingestive behavior, ruminal and blood parameters of lambs

Using agricultural wastes as substrates of mushroom cultivation can minimize environmental pollution and provide a high-quality substrate that might be used for animal feeding after cultivation, which is beneficial for ruminants. Three experiments were conducted to evaluate the nutritional value of cultivated mushroom residue in lamb diets. Seven inoculation times (0, 5, 10, 15, 20, 25, and 30 days of cultivation) of mushroom substrates by Pleurotus ostreatus were evaluated in a completely randomized design with five replications to characterize the mushroom crop substrate. Within 30 days of cultivation, the mushroom crop residue (MCR) was sun-dried and tested on the lambs’ diet. The first experiment involved 40 uncastrated crossbred lambs (Santa Ines × Dorper), with a mean body weight (BW) of 27.8 ± 2.37 kg (mean ± SD), which were randomly assigned to five groups of six lambs each. They received five levels of MCR replacing Tifton-85 hay: 0, 25, 50, 75, and 100 % on dry matter basis (DM) to evaluate performance, carcass traits, ingestive behavior, and blood parameters. In the second experiment, 25 lambs (40.0 ± 3.0 kg BW) were distributed in metabolic cages in a completely randomized design with the same five treatments of experiment 1 (MRC replacing Tifton-85 hay) and six replications to determine nutrient digestibility and nitrogen balance. To evaluate ruminal parameters, a third experiment was conducted with five Santa Ines × Dorper crossbreed rumen-cannulated sheep weighing 42.0 ± 4.0 kg, which were distributed in a 5 × 5 Latin square. After 30 days of cultivation of the fungus Pleurotus ostreatus, there was a reduction in the MCR contents of DM, ether extract (EE), and non-fiber carbohydrates (NFC). In contrast, ash, crude protein (CP), neutral detergent fiber expressed exclusive of residual ash (aNDF), acid detergent fiber (ADF), and in vitro DM digestibility coefficient (IVDMD) increased (P ≤ 0.05) over the cultivation time. The intake of DM, CP, aNDF and NFC quadratically increased (P ≤ 0.05) with the addition of dehydrated MCR in the lambs’ diet. The effective consumed CP composition and the digestibility coefficient of DM, CP, and aNDF decreased linearly (P ≤ 0.05) due dehydrated MCR addition in the lambs’ diet. The time spent eating and idling, and the rumination efficiency rates (g DM and NDF/h) increased linearly (P ≤ 0.05) with the replacement of Tifton-85 hay by the dehydrated MCR. The time spent on rumination and chewing, the nº of boli chewed, and the DM intake efficiency rate reduced linearly (P ≤ 0.05). There was a linear (P ≤ 0.05) increase in N-intake, N-fecal, and N-retention and linear reduction (P ≤ 0.05) in N-urinary excretion and rumen protozoa count due to the inclusion of MCR in the lambs’ diet. Growth performance, carcass traits, rumen pH, ammonia nitrogen (NH3-N), and blood parameters were not changed by the replacement of hay with MCR. Dehydrated mushroom crop residue inclusion at 75 % of total DM replacing Tifton-85 hay in lambs’ diet is recommended because it improves rumination efficiency, and N-retention without any negative effect on rumen pH, blood metabolites, and carcass traits.

Biodegradation of Trichloroethylene by Trametes versicolor and its Physiological Response to Contaminant Stress.

Trichloroethylene (TCE) poses a potentially toxic threat to humans and the environment and widely exists in contaminated sites. White rot fungi effectively degrade refractory pollutants, while a few research studies use white rot fungi to degrade TCE. In this study, we investigated TCE biodegradation by white rot fungi and the potential influencing factors in the environment and attempted to research the effect of TCE on the physiological characteristics of white rot fungi. White rot fungi (Trametes versicolor, Pseudotrametes gibbosa, Pycnoporus sanguines and Pleurotus ostreatus) were added to the liquid medium for shock culture. The results revealed that T. versicolor exhibited the most pronounced efficacy in removing TCE, with a degradation rate of 81.10% within a 7 d period. TCE induces and is degraded by cytochrome P450 enzymes. High pH and Cr(VI) adversely affected the effectiveness of the biodegradation of TCE, but the salinity range of 0-1% had less effect on biodegradation. Overall, the effectiveness of degradation of TCE by T. versicolor has been demonstrated, and it provides a reference for the application prospects of white rot fungi in TCE-contaminated soils.

Functional analysis of basidiomycete specific chitin synthase genes in the agaricomycete fungus Pleurotus ostreatus

Chitin is an essential structural component of fungal cell walls composed of transmembrane proteins called chitin synthases (CHSs), which have a large range of reported effects in ascomycetes; however, are poorly understood in agaricomycetes. In this study, evolutionary and molecular genetic analyses of chs genes were conducted using genomic information from nine ascomycete and six basidiomycete species. The results support the existence of seven previously classified chs clades and the discovery of three novel basidiomycete-specific clades (BI–BIII). The agaricomycete fungus Pleurotus ostreatus was observed to have nine putative chs genes, four of which were basidiomycete-specific. Three of these basidiomycete specific genes were disrupted in the P. ostreatus 20b strain (ku80 disruptant) through homologous recombination and transformants were obtained (Δchsb2, Δchsb3, and Δchsb4). Despite numerous transformations Δchsb1 was unobtainable, suggesting disruption of this gene causes a crucial negative effect in P. ostreatus. Disruption of these chsb2–4 genes caused sparser mycelia with rougher surfaces and shorter aerial hyphae. They also caused increased sensitivity to cell wall and membrane stress, thinner cell walls, and overexpression of other chitin and glucan synthases. These genes have distinct roles in the structural formation of aerial hyphae and cell walls, which are important for understanding basidiomycete evolution in filamentous fungi.

Bioconversion of waste of macauba as indication of use for input in animal feeds

Acrocomia aculeata, belonging to the Arecaceae family, a palm tree known locally as macauba or bocaiuva, displays potential for obtaining vegetable oil with application in the production of biofuels, food and pharma-ceuticals. The objective of this work was to improve the nutritional aspects of macauba residues by myceliation by the fungi Pleurotus ostreatus and Pleurotus sajor-caju. The extraction of its oils (from the pulp and the kernel) generates residue, the most interesting being the bran or cakes. In this study, macauba’s kernel and pulp bran, as well as their mixture with parts of the fruit, such as the epicarp, were submitted to the bioconversion treatment with the fungi P. ostreatus and P. sajor-caju. The composition of ash, crude protein, neutral and acid detergent fiber, lignin, cellulose, crude fiber, ether extract and in vitro digestibility were determined, in comparison to the control samples. In all samples there was a considerable increase in ash, protein and digestibility when compared to the control. Among the results obtained, the sample of the mixture of pulp bran and kernel in a 1:1 ratio stands out, which went from roughage to concentrate and was classified as protein. In the kernel bran-pulp bran (1:1) sample, production was carried out until the maturation phase with the fungus P. ostreatus. Fruiting occurred 80 days after the initial mycelium. The biological efficiency of this culture was 34.42%, and the value found for the crude protein of the mushroom produced was 33.11%.

Crude Extracts of Pleurotus Spp. and the Presence of Their Proteins in the Ovicidal and Larvicidal Activity of Haemonchus contortus.

Mushrooms of the genus Pleurotus have shown nematophagous activity as it produces many chemical compounds and enzymes affecting parasitic nematodes. This study aimed to extract the inhibitory activity of the five strains of the fungus Pleurotus spp. It was evaluated against eggs and larvae of Haemonchus contortus. The extract of P. ostreatus obtained the highest level of inhibition of eggs at 97.6% (1341 μg/mL) followed by P. pulmonarius (EPP) at 81.2% (774 μg/mL). The extract selected for evaluation against larvae was P. pulmonarius, showing no effect for L3 larvae, but for L4 larvae an immobility effect of 56.93% was observed at 900 μg/mL. The protein profile showed the presence of 23 protein bands in the extract. The crude extract of P. pulmonarius showed degradation of tissues both inside the eggs and larvae L1. Metabolites produced by Pleurotus mushrooms can consider using in agriculture sustainable by utilizing in producing of ovicidal and larvicidal against H. contortus instead of chemical compounds.

Persistent polycyclic aromatic hydrocarbons removal from sewage sludge-amended soil through phytoremediation combined with solid-state ligninolytic fungal cultures

Polycyclic aromatic hydrocarbons (PAHs) are widely present in the environment, causing increasing concern because of their impact on soil health, food safety and potential health risks. Four bioremediation strategies were examined to assess the dissipation of PAHs in agricultural soil amended with sewage sludge over a period of 120 days: soil-sludge natural attenuation (SS); phytoremediation using maize (Zea mays L.) (PSS); mycoremediation (MR) separately using three white-rot fungi (Pleurotus ostreatus, Phanerochaete chrysosporium and Irpex lacteus); and plant-assisted mycoremediation (PMR) using a combination of maize and fungi. In the time frame of the experiment, mycoremediation using P. chrysosporium (MR-PH) exhibited a significantly higher (P < 0.05) degradation of total PAHs compared to the SS and PSS treatments, achieving a degradation rate of 52 %. Both the SS and PSS treatments demonstrated a lower degradation rate of total PAHs, with removal rates of 18 % and 32 %, respectively. The PMR treatments showed the highest removal rates of total PAHs at the end of the study, with degradation rates of 48–60 %. In the shoots of maize, only low- and medium-molecular-weight PAHs were found in both the PSS and PMR treatments. The calculated translocation and bioconversion factors always showed values < 1. The analysed enzymatic activities were higher in the PMR treatments compared to other treatments, which can be positively related to the higher degradation of PAHs in the soil.

Copper removal from aqueous solutions by white rot fungus Pleurotus ostreatus GEMB-PO1 and its potential in co-remediation of copper and organic pollutants

Addressing the environmental contamination from heavy metals and organic pollutants remains a critical challenge. This study explored the resilience and removal potential of Pleurotus ostreatus GEMB-PO1 for copper. P. ostreatus GEMB-PO1 showed significant tolerance, withstanding copper concentrations up to 2 mM. Its copper removal efficiency ranged from 64.56 % at 0.5 mM to 22.90 % at 8 mM. Transcriptomic insights into its response to copper revealed a marked upregulation in xenobiotic degradation-related enzymes, such as laccase and type II peroxidases. Building on these findings, a co-remediation system using P. ostreatus GEMB-PO1 was developed to remove both copper and organic pollutants. While this approach significantly enhanced the degradation efficiency of organic contaminants, it concurrently exhibited a diminished efficacy in copper removal within the composite system. This study underscores the potential of P. ostreatus GEMB-PO1 in environmental remediation. Nevertheless, further investigation is required to optimize the simultaneous removal of organic pollutants and copper.

Copper increases laccase gene transcription and extracellular laccase activity in Pleurotus eryngii KS004.

The white-rot fungus Pleurotus eryngii secretes various laccases involved in the degradation of a wide range of chemical compounds. Since the laccase production is relatively low in fungi, many efforts have been focused on finding ways to increase it, so in this study, we investigated the effect of copper on the transcription of the pel3 laccase gene and extracellular laccase activity. The results indicate that adding 0.5 to 2 mM copper to liquid cultures of P. eryngii KS004 increased both pel3 gene transcription and extracellular laccase activity in a concentration-dependent manner. The most significant increase in enzyme activity occurred at 1 mM Cu2+, where the peak activity was 4.6 times higher than in control flasks. Copper also induced the transcription of the laccase gene pel3. The addition of 1.5 and 2 mM Cu2+ to fungal culture media elevated pel3 transcript levels to more than 13-fold, although the rate of induction slowed down at Cu2+ concentrations higher than 1.5 mM. Our findings suggest that copper acts as an inducer in the regulation of laccase gene expression in P. eryngii KS004. Despite its inhibitory effect on fungal growth, supplementing cultures with copper can lead to an increased extracellular laccase production in P. eryngii.

Label-free comparative proteomic analysis of Pleurotus eryngii grown on sawdust, bagasse, and peanut shell substrates

The white rot fungi Pleurotus eryngii are environmental microorganisms that can effectively break down lignocellulosic biomass. However, understanding of the mechanisms by which P. eryngii is effective in degrading lignocellulose is still limited. This work aimed to examine the extracellular secretory proteins implicated in the breakdown of lignocellulose in P. eryngii and identify degradation tactics across various cultivation substrates. Thus, a comparative analysis of the secretory proteins based on Nanoliquid chromatography combined with tandem mass spectrometry was conducted among P. eryngii cultivated on sawdusts, bagasse, peanut shells, and glucose. In total, 647, 616, 604, and 511 proteins were identified from the four samples, respectively. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis of protein expression differences identified pathways (hydrolytic enzymes, catalytic activity, metabolic processes, cellular processes, and response to stimuli) significantly enriched in proteins associated with lignocellulose degradation in P. eryngii. An integrated analysis of proteome data revealed specifically or differentially expressed genes secreted by P. eryngii in different cultivation substrates. The most prevalent carbohydrate-active enzymes involved in lignocellulose degradation in the secretome of the four samples were laccase (Lac), manganese peroxidase (MnP), aryl alcohol oxidase (AaO), and copper radical oxidase (CRO). Among them, Lac 2 mainly involved in the lignin degradation of sawdust peanut shells, and bagasse by P. eryngii, and Mnp 3 was mainly involved in the degradation of peanut shells. AaO and Lac 4 were mainly involved in glucose substrate defense and oxidative stress. It was found that exogenous addition of sawdust and peanut shells significantly increased lignolytic enzyme abundance. These findings provide insight and guidance for improving agricultural waste resource recovery.In this study, the secretomes of P. eryngii grown on four different carbon sources were compared. The findings revealed the extracellular enzymes implicated in the degradation of lignocellulose, offering avenues for further investigation into the biotransformation mechanisms of P. eryngii biomass and the potential utilization of agricultural wastes. SignificanceThe cost of the substrate for mushroom cultivation has increased as the production of edible fungus has risen year after year. Therefore, the use of these locally available lignocellulosic wastes as substrates offers a cost-cutting option.Further, the overuse of wood for the cultivation of edible mushrooms is also detrimental to the conservation of forest resources or the ecological environment.Consequently, the use of other agricultural wastes as an alternative to sawdust or other woody substrates is a viable approach for cultivating P. eryngii.The distribution of extracellular lignocellulosic degrading enzymes, inferred in the present study could help improve the cultivation efficiency of P. eryngii vis-à-vis managing agricultural waste.

Induction of Extracellular Hydroxyl Radicals Production in the White-Rot Fungus Pleurotus eryngii for Dyes Degradation: An Advanced Bio-oxidation Process.

Among pollution remediation technologies, advanced oxidation processes (AOPs) are genuinely efficient since they are based on the production of strong, non-selective oxidants, mainly hydroxyl radicals (·OH), by a set of physicochemical methods. The biological counterparts of AOPs, which may be referred to as advanced bio-oxidation processes (ABOPs), have begun to be investigated since the mechanisms of induction of ·OH production in fungi are known. To contribute to the development of ABOPs, advanced oxidation of a wide number of dyes by the white-rot fungus Pleurotus eryngii, via a quinone redox cycling (QRC) process based on Fenton's reagent formation, has been described for the first time. The fungus was incubated with 2,6-dimethoxy-1,4-benzoquinone (DBQ) and Fe3+-oxalate, with and without Mn2+, leading to different ·OH production rates, around twice higher with Mn2+. Thanks to this process, the degradative capacity of the fungus increased, not only oxidising dyes it was not otherwise able to, but also increasing the decolorization rate of 20 dyes by more than 7 times in Mn2+ incubations. In terms of process efficacy, it is noteworthy that with Mn2+ the degradation of the dyes reached values of 90-100% in 2-4 h, which are like those described in some AOPs based on the Fenton reaction.