Lentinus crinitus basidiocarp stipe and pileus: chemical composition, cytotoxicity and antioxidant activity

Lentinus crinitus: Traditional use, phytochemical and pharmacological activities, and industrial and biotechnological applications

The saprophytic basidiomycete Lentinus crinitus (L.) Fr is a Brazilian native fungus with pantropical occurrence. L. crinitus produces edible fruiting bodies with medicinal, nutritional, and biotechnological applications. The compounds from fungal fruiting bodies can be applied to the preparation of products in the food, cosmetic, biomedical, and pharmaceutical industries. Our aim was to review the literature on L. crinitus concerning its botanical description, geographical distribution, phytochemistry, pharmacological properties, nutritional value, and biotechnology potential (in vitro cultivation and enzyme production). Scientific search engines, including ScienceDirect, CAPES Journals Portal, Google Scholar, PubMed, SciELO, MEDLINE, LILACS, and SciFinder, were consulted to gather data on L. crinitus. The present review is an up-to-date and comprehensive analysis of the phytochemical compounds, phytopharmacological activities, and biotechnological value of L. crinitus. Extracts from L. crinitus have been reported to exhibit numerous in vitro pharmacological activities such as antioxidant, antifungal, antibacterial, antiviral, and anticancer. The substances in these extracts belong to different classes of chemical compounds such as polysaccharides, fatty acids, terpenes, phenolic acids, and flavonoids. Reviews on Brazilian native fungi are of great importance for scientific knowledge, with great applicability as a mirror for species of the same family. The ethnobotanical, phytochemical, pharmacological, ethnomedicinal, and biotechnological properties of L. crinitus highlighted in this review provide information for future studies and commercial exploitation, and reveal that this fungus has enormous potential for pharmaceutical, nutraceutical, biotechnological, and ecological applications.

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.

Occurrence, Biological and Enzymatic Activities of Agaricomycetes from the Brazilian Amazon - A Systematic Review

Agaricomycetes are highlighted for producing a variety of compounds and enzymes with nutritional and medicinal properties. However, the knowledge of the diversity of this group of fungi is still insufficient, as well as their biological and enzymatic activities. Thus, the objective of this work is to describe the occurrence, biological and enzymatic activities of Agaricomycetes from the Brazilian Amazon. The present study is a systematic review with the literature search done in the following databases: Scielo, Google Scholar, PubMed and ScienceDirect. The descriptors used were Basidiomycota, Agaricomycetes, mushroom, antimicrobial activity, antitumor activity, antioxidant activity, anti-inflammatory activity, immunomodulator, enzymatic activity, and Brazilian Amazon. We used as inclusion criteria articles in Portuguese and English, published between 2010 and 2021 and that had the full text available and presented relevance to the exposed topic, and as exclusion criteria, works not done in the Brazilian Amazon, duplicate articles in the databases search or outside the topic under study. A total of 40 articles, published between 2010 and 2021, were selected for analysis. 230 species of Agaricomycetes fungi were described for the Brazilian Amazon, with the most frequent orders being Polyporales (52.60%), Agaricales (14.35%), and Hymenochaetales (13.91%). Six studies were found on antimicrobial activity for promising Agaricomycete fungi against the bacteria Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and the fungi Candida albicans, C. parapsilosis and C. tropicalis. For the antioxidant activity, a study described the species Lentinus citrinus with high amounts of antioxidant compounds. For enzymatic activity, five studies reported Agaricomycete fungi producing protease, cellulase, amylase, pectinase, laccase, and xylanase enzymes. This review shows the scarcity of studies on the description and technological potential of Agaricomycetes from the Brazilian Amazon, highlighting the need to encourage the study of this group of organisms.

Lithium bioaccumulation in Lentinus crinitus mycelia grown in media with different lithium sources and pH values

Lentinus crinitus bioaccumulates lithium in mycelia, but bioaccumulation may be affected by pH of the culture medium. Lithium is used in clinical practice as a mood stabilizer and antidepressant. This study aimed to assess the effect of culture medium pH and lithium source (LiCl or Li₂CO₃) on lithium bioaccumulation in vegetative mycelia of L. crinitus grown in malt extract broth. Lentinus crinitus U9-1 was cultured in malt extract broth supplemented with Li₂CO₃ or LiCl (50 mg L^-1 lithium) in the pH range of 3.0 to 6.0. The pH was adjusted using HCl solution. The results showed that medium pH affected mycelial biomass production, lithium bioaccumulation in mycelial biomass, and lithium transfer from the culture medium to mycelial biomass. The effect of lithium source on the bioaccumulation capacity of mycelial biomass varied according to pH. At pH 4.0, both lithium sources stimulated mycelial biomass production compared to the control without the addition of lithium. At pH 5.5, Li₂CO₃ provided the highest lithium bioaccumulation in mycelial biomass. Lithium transfer from the culture medium to mycelia was highest in Li₂CO₃-supplemented cultures at pH 4.5. LiCl reduced hyphal width compared with Li₂CO₃ and the control. However, pH and lithium sources did not affect the formation of clamp connections in hyphae. For the first time, the influence of the pH of the culture medium on lithium bioaccumulation by Lentinus crinitus is reported. Finally, we conclude that the culture medium pH affected lithium transfer and bioaccumulation in mycelial biomass differently depending on the lithium source. Additionally, we report the presence of clamp connections in the hyphae of L. crinitus as an indicator of even growth.

Light conditions affect the growth, chemical composition, antioxidant and antimicrobial activities of the white-rot fungus Lentinus crinitus mycelial biomass

The mycelial biomass of basidiomycetes is a promising source of compounds and represents an alternative for industrial and biotechnological applications. Fungi use light as information and hold photoresponse mechanisms, in which sensors respond to light wavelengths and regulate various biological processes. Therefore, this study aimed to investigate the effects of blue, green, and red lights on the growth, chemical composition, and antioxidant and antimicrobial activity of Lentinus crinitus mycelial biomass. The chemical composition of the mycelial biomass was determined by chromatographic methods, antioxidant activity was analyzed by in vitro assays, and antimicrobial activity was investigated by the microdilution assay. The highest mycelial biomass yield was observed under blue-light cultivation. Many primordia arose under blue or green light, whereas the stroma was formed under red light. The presence of light altered the primary fungal metabolism, increasing the carbohydrate, tocopherol, fatty acid, and soluble sugar contents, mostly mannitol, and reducing the protein and organic acid concentrations. Cultivation under red light increased the phenol concentration. In contrast, cultivation under blue and green lights decreased phenol concentration. Benzoic and gallic acids were the main phenolic acids in the hydroalcoholic extracts, and the latter acids increased in all cultures under light, especially red light. Mycelial biomass cultivated under red light showed the highest antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The ferric reducing antioxidant power (FRAP) method showed that all light wavelengths increased the antioxidant activity of mycelial biomass, with the highest value under red light. Moreover, the β-carotene/linoleic acid co-oxidation (BCLA) assay demonstrated that the antioxidant activity was affected by light cultivation. Mycelial biomass grown under all conditions exhibited antibacterial and antifungal activities. Thus, mycelial biomass cultivation of L. crinitus under light conditions may be a promising strategy for controlling the mycelial chemical composition and biomass yield.

Long-term cryopreservation of Lentinus crinitus strains by wheat grain technique

Lentinus crinitus (Basidiomycota: Polyporales) is a saprophytic fungus with biotechnological importance described more than 20 years ago. However, there are few studies on the long-term preservation of this basidiomycete. Cryopreservation is a long-term storage technique that reduces the metabolic activity of microorganisms, but its success depends on the adjustment of the freezing process, the cryoprotectants, and the protective substrates for each species. This study aimed to assess the mycelial viability and genetic stability of L. crinitus strains cryopreserved at -86 °C for two years by the wheat grain technique using different cryoprotectants and freezing methods. Three strains of L. crinitus (U9-1, U13-5, and U15-12) were subjected to different concentrations and types of cryoprotectants (dimethyl sulfoxide, glycerol, glucose, and sucrose), freezing methods such as immediate freezing from 25 to -86 °C and progressing freezing from 25 to -86 °C in a freezing container with isopropyl alcohol to control the rate of cell freezing at -1 °C min^-1, protective substrate (wheat grain and 2% malt extract agar), and cryopreservation period (1, 6, 12, and 24 months). After thawing, samples were evaluated for mycelial viability, time to mycelial recovery, mycelial stability, and genetic stability of the fungus. All techniques achieved effective cryopreservation at -86 °C, mainly with the wheat grain technique. All cryoprotectants (3.5% glycerol, 1.5% dimethyl sulfoxide, 25% sucrose, and 5% glucose), freezing methods (immediate and gradual), and protective substrate (wheat grain and malt extract agar) were effective for cryopreservation of the three L. crinitus strains in an ultra-low temperature freezer for two years. Mycelial viability, mycelial stability, and genetic stability of the fungus were not affected after two-year cryopreservation, evidencing the robustness of the long-term cryopreservation technique and the fungus.

Proteome Analysis and In Vitro Antiviral, Anticancer and Antioxidant Capacities of the Aqueous Extracts of Lentinula edodes and Pleurotus ostreatus Edible Mushrooms

In this study, we examined aqueous extracts of the edible mushrooms Pleurotus ostreatus (oyster mushroom) and Lentinula edodes (shiitake mushroom). Proteome analysis was conducted using LC-Triple TOF-MS and showed the expression of 753 proteins by Pleurotus ostreatus, and 432 proteins by Lentinula edodes. Bioactive peptides: Rab GDP dissociation inhibitor, superoxide dismutase, thioredoxin reductase, serine proteinase and lectin, were identified in both mushrooms. The extracts also included promising bioactive compounds including phenolics, flavonoids, vitamins and amino acids. The extracts showed promising antiviral activities, with a selectivity index (SI) of 4.5 for Pleurotus ostreatus against adenovirus (Ad7), and a slight activity for Lentinula edodes against herpes simplex-II (HSV-2). The extracts were not cytotoxic to normal human peripheral blood mononuclear cells (PBMCs). On the contrary, they showed moderate cytotoxicity against various cancer cell lines. Additionally, antioxidant activity was assessed using DPPH radical scavenging, ABTS radical cation scavenging and ORAC assays. The two extracts showed potential antioxidant activities, with the maximum activity seen for Pleurotus ostreatus (IC50 µg/mL) = 39.46 ± 1.27 for DPPH; 11.22 ± 1.81 for ABTS; and 21.40 ± 2.20 for ORAC assays. This study encourages the use of these mushrooms in medicine in the light of their low cytotoxicity on normal PBMCs vis à vis their antiviral, antitumor and antioxidant capabilities.