Multifunctions of Pleurotus sajor-caju (Fr.) Singer: A highly nutritious food and a source for bioactive compounds

The yield, nutritional value, umami components and mineral contents of the first-flush and second-flush Pleurotus pulmonarius mushrooms grown on three forestry wastes

This study was carried out to evaluate the yields and quality of the first-flush and second-flush Pleurotus pulmonarius mushrooms grown on three forestry wastes (pine, poplar, and honeysuckle rattan). The biological efficiency (BE) of the substrates varied from 61.89% to 81.01%. The total protein content, gamma-aminobutyric acid (GABA) content and equivalent umami concentration (EUC) values of the mushrooms were greatly influenced by the flush number and the substrate, however, the total sugar content and ergosterol content of the mushrooms were not significantly affected. The first-flush mushrooms that were grown on the pine sawdust-based substrate had the highest protein content, and the first-flush mushrooms that were grown on the honeysuckle rattan sawdust-based substrate had the highest GABA content and EUC values. All the mushroom samples accumulated Cu but excluded Ca, Mn, Pb, Cr, and Cd, and the concentrations of Mg, Fe, and Mn are species and flush number dependent.

Evaluation of Volatile Profile and In Vitro Antioxidant Activity of Fermented Green Tea Infusion With Pleurotus sajor-caju (Oyster Mushroom)

Green tea has distinct astringency, bitter taste, and typical green flavor because of its post-harvest treatment without withering and enzymatic oxidation. Microbial fermentation has been identified as a promising strategy that could give green tea infusion a special taste flavor. This might be linked to the metabolic transformation ability of microorganisms. In this study, starter culture of edible mushroom Pleurotus sajor-caju (oyster mushroom) was used for submerged fermentation of green tea infusion in order to improve its flavor and taste quality. The volatile profile determined by headspace solid-phase microextraction, coupled with gas chromatography mass spectrometry, showed that the contents of (Z)-2-penten-1-ol and methyl heptadienone in green tea infusion were decreased significantly by the fermentation with the basidiomycete P. sajor-caju (p < 0.01), which would alleviate the herbal and grass flavor of green tea infusion to a certain extent. Meanwhile, the contents of linalool and geraniol were increased 9.3 and 11.3 times, respectively, whereas methyl salicylate was newly produced after fermentation by P. sajor-caju, endowing the fermented tea infusion with a pleasant flower and fruit aroma. In addition, the polyphenol profile was determined using high-performance liquid chromatography equipped with ion trap mass spectrometry, and the results indicated that the contents of most polyphenols in green tea infusion decreased significantly after fermentation by P. sajor-caju. The reduction of catechins and anthocyanins in fermented green tea infusion alleviated the astringency and bitterness. Moreover, the antioxidant activity of fermented green tea infusion was obviously decreased, especially the DPPH-free radical-scavenging ability and the ferric-reducing power. However, it is noteworthy that the ABTS-free radical scavenging ability was improved compared with the unfermented one, indicating that the increased tea pigments and volatile metabolites (such as linalool and geraniol) after fermentation with P. sajor-caju may also contribute to the antioxidant capacity of fermented green tea infusion. Overall, the innovative approach driven by P. sajor-caju fermentation has achieved promising potential to manipulate the green tea flavor.

Pro-Health and Anti-Cancer Activity of Fungal Fractions Isolated from Milk-Supplemented Cultures of Lentinus (Pleurotus) Sajor-caju

The present study aimed to demonstrate Lentinus (formerly Pleurotus) sajor-caju (PSC) as a good source of pro-health substances. It has also shown that supplementation of its culture medium with cow milk may further improve its beneficial properties. Intracellular fractions from fungi grown on a medium supplemented with cow milk were analyzed using various biochemical methods for determination of the nutrient composition. Furthermore, anti-cancer properties of selected extracts were investigated on colorectal cancer cell lines (HT-29, LS 180, and SW948) in vitro. Biochemical analysis showed enrichment in health-enhancing compounds, such as proteins or polysaccharides (about 3.5- and 4.5-fold increase in concentration of proteins and carbohydratesin extracts of mycelia cultured on whole milk (PSC2-I), respectively), with a decrease in the level of free radicals (10-fold decrease in extract grown on milk and medium mixture (1:1) (PSC3-II)), which was related to increased catalase and superoxide dismutase activity (7.5-fold increase in catalase activity and 5-fold in SOD activity in PSC3-II compared to the control). Moreover, the viability of the cancer cells was diminished (to 60.0 ± 6.8% and 40.0 ± 8.6% of the control, on HT-29 and SW948 cells, respectively), along with pro-apoptotic (to 18.8 ± 11.8 and 14.7 ± 8.0% towards LS 180 and SW948 cells, respectively) and NO-secreting effects (about 2-fold increase) of the extracts. This study suggests that PSC has multiple nutritional and anti-cancer properties and can be used as a source of healthy biomolecules in modern medicine or functional foods.

Novel Treatments and Preventative Strategies Against Food-Poisoning Caused by Staphylococcal Species

Staphylococcal infections are a widespread cause of disease in humans. In particular, S. aureus is a major causative agent of infection in clinical medicine. In addition, these bacteria can produce a high number of staphylococcal enterotoxins (SE) that may cause food intoxications. Apart from S. aureus, many coagulase-negative Staphylococcus spp. could be the source of food contamination. Thus, there is an active research work focused on developing novel preventative interventions based on food supplements to reduce the impact of staphylococcal food poisoning. Interestingly, many plant-derived compounds, such as polyphenols, flavonoids, or terpenoids, show significant antimicrobial activity against staphylococci, and therefore these compounds could be crucial to reduce the incidence of food intoxication in humans. Here, we reviewed the most promising strategies developed to prevent staphylococcal food poisoning.

A Review on Antistaphylococcal Secondary Metabolites from Basidiomycetes

Fungi are a rich source of secondary metabolites with several pharmacological activities such as antifungal, antioxidant, antibacterial and anticancer to name a few. Due to the large number of diverse structured chemical compounds they produce, fungi from the phyla Ascomycota, Basidiomycota and Muccoromycota have been intensively studied for isolation of bioactive compounds. Basidiomycetes-derived secondary metabolites are known as a promising source of antibacterial compounds with activity against Gram-positive bacteria. The continued emergence of antimicrobial resistance (AMR) poses a major challenge to patient health as it leads to higher morbidity and mortality, higher hospital-stay duration and substantial economic burden in global healthcare sector. One of the key culprits for AMR crisis is Staphylococcus aureus causing community-acquired infections as the pathogen develops resistance towards multiple antibiotics. The recent emergence of community strains of S. aureus harbouring methicillin-resistant (MRSA), vancomycin-intermediate (VISA) and vancomycin-resistant (VRSA) genes associated with increased virulence is challenging. Despite the few significant developments in antibiotic research, successful MRSA therapeutic options are still needed to reduce the use of scanty and expensive second-line treatments. This paper provides an overview of findings from various studies on antibacterial secondary metabolites from basidiomycetes, with a special focus on antistaphylococcal activity.

Bacterial Resistance: Antibiotics of Last Generation used in Clinical Practice and the Arise of Natural Products as New Therapeutic Alternatives

Bacterial resistance to therapeutical drugs has been a serious issue over the last decades. In fact, the quick development of resistance mechanisms by the microorganisms has been fatal for millions of people around the world, turning into a public health issue. The major cause of the resistance mechanisms is the overuse of antimicrobials. European countries try to implement mechanisms to overcome antimicrobial resistance in the community through the rational use of antimicrobials. The scientific community has been exhaustively dedicated to the discovering of new, safer and efficient drugs, being the exploitation of natural resources, mainly plants and fungi, considered as a hot topic in the field of antimicrobial agents. Innumerous reports have already shown the promising capacity of natural products or molecules extracted from these natural resources, to act as bacteriostatic and bactericidal agents. More importantly, these natural agents present significantly lower harmful effects. Bearing that in mind, this review aims at giving a contribution to the knowledge about the synthetic antibiotics of the last generation. Moreover, it is intended to provide information about the last advances regarding the discovery of new antimicrobial agents. Thus, a compilation of the chemical characteristics, efficiency, harmful outcomes and resistance mechanisms developed by the microorganisms can be consulted in the following sections together with a critical discussion, in line with the recent approaches. Furthermore, modern strategies for the prospection of novel anti-infective compounds for tackling resistant bacteria have been considered as also a current synopsis of plants and mushrooms with relevant antimicrobial potentials.

The Effects of Fungal Feed Additives in Animals: A Review

As probiotics, fungi enhance animal health and are suitable animal feed additives. In addition to brewing fungi, there are also edible and medicinal fungi. Common fungi utilized in feeding programs include Saccharomyces cerevisiae, Aspergillus oryzae, Pleurotus spp., Antrodia cinnamomea, and Cordyceps militaris. These fungi are rich in glucans, polysaccharides, polyphenols, triterpenes, ergosterol, adenosine, and laccases. These functional components play important roles in antioxidant, anti-inflammatory, anti-obesity, and immune system regulation. As such, fungal feed additives could be of potential use when breeding livestock. In previous studies, fungal feed additives enhanced body weight and egg production in poultry and improved the feed conversion rate. Several mycotoxins can be produced by hazardous fungi but fortunately, the cell walls constituents and enzymes of fungal probiotics can also act to decrease the toxicity of mycotoxins. Overall, fungal feed additives are of value, but their safety and usage must be studied further, including cost-benefit economic analyses.

Mycoremediation of vinasse by surface response methodology and preliminary studies in air-lift bioreactors

This work evaluated the degradation of sugarcane vinasse with the production of biomass by Pleurotus sajor-caju CCB020, considering the combination of temperature and pH effects, using surface response methodology (RSM). A 2² complete central factorial composite experiment was used to analyze the results. The optimum temperature and pH values were respectively 27 °C and 5.6 for maximum decolorization yield and 20 °C and 6.8 for maximum biomass production. In parallel, scale-up experiments under conditions of 30 °C and initial pH 5.0 were evaluated in two different air-lift bioreactors of 7.0 L. Under these conditions, reductions of 53% and 58% in chemical oxygen demand (COD) and 71% and 58% in biological oxygen demand (BOD) were obtained respectively with the concentric tube type air-lift bioreactor with an increased degassing zone and without an increased degassing zone. Under these conditions, this study concluded that the systematic combination of P. sajor-caju and vinasse can be applied in the biodegradation process of refractory compounds contained in vinasse, concomitant to obtaining biomass and laccase and manganese peroxidase enzymes. Due to the good performance of the air-lift bioreactors, they can be used in scale studies in future industrial vinasse applications, besides it is possible to emphasize that different configurations in the bioreactor can affect the efficiency of the process.

Enhancing Activity of Pleurotus sajor-caju (Fr.) Sing β-1,3-Glucanoligosaccharide (Ps-GOS) on Proliferation, Differentiation, and Mineralization of MC3T3-E1 Cells through the Involvement of BMP-2/Runx2/MAPK/Wnt/β-Catenin Signaling Pathway

Osteoporosis is a leading world health problem that results from an imbalance between bone formation and bone resorption. β-glucans has been extensively reported to exhibit a wide range of biological activities, including antiosteoporosis both in vitro and in vivo. However, the molecular mechanisms responsible for β-glucan-mediated bone formation in osteoblasts have not yet been investigated. The oyster mushroom Pleurotus sajor-caju produces abundant amounts of an insoluble β-glucan, which is rendered soluble by enzymatic degradation using Hevea glucanase to generate low-molecular-weight glucanoligosaccharide (Ps-GOS). This study aimed to investigate the osteogenic enhancing activity and underlining molecular mechanism of Ps-GOS on osteoblastogenesis of pre-osteoblastic MC3T3-E1 cells. In this study, it was demonstrated for the first time that low concentrations of Ps-GOS could promote cell proliferation and division after 48 h of treatment. In addition, Ps-GOS upregulated the mRNA and protein expression level of bone morphogenetic protein-2 (BMP-2) and runt-related transcription factor-2 (Runx2), which are both involved in BMP signaling pathway, accompanied by increased alkaline phosphatase (ALP) activity and mineralization. Ps-GOS also upregulated the expression of osteogenesis related genes including ALP, collagen type 1 (COL1), and osteocalcin (OCN). Moreover, our novel findings suggest that Ps-GOS may exert its effects through the mitogen-activated protein kinase (MAPK) and wingless-type MMTV integration site (Wnt)/β-catenin signaling pathways.

Extracción de sustancias bioactivas de <i>Pleurotus ostreatus</i> (Pleurotaceae) por maceración dinámica

La extracción de compuestos bioactivos de Pleurotus ostreatus por maceración dinámica, es un proceso sencillo y económico, que normalmente presenta baja eficiencia. El objetivo de este trabajo fue evaluar el proceso de extracción para determinar qué tratamiento permite la mayor eficiencia, analizando la influencia de los factores de estudio: concentración de etanol (50 %, 80 %, 95 %) y relación sólido/solvente (1:10, 1:20, 1:30). Se maceraron 5 g de polvo fúngico en etanol acuoso durante 90 minutos, a 150 rpm, 25 °C y tamaño de partícula de 0,5 a 1,0 mm. Se trataron los datos mediante estadística paramétrica con un nivel de confianza del 95 %. Los resultados revelaron que la mayor eficiencia de extracción total (40,9 %) en base seca se obtuvo con etanol al 50 % y una relación sólido/solvente de 1:30. Por componentes se encontró que, el etanol al 50 % con una relación de 1:20 permitió la máxima eficiencia para carbohidratos totales (17,9 %) y polisacáridos (17,2 %), mientras que con una relación de 1:30 se obtuvo la máxima eficiencia para azúcares reductores (0,91 %) y polifenoles (0,23 %). Por otro lado, el etanol al 95 % y la relación 1:30 permitió la máxima eficiencia para proteínas (29,4 %). La extracción de beta-glucanos no fue significativa. La eficiencia de la extracción está muy influenciada por los parámetros de operación, principalmente por la concentración de etanol; en particular, la de 50 % resultó más favorable para la obtención de la mayoría de sustancias bioactivas con potencial nutracéutico.

Optimization of ergosterol extraction from Pleurotus mushrooms using response surface methodology

In this study, heat-assisted extraction (HAE) was used to optimise the extraction of ergosterol from Pleurotus ostreatus (PO) and Pleurotus eryngii (PE) using response surface methodology (RSM).

Homology models of mouse and rat estrogen receptor-α ligand-binding domain created by in silico mutagenesis of a human template: molecular docking with 17ß-estradiol, diethylstilbestrol, and paraben analogs

Crystal structures exist for human, but not rodent, estrogen receptor-α ligand-binding domain (ERα-LBD). Consequently, rodent studies involving binding of compounds to ERα-LBD are limited in their molecular-level interpretation and extrapolation to humans. Because the sequences of rodent and human ERα-LBDs are > 95% identical, we expected their 3D structures and ligand binding to be highly similar. To test this hypothesis, we used the human ERα-LBD structure (PDB 3UUD) as a template to produce rat and mouse homology models. Employing the rodent models and human structure, we generated docking poses of 23 Group A ligands (17ß-estradiol, diethylstilbestrol, and 21 paraben analogs) in AutoDock Vina for interspecies comparisons. Ligand RMSDs (Å) (median, 95% CI) were 0.49 (0.21-1.82) (human-mouse) and 1.19 (0.22-1.82) (human-rat), well below the 2.0-2.5 Å range for equivalent docking poses. Numbers of interspecies ligand-receptor residue contacts were highly similar, with Sorensen Sc (%) = 96.8 (90.0-100) (human-mouse) and 97.7 (89.5-100) (human-rat). Likewise, numbers of interspecies ligand-receptor residue contacts were highly correlated: Pearson r = 0.913 (human-mouse) and 0.925 (human-rat). Numbers of interspecies ligand-receptor atom contacts were even more tightly correlated: r = 0.979 (human-mouse) and 0.986 (human-rat). Pyramid plots of numbers of ligand-receptor atom contacts by residue exhibited high interspecies symmetry and had Spearman r s = 0.977 (human-mouse) and 0.966 (human-rat). Group B ligands included 15 ring-substituted parabens recently shown experimentally to exhibit decreased binding to human ERα and to exert increased antimicrobial activity. Ligand efficiencies calculated from docking ligands into human ERα-LBD were well correlated with those derived from published experimental data (Pearson partial r p = 0.894 and 0.918; Groups A and B, respectively). Overall, the results indicate that our constructed rodent ERα-LBDs interact with ligands in like manner to the human receptor, thus providing a high level of confidence in extrapolations of rodent to human ligand-receptor interactions.