Production, purification and characterisation of polysaccharides from Pleurotus ostreatus with antitumour activity

Plant endophytic fungal polysaccharides and their activities: A review

Endophytic fungi, essential constituents of plant microecosystems, have attracted considerable scientific interest due to their remarkable biodiversity, ecological adaptability, and capacity to synthesize a wide range of bioactive metabolites. Among these, polysaccharides produced by endophytic fungi represent a promising yet insufficiently investigated class of macromolecules with significant pharmacological and biotechnological applications. However, research on these polysaccharides remains constrained by limited exploration. This review systematically consolidates current advances in the classification, extraction, purification, structural elucidation, and biological functions of endophytic fungal polysaccharides (EFPs), while also examining their interactions with host plants. The potential of polysaccharide-producing endophytic fungi remains largely underexplored. Furthermore, inherent polysaccharide complexity, combined with technical limitations, has confined most studies to extracellular polysaccharides, leaving comprehensive structural analyses scarce. EFPs demonstrate antioxidant, antibacterial, immunomodulatory, and antitumor activities, and contribute substantially to the symbiotic dynamics between fungi and host plants, yet systematic activity profiling is insufficient. This review proposes establishing a targeted resource development framework to enhance the diversity of polysaccharide compounds and advocates for the integration of conventional and advanced methodologies to advance pharmacological investigations and functional analyses of EFPs, thereby offering strategic insights for future applications and facilitating deeper exploration and utilization.

Application of combined Box-Behnken design with response surface methodology and desirability function in optimizing pectin extraction from fruit peels

BACKGROUND

This study aimed to extract pectin from various fruit peels, namely apple, orange, green citron, and pomegranate, and to evaluate the effects of various experimental conditions. The extraction was conducted at temperatures of 50-90 °C, with a solid-liquid ratio of 0.03-0.08 g/mL, for 120-180 min. The Box-Behnken design was applied in a three-level and four-factor factorial approach, including 29 experiments for each extraction, with varying conditions. The interaction effects were investigated. Each experiment's conditions were optimized.

RESULTS

The percentage yield varied (11.70-37.37%). The maximum yield was found in apples, whereas the lowest was in pomegranates.

CONCLUSION

Under optimized experimental conditions,high-quality pectin was extracted from pomegranate, orange, green citron, and apple peel waste. The extract was considered to be high methyl ester pectin with a degree of esterification greater than 50% and with an Anhydrouronic acid (AUA) content greater than 65%. The peel pectin that was studied could therefore be a food additive with numerous uses. The procedure developed here reuses waste resources effectively and contributes to a novel concept for exploring natural assets for use in food and pharmaceutical applications. © 2023 Society of Chemical Industry.

A Comparative Analysis of the Physico-Chemical Properties of Pectin Isolated from the Peels of Seven Different Citrus Fruits

In the present research work, pectin was isolated from the peels of seven citrus fruits (Citrus limon, Citrus limetta, Citrus sinensis, Citrus maxima, Citrus jambhiri, Citrus sudachi, and Citrus hystrix) for a comparison of its physicochemical parameters and its potential use as a thickening agent, gelling agent, and food ingredient in food industries. Among the seven citrus fruits, the maximum yield of pectin was observed from Citrus sudachi, and the minimum yield of pectin was observed from Citrus maxima. The quality of each pectin sample was compared by using parameters such as equivalent weight, anhydrouronic acid (AUA) content, methoxy content, and degree of esterification. It was observed that all seven pectin samples had a high value of equivalent weight (more than 1000), suggesting that all the pectin samples had a high content of non-esterified galacturonic acid in the molecular chains, which provides viscosity and water binding properties. The methoxy content and degree of esterification of all the pectins was lower than 50%, which suggests that it cannot easily disperse in water and can form gel only in presence of divalent cations. The AUA content of all isolated pectins samples was above 65%, which suggests that the pectin was pure and can be utilized as a food ingredient in domestic foods and food industries. From the FTIR analysis of pectin, it was observed that the bond pattern of Citrus maxima, Citrus jambhiri, and Citrus hystrix was similar. The bond pattern of Citrus limon, Citrus limetta, and Citrus sinensis was similar. However, the bond pattern of Citrus sudachi was different from that of all other citrus fruits. The difference in the bond pattern was due to the hydrophobic nature of pectin purified from Citrus limon, Citrus limetta, Citrus sudachi, and Citrus sinensis and the hydrophilic nature of pectin purified from Citrus maxima, Citrus jambhiri, and Citrus hystrix. Hence, hydrophobic pectin can be utilized in the preparation of hydrogels, nanofibers, food packaging material, polysoaps, drug delivery agents, and microparticulate materials, whereas hydrophilic pectin can be utilized for the preparation of gelling and thickening agents.

Effects of Rosa roxburghii Tratt Must on the Growth, Nutrient Composition, and Antioxidant Activity of Pleurotus ostreatus Mycelia

Rosa roxburghii Tratt, a Rosaceae plant endemic to China, produces fruit with high nutritional and medicinal value. The effects of R. roxburghii must on the growth, nutrient composition, and antioxidant activity of Pleurotus ostreatus mycelia was investigated. We measured the mycelial growth rate, proximate composition, amino acid and crude polysaccharide content, and the antioxidant activity of the crude polysaccharides of P. ostreatus mycelia cultivated under different concentrations of R. roxburghii must (2%, 4%, and 8%, v/v). Low concentrations of R. roxburghii must (2% and 4%) promoted mycelial growth, while a high concentration (8%) inhibited mycelial growth. Low concentrations of R. roxburghii must had no significant effects on the soluble substances, fat, ash, and crude fiber in P. ostreatus mycelia, but significantly increased the crude protein and total amino acid contents (p < 0.05). The addition of R. roxburghii must at low concentrations significantly increased the crude polysaccharide content in mycelia (p < 0.05) but had no impact on the scavenging of hydroxyl radicals and 2,2-diphenyl-1-picrylhydrazyl (DPPH). Therefore, R. roxburghii must at low concentration can be used as a substrate for P. ostreatus cultivation to increase the protein and polysaccharide contents in mycelia.

Synthesis, Optimization, and Characterization of Ecofriendly Production of Gold Nanoparticles Using Lemon Peel Extract

This study examines the importance of utilizing green synthesis using lemon peel for gold nanoparticles over other chemicals since it is environmentally friendly, available, and cheap. Several parameters were optimized to ensure the extraction of the GNPs concentration of lemon peels using HAuCl₄ and lemon peel extract having a ratio of 2 : 1. For the optimum result, the ratio used was 2 : 1. The gold nanoparticles fabrication happened in 10 minutes. The initial observation was the color change of the solution. The UV-visibility spectroscopic studies are performed to confirm the result. The experiments are done concurrently to ensure the solution is mixed on the proper ratio. The GNP is also characterized by the different techniques in their sizes and electronic transmission microscopy, essential in extracting gold nanoparticles. Other elements of the composition are removed by the EDAX methods, the FTIR method, and the TEM methods, all of which reveal the real reason behind the required extraction capacity. Most gold nanoparticles show a maximum absorption rate at the peak of 535 to 579 nm. The result obtained from the TEM and the SEM analysis revealed that the grain size is analogized to the average size of 6.67 nm. With a simple synthesis of the price, some processes show that the medically available nanoparticles are necessary. The used method in this paper to fabricate GNPs is cheap, easy, fast, and sustainable and it can be done with ease in any laboratory.

Promising anticancer activity of polysaccharides and other macromolecules derived from oyster mushroom (Pleurotus sp.): An updated review

Cancer dominates among many causes of mortality worldwide. Traditional chemotherapeutic agents are powerful anti-cancer agents employed for treatment of this deadly disease. However, they are always associated with toxic side effects and immunosuppression making person more vulnerable to tumor relapse and fatalities. A promising alternative could be identification, isolation and transfer of naturally occurring bioactive macromolecules to the tumorigenic population. Oyster mushroom, a major source of nutraceuticals, belonging to class basidiomycetes of kingdom Mycota is known to have immense therapeutic properties. It is a reservoir of macromolecules like β-glucan, α-glucan, resveratrol, concanavalin A, cibacron blue affinity protein, p-hydroxybenzoic acid, ergosterol, linoleic acid etc. that are responsible for mediating anti-tumor, immunomodulatory, antioxidant, and anti-diabetic roles. Various studies have shown that extracts derived from oyster mushroom is rich in polysaccharides like β-glucan and other macro molecules which have an anti-proliferative effect against cancer cell lines, without harming the normal cells. This review presents a brief highlight of the work covering the overall significance of oyster mushroom in different types of cancer treatment. It also explores the immunomodulatory effects of polysaccharides, proteoglycans and polypeptides derived from oyster mushroom that boosts the immune system to overcome the limitation of traditional cancer therapies.

Sulfated modification, characterization and bioactivities of an acidic polysaccharide fraction from an edible mushroom Pleurotus eous (Berk.) Sacc

The acidic fraction (P3a) of Pleurotus eous was successfully sulfated by sulphur trioxide-pyridine complex method. The effect of sulfate modification (SP3a) on the structure, physicochemical properties and in vitro biological activity of P3 was studied. The structural characteristics were established by UV absorption, FT-IR, HPGPC and GC-MS. Biological studies were carried out, such as in vitro antioxidant, anticoagulant, anti-tumour and antibacterial activities. The sulfation process changed its physicochemical and biological characteristics. Compared with P3a, the molecular weight of SP3a is reduced. P3a and SP3a are composed of galactose, xylose, arabinose with different molar percentages. Sulfated derivatives have strong antioxidant and anticoagulant properties. Compared with P3a, SP3a showed obvious cytotoxicity to Jurkat and HeLa cells. SP3a showed a higher inhibition zone for Gram-positive and Gram-negative bacteria. This article demonstrates that sulfation is an effective way to enhance biological activity, especially SP3a is a promising candidate for bioactive macromolecules and has great potential for industrial and biomedical applications.

Promotion of the growth and plant biomass degrading enzymes production in solid-state cultures of Lentinula edodes expressing Vitreoscilla hemoglobin gene

Vitreoscilla hemoglobin (VHb), encoded by the Vitreoscilla hemoglobin gene (vgb), is highly effective at binding oxygen and delivering it to both prokaryotes and eukaryotes under hypoxic conditions. In this study, we introduced the vgb gene into shiitake mushrooms, and the mycelia of the transformatants grew faster. In particular, they spread into the solid substrate located in the lower part of the test tubes and bags where the oxygen was hypoxic and produced more β-glucan and plant biomass degrading enzymes compared to the original strain. The maximum growth rate of the transformants was 8.5%-15.9% higher than that of the original strain on sawdust-based cultures in plastic bags. The laccase and amylase activities were 17.7%-40.3% and 16.7%-37.9% higher than that of the original strain, respectively. In addition, the β-glucan contents of the transformant mycelia from the submerged fermentation were 12.9%-24.0% higher than that of the original strain. These results reveal that the expression of VHb in mushroom fungi promots the mycelial growth in solid-state cultures under the hypoxic condition as well as enhances β-glucan and plant biomass degrading enzymes production.

Synthesis of porous Pd nanoparticles by therapeutic chaga extract for highly efficient tri-modal cancer treatment

Porous palladium nanoparticles were designed and synthesized to maximize the pharmacological activity of the chaga mushroom (Inonotus obliquus) extract, which has anticancer and antibacterial activities. In the present study, we synthesized anisotropic porous Pd nanostructures with ultraviolet-visible-near infrared whole wavelength region absorption using chaga extract concentration-dependent reductant-mediated synthesis. The porous Pd nanoparticles exhibited a surface chaga extract-derived anticancer effect, controlled delivery of doxorubicin through electrostatic interaction, and a photothermal conversion effect under 808 nm laser irradiation. The combined application of the three cancer treatment approaches clearly demonstrated the feasibility of synergistic tri-modal therapy. The present platform using Pd, which is a key constituent element of nanocatalysts but is not commonly used in biological applications, suggests numerous applications utilizing Pd nanostructures, as well as the potential development of new cancer therapies.

Rare earth elements concentration in mushroom cultivation substrates affects the production process and fruit-bodies content of Pleurotus ostreatus and Cyclocybe cylindracea

BACKGROUND

Concentrations of 16 rare earth elements (REEs) and two actinides were determined for the first time both in cultivated mushrooms and in their production substrates by inductively coupled plasma mass spectroscopy. Moreover, the effect of REEs on cultivation parameters and composition of the final product was assessed, together with their potential use for authentication purposes.

RESULTS

The concentrations of REEs varied greatly among seven cultivation substrates and correlated with measurements in Cyclocybe cylindracea mushrooms; no such correlation was established in Pleurotus ostreatus. Reduction of hemicellulose, cellulose, and lignin in substrates during P. ostreatus cultivation was positively correlated with REE concentrations, which also affected the production performance depending on the species examined. In all cases, a negative correlation was established between bioconcentration factors (BCF) in mushrooms and REE content in substrates, while the effect of substrate composition on BCF values varied according to the element studied. The estimated daily intake values of REEs through mushroom consumption was at much lower levels than those reported as potentially harmful for human health.

CONCLUSION

The content of REEs in cultivation substrates and in mushrooms revealed that the bioaccumulation of elements differed in each fungus. The nature/origin of substrates seemed to affect the concentration of REEs in mushrooms to a considerable extent. © 2018 Society of Chemical Industry.

Factors affecting mushroom Pleurotus spp

Pleurotus genus is one of most extensively studied white-rot fungi due to its exceptional ligninolytic properties. It is an edible mushroom and it also has several biological effects, as it contains important bioactive molecules. In basidiomycete fungi, lignocellulolytic enzymes are affected by many typical fermentation factors, such as medium composition, ratio of carbon to nitrogen, pH, temperature, air composition, etc. The survival and multiplication of mushrooms is related to a number of factors, which may act separately or have interactive effects among them. Out that understanding challenges in handling Pleurotus species mushroom requires a fundamental understanding of their physical, chemical, biological and enzymatic properties. This review presents a practical checklist of available intrinsic and extrinsic factors, providing useful synthetic information that may help different users. An in-depth understanding of the technical features is needed for an appropriate and efficient production of Pleurotus spp.

Proteomic analysis of intestinal tissues from mice fed with Lentinula edodes-derived polysaccharides

Lentinula edodes-derived polysaccharides induce the differential proteins in abundance in mouse colon and small intestine.

Novel polyol-responsive monoclonal antibodies against extracellular β-D-glucans from Pleurotus ostreatus

β-D-glucans from mushroom strains play a major role as biological response modifiers in several clinical disorders. Therefore, a specific assay method is of critical importance to find useful and novel sources of β-d-glucans with anti-tumor activity. Hybridoma technology was used to raise monoclonal antibodies (Mabs) against extracellular β-d-glucans (EBG) from Pleurotus ostreatus. Two of these hybridoma clones (3F8_3H7 and 1E6_1E8_B3) secreting Mabs against EBG from P. ostreatus were selected and 3F8_3H7 was used to investigate if they are polyol-responsive Mabs (PR-Mabs) by using ELlSA-elution assay. This hybridoma cell line secreted Mab of IgM class, which was purified in a single step by gel filtration chromatography on Sephacryl S-300HR, which revealed a protein band on native PAGE with Mr of 917 kDa. Specificity studies of Mab 3F8_3H7 revealed that it recognized a common epitope on several β-d-glucans from different basidiomycete strains as determined by indirect ELlSA and Western blotting under native conditions. This Mab exhibited high apparent affinity constant (KApp) for β-d-glucans from several mushroom strains. However, it revealed differential reactivity to some heat-treated β-d-glucans compared with the native forms suggesting that it binds to a conformation-sensitive epitope on β-d-glucan molecule. Epitope analysis of Mab 3F8_3H7 and 1E6_1E8_B3 was investigated by additivity index parameter, which revealed that they bound to the same epitope on some β-d-glucans and to different epitopes in other antigens. Therefore, these Mab can be used to assay for β-d-glucans as well as to act as powerful probes to detect conformational changes in these biopolymers.

A high throughput colorimetric assay of β-1,3-D-glucans by Congo red dye

Mushroom strains contain complex nutritional biomolecules with a wide spectrum of therapeutic and prophylactic properties. Among these compounds, β-d-glucans play an important role in immuno-modulating and anti-tumor activities. The present work involves a novel colorimetric assay method for β-1,3-d-glucans with a triple helix tertiary structure by using Congo red. The specific interaction that occurs between Congo red and β-1,3-d-glucan was detected by bathochromic shift from 488 to 516 nm (>20 nm) in UV-Vis spectrophotometer. A micro- and high throughput method based on a 96-well microtiter plate was devised which presents several advantages over the published methods since it requires only 1.51 μg of polysaccharides in samples, greater sensitivity, speed, assay of many samples and very cheap. β-D-Glucans of several mushrooms (i.e., Coriolus versicolor, Ganoderma lucidum, Pleurotus ostreatus, Ganoderma carnosum, Hericium erinaceus, Lentinula edodes, Inonotus obliquus, Auricularia auricular, Polyporus umbellatus, Cordyseps sinensis, Agaricus blazei, Poria cocos) were isolated by using a sequence of several extractions with cold and boiling water, acidic and alkaline conditions and quantified by this microtiter plate method. FTIR spectroscopy was used to study the structural features of β-1,3-D-glucans in these mushroom samples as well as the specific interaction of these polysaccharides with Congo red. The effect of NaOH on triple helix conformation of β-1,3-D-glucans was investigated in several mushroom species.

β-Glucan synthase gene overexpression and β-glucans overproduction in Pleurotus ostreatus using promoter swapping

Mushroom β-glucans are potent immunological stimulators in medicine, but their productivities are very low. In this study, we successfully improved its production by promoter engineering in Pleurotus ostreatus. The promoter for β-1,3-glucan synthase gene (GLS) was replaced by the promoter of glyceraldehyde-3-phosphate dehydrogenase gene of Aspergillus nidulans. The homologous recombination fragment for swapping GLS promoter comprised five segments, which were fused by two rounds of combined touchdown PCR and overlap extension PCR (TD-OE PCR), and was introduced into P. ostreatus through PEG/CaCl2-mediated protoplast transformation. The transformants exhibited one to three fold higher transcription of GLS gene and produced 32% to 131% higher yield of β-glucans than the wild type. The polysaccharide yields had a significant positive correlation to the GLS gene expression. The infrared spectra of the polysaccharides all displayed the typical absorption peaks of β-glucans. This is the first report of successful swapping of promoters in filamentous fungi.