Extracellular polysaccharides from Ascomycota and Basidiomycota: production conditions, biochemical characteristics, and biological properties

An Attempted Correlation Between the Fecal Microbial Community of Chinese Forest Musk Deer (Moschus berezovskii) and Differences in Musk Production and Quality

Musk, a dried secretion from the sac gland near the urethral foramen of adult male forest musk deer (Moschus berezovskii), has significant economic value and is extensively utilized as a valuable component in traditional Chinese medicine. In the practice of forest musk deer breeding, musk with different colors and varying moisture contents is observed during the season when the musk reaches maturity. For many years, researchers have focused mainly on musk composition and symbiotic bacteria. However, the influence of fecal fungi on the production and quality of musk is unknown. In this study, internal transcribed spacer (ITS) analysis was employed to explore the relationships between the fungal composition of musk deer fecal and the quality and production of musk produced by each individual. The results indicate that fungal genera known to cause diseases, such as Colletotrichum and Apiotrichum, are prevalent in the feces of musk deer that produce abnormal musk. Furthermore, the fecal microbiota health index (GMHI) is lower and the intestinal microbiota dysbiosis index (MDI) is greater in musk deer producing white musk than in normal individuals. Additionally, by correlating musk production with fecal fungi, we also found that Dolichousnea and Scolecoleotia were significantly positively correlated with musk production. Moreover, Metschnikowia, Ganodermataceae_gen_Incertae_sedis, Hypoxylon, Neovaginatispora, Didymella, Dothidea, and Trichoderma were negatively correlated with musk production. This study is the first to investigate gut fungi in relation to musk production/quality, establish gut health and fungal dysbiosis links, and identify candidate fungi tightly associated with musk traits. This exploratory approach is critical for exploring uncharted territories like gut fungi in musk deer and musk traits.

Statistical Optimization of Exopolysaccharide and Biomass Production by Mangrove Fungi Fusarium equiseti ANP2 and its Potential Application as Bioemulsifier and Chelator

The rationale of the study is to explore the bio functional industrial potential and optimized culture conditions of a Manno glucan heteropolysaccharide MF-1 (purified EPS fraction) produced by a newly discovered mangrove derived fungi Fusarium equiseti ANP2, isolated from the Krishna River delta mangrove sediments. Response surface methodology (RSM) was employed to optimize fungal EPS and Biomass production, achieving a significant 1.4-fold increase to 6.94 g/L in EPS yield and a 2.1-fold increase in biomass production. RSM identified optimal levels of glucose, NH₄NO₃, NaCl, leucine, temperature, and pH, while minimizing the required glucose and nitrogen content compared to conventional methods. Notably, MF-1 exhibited promising emulsification potential (69.5% n-hexadecane emulsification), suggesting its prospective role as a novel emulsifier, particularly for n-hexadecane-based applications. Additionally, MF-1 also displayed a chelating activity for Fe2⁺ ions, suggesting its applicability as a natural chelating agent. The current study optimized the EPS production using RSM design and explored its potential for industrial applications as emulsification and chelating properties of the purified EPS fraction. Future research could explore the structural modifications of the fungal EPS to enhance its functionalities and delve deeper into the mechanisms governing EPS and biomass for large-scale, sustainable industrial production.

Comparative evaluation of free radical scavenging activity and total metabolite profiles among 30 macrofungi species

The high antioxidant content of mushrooms such as polyphenols, polysaccharides, carotenoids, ergothioneine, glutathione, vitamins, and other compounds, has sparked interest in their potential use in preventive and therapeutic medicine. Therefore, this study aimed to evaluate the antioxidant potential of various macrofungi by measuring 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity and quantifying two classes of compounds: phenolics (TPC) and polysaccharides, both endo- (IPS) and exopolysaccharides (EPS). Species-specific abilities to produce mycelium, polysaccharides, and polyphenols were observed under submerged cultivation without agitation over 14 days. Mycelium productivity (PM) ranged significantly from 292 ± 11 to 1110 ± 37 mg·L⁻1·day⁻1, with the highest values observed in Ophiocordyceps sinensis (1110 ± 37 mg·L⁻1 ·day⁻1), Pleurotus djamor (1090 ± 14 mg·L⁻1·day⁻1), and Cordyceps militaris (1080 ± 90 mg· L⁻1·day⁻1). The DPPH inhibition values of the extracts varied from 4.30 ± 0.20 to 87.9 ± 0.80%, while TPC ranged from 0.35 ± 0.10 to 34.6 ± 0.80 mg GAE/g d.w. Lentinula edodes was the best source of produced IPS (10.3 ± 0.35 g·L-1), while Hypsizygus marmoreus exhibited the highest EPS content (2.24 ± 0.30 g·L-1). Overall, IPS levels across species were higher, ranging from 1.56 to 10.3 g·L-1. In half of the fungal species, the mycelium exhibited superior antioxidant activity compared to culture broth. However, in the majority (66.7%), TPC was higher in the culture broth than in the fungal mycelium. Distinct scavenging abilities and metabolite profiles were observed among different isolates. Notably, the mycelium of Fomitopsis pinicola and L. edodes showed the highest DPPH inhibition and TPC. The antioxidant activity and TPC varied depending on the culture medium, and solvents used. The highest DPPH inhibition (90%) and TPC (38.5 ± 0.40 mg GAE/g d.w.) were observed in the methanol (MeOH) extract of F. pinicola mycelium grown in Sabouraud dextrose medium. Similarly, MeOH and ethyl acetate (EtOAc) extracts demonstrated strong DPPH inhibition (over 87%), while the maximum TPC (40.0 ± 0.60 mg GAE/g d.w.) was detected in the water (H2O) extract of L. edodes mycelium cultivated in glucose-peptone-yeast medium. A positive correlation was found between TPC and antioxidant activity, with Pearson's coefficient of 0.6615 for fungal mycelium, 0.1192 for culture broth, and 0.8924 and 0.7143 for F. pinicola and L. edodes, respectively. Both fungal mycelium and culture broth exhibit significant potential as natural antioxidants. These can be applied in nutraceuticals, food products, and nutritional supplements, offering diverse health benefits. Additionally, this study is a pioneering exploration of Auriporia aurea, Hohenbuehelia myxotricha, Lepista luscina, Oxyporus obducens, and Pseudospongipellis litschaueri, highlighting their largely unexplored potential for antioxidant applications.

Interactive effects of microplastics and cadmium on soil properties, microbial communities and bok choy growth

The simultaneous presence of microplastics (MPs) and cadmium (Cd) in soil environments has raised concerns regarding their potential interactive effects on soil-plant ecosystems. This study explores how polyethylene (PE) at concentrations of 0.5 % (w/w), 1 % (w/w), and 2 % (w/w), and Cd at concentrations of 3 mg kg-1 and 12 mg kg-1, either alone or combined, impact soil physicochemical properties, microbial community structures, and bok choy growth through a 40-day pot experiment. Our findings reveal that the addition of 2 % (w/w) PE significantly increased soil organic carbon (SOC). However, when 2 % PE coexisted with Cd, SOC levels decreased, potentially due to a reduction in enzyme activity (β-1,4-glucosidase). PE increased the proportion of 1-2 mm soil aggregates, while the coexistence of 2 % PE and Cd significantly increased the content of soil aggregates larger than 2 mm. The coexistence of PE and Cd increased available potassium (AK) in the soil by approximately 13 % to 41 %. Regarding bok choy growth, the aboveground biomass under 2 % PE was approximately 210 % of that under 0.5 % PE, possibly because of the enhancement in soil nutrients. The presence of Cd, however, reduced the chlorophyll content of bok choy by approximately 18 % to 34 %. Notably, the coexistence of high PE concentration (2 % w/w) and low Cd concentration (3 mg kg-1) resulted in the highest aboveground biomass among all coexistence treatments. Furthermore, the addition of PE and Cd significantly altered the structure of soil bacterial and fungal communities, with fungi showing a greater response. Bacteria were significantly associated with soil inorganic N content and plant growth. This study provides new insights into the interactions of microplastics and Cd within microbial-soil-plant systems.

Optimization and scaling up of extracellular polysaccharide production by submerged culture of Ganoderma lucidum on starch-containing medium using response surface methodology and laboratory bioreactors of various designs

Basidiomycetes, known for their production of bioactive compounds, traditionally use simple sugars for fermentation. However, their ability to degrade complex plant polysaccharides through enzyme secretion presents potential for the use of renewable raw materials. This study focused on the optimization of exopolysaccharide (EPS) production and efficient substrate consumption by Ganoderma lucidum using response surface methodology (RSM). Using an optimized medium containing 15 g⋅l-1 wheat starch, 0.375 g⋅l-1 NH4Cl, and 0.75 g⋅l-1 CaCl2 (C/N ratio of 40), a significant increase in EPS concentration from 121.1 ± 10.2 mg⋅l-1 to 229.0 ± 20.3 mg⋅l-1 and starch degradation degree (SDD) from 9.1% to 57.6% was achieved after 9 d of submerged cultivation. Scale-up experiments were conducted in both column and stirred tank bioreactors, employing submerged and immobilized cultivation modes. Submerged cultivation in the column bioreactor yielded the highest process desirability of 0.56, achieving EPS concentration of 192.5 ± 5.4 mg⋅l-1 and 60.2% SDD within 7 d. These results highlight the potential of the used column bioreactor for efficient and rapid EPS production. Notably, bioreactor experiments revealed local maxima in EPS content at specific time points, suggesting that cell wall degradation, potentially induced by shear stress, may contribute to the release of polysaccharides into the culture broth.

Polysaccharides and Peptides With Wound Healing Activity From Bacteria and Fungi

Bacteria and fungi are natural sources of metabolites exhibiting diverse bioactive properties such as wound healing, antioxidative, antibacterial, antifungal, anti-inflammatory, antidiabetic, and anticancer activities. Two important groups of bacteria or fungi-derived metabolites with wound-healing potential are polysaccharides and peptides. In addition to bacteria-derived cellulose and hyaluronic acid and fungi-derived chitin and chitosan, these organisms also produce different polysaccharides (e.g., exopolysaccharides) with wound-healing potential. The most commonly used bacterial peptides in wound healing studies are bacteriocins and lipopeptides. Bacteria or fungi-derived polysaccharides and peptides exhibit both the in vitro and the in vivo wound healing potency. In the in vivo models, including animals and humans, these metabolites positively affect wound healing by inhibiting pathogens, exhibiting antioxidant activity, modulating inflammatory response, moisturizing the wound environment, promoting the proliferation and migration of fibroblasts and keratinocytes, increasing collagen synthesis, re-epithelialization, and angiogenesis. Therefore, peptides and polysaccharides derived from bacteria and fungi have medicinal importance. This study aims to overview current literature knowledge (especially within the past 5 years) on the in vitro and in vivo wound repair potentials of polysaccharides and peptides obtained from bacteria (Actinobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, and Proteobacteria) and fungi (yeasts, filamentous microfungi, and mushrooms).

The analgesic and gastroprotective activities of the three fungal extracts and their possible correlation with the inhibition of the P2X7 receptor

P2X7 is a purinergic receptor physiologically activated by extracellular ATP. Its activation induces proinflammatory responses, including cytokine release, reactive oxygen species formation, and cell death. Previous in vivo experimental models demonstrated that P2X7 blockade has anti-inflammatory effects; however, there are no drugs used in clinical therapy that act on the P2X7 receptor. In the context of inflammatory diseases, nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used as the first-line treatment; however, their major side effects include stomach ulcer formation, which increases patient morbidity and mortality. Here, we analyzed for the first time the analgesic and gastroprotective activities of three fungal extracts that showed antagonistic effects on P2X7 in vitro. The Antarctic fungal extracts obtained from Vishniacozyma victoriae, Metschnikowia australis, and Ascomycota sp. were tested in animal models of acute pain and ethanol-induced ulceration. These three extracts reduced paw licking by approximately 50 %, which is related to pain behavior, and reduced the number of stomach ulcers 3-7 times compared with the control (70 % ethanol), making them more efficient than the lansoprazole, an NSAID drug, and Brilliant Blue G (BBG), a known P2X7 antagonist, which only halves the number of ulcers. Furthermore, the extracts also protected the gastric mucosa and significantly reduced the levels of liver and renal enzymes compared with those in the ethanol group. Taken together, the fungal extracts presented both analgesic and possibly anti-inflammatory activities and had a protective effect on the gastric epithelium.

Sulfated xylogalactofucans from Spatoglossum asperum: Production, structural features and antiviral activity

In cultured cells, herpes simplex virus (HSV) infectivity is successfully inhibited by sulfated polysaccharides. Herein, we utilized an amalgamated extraction-sulfation procedure to produce two xylogalactofucan sulfates (S203 and S204) from Spatoglossum asperum using ClSO3H.Pyr/DMF and SO3.Pyr/DMF reagents, respectively. Among these xylogalactofucans, the 17 ± 12 kDa polymer (S203) with 14 % sulfate exhibited activity on several HSV variants, including an acyclovir-resistant HSV-1 strain. This is the first report of the anti-HSV activity of a sulfated xylogalactofucan of S. asperum. The effective concentration 50 % (EC50) value of S203 against HSV-1 strain F was 0.6 μg/mL with a selectivity index of 833. The backbone of this polymer (S203) is made up mostly of (1 → 4)-linked-α-l-Fucp units having sulfate groups typically at O-3 and sometimes at O-2 positions. Oligosaccharides containing Xyl, Gal and Fuc units confirms that they are an integral part of a single polymer, another novelty of this study. The EC50 values of the native xylogalactofucan (S202) and the SO3.Pyr/DMF modified polymer (S204), containing 2 % and 6 % sulfates, were >100 and 3.3 μg/mL, respectively. Introduction of sulfate groups enhanced their capability to inhibit the infection of cells by HSV-1. These findings suggest feasibility of inhibiting HSV attachment to cells by blocking viral entry with polysaccharide having specific structure.

Improvement in Glycolipid Metabolism Parameters After Supplementing Fish Oil-Derived Omega-3 Fatty Acids Is Associated with Gut Microbiota and Lipid Metabolites in Type 2 Diabetes Mellitus

BACKGROUND/OBJECTIVES

This study aimed to investigate the effects of fish oil-derived omega-3 polyunsaturated fatty acids (omega-3 PUFAs) on gut microbiota and serum lipid metabolites in T2DM.

METHODS

In a three-month, randomized, double-blind, placebo-controlled study, 110 T2DM patients received either fish oil (n = 55) or corn oil (n = 55) capsules daily. Serum lipids, glycemic parameters, gut microbiota diversity, and lipidomics were assessed.

RESULTS

This study found that fish oil-derived omega-3 PUFAs intervention did not significantly lower the fasting plasma glucose levels when compared with the baseline level (p > 0.05). However, serum fasting blood glucose (p = 0.039), glycosylated hemoglobin levels (p = 0.048), HOMA-IR (p = 0.022), total cholesterol (p < 0.001), triglyceride (p = 0.034), LDL cholesterol (p = 0.048), and non-HDL levels (p = 0.046) were significantly lower in the fish oil group compared with the corn oil group after three months of intervention. Also, it altered glycerophospholipid metabolism and gut microbiota. After three months, the fish oil group showed a significantly lower abundance of Desulfobacterota compared with the corn oil control group (p = 0.003), with reduced levels of Colidextribacter (p = 0.002), Ralstonia (p = 0.021), and Klebsiella (p = 0.013). Conversely, the abundance of Limosilactobacillus (p = 0.017), Lactobacillus (p = 0.011), and Haemophilus (p = 0.018) increased significantly. In addition, relevant glycolipid metabolism indicators showed significant correlations with the altered profiles of serum lipid metabolites, intestinal bacteria, and fungi.

CONCLUSIONS

This study highlights the impact of fish oil-derived omega-3 PUFAs on intestinal microbiota structure and function in patients with type 2 diabetes. The observed decrease in pathogenic bacterial species and the enhancement of beneficial species may have significant implications for gut health and systemic inflammation, both of which are pivotal in managing diabetes. Further research is warranted to comprehensively elucidate the long-term benefits and underlying mechanisms of these microbiota alterations.

Bio-stimulating effect of endophytic Aspergillus flavus AUMC 16068 and its respective ex-polysaccharides in lead stress tolerance of Triticum aestivum plant

Heavy metal accumulation is one of the major agronomic challenges that has seriously threatened food safety. As a result, metal-induced phytotoxicity concerns require quick and urgent action to retain and maintain the physiological activities of microorganisms, the nitrogen pool of soils, and the continuous yields of wheat in a constantly worsening environment. The current study was conducted to evaluate the plant growth-promoting endophytic Aspergillus flavus AUMC 16,068 and its EPS for improvement of plant growth, phytoremediation capacity, and physiological consequences on wheat plants (Triticum aestivum) under lead stress. After 60 days of planting, the heading stage of wheat plants, data on growth metrics, physiological properties, minerals content, and lead content in wheat root, shoot, and grains were recorded. Results evoked that lead pollution reduced wheat plants' physiological traits as well as growth at all lead stress concentrations; however, inoculation with lead tolerant endophytic A. flavus AUMC 16,068 and its respective EPS alleviated the detrimental impact of lead on the plants and promoted the growth and physiological characteristics of wheat in lead-contaminated conditions and also lowering oxidative stress through decreasing (CAT, POD, and MDA), in contrast to plants growing in the un-inoculated lead polluted dealings. In conclusion, endophytic A. flavus AUMC 16,068 spores and its EPS are regarded as eco-friendly, safe, and powerful inducers of wheat plants versus contamination with heavy metals, with a view of protecting plant, soil, and human health.

Enhanced production of mycelium biomass and exopolysaccharides of Pleurotus ostreatus by integrating response surface methodology and artificial neural network

This study aimed to enhance the production of mycelium biomass and exopolysaccharides (EPS) of Pleurotus ostreatus in submerged fermentation. Response Surface Methodology (RSM)sought to optimize culture conditions, whereas Artificial Neural Network (ANN)aimed to predict the mycelium biomass and EPS. After optimization of RSM model conditions, the maximum biomass (36.45 g/L) and EPS (6.72 g/L) were obtained at the optimum temperature of 22.9 °C, pH 5.6, and agitation of 138.9 rpm. Further, the Genetic Algorithm (GA) was employed to optimize the cultivation conditions in order to maximize the mycelium biomass and EPS production. The ANN model with an optimized network structure gave the coefficient of determination (R2) value of 0.99 and the least mean squared error of 1.9 for the validation set. In the end, a graphical user interface was developed to predict mycelium biomass and EPS production.

Adaptive laboratory evolution of Naematelia aurantialba under high temperature for efficient production of exopolysaccharide

Liquid fermentation could revolutionize mushroom polysaccharide production, but the low temperature constraint hampers the process. This study implemented adaptive laboratory evolution (ALE) to enhance the thermotolerance of Naematelia aurantialba strains and increase expolysaccharide production. After 75 ALE cycles at 30 °C, the adaptive strain surpassed the wild-type strain by 5 °C. In a 7.5 L fermentor at 30 °C, the ALE strain yielded 17 % more exopolysaccharide than the wild type strain at 25 °C. Although the exopolysaccharide synthesized by both strains shares a consistent monosaccharide composition, infrared spectrum, and glycosidic bond composition, the ALE strain's exopolysaccharide has a larger molecular weight. Furthermore, the ALE strain's exopolysaccharide exhibits superior cryoprotection performance compared to that produced by the original strain. The adapted strain demonstrated lower ROS levels and increased activity of antioxidant enzymes, indicating improved performance. Fatty acid profiling and transcriptomics revealed reconfiguration of carbohydrate metabolism, amino acid metabolism, and membrane lipid synthesis in thermophilic strains, maintaining cellular homeostasis and productivity. This study provides efficient strains and fermentation methods for high-temperature mushroom polysaccharide production, reducing energy consumption and costs.

Effects of polypropylene microplastics on carbon dioxide dynamics in intertidal mangrove sediments

Microplastics (MPs) in soil can influence CO2 dynamics by altering organic carbon (OC) and microbial composition. Nevertheless, the fluctuation of CO2 response attributed to MPs in mangrove sediments is unclear. This study explores the impact of micro-sized polypropylene (mPP) particles on the carbon dynamics of intertidal mangrove sediments. In the high-tide level sediment, after 28 days, the cumulative CO2 levels for varying mPP dosages were as follows: 496.86 ± 2.07, 430.38 ± 3.84 and 447.09 ± 1.72 mg kg-1 for 0.1%, 1% and 10% (w/w) mPP, respectively. The CO2 emissions were found to be increased with a 0.1% (w/w) mPP level and decreased with 1% and 10% (w/w) mPP at high-tide level sediment, suggesting a tide level-specific dose dependence of the CO2 emission pattern in mangrove sediments. Overall, results indicated that the presence of mPP in mangrove sediments would potentially affect intertidal total CO2 storage under given experimental conditions.

Effects of short and long-term thermal exposure on microbial compositions in soils contaminated with mixed benzene and benzo[a]pyrene: A short communication

Polycyclic aromatic hydrocarbons (PAHs) and benzene, toluene, ethylbenzene, and xylene (BTEX) are the most persistent and toxic organic contaminants often found co-contaminated in anthropogenic and petrochemical industrial sites. Therefore, an experiment was performed for the safe biodegradation of benzene and benzo[a]pyrene (BaP) through thermally-enhanced biodegradation, and to explore the influence of elevated thermal treatments on microbial diversity and composition. The results revealed that elevated thermal treatments (15 to 45 °C) significantly enhanced the diversity of both bacteria and fungi. The composition analysis revealed that short-term and long-term elevated temperature conditions can directly enhance the specificity of microorganisms that play a crucial role in the biodegradation of benzene and BaP co-contaminated soil. Moreover, the indirect role of elevated temperature conditions on microbial compositions was through the fluctuations of soil properties, especially soil pH, moisture, TOC, potassium, phosphorous, total Fe, Fe(II), and Fe(III). In addition, the correlation analyses revealed that thermal exposure enhances the synergistic association (fungal-fungal, fungal-bacterial, bacterial-bacterial) of microbes to degrade the toxic contaminants and to cope with harsh environmental conditions. These results concluded that the biodegradation of benzene and BaP co-contamination was efficiently enhanced under the thermally-enhanced biodegradation approach and the elevation of temperature can affect the microbial compositions directly via microbial specificity or indirectly by influencing the soil properties.

Influence of Organic and Inorganic Compounds of Various Metals on the Synthesis of Polysaccharides by the Medicinal Mushroom Trametes versicolor

BACKGROUND

To date, basidiomycetes are considered to be promising objects of biotechnology, due to a number of biologically active compounds, such as polysaccharides and triterpenes. These compounds have a high therapeutic potential and demonstrate immunomodulatory, antiviral, and antifungal activities.

OBJECTIVE

The purpose of this study was to study the effect of various concentrations of metal citrates and sulphates on the content of exo- and endopolysaccharides of the fungus Trametes versicolor.

METHOD

The mycelium was grown by deep cultivation on a semisyntheticglucose-peptone-yeast medium with different contents of zinc, copper, and manganese salts, after which the extraction and measurement of the concentration of polysaccharides were carried out.

RESULTS

The results obtained showed that copper citrate at a concentration of 4 mg/L had the greatest positive effect on biomass yield. The intensity of biomass growth on a nutrient medium with copper citrate increased by 80%. Zinc citrate increased the content of exopolysaccharides by 29% compared to the medium without metal salts. When manganese citrate was added to the medium, the productivity of synthesis decreased, but an increase in the growth rate of mycelium biomass was observed. Sulphates of these metals led to a decrease in the productivity of exopolysaccharide synthesis by 12% for zinc and 35% for manganese.

CONCLUSIONS

The addition of both copper citrate and copper sulphate to the medium led to a decrease in the synthesis productivity by 66 and 24%, respectively. The introduction of both citrates and sulphates of these metals into the culture medium led to an increase in the percentage of endopolysaccharides in the mycelium of the fungus.

HIGHLIGHTS

Copper citrate enhances Trametes versicolor biomass by 80%. Zinc citrate increases exopolysaccharide content by 29%. Copper sulphate optimizes endopolysaccharide production.

Characterization of Mannoprotein Structural Diversity in Wine Yeast Species

The structure of yeast cell wall (CW) mannoproteins (MPs) influences their impact on wine properties. Yeast species produce a diverse range of MPs, but the link between properties and specific structural features has been ill-characterized. This study compared the protein and polysaccharide moieties of MP-rich preparations from four strains of four different enologically relevant yeast species, named Saccharomyces boulardii (SB62), Saccharomyces cerevisiae (SC01), Metschnikowia fructicola (MF77), and Torulaspora delbrueckii (TD70), and a commercial MP preparation. Monosaccharide determination revealed that SB62 MPs contained the highest mannose/glucose ratio followed by SC01, while polysaccharide size distribution analyses showed maximum molecular weights ranging from 1349 kDa for MF77 to 483 kDa for TD70. Protein identification analysis led to the identification of unique CW proteins in SB62, SC01, and TD70, as well as some proteins shared between different strains. This study reveals MP composition diversity within wine yeasts and paves the way toward their industrial exploitation.

Variations in Rhizospheric and Endophytic Root Fungal Communities of Scrophularia ningpoensis in Different Producing Areas

Few studies have examined the association of factors associated with soil fertility and composition with the structure of microbial communities in the rhizosphere and endosphere. Hence, this study aimed to explore the effects of geographical differences on fungal communities in the roots of Scrophularia ningpoensis and the relationship between the fungal communities and secondary metabolic components in the host plant. We found that there was greater diversity in the fungal communities of the rhizosphere compartment than in endosphere communities. Ascomycota and Basidiomycota were dominant among the endosphere fungi, whereas Mortierellomycota was distributed in the rhizosphere. The composition of bulk soil obtained from different producing areas was significantly different, and the correlation between the rhizospheric and physicochemical compartments of the soil was higher than that observed with the endophytic compartment. Redundancy analysis and canonical correspondence analysis of the rhizospheric and endophytic samples revealed that the organic matter, total organic carbon, total nitrogen, and Hg levels were adequately correlated with the composition of rhizospheric and endophytic fungal communities. Multiple linear regression analyses facilitated the identification of potentially beneficial fungi whose abundance was correlated with levels of secondary metabolites, such as harpagide and harpagoside. These fungi could potentially provide valuable information regarding the use of S. ningpoensis in the medicinal plant industry.

Aqueous Extracts of Fermented Macrofungi Cultivated in Oilseed Cakes as a Carbon Source for Probiotic Bacteria and Potential Antibacterial Activity

Plant biomass colonized by macrofungi can contain molecules with bioactive properties with applications to human/animal health. This work aimed to verify antibacterial activities from aqueous extracts from oil seed cakes of Jatropha curcas (JSC) and cottonseed (CSC), fermented by macrofungi for probiotic bacteria cultivation. Coriolopsis sp., Tyromyces sp., Panus lecomtei, and Pleurotus pulmonarius were cultivated in solid and submerged media. The aqueous extract of unfermented JSC was more efficient than glucose for the growth of all probiotic bacteria. Extracts from four macrofungi fermented in CSC favored Lactobacillus acidophilus growth. In solid fermentation, macrofungi extracts cultivated in JSC favored Bifidobacterium lactis growth. All fungi extracts showed more significant growth than carbohydrates among the four probiotic bacteria evaluated. Regarding antimicrobial activities, no fungal extract or bacterial supernatant showed a more significant inhibition halo for enteropathogenic bacteria than ampicillin (control). Extracts from P. lecomtei and Coriolopsis sp. in CSC showed inhibition halos for Salmonella enterica. Supernatants from L. acidophilus, B. lactis, and Lactobacillus rhamnosus resulted in more significant inhibition of Staphylococcus aureus than the control, which indicates possible antimicrobial activity. Unfermented JSC supernatant showed better results for bacterial growth, while supernatants and aqueous extracts from CSC fermentation can be used for probiotic bacteria culture.

Differences in the Production of Extracellular Polymeric Substances (EPS) and Other Metabolites of Plenodomus (Leptosphaeria) Infecting Winter Oilseed Rape (Brassica napus L.)

Species of the genus Plenodomus (Leptosphaeria) are phytopathogens of the Brassicaceae family, which includes oilseed rape. The spores of these fungi spread by airborne transmission, infect plants, and cause crop losses. The secondary metabolism of P. lingam and P. biglobosus was studied and compared, with the main focus being on the ability to produce Extracellular Polymeric Substances (EPS). In spite of the 1.5-2-fold faster growth rate of P. biglobosus on Czapek-Dox and other screening media, the average yield of EPS in this fungus was only 0.29 g/L, compared to that of P. lingam (0.43 g/L). In turn, P. biglobosus showed a higher capacity to synthesise IAA, i.e., 14 µg/mL, in contrast to <1.5 µg/mL produced by P. lingam. On the other hand, the P. lingam strains showed higher β-glucanase activity (350-400 mU/mL), compared to 50-100 mU/mL in P. biglobosus. Invertase levels were similar in both species (250 mU/mL). The positive correlation between invertase activity and EPS yield contrasted with the absence of a correlation of EPS with β-glucanase. Plenodomus neither solubilised phosphate nor used proteins from milk. All strains showed the ability to synthesise siderophores on CAS agar. P. biglobosus exhibited the highest efficiency of amylolytic and cellulolytic activity.

Rhizoctonia solani AG1 IA extracellular polysaccharides: Structural characterization and induced resistance to rice sheath blight

Sheath blight, caused by Rhizoctonia solani (R. solani), is one of the most serious diseases of rice. Extracellular polysaccharides (EPS) are complex polysaccharides secreted by microbes that have a pivotal role in the plant-microbe interaction. At present, many studies have been carried out on R. solani, but it is not very clear whether the EPS is secreted by R. solani exists. Therefore, we isolated and extracted the EPS from R. solani, two kinds of EPS (EW-I and ES-I) were obtained by DEAE-cellulose 52 and Sephacryl S-300HR column further purification, and their structures were characterized by FT-IR, UV, GC, and NMR analysis. The results showed that EW-I and ES-I had similar monosaccharide composition but different molar ratio, they were composed of fucose, arabinose, galactose, glucose, and mannose with a ratio of 7.49: 27.72: 2.98: 6.66: 55.15 and 3.81: 12.98: 6.15: 10.83: 66.23, and their backbone may be composed of →2)-α-Manp-(1→ residues, beside ES-I was highly branched compared to EW-I. The exogenous application of EW-I and ES-I had no effect on the growth of R. solani AG1 IA itself, but their pretreatment of rice induced plant defense through activation of the salicylic acid pathway, resulting in enhanced resistance to sheath blight.

Deciphering endogenous and exogenous regulations of anammox consortia in responding to lincomycin by multiomics: quorum sensing and CRISPR system

The widespread use of antibiotics has created an antibiotic resistance genes (ARGs)-enriched environment, which causes high risks on human and animal health. Although antibiotics can be partially adsorbed and degraded in wastewater treatment processes, striving for a complete understanding of the microbial adaptive mechanism to antibiotic stress remains urgent. Combined with metagenomics and metabolomics, this study revealed that anammox consortia could adapt to lincomycin by spontaneously changing the preference for metabolite utilization and establishing interactions with eukaryotes, such as Ascomycota and Basidiomycota. Specifically, quorum sensing (QS) based microbial regulation and the ARGs transfer mediated by clustered regularly interspaced short palindromic repeats (CRISPR) system and global regulatory genes were the principal adaptive strategies. Western blotting results validated that Cas9 and TrfA were mainly responsible for the alteration of ARGs transfer pathway. These findings highlight the potential adaptative mechanism of microbes to antibiotic stress and fill gaps in horizontal gene transfer pathways in the anammox process, further facilitating the ARGs control through molecular and synthetic biology techniques.

Exopolysaccharides of Fungal Origin: Properties and Pharmaceutical Applications

Fungal exopolysaccharides (EPSs) represent an important group of bioactive compounds secreted by fungi. These biopolymers can be utilized individually or in combination with different bioactive substances for a broad range of pharmaceutical field applications, due to their various biological activities, such as antioxidant, antimicrobial, anti-inflammatory, antiviral, anti-diabetic, and anticoagulant effects. The paper presents an up-to-date review of the main fungal polysaccharides (pullulan, schizophyllan, scleroglucan, botryosphaeran, lentinan, grifolan, and lasiodiplodan), highlighting their structures, producing strains, and useful properties in a double position, as controlled release (rate and selectively targeting) drug carriers, but mostly as active immunomodulating and antitumor compounds in cancer therapy.

Production, characterization and antioxidant activity of exopolysaccharide from Sporidiobolus pararoseus PFY-Z1

At present, the study on exopolysaccharid is mainly focused on lactic acid bacteria, and the research on exopolysaccharide produced by yeast, especially Sporidiobolus pararoseus, is relatively few. Therefore, the aim of this study was to explore the characterization and antioxidant activities of a novel neutral exopolysaccharide SPZ, which was isolated and purified from S. pararoseus PFY-Z1. The results showed that SPZ was mainly composed of mannose, followed by glucose, with a molecular weight was 24.98 kDa, had O-glycosidic bonds, no crystalline, and no triple helix structure. Based on fourier transform-infrared, high-performance liquid chromatography and nuclear magnetic resonance analyses, SPZ was identified to be a exopolysaccharide with some side chains, presence of α-, β-pyranose ring and nine sugar residues. Furthermore, the morphology features of SPZ have performed a relatively rough and uneven surface, covered with small pores and fissures. Moreover, SPZ had higher antioxidant activities and the maximum scavenging abilities of ⋅OH, NO₂^- and reducing power were 28.05 ± 0.73%, 92.76 ± 1.86% and 0.345 ± 0.024, respectively. Hence, SPZ could be used as a potential antioxidant application in the food and pharmaceutical industries.

Potential functions and applications of diverse microbial exopolysaccharides in marine environments

Exopolysaccharides (EPSs) from microorganisms are essential harmless natural biopolymers used in applications including medications, nutraceuticals and functional foods, cosmetics, and insecticides. Several microbes can synthesize and excrete EPSs with chemical properties and structures that make them suitable for several important applications. Microbes secrete EPSs outside their cell walls, as slime or as a "jelly" into the extracellular medium. These EPS-producing microbes are ubiquitous and can be isolated from aquatic and terrestrial environments, such as freshwater, marine water, wastewater, and soils. They have also been isolated from extreme niches like hot springs, cold waters, halophilic environments, and salt marshes. Recently, microbial EPSs have attracted interest for their applications such as environmental bio-flocculants because they are degradable and nontoxic. However, further efforts are required for the cost-effective and industrial-scale commercial production of microbial EPSs. This review focuses on the exopolysaccharides obtained from several extremophilic microorganisms, their synthesis, and manufacturing optimization for better cost and productivity. We also explored their role and applications in interactions between several organisms.

Comparative transcriptome analysis of Monascus purpureus at different fermentation times revealed candidate genes involved in exopolysaccharide biosynthesis

Exopolysaccharides (EPS), metabolites of the medicinal edible fungus Monascus purpureus, have antioxidant, immunomodulatory, and anti-inflammatory effects. However, the biosynthetic mechanism of EPS from M. purpureus is still unclear, which hinders its utilization. In this study, the fermentation conditions of M. purpureus were optimized and comparative transcriptomic analysis was performed to understand the mechanisms and effects of fermentation on EPS synthesis. The optimal medium composition was 40 g/L mannose, 4 g/L yeast powder, 1 g/L MgSO4·7H2O, 0.8 g/L KH2PO4, 1.6 g/L K2HPO4·3H2O, and 2 mL/L Tween 80, and the optimal cultivation conditions were an inoculum of 7 %, culture temperature 30 °C, initial pH 6.0, and 180 rpm for 4 d. A total of 8095 unigenes were obtained, and 17 key enzymes for EPS synthesis were identified. Interestingly, 12 carbohydrate metabolism subcategories were enriched in the group with 4 days of fermentation compared to 2 days, with most of the differentially expressed genes (DEGs) being upregulated, but only nine carbohydrate metabolism subcategories were enriched with longer fermentation time, with all DEGs being downregulated. This study provides a theoretical basis for enhancing the EPS content and reveals the dynamics of EPS synthesis in M. purpureus, providing important targets for future EPS molecular modifications and gene knockdown studies.

Bioactivity of Biomass and Crude Exopolysaccharides Obtained by Controlled Submerged Cultivation of Medicinal Mushroom Trametes versicolor

The aim of this study is to characterize the bioactivity of mycelial biomass and crude exopolysaccharides (EPS) produced by Trametes versicolor NBIMCC 8939 and to reveal its nutraceutical potential. The EPS (1.58 g/L) were isolated from a culture broth. The macrofungal biomass was rich in protein, insoluble dietary fibers and glucans. The amino acid composition of the biomass was analyzed and 18 amino acids were detected. Three mycelial biomass extracts were prepared and the highest total polyphenol content (16.11 ± 0.14 mg GAE/g DW) and the total flavonoid content (5.15 ± 0.03 mg QE/g DW) were found in the water extract. The results indicated that the obtained EPS were heteropolysaccharides with glucose as the main building monosaccharide and minor amounts of mannose, xylose, galactose, fucose and glucuronic acid. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the complex structure of the crude EPS. Five probiotic lactic acid bacteria strains were used for the determination of the prebiotic effect of the crude EPS. The anti-inflammatory potential was tested in vitro using cell line HT-29. The significant decrease of IL-1 and IL-8 and increase of TGF-beta expression revealed anti-inflammatory potential of the crude exopolysaccharides from T. versicolor.

Plant-Microbiota Interactions in Abiotic Stress Environments

Abiotic stress adversely affects cellular homeostasis and ultimately impairs plant growth, posing a serious threat to agriculture. Climate change modeling predicts increasing occurrences of abiotic stresses such as drought and extreme temperature, resulting in decreasing the yields of major crops such as rice, wheat, and maize, which endangers food security for human populations. Plants are associated with diverse and taxonomically structured microbial communities that are called the plant microbiota. Plant microbiota often assist plant growth and abiotic stress tolerance by providing water and nutrients to plants and modulating plant metabolism and physiology and, thus, offer the potential to increase crop production under abiotic stress. In this review, we summarize recent progress on how abiotic stress affects plants, microbiota, plant-microbe interactions, and microbe-microbe interactions, and how microbes affect plant metabolism and physiology under abiotic stress conditions, with a focus on drought, salt, and temperature stress. We also discuss important steps to utilize plant microbiota in agriculture under abiotic stress.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Trends in Microbial Community Composition and Function by Soil Depth

Microbial communities play important roles in soil health, contributing to processes such as the turnover of organic matter and nutrient cycling. As soil edaphic properties such as chemical composition and physical structure change from surface layers to deeper ones, the soil microbiome similarly exhibits substantial variability with depth, with respect to both community composition and functional profiles. However, soil microbiome studies often neglect deeper soils, instead focusing on the top layer of soil. Here, we provide a synthesis on how the soil and its resident microbiome change with depth. We touch upon soil physicochemical properties, microbial diversity, composition, and functional profiles, with a special emphasis on carbon cycling. In doing so, we seek to highlight the importance of incorporating analyses of deeper soils in soil studies.

Diversity of Microorganisms in Biocrusts Surrounding Highly Saline Potash Tailing Piles in Germany

Potash tailing piles located in Germany represent extremely hypersaline locations that negatively affect neighbouring environments and limit the development of higher vegetation. However, biocrusts, as cryptogamic covers, inhabit some of these areas and provide essential ecological functions, but, nevertheless, they remain poorly described. Here, we applied high-throughput sequencing (HTS) and targeted four groups of microorganisms: bacteria, cyanobacteria, fungi and other eukaryotes. The sequencing of the 16S rRNA gene revealed the dominance of Proteobacteria, Cyanobacteria and Actinobacteria. Additionally, we applied yanobacteria-specific primers for a detailed assessment of the cyanobacterial community, which was dominated by members of the filamentous orders Synechococcales and Oscillatoriales. Furthermore, the majority of reads in the studied biocrusts obtained by sequencing of the 18S rRNA gene belonged to eukaryotic microalgae. In addition, sequencing of the internal rDNA transcribed spacer region (ITS) showed the dominance of Ascomycota within the fungal community. Overall, these molecular data provided the first detailed overview of microorganisms associated with biocrusts inhabiting highly saline potash tailing piles and showed the dissimilarities in microbial diversity among the samples.

Production, characterization, and bioactivities of exopolysaccharides from the submerged culture of Ganoderma cantharelloideum M. H. Liu

In this study, the submerged culture conditions for exopolysaccharide (EPS) production by Ganoderma cantharelloideum M. H. Liu were screened and optimized, and the physicochemical and biological properties of EPS were investigated. Results showed that the glucose and tryptone were the best C and N sources for the maximum EPS production, respectively. Under the optimal culture conditions, the EPS production achieved 1.60 g/L at day 6 in a 5 L stirred tank reactor. Two purified fractions (i.e., Fr-I and Fr-II) were obtained from the G. cantharelloideum EPS by gel permeation chromatography. Fr-II had a higher yield (87.54%), carbohydrate (95.86%), and protein (3.07%) contents and lower molecular weight (74.56 kDa) than that of Fr-I. Both Fr-I and Fr-II were polysaccharide-protein complexes with different monosaccharide compositions and chemical structures. Fr-II also exhibited stronger radical scavenging abilities, antioxidant capacities, and α-amylase and α-glycosidase inhibitory activities in vitro than that of Fr-I. Therefore, Fr-II obtained from G. cantharelloideum EPS might be explored as potential natural functional components or supplements for applications in food, medicine, and cosmetics.

Effects of supplementation of sea buckthorn press cake on mycelium growth and polysaccharides of Inonotus obliquus in submerged cultivation

AIMS

Investigation of the influence of cultivation time and sea buckthorn press cake (Hippophaë rhamnoides) dosage on mycelium yield of Inonotus obliquus in submerged cultivation and on the yield, monomer composition, and macromolecular properties of the exopolysaccharides (EPS) from culture media and intracellular polysaccharides (IPS) extracted from mycelia.

METHODS AND RESULTS

Supplementation at 5 g l^-1 combined with cultivation time of 250 h granted highest yield increase in mycelia (by 122%). The supplementation reduced extraction yield and decreased the molecular weight of the main IPS population. The supplementation increased production and molecular weight of EPS. The relative content of arabinose and rhamnose in EPS positively correlated with dosage of the press cake. The press cake supplementation increased the content of galacturonic acid in IPS, but not in EPS.

CONCLUSION

Sea buckthorn press cake is a food industry fibrous side stream with high oil content. It increases the cultivation yield of Inonotus obliquus mycelium and influences the produced polysaccharides.

SIGNIFICANCE AND IMPACT OF THE STUDY

Mycelium is a resource of bioactive polysaccharides, attracting the interest of nutraceutical companies. Sea buckthorn press cake is a promising supplement for increasing mycelium production. The utilization of this agricultural side stream would therefore favour circular economy.

Pink oyster mushroom Pleurotus flabellatus mycelium produced by an airlift bioreactor-the evidence of potent in vitro biological activities

Four types of mycelial extracts were derived from the airlift liquid fermentation (ALF) of Pleurotus flabellatus, namely exopolysaccharide (EX), endopolysaccharide (EN), hot water (WE), and hot alkali (AE) extracts. Such extracts were screened for their active components and biological potential. EN proved to be most effective in inhibition of lipid peroxidation (EC₅₀ = 1.71 ± 0.02 mg/mL) and in Cupric ion reducing antioxidant capacity (CUPRAC) assay (EC₅₀ = 2.91 ± 0.01 mg TE/g). AE exhibited most pronounced ability to chelate ferrous ions (EC₅₀ = 4.96 ± 0.08 mg/mL) and to scavenge ABTS radicals (EC₅₀ = 3.36 ± 0.03 mg TE/g). β-glucans and total phenols contributed most to the chelating ability and quenching of ABTS radicals. Inhibition of lipid peroxidation correlated best with total glucans, total proteins, and β-glucans. Total proteins contributed most to CUPRAC antioxidant capacity. Antifungal effect was determined against Candida albicans ATCC 10231 (MIC: 0.019-0.625 mg/mL; MFC: 0.039-2.5 mg/mL), and towards C. albicans clinical isolate (MIC and MFC: 10.0-20.0 mg/mL). Comparison of cytotoxicity against colorectal carcinoma HCT 116 cells (IC₅₀: 1.8 ± 0.3-24.6 ± 4.2 mg/mL) and normal lung MRC-5 fibroblasts (IC₅₀: 17.0 ± 4.2-42.1 ± 6.1 mg/mL) showed that EN, and especially AE possess selective anticancer activity (SI values 3.41 and 9.44, respectively). Slight genotoxicity was observed only for AE and EX, indicating the low risk concerning this feature. Notable antioxidative and anticandidal activities, selective cytotoxicity against colorectal carcinoma cells, and absence/low genotoxicity pointed out that ALF-cultivated P. flabellatus mycelium could be considered as a valuable source of bioactive substances.

Chemopreventive activity of bioactive fungal fractions isolated from milk-supplemented cultures of Cerrena unicolor and Pycnoporus sanguineus on colon cancer cells

The biochemical properties and anti-tumorigenic activity of Cerrena unicolor (CU) and Pycnoporus sanguineus (PS) towards colon cancer cells and the effect of supplementation of the fungal culture medium with cow milk on these activities were examined. CU1-II and PS4-II exhibited anticancer properties through various mechanisms. The extracts at the 200 µg/mL concentration significantly decreased the viability of HT-29 and SW948 cells. They also exhibited pro-apoptotic properties towards the cancer cell lines (HT-29, LS 180, and SW948). Furthermore, culturing the studied fungi on milk-supplemented media may improve the pro-health properties of both milk and mushrooms. The extracts had a higher concentration of proteins, lower levels of free amino acids, and higher content of phenolic compounds than milk. They also exerted a free radical scavenging effect, which may be connected with the high activity of catalase and superoxide dismutase. The tested extracts exhibited anticancer activity: C. unicolor grown on the medium without milk and P. sanguineus grown on the medium with milk. The CU1-II and PS4-II extracts exhibited the strongest anticancer properties; however, PS4-II exerted a milder effect on normal CCD 841 CoTr cells than CU1-II. CU3-II exerted the mildest effect among all extracts on both normal and cancer cells.

Bioactivity assessment of exopolysaccharides produced by Pleurotus pulmonarius in submerged culture with different agro-waste residues

Pleurotus spp. are white-rot fungi that utilize different agro-wastes to produce useful biologically active compounds. In this study, exopolysaccharides (EPS) were produced by Pleurotus pulmonarius in submerged culture supplemented with different agro-wastes. Functional groups in EPS were revealed using Fourier Transform-Infrared (FT-IR) spectroscopy. Antimicrobial activity of EPS was tested against microorganisms using agar well diffusion. Scavenging potentials of EPS was tested against 1, 1- diphenyl-2-picryhydrazyl (DPPH), hydroxyl (OH), iron (Fe2+) and nitric oxide (NO) radicals. In vitro prebiotic activity of EPS was carried out. The highest yield (5.60 g/L) of EPS was produced by P. pulmonarius in submerged culture supplemented with groundnut shell (20.0 g/L). The functional groups in EPS were hydroxyl (-OH), methyl (-CH3), ketone (-RCOH) and carbonyl group (-C=O). EPS displayed zones of inhibition (5.00-14.00 mm) against tested microorganisms. Scavenging activity of EPS ranged from 65.70-81.80% against DPPH. EPS supported the growth of Lactobacillus delbrueckii and Streptococcus thermophiles with values ranged from 3.04 × 104-3.40 × 104 cfu/ml and 2.50 × 104-2.81 × 104 cfu/ml, respectively. Submerged culture of P. pulmonarius with addition of agro-wastes enhanced yield of EPS. The EPS exhibited bio-functional properties like antimicrobial, antioxidant and prebiotic activities. Hence, agrowastes can be recycled in submerged fermentation with fungi to produce promising biomaterials for biopharmaceutical applications.

Antioxidant Molecules from Marine Fungi: Methodologies and Perspectives

The marine environment represents a prosperous existing resource for bioprospecting, covering 70% of the planet earth, and hosting a huge biodiversity. Advances in the research are progressively uncovering the presence of unknown microorganisms, which have evolved unique metabolic and genetic pathways for the production of uncommon secondary metabolites. Fungi have a leading role in marine bioprospecting since they represent a prolific source of structurally diverse bioactive metabolites. Several bioactive compounds from marine fungi have already been characterized including antibiotics, anticancer, antioxidants and antivirals. Nowadays, the search for natural antioxidant molecules capable of replacing those synthetic currently used, is an aspect that is receiving significant attention. Antioxidants can inactivate reactive oxygen and nitrogen species, preventing the insurgence of several degenerative diseases including cancer, autoimmune disorders, cardiovascular and neurodegenerative diseases. Moreover, they also find applications in different fields, including food preservation, healthcare and cosmetics. This review focuses on the production of antioxidants from marine fungi. We begin by proposing a survey of the available tools suitable for the evaluation of antioxidants, followed by the description of various classes of marine fungi antioxidants together with their extraction strategies. In addition, a view of the future perspectives and trends of these natural products within the "blue economy" is also presented.

Valorization of low-cost, carbon-rich substrates by edible ascomycetes and basidiomycetes grown on liquid cultures

Three ascomycetes (Morchella vulgaris AMRL 36, M. elata AMRL 63, Tuber aestivum AMRL 364) and four basidiomycetes strains (Lentinula edodes AMRL 124 and 126, Agaricus bisporus AMRL 208 and 209) were screened for their ability to grow on liquid static flask cultures of glucose, glycerol, molasses and waste flour-rich hydrolysates with C/N ratio of 20 and produce biomass, exopolysaccharides and lipids. The profile of lipid fatty acids was also assessed. Selected strains were furthermore cultivated in C/N = 50. Results showed that substrate consumption, biomass formation and secondary metabolites production were strain, substrate and C/N ratio dependent. The maximum biomass (X), lipid (L) and exopolysaccharides (EPS) values noted were Xmax = 25.2 g/L (C/N = 20; molasses) and Lmax = 6.51 g/L (C/N = 50; rice cereal hydrolysates) by T. aestivum strain AMRL 364 and EPSmax = 2.41 g/L by M. elata strain AMRL 63 (C/N = 50; molasses), respectively. When C/N ratio of 50 was applied, biomass, lipid production and substrate consumption seem to be negatively affected in most of the trials. The adaptation and capability of the mushroom strains to be cultivated on substrates based on agro-industrial waste streams and infant food of expired shelf date offers the opportunity to set a circular oriented bioprocess.

Enhancement of exopolysaccharide production from Ganoderma lucidum using a novel submerged volatile co-culture system

Based on the impact of volatile organic compounds (VOCs) on secondary metabolite pathways, a novel submerged volatile co-culture system was constructed, and the effects of thirteen fungal and bacterial VOCs were investigated on Ganoderma lucidum exopolysaccharides production. The results demonstrated at least a 2.2-fold increase in exopolysaccharide (EPS) specific production yield in 6 days submerged volatile co-culture of G. lucidum with Pleurotus ostreatus. Therefore, P. ostreatus was selected as a variable culture, and the effects of agitation speed, inoculum size, initial pH, and co-culture volume on EPSs production were investigated using a Taguchi L₉ orthogonal array. Finally, the highest concentration of EPSs (3.35 ± 0.22 g L^-1) was obtained under optimized conditions; initial pH 5.0, inoculum size 10%, 150 rpm, and 3:1 volume ratio of variable culture to main culture.

Botryosphaeran, a (1 → 3)(1 → 6)-β-D-glucan, reduces tumor development and cachexia syndrome in obese male rats by increasing insulin sensitivity and FOXO3a activity

Obesity is an important risk factor in tumor development. Botryosphaeran, a (1 → 3)(1 → 6)-β-D-glucan, produced by the fungus Botryosphaeria rhodina (MAMB-05), is a high molecular mass, water-soluble exopolysaccharide. It consists of a main chain of (1 → 3)-linked β-d-glucose units, with a degree of branching of ~22% at carbon-6 with glucose and gentiobiose residues linked through β-(1 → 6)-bonds, and presents a triple helix conformation. Botryosphaeran presents anticlastogenic, antiproliferative, pro-apoptotic and anti-obesogenic activities. This study evaluated the effects of botryosphaeran on tumor development in obesity and analyzed its mechanism of action. Obesity was induced in male Wistar rats by a high-fat/high-sugar diet. After 9 weeks, rats were divided into two groups: Obese Tumor (OT) and Obese Tumor Botryosphaeran (OTB), and inoculated with 1 × 10⁷ Walker-256 tumor cells, and treatment with botryosphaeran (30 mg/kg b.w./day via gavage for 15 days) commenced. On the 11th week, biological parameters, tumor development, metabolic profile, erythrogram and protein expression were evaluated. Botryosphaeran significantly reduced tumor growth, body-weight loss and cachexia. Furthermore, botryosphaeran decreased mesenteric fat and insulin resistance, corrected macrocytic anemia, and increased Forkhead transcription factor-3a (FOXO3a) activity. Our study demonstrated the potential role of botryosphaeran in the management of cancer in tumor-bearing obese rats by increasing insulin sensitivity and FOXO3a activity.

Concentration of exopolysaccharides produced by Fusarium fujikuroi and application of bioproduct as an effective bioherbicide

Exopolysaccharides are secondary metabolites produced by microorganisms and are a subject of research in many fields of science and industry due to some of their confirmed properties, especially in the pharmaceutical and agrochemical areas. In this context, the objectives of this work were to evaluate the potential of Fusarium fujikuroi for producing exopolysaccharides and to concentrate such compounds in order to increase the herbicidal activity. Exopolysaccharides were produced by submerged fermentation and different concentration methods (membranes, lyophilization, and evaporation) were evaluated. The phytotoxic effects were assessed through absorption assays in detached leaves of Cucumis sativus and evaluated on the seventh day after application. The surface tension was evaluated for each concentration method. The production of exopolysaccharides in the crude broth without concentration was 5.94 g/L. When using the lyophilization method, a maximum yield of exopolysaccharides of 10.64 g/L was obtained. The membranes also presented satisfactory results of exopolysaccharides: 9.60 g/L. The increase of bioherbicidal activity and the lower surface tension are proportionally related to the increase of the concentration of exopolysaccharides.

M. B. Morais A, Freitas AC, C. F. R. Ferreira I, Pintado M. Valorization of Mushroom By-Products as a Source of Value-Added Compounds and Potential Applications

Nowadays, the food sector is highly concerned with environmental issues and foreseen to develop strategies to reduce waste and losses resulting from activities developed in the food system. An approach is to increment added value to the agro-industrial wastes, which might provide economic growth and environmental protection, contributing to a circular economy. Mushroom by-products represent a disposal problem, but they are also promising sources of important compounds, which may be used due to their functional and nutritional properties. Research has been developed in different fields to obtain value added solutions for the by-products generated during mushroom production and processing. Bioactive compounds have been obtained and applied in the development of nutraceutical and pharmaceutical formulations. Additionally, other applications have been explored and include animal feed, fertilizer, bioremediation, energy production, bio-based materials, cosmetics and cosmeceuticals. The main purpose of this review is to highlight the relevant composition of mushroom by-products and discuss their potential as a source of functional compounds and other applications. Future research needs to explore pilot and industrial scale extraction methods to understand the technological feasibility and the economic sustainability of the bioactive compounds extraction and valorization towards different applications.

Tumor development in rats and cancer cachexia are reduced by treatment with botryosphaeran by increasing apoptosis and improving the metabolic profile

AIMS

Cancer is a multifactorial disease characterized by an uncontrolled growth of cells that can lead to cachexia-anorexia syndrome. Botryosphaeran, a fungal (1 → 3)(1 → 6)-β-D-glucan produced by Botryosphaeria rhodina MAMB-05, has presented antimutagenic, antiproliferative, pro-apoptotic, hypoglycemic and hypocholesterolemic effects. This study evaluated the effects of botryosphaeran (30 mg/kg b.w./day) on tumor development and cachexia syndrome in Walker-256 tumor-bearing rats, and also the metabolic and hematological profiles of these animals.

MATERIALS AND METHODS

Male Wistar rats were divided into 3 groups: control (C), control tumor (CT) and control tumor botryosphaeran (CTB). On the first day, 1 × 10⁷ Walker-256 tumor cells were inoculated subcutaneously into the right flank of the CT and CTB rats, and concomitantly treatment with botryosphaeran (30 mg/kg b.w./day) started. After the 15th day of treatment, biological parameters, tumor development, cachexia, glucose and lipid profiles, hemogram and protein expression were analyzed.

KEY FINDINGS

Botryosphaeran significantly reduced tumor development (p = 0.0024) and cancer cachexia, modulated the levels of glucose, triglycerides and HDL-cholesterol, and corrected macrocytic anemia. Botryosphaeran also increased significantly the bax expression in the tumor tissue (p = 0.038) demonstrating that this (1 → 3)(1 → 6)-β-D-glucan is increasing the apoptosis of tumor cells. p53, p27, bcl-2, caspase-3 and Forkhead transcription factor 3a (FOXO3a) protein expression were similar among the groups.

SIGNIFICANCE

This study demonstrated that botryosphaeran was effective in decreasing tumor development and cachexia by direct and indirect mechanisms increasing apoptosis and improving the metabolic and hematological profiles.

Differences in Production, Composition, and Antioxidant Activities of Exopolymeric Substances (EPS) Obtained from Cultures of Endophytic Fusarium culmorum Strains with Different Effects on Cereals

Exopolymeric substances (EPS) can determine plant-microorganism interactions and have great potential as bioactive compounds. The different amounts of EPS obtained from cultures of three endophytic Fusarium culmorum strains with different aggressiveness-growth promoting (PGPF), deleterious (DRMO), and pathogenic towards cereal plants-depended on growth conditions. The EPS concentrations (under optimized culture conditions) were the lowest (0.2 g/L) in the PGPF, about three times higher in the DRMO, and five times higher in the pathogen culture. The EPS of these strains differed in the content of proteins, phenolic components, total sugars, glycosidic linkages, and sugar composition (glucose, mannose, galactose, and smaller quantities of arabinose, galactosamine, and glucosamine). The pathogen EPS exhibited the highest total sugar and mannose concentration. FTIR analysis confirmed the β configuration of the sugars. The EPS differed in the number and weight of polysaccharidic subfractions. The EPS of PGPF and DRMO had two subfractions and the pathogen EPS exhibited a subfraction with the lowest weight (5 kDa). The three EPS preparations (ethanol-precipitated EP, crude C, and proteolysed P) had antioxidant activity (particularly high for the EP-EPS soluble in high concentrations). The EP-EPS of the PGPF strain had the highest antioxidant activity, most likely associated with the highest content of phenolic compounds in this EPS.