Antioxidation and Hepatoprotection of Selenium Mycelium Polysaccharides Against Alcoholic Liver Diseases from the Cultivated Morel Mushroom Morchella esculenta (Ascomycota).

The liver was regarded as the most important metabolic and detoxification organ in vivo, and Morchella esculenta had been reported as the admittedly rare edible fungus belonging to Ascomycetes contributing to the abundant bioactivities. The objective of this study aimed to confirm the potential antioxidant activities of selenium mycelium polysaccharides (Se-MIP) from M. esculenta against alcoholic liver diseases (ALD) in mice. The results indicated that a selenium concentration of 25 µg/mL exhibited potential in vitro antioxidant capacities of Se-MIP. The in vivo mice results demonstrated that Se-MIP showed potential anti-ALD effects by improving the antioxidant activities and alleviating the hepatic dysfunctions. The present conclusions suggested that Se-MIP could be used as a candidate on improving ALD and its complications for further clinical investigations.

Safe utilization of bioresources in gentamicin mycelial residues by thermal treatment: Antibiotic degradation, resistance gene inactivation and available nutrients promotion.

Gentamicin mycelium residues (GMRs) abundant in organic substances were generated during the production of gentamicin. Inappropriate handling techniques not only waste valuable resources, they could also result in residual gentamicin into the natural environment, leading to the generation of antibiotic resistance genes (ARGs), which would cause a significant threat to ecological system and human health. In the present work, the effects of thermal treatment on the removal of residual gentamicin in GMRs, as well as the changes of associated ARGs abundance, antimicrobial activity and bioresources properties were investigated. The results indicated that the hazards of GMRs was significantly reduced through thermal treatment. The degradation rate of residual gentamicin in GMRs reached 100 %, the total abundance of gentamicin resistance genes declined from 8.20 to 1.14 × 10-5 and the antibacterial activity of the decomposition products of GMRs on Vibrio fischeri was markedly reduced at 200 °C for 120 min. Additionally, the thermal treatment remarkably influenced the bioresource properties of GMRs-decomposition products. The release of soluble organic matters including soluble carbohydrates and soluble proteins have been enhanced in GMRs, while excessively high temperatures could lead to a reduction of nutrient substances. Generally, thermal treatment technology was a promising strategy for synergistic reducing hazards and utilizing bioresources of GMRs.

Characterization of Secondary Metabolites from Mycelial Cultures of Black Morel Mushroom Morchella importuna (Ascomycota).

Species of the genus Morchella are highly prized worldwide for their excellent flavor and high medicinal value. In recent years, artificial cultivations of medicinal fungi with many advantages have elicited great interest as a promising alternative to produce certain valuable metabolites. Therefore, the secondary metabolites of fermented M. importuna belonging to the black morel clade isolated from China were investigated. The strain was cultured in a fermentation tank in PDB liquid medium by two-step method. The mycelia and fermentation broth were extracted by ethyl acetate. The secondary metabolites were separated and purified by repeated silica gel column chromatography. Structures of compounds were determined by NMR data and references. One new natural compound (1) and six known compounds (2-7) were obtained. Compounds 1, 2, 4, and 5 were first isolated from genus Morchella and compounds 3, 6, and 7 are first isolated from species M. importuna.

The Influence of Tyrosol-Enriched Rhodiola sachalinensis Extracts Bioconverted by the Mycelium of Bovista plumbe on Scopolamine-Induced Cognitive, Behavioral, and Physiological Responses in Mice.

Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterized by cognitive deficits, which are accompanied by memory loss and cognitive disruption. Rhodiola sachalinensis (RSE) is a medicinal plant that has been used in northeastern Asia for various pharmacological activities. We attempted to carry out the bioconversion of RSE (Bio-RSE) using the mycelium of Bovista plumbe to obtain tyrosol-enriched Bio-RSE. The objective of this study was to investigate the effects of Bio-RSE on the activation of the cholinergic system and the inhibition of oxidative stress in mice with scopolamine (Sco)-induced memory impairment. Sco (1 mg/kg body weight, i.p.) impaired the mice's performance on the Y-maze test, passive avoidance test, and water maze test. However, the number of abnormal behaviors was reduced in the groups supplemented with Bio-RSE. Bio-RSE treatment improved working memory and avoidance times against electronic shock, increased step-through latency, and reduced the time to reach the escape zone in the water maze test. Bio-RSE dramatically improved the cholinergic system by decreasing acetylcholinesterase activity and regulated oxidative stress by increasing antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)). The reduction in nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling in the brain tissue due to scopolamine was restored by the administration of Bio-RSE. Bio-RSE also significantly decreased amyloid-beta 1-42 (Aß1-42) and amyloid precursor protein (APP) expression. Moreover, the increased malondialdehyde (MDA) level and low total antioxidant capacity in Sco-treated mouse brains were reversed by Bio-RSE, and an increase in Nrf2 and HO-1 was also observed. In conclusion, Bio-RSE protected against Sco-induced cognitive impairment by activating Nrf2/HO-1 signaling and may be developed as a potential beneficial material for AD.

Fruit body formation and intra-species DNA polymorphism in Japanese Wolfiporia cocos strains.

Poria, the dried sclerotium of Wolfiporia cocos, is a medicinal mushroom that is widely used in traditional Japanese medicine. The fruit body of W. cocos is rarely found in the natural environment in Japan, therefore an optimized technique for fruit body formation is essential for producing new strains through crossbreeding and for biological research. Here, we developed a cultivation technique for fruit body formation of W. cocos using three strains collected from different areas of Japan. When mycelia were cultured on sawdust-based medium after liquid medium culture, all strains successfully formed fruit bodies as a brown honeycomb-like structure. Furthermore, we analyzed single nucleotide polymorphisms of the three strains using the STE3-like pheromone receptor protein gene, STE3.2, and found a genetic marker for discriminating one strain from the others. The results are expected to promote extensive studies on crossbreeding and domestic production of W. cocos.

Immunomodulatory activity of polysaccharides from the mycelium of Aspergillus cristatus, isolated from Fuzhuan brick tea, associated with the regulation of intestinal barrier function and gut microbiota.

Aspergillus cristatus is the dominant fungus involved in the fermentation of Fuzhuan brick tea (FBT). The intracellular polysaccharides (IPSs) from A. cristatus (MK346334, NCBI), isolated from FBT, exhibited immunomodulatory activity in vitro while the effects in vivo on immune system and gut microbiota remain unclear. In this study, IPSs and the purified fraction (IPSs-2) from IPSs were prepared and their immunomodulatory activities were investigated with cyclophosphamide (Cy)-induced immunosuppressive mice. As results, IPSs strengthened the immune function, manifesting in the improvement of body weight, daily intake, immune organ indices, cytokines and immunoglobulin. Meanwhile, IPSs attenuated Cy-induced intestinal barrier injury and promoted the expression of tight junction proteins and mucin, reinforcing the intestinal barrier function. Moreover, IPSs not only promoted the production of short-chain fatty acids and the expression of G protein-coupled receptor (GPR), but also balanced dysbiosis of gut microbiota through elevating the growth of beneficial bacteria while reducing pathobionts to maintain the homeostasis of the microbial ecology. These results suggested that IPSs exerted immunomodulatory activity linking with the restoration of intestinal barrier function and regulation of gut microbiota, which contributes to the development of novel probiotics and effective immunomodulators for strengthening host immunity and gut health.

Stimulating mechanism of corn oil on biomass and polysaccharide production of Pleurotus tuber-regium mycelium.

Hyperbranched polysaccharides (HBPSs) are the main components in cell wall and exopolysaccharide (EPS) of Pleurotus tuber-regium. To enhance the yield of these macromolecules, corn oil at 4% addition exhibited the best effect for production of mycelial biomass at 20.49 g/L and EPS at 0.59 g/L, which was 2.56 folds and 1.90 folds of the control, respectively. The treated hyphae were much thicker with smooth surface, while its cell wall content (43.81 ± 0.02%) was 1.96 times of the control (22.34 ± 0.01%). Moreover, a large number of lipid droplets could be visualized under the view of confocal laser scanning microscopy (CLSM). RNA-seq analysis revealed that corn oil could enter the cells and result in the up-regulation of genes on cell morphology and membrane permeability, as well as the down-regulation on expression level of polysaccharide hydrolase and genes involved in the MAPK pathway, all of which probably contribute to the increase of polysaccharides production.

The MADS-box transcription factor GlMADS1 regulates secondary metabolism in Ganoderma lucidum.

MADS-box transcription factors play crucial roles in regulating development processes and biosynthesis of secondary metabolites in eukaryotes. However, the role of MADS-box transcription factors vary among fungal species, and their function remains unclear in the medicinally and economically important fungus Ganoderma lucidum. In this study, we characterized a MADS-box gene, GlMADS1, in G. lucidum. Analyses using quantitative real-time polymerase chain reaction (qRT-PCR) showed that GlMADS1 expression levels were up-regulated from the mycelia to the primordia stage. In order to further evaluate the effect of MADS-box transcription factors on secondary metabolism, we utilized RNA interference (RNAi) to silence GlMADS1 in G. lucidum. Ganoderic acid (GA) and flavonoid contents were enhanced in GlMADS1-silenced strains, suggesting that GlMADS1 negatively regulates GA and flavonoid accumulation.

Enhanced bio-recovery of aluminum from low-grade bauxite using adapted fungal strains.

Filamentous fungi have been proved to have a pronounced capability to recover metals from mineral ores. However, the metal recovery yield is reduced due to toxic effects triggered by various heavy metals present in the ore. The current study highlights the fungal adaptations to the toxic effects of metals at higher pulp densities for the enhanced bio-recovery of aluminum from low-grade bauxite. In the previous studies, a drastic decrease in the aluminum dissolution was observed when the bauxite pulp density was increased from 1 to 10% (w/v) due to the high metal toxicity and low tolerance of Aspergillus niger and Penicillium simplicissium to heavy metals. These fungi were adapted in order to increase heavy metal tolerance of these fungal strains and also to get maximum Al dissolution. A novel approach was employed for the adaptation of fungal strains using a liquid growth medium containing 5% bauxite pulp density supplemented with molasses as an energy source. The mycelia of adapted strains were harvested and subsequently cultured in a low-cost oat-agar medium. Batch experiments were performed to compare the aluminum leaching efficiencies in the direct one-step and the direct two-step bioleaching processes. FE-SEM analysis revealed the direct destructive and corrosive action by the bauxite-tolerant strains due to the extension and penetration of the vegetative mycelium filaments into the bauxite matrix. XRD analysis of the bioleached bauxite samples showed a considerable decline in oxide minerals such as corundum and gibbsite. Results showed a high amount of total Al (≥ 98%) was successfully bioleached and solubilized from low-grade bauxite by the adapted fungal strains grown in the presence of 5% pulp density and molasses as a low-cost substrate. Graphical abstract.

Distribution of Zinc in Mycelial Cells and Antioxidant and Anti-Inflammatory Activities of Mycelia Zinc Polysaccharides from Thelephora ganbajun TG-01.

This study demonstrates that Thelephora ganbajun had a strong ability to absorb zinc, and zinc can be compartmentally stored in the small vesicles and mainly accumulated in the form of zinc-enriched polysaccharides (zinc content was 25.0 ± 1.27 mg/g). Mycelia zinc polysaccharides (MZPS) and its fractions were isolated. The main fraction (MZPS-2) with the highest antioxidant activity in vitro was composed of mannose : galacturonic acid : glucose : galactose in a molar ratio of 61.19 : 1 : 39.67 : 48.67, with a weight-averaged molecular weight of 5.118 × 105 Da. MZPS-2 had both α-pyranose and ß-pyranose configuration and had a triple helical conformation. By establishing zebrafish models, we found that MZPS-2 can significantly scavenge free radicals, reduce the generation of reactive oxygen species caused by inflammation, and inhibit the recruitment of neutrophils toward the injury site. Therefore, MZPS-2 exhibited antioxidant and anti-inflammatory effects and can be used as a zinc supplement with specific biological activities to alleviate zinc deficiency complications, such as chronic oxidative stress or inflammation.

Necrotrophic lifestyle of Rhizoctonia solani AG3-PT during interaction with its host plant potato as revealed by transcriptome analysis.

The soil-borne pathogen Rhizoctonia solani infects a broad range of plants worldwide and is responsible for significant crop losses. Rhizoctonia solani AG3-PT attacks germinating potato sprouts underground while molecular responses during interaction are unknown. To gain insights into processes induced in the fungus especially at early stage of interaction, transcriptional activity was compared between growth of mycelium in liquid culture and the growing fungus in interaction with potato sprouts using RNA-sequencing. Genes coding for enzymes with diverse hydrolase activities were strongly differentially expressed, however with remarkably dissimilar time response. While at 3 dpi, expression of genes coding for peptidases was predominantly induced, strongest induction was found for genes encoding hydrolases acting on cell wall components at 8 dpi. Several genes with unknown function were also differentially expressed, thus assuming putative roles as effectors to support host colonization. In summary, the presented analysis characterizes the necrotrophic lifestyle of R. solani AG3-PT during early interaction with its host.

The Influence of Complex Additives on the Synthesis of Aroma Substances by Gray Oyster Culinary-Medicinal Mushroom, Pleurotus ostreatus (Agaricomycetes) during the Substrate Cultivation.

Aroma substances of mushrooms not only determine the qualitative characteristics of Basidiomycetes fruit bodies, but also exhibit medicinal properties. The chemical composition of the substrate for mushroom cultivation affects not only the growth processes and yield, but also is capable of causing the synthesis of secondary metabolites by mycelium and fruit bodies, such as volatiles, which exhibit a spectrum of biological activity. The purpose of the study was to determine the productivity and aroma profile of Pleurotus ostreatus (Jacq.: Fr.) P. Kumm. (strains IBK-549, IBK-551, IBK-1535) cultivated on sunflower husk and barley straw supplemented with corn husk, wheat bran, rye malt, and soy flour. The sensory profile analysis of mushroom aroma indicated a significant influence of studied additives on the synthesis of volatile flavor compounds. In particular, an increase in the intensity of mushroom, herbaceous, floral, and sweet notes of aroma was recorded in some variants of the experiment. The study has significant practical value for mushroom cultivation, because the use of such complex additives as soy flour, corn husk, wheat bran, and rye malt contributes not only to higher yields, but also affects the quality of the resulting fruit bodies, their biological activity, and medicinal properties.

Verticillium dahliae VdTHI20, Involved in Pyrimidine Biosynthesis, Is Required for DNA Repair Functions and Pathogenicity.

Verticillium dahliae (V. dahliae) infects roots and colonizes the vascular vessels of host plants, significantly reducing the economic yield of cotton and other crops. In this study, the protein VdTHI20, which is involved in the thiamine biosynthesis pathway, was characterized by knocking out the corresponding VdTHI20 gene in V. dahliae via Agrobacterium tumefaciens-mediated transformation (ATMT). The deletion of VdTHI20 resulted in several phenotypic defects in vegetative growth and conidiation and in impaired virulence in tobacco seedlings. We show that VdTHI20 increases the tolerance of V. dahliae to UV damage. The impaired vegetative growth of ΔVdTHI20 mutant strains was restored by complementation with a functional copy of the VdTHI20 gene or by supplementation with additional thiamine. Furthermore, the root infection and colonization of the ΔVdTHI20 mutant strains were suppressed, as indicated by green fluorescent protein (GFP)-labelling under microscope observation. When the RNAi constructs of VdTHI20 were used to transform Nicotiana benthamiana, the transgenic lines expressing dsVdTHI20 showed elevated resistance to V. dahliae. Together, these results suggest that VdTHI20 plays a significant role in the pathogenicity of V. dahliae. In addition, the pathogenesis-related gene VdTHI20 exhibits potential for controlling V. dahliae in important crops.

Pleurotus spp. Mycelia Enriched in Magnesium and Zinc Salts as a Potential Functional Food.

Worldwide, mushrooms belonging to the Pleurotus spp. such as P. citrinopileatus, P. djamor, and P. pulmonarius are highly valued not only for their taste and aroma but also for their health-promoting properties. These species are rich in bioelements, vitamins, and above all, compounds that exhibit immunostimulatory activity. Therefore, in this study, we aimed to determine the effect of the supplementation of culture media using inorganic Mg and Zn salts. This is the first study to establish the bioavailability of the selected elements (Mg and Zn) and anions (Cl-, SO42-) from the enriched biomass by means of the extraction of lyophilized mycelium into artificial digestive juices. The following salts were added to the liquid Oddoux medium: ZnSO4·7H2O, ZnCl2, MgSO4·7H2O or MgCl2·6H2O. The bioelements, anions and organic compounds in the obtained biomass were determined. The addition of Zn and Mg salts to the media increased the production of biomass by 30% and increased the bioaccumulation of the inorganic salts. Maintaining in vitro cultures under optimized and controlled conditions produced mycelium with a better composition and health properties than otherwise. Such enriched biomass may be classified as potential functional foods, aiding in overcoming deficiencies of elements and organic compounds with biological activity in humans.

Comparative Analysis of Triterpene Composition between Ganoderma lingzhi from China and G. lucidum from Slovakia under Different Growing Conditions.

The mushroom today known as Ganoderma lingzhi has been used for centuries in the countries of Eastern Asia as a very important medicinal mushroom. It prefers growing on rotten wood of broadleaf trees and is mainly distributed in the tropics and subtropics. Its relative G. lucidum occurs naturally almost all the Earth, and it colonizes mostly oak and beech trees in Central Europe. G. lingzhi and G. lucidum are similar species. To obtain the qualitative parameters of G. lingzhi and G. lucidum, several strains (five G. lingzhi strains and five G. lucidum ones) were chosen and cultivated in both Slovakia and China, using wood chip (beech and oak) substrate and liquid fermentation method, respectively. It was found that there were more low-polarity triterpenes in G. lucidum, while G. lingzhi contained more high-polarity triterpenes. Beech substrate was more suitable for the accumulation of triterpenes in solid cultivation for both strains of G. lucidum and G. lingzhi. Strain C4 of G. lingzhi and strain K2 of G. lucidum contained higher triterpenes in either mycelium or fruiting bodies. Data in this study can help to identify these two species and bring a great benefit to the production of bioactive compounds of G. lucidum from Slovakia.

Cultivation and Medicinal Value of the Red Belt Conk Mushroom Fomitopsis pinicola (Agaricomycetes).

This study examined biological characteristics, liquid fermentation, and cultivation of Fomitopsis pinicola. A single-factor test concluded that the optimal carbon and nitrogen sources for mycelial growth were soluble starch and yeast paste; the optimal culture temperature was 31°C, and the optimal pH was 6.0. The orthogonal experiment indicated that the optimal formula for mycelial culture was 25 g soluble starch, 2 g yeast extract, 1 g KH2PO4, and 1.5 g MgSO4 added to 1 L water. The optimal conditions for liquid fermentation culture consisted of the following: a loading volume 90 mL, inoculation volume 30 mL, and rotation speed 160 rpm. The optimal substrate formula for domestic culture was 20% corn cob, 30% sawdust, 20% wheat bran, 25% cotton seed shell, 3% corn meal, 1% gypsum, and 1% lime, which produced the highest yield of fruiting bodies. The results provided basic data for deep liquid fermentation culture and recommendations for the further development and utilization of F. pinicola.

Elucidation of the Higher Basidiomycetes Enzyme Activity in Dependence on the Medicinal Mushroom Inoculum Form, Precultivation Medium, Age, and Size.

The impact of five mushroom inoculum form, age, size, and precultivation medium on the lignocellulose-deconstracting enzyme (LCDE) production was evaluated in the submerged fermentation of mandarin marc. The results obtained evidence that an adaptation of individual fungi to lignocellulose during maintenance in culture collection and inoculum cultivation may be useful for the production of individual LCDE. Homogenization of submerged mycelium was beneficial for all LCDE production by Cerrena unicolor 305 and Ganoderna lucidum 447 and for LME secretion by Coriolopsis gallica 142 and Trametes multicolor 511. Finely chopped mycelial agar favored CMCase and xylanase production by T. multicolor 511 and LiP secretion by C. unicolor 305 and G. lucidum 447 while homogenized mycelial agar proved to be the worst form of inoculum for the production of most enzymes. Four-days inoculum was the most appropriate for the laccase and MnP production by G. lucidum 447 and T. multicolor 511 while the 7-days mycelium provided the highest yields of these enzymes in the cultivation of C. unicolor 305. Use of the 12-days homogenized mycelium from the late stationary phase resulted in lowest laccase activity of all fungi but provided the highest cellulase activity. Overall, the study showed that the LCDE activity and their accumulation profiles in the cultures with different inoculum size was species dependent.

Cultivation and growth dynamics of endophytic fungi in a solid culture medium based on sugar beet pulp.

BACKGROUND: The production of mycelium from endophytic fungi is of interest for applications ranging from inoculants and biofertilizers for crop production to fermentations for enzyme and metabolite production. The purpose of this study was to test the capacity of a solid growth medium based on beet pulp for growing different strains of endophytes. RESULTS: The ergosterol content of inoculated medium was measured to estimate fungal growth. Several parameters related to the preparation of the growth medium, such as water content, calcium salts and incubation time, were evaluated. The greatest fungal biomass production was observed in a medium prepared with a 1:2 (beet pulp:water) ratio, containing calcium sulfate and carbonate. Strains belonging to different fungal species grew well in the growth medium finally selected, producing yields ranging from 50 to 500 g mycelium per kilogram of dry culture, after 22-27 days. Cultures containing up to 400 g beet pulp grew successfully, and could be scaled up. CONCLUSION: A solid culture medium based on beet pulp supported the growth of diverse taxa of fungal endophytes. Both the water and calcium salt content of the growth medium affected the efficiency of mycelium production. Considering these factors, beet pulp medium was an excellent endophyte cultivation medium because of the high yield of fungal biomass observed, together with its ease of handling and scaling-up production. © 2019 Society of Chemical Industry.

Showing their mettle: extraradical mycelia of arbuscular mycorrhizae form a metal filter to improve host Al tolerance and P nutrition.

BACKGROUND: New evidence has shown that arbuscular mycorrhizal (AM) fungi can contribute to the aluminum (Al3+ ) tolerance of host plants growing in acidic soils with phytotoxic levels of Al3+ . The aim of this study was to investigate the role of AM fungi isolated from naturally occurring Al3+ acidic soils in conferring host tolerance to Al3+ toxicity in three wheat cultivars differing in Al3+ sensitivity. The experiment was conducted in a soilless substrate (vermiculite/perlite, 2:1 v/v) using two Al3+ -tolerant wheat genotypes and one Al3+ -sensitive wheat genotype. The wheat was colonized with a consortium of AM fungi isolated from an Andisol, with or without Al3+ at a concentration of 200 µmol L-1 . RESULTS: The response of wheat to Al3+ in the medium was dependent on both the plant genotype and AM colonization. The benefits of the AM fungi to the wheat cultivars included an increased P concentration and relatively low Al3+ accumulation in the plants. This was achieved through two mechanisms. First, the metal-chelating capacity of the AM fungi was clear in two of the cultivars ('Tukan' and 'Porfiado'), in which the enhanced extraradical mycelium development was able to retain Al3+ in the glomalin and hyphae. Second, the increased AM-induced acid phosphatase activity in the rhizosphere of the other cultivar ('Atlas 66') increased host nutrition possibly by hyphae-mediated nutrient uptake and glomalin-related soil protein. CONCLUSION: The results suggest that the role of AM fungi in cultivar-specific Al3+ detoxification can be achieved by increased extraradical mycelial filters and enhanced bioavailability of P in the host rhizosphere. © 2019 Society of Chemical Industry.

Therapeutic Potential of Hericium erinaceus for Depressive Disorder.

Depression is a common and severe neuropsychiatric disorder that is one of the leading causes of global disease burden. Although various anti-depressants are currently available, their efficacies are barely adequate and many have side effects. Hericium erinaceus, also known as Lion's mane mushroom, has been shown to have various health benefits, including antioxidative, antidiabetic, anticancer, anti-inflammatory, antimicrobial, antihyperglycemic, and hypolipidemic effects. It has been used to treat cognitive impairment, Parkinson's disease, and Alzheimer's disease. Bioactive compounds extracted from the mycelia and fruiting bodies of H. erinaceus have been found to promote the expression of neurotrophic factors that are associated with cell proliferation such as nerve growth factors. Although antidepressant effects of H. erinaceus have not been validated and compared to the conventional antidepressants, based on the neurotrophic and neurogenic pathophysiology of depression, H. erinaceus may be a potential alternative medicine for the treatment of depression. This article critically reviews the current literature on the potential benefits of H. erinaceus as a treatment for depressive disorder as well as its mechanisms underlying the antidepressant-like activities.