Mycelial Polysaccharide Research Articles

Enhanced Effects of Iron on Mycelial Growth, Metabolism and In Vitro Antioxidant Activity of Polysaccharides from Lentinula edodes.

The polysaccharides found in Lentinula edodes have a variety of medicinal properties, such as anti-tumor and anti-viral effects, but their content in L. edodes sporophores is very low. In this study, Fe2+ was added to the liquid fermentation medium of L. edodes to analyze its effects on mycelial growth, polysaccharide and enzyme production, gene expression, and the activities of enzymes involved in polysaccharide biosynthesis, and in vitro antioxidation of polysaccharides. The results showed that when 200 mg/L of Fe2+ was added, with 7 days of shaking at 150 rpm and 3 days of static culture, the biomass reached its highest value (0.28 mg/50 mL) 50 days after the addition of Fe2+. Besides, Fe2+ addition also enhanced intracellular polysaccharide (IPS) and exopolysaccharide (EPS) productions, the levels of which were 2.98- and 1.79-fold higher than the control. The activities of the enzymes involved in polysaccharides biosynthesis, including phosphoglucomutase (PGM), phosphoglucose isomerase (PGI), and UDPG-pyrophosphorylase (UGP) were also increased under Fe2+ addition. Maximum PGI activity reached 1525.20 U/mg 30 days after Fe2+ addition, whereas PGM and UGP activities reached 3607.05 U/mg and 3823.27 U/mg 60 days after Fe2+ addition, respectively. The Pearson correlation coefficient showed a strong correlation (p < 0.01) between IPS production and PGM and UGP activities. The corresponding coding genes of the three enzymes were also upregulated. When evaluating the in vitro antioxidant activities of polysaccharides, EPS from all Fe2+-treated cultures exhibited significantly better capacity (p < 0.05) for scavenging -OH radicals. The results of the two-way ANOVA indicated that the abilities of polysaccharides to scavenge O2− radicals were significantly (p < 0.01) affected by Fe2+ concentration and incubation time. These results indicated that the addition of iron provided a good way to achieve desirable biomass, polysaccharide production, and the in vitro antioxidation of polysaccharides from L. edodes.

Effects of polysaccharides autoclave extracted from Flammulina velutipes mycelium on freeze-thaw stability of surimi gels

Quality deterioration caused by ice formation and growth is a prevailing problem in frozen food, therefore, exploration of natural cryoprotectants has been attracting more attention. In this study, Flammulina velutipes mycelium polysaccharides (FVP) were obtained by autoclave extraction and their effect on freeze-thaw stability of surimi gels were investigated. The results showed that FVP consisted mainly (59.02%) of high-molecular-weight polysaccharides (>450 kDa), and were composed of Glu, Xyl, Man, Gal, and Fuc in a molar ratio of 33.4: 28.72: 26.31: 8.01: 3.55. FVP (1.0 mg/mL) showed superior Ice Recrystallization Inhibition (IRI) activity. Freeze-thaw stability tests demonstrated that frozen-thawed surimi gels with FVP addition exhibited a more uniform and continuous matrices than the control ones. FVP could significantly improve the water holding capacity, the hardness, springiness and cohesiveness of surimi gels during the repeated freeze-thaw cycles. Studies on water state and properties showed that FVP could decrease the freezable water content, restrict water mobility, and inhibit water migration in frozen surimi gels. These results suggest the potential of FVP as a promising cryoprotectant candidate in the frozen food industry.

Al-MPS Obstructs EMT in Breast Cancer by Inhibiting Lipid Metabolism via miR-215-5p/SREBP1.

Alkali-extractable mycelial polysaccharide (Al-MPS) is a natural macromolecular polymer that has shown anti-hyperlipidemic and antitumor abilities. This study investigates the mechanism by which Al-MPS inhibits lipid metabolism and epithelial-mesenchymal transition (EMT) in breast cancer (BC). BC cells (MCF-7 and MDA-MB-231) were transfected and/or treated with Al-MPS. CCK-8, Transwell, and scratch assays were used to evaluate the tumorigenic behaviors of BC cells. The expression levels of SREBP1, E-cadherin, N-cadherin, Snail, vimentin, FASN, ACLY, and ACECS1 in BC cells were detected by Western blotting. Dual-luciferase reporter and RNA pull-down assays were performed to verify the binding between miR-215-5p and SREBP1 mRNA. Nude mice were injected with MDA-MB-231 cells and treated with Al-MPS. The changes in tumor volume and protein expression were monitored. miR-215-5p was downregulated and SREBP1 was upregulated in BC. Al-MPS increased miR-215-5p expression and inhibited SREBP1 expression, lipid metabolism, and EMT in BC. Inhibition of miR-215-5p or overexpression of SREBP1 promoted the tumorigenic behaviors of BC cells by stimulating lipid metabolism and counteracted the antitumor effect of Al-MPS. SREBP1 was a downstream target of miR-215-5p. In conclusion, Al-MPS inhibits lipid metabolism and EMT in BC via the miR-215-5p/SREBP1 axis. This study supports the application of polysaccharides in cancer treatment and the molecules regulated by Al-MPS may be used as biomarkers or therapeutic targets for BC.

Effect of Crude Oil on Biomass Production, Polysaccharide, and Polyphenol Content of Leucocoprinus cretaceus(Bull.) Locq. a white rot fungus

There is need to establish the best lignocellulosic wastes with bio-stimulatory effects on mushrooms been investigated for myco-remediation purposes. Solid state fermentation of four substrates (sawdust of Anthostema aubryanum Baill, Mansonia altissima (A. Chev.) A. Chev., Nauclea diderrichii (De Eild &amp; T. Durand) Merr and Malt Extract Agar) contaminated with various levels of crude oil contamination by Leucocoprinus cretaceus (Bull.) Locq., was studied. The effect of crude oil on mycelial biomass production, polysaccharide, and polyphenol contents of L. cretaceus during solid state fermentation of lignocellulosic wastes was determined. The polysaccharide and polyphenol content of the mycelia was determined with the Phenol-Sulphuric acid and Folin-Ciocalteu methods, respectively. Solid state fermentation of crude contaminated substrates improved biomass and polysaccharide content of L. cretaceus. The fungus is a good bioremediation agent degrading crude oil with increasing levels of crude oil contamination (28.00% in 1.00% crude oil contamination to 81% in 10.00% crude oil contamination). Radial mycelial extension increased with increasing levels of crude oil contamination. Crude oil did not cause increased polyphenol concentration and therefore not a stress factor. There was increase in polysaccharide content indicating metabolization of crude oil for metabolic build up. Supplementing crude oil contaminated substrates with the sawdust of M. altissima resulted in the highest level of crude oil degradation by the test fungus. L. cretaceus is a potential strong myco-remediation agent. This study records the first time the fungus is used for degradation of crude oil contaminated substrates. The mushroom has the potential to completely mineralize petroleum hydrocarbons.

Comparison of Protective Effects of Hericium erinaceus Extracts Prepared by Different Methods on Acute Gastric Mucosal Injury in Rats

Using absolute ethanol as an inducer, a rat model of acute gastric mucosal injury was constructed, and the protective effects of Hericium erinaceus crude extract prepared in several different ways on the model of acute gastric mucosal injury induced by absolute ethanol were studied. Female SD rats were randomly divided into 7 groups (n=12): Normal control group (NC), model control group (ETH), Hericium erinaceus fruit body polysaccharide intervention group(WEH1), Hericium erinaceus mycelium polysaccharide intervention group (WEH2), Hericium erinaceus water extract intervention group (WEH3), liquid fermentation water extract intervention group (WEH4) and bismuth potassium citrate granule drug group (YWZ). In each sample groups, the gavage dose (10 mL/kg) of the sample was adjusted according to the weight change, and the sample was given 167 mg/kg, bismuth potassium citrate granules (0.24 g/kg, containing 24.1 mg of bismuth) for continuous intragastric administration for 30 days. Then the normal control group and the model group were directly given distilled water, and 5 mL/kg of absolute ethanol was used to make the model. By comparing the degree of injury of gastric mucosal tissue slices, the level of inflammatory factors and the antioxidant capacity. Finally the results showed that comparing with the model group, the experimental group had significantly reduced gastric mucosal bleeding, congestion, necrosis, and pathology, and the total pathological scores were significantly different (P<0.05), the activities of superoxide dismutase (SOD) and glutathione (GSH) were significantly increased (P<0.05), the content of malondialdehyde (MDA), tumor necrosis factor-α in serum and gastric tissue (TNF-α), interleukin-6(IL-6), interleukin-1β (IL-1β) inflammatory factors levels were significantly reduced (P<0.05). So the tests have shown that several Hericium erinaceus extracts have varying degrees of protection against gastric mucosal damage in rats induced by absolute ethanol, among of them, the Hericium erinaceus mycelium polysaccharide has the best protective effect, while its mechanism of action may be similar to that of anti- oxidation is related to anti-inflammatory effects. The research results could provide a research foundation for the development and promotion of functional products of different Hericium erinaceus extracts.

Mycelium polysaccharides of Macrolepiota procera alleviate reproductive impairments induced by nonylphenol.

Nonylphenol (NP) exposure has become a crucial inducement of male reproductive disorders in the world. Therefore, it is urgent to seek solutions to alleviate the toxicity of NP. This study was oriented toward studying the protective effects of Macrolepiota procera mycelium polysaccharides (MMP) on NP-induced reproductive impairments. After NP administration, declined sperm amounts and testis index, increased the deformity rate of sperms, aberrant hormone secretion and testicular pathological injury were observed, corporately leading to reproductive capacity attenuation. Importantly, MMP significantly reversed the foregoing changes in NP-treated mice. Notably, it has been observed that the MMP therapy remarkably improved oxidative stress, apoptosis, autophagy and inflammatory responses, and suppressed the Akt/mTOR signaling pathway in testicular tissues. These results manifested that MMP might be a promising treatment strategy for ameliorating the biotoxicity of NP.

Comparison of the Anti-Inflammatory and Antioxidant Activities of Mycelial Polysaccharides from Different Strains of Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes).

Ganoderma lucidum is a popular tonic medicine in China, and its polysaccharides are believed to promote health benefits. However, G. lucidum and the composition, structure, and molecular weight of G. lucidum polysaccharides (GLPs) are very heterogeneous. There are limited studies on the relationship between GLPs and their function. Therefore, this study sought to evaluate the cosmetic efficacy of six types of GLPs and analyze the structure of the identified polysaccharides. GLPs (GLP1-GLP6) were prepared with conventional methods by selecting six G. lucidum strains. The 8-methoxypsoralan-induced melanin model of B16 cells, the lipopolysaccharide-induced inflammation model of HaCaT cells, and the hydrogen peroxide-induced oxidative stress model of human skin fibroblasts (HSFs) were used. The whitening, anti-inflammatory, and antioxidative effects of GLP1-GLP6 were determined. After initial screening, promising GLPs were selected for further analysis. These were purified and their structure was characterized. GLP1-GLP6 had no whitening effect as assessed by cellular tyrosinase level and melanin content. Meanwhile, GLP1 and GLP4 had strong inhibitory effect on hyaluronidase, and GLP1 and GLP2 significantly reduced the relative expression of inflammatory cytokine interleukin-1α. All GLPs could significantly increase the activity of HSFs and reduce the proportion of senescent cells. The comprehensive score of GLP1 was the highest. GLP1-I and GLP1-II were obtained by DEAE-52 ion exchange resin. Morphological analysis showed that there were significant differences between GLP1 and its two components. The results of infrared spectroscopy showed that GLP1-I had a β-glycosidic bond, and high-performance gel penetration chromatography showed that GLP1-I had a low molecular weight. GLPs showed no whitening but had significant antioxidant activity. GLPs are promising compounds to be developed into natural antioxidants and potentially used in cosmetics, health products, and functional foods.

The β-1,3-glucan synthase gene GFGLS2 plays major roles in mycelial growth and polysaccharide synthesis in Grifola frondosa.

β-1,3-Glucans are well-known biological and health-promoting compounds in edible fungi. Our previous results characterized a glucan synthase gene (GFGLS) of Grifola frondosa for the first time to understand its role in mycelial growth and glucan biosynthesis. In the present study, we identified and functionally reannotated another glucan synthase gene, GFGLS2, based on our previous results. GFGLS2 had a full sequence of 5944bp including 11 introns and 12 exons and a coding information for 1713 amino acids of a lower molecular weight (195.2kDa) protein with different conserved domain sites than GFGLS (5927bp with also 11 introns and a coding information for 1781 aa). Three dual-promoter RNA-silencing vectors, pAN7-iGFGLS-dual, pAN7-iGFGLS2-dual, and pAN7-CiGFGLS-dual, were constructed to downregulate GFGLS, GFGLS2, and GFGLS/GFGLS2 expression by targeting their unique exon sequence or conserved functional sequences. Silencing GFGLS2 resulted in higher downregulation efficiency than silencing GFGLS. Cosilencing GFGLS and GFGLS2 had a synergistic downregulation effect, with slower mycelial growth and glucan production by G. frondosa. These findings indicated that GFGLS2 plays major roles in mycelial growth and polysaccharide synthesis and provides a reference to understand the biosynthesis pathway of mushroom polysaccharides. KEY POINTS: • The 5944-bp glucan synthase gene GFGLS2 of G. frondosa was cloned and reannotated • GFGLS2 showed identity and significant differences with the previously identified GFGLS • GFGLS2 played a major role in fermentation and glucan biosynthesis.

Structural characterization of two Hericium erinaceus polysaccharides and their protective effects on the alcohol-induced gastric mucosal injury

Hericium erinaceus, a traditional edible mushroom, is known as a medicine food homology to ameliorate gastrointestinal diseases. However, the relationship between the structural characteristics of Hericium erinaceus and its stomach-protecting activity remains unclear. Here, the structural properties of two polysaccharides from Hericium erinaceus, mycelium polysaccharide (HMP) and fruiting body polysaccharide (HFP) were investigated by spectral approaches. The results showed that the distribution of HMP was more uniform compared to HFP. Both HMP and HFP have triple helix structures, but the HMP conformation showed greater stability. Subsequently, the preventive effect of HMP and HFP on ethanol-induced gastric mucosal injury was also evaluated in rats and GES-1 cells, and it showed that both HMP and HFP had significant protective activity against gastric mucosal injury, but HMP showed better activity than HFP. These results suggested that conformational stability polysaccharide in Hericium erinaceus is more related to its gastric-protecting activity.

Study on the interaction of Hericium erinaceus mycelium polysaccharides and its degradation products with food additive silica nanoparticles

Gastric mucosal injury is a common gastrointestinal disorder. Hericium erinaceus polysaccharide, the major active ingredient in Hericium erinaceus, can reduce gastric mucosal damage to some extent. In this study, two different products HMP-Vc and HMP-Ce were obtained by Vitamin C and cellulase degradation of Hericium erinaceus mycelium polysaccharide (HMP). The gastroprotective activity of polysaccharides and its interaction products with food additives silica nanoparticles (nSiO2) were studied in GES-1 cells. It was found that gastroprotective activity of HMP was significantly higher than that of degradation products, and the addition of nSiO2 could enhance this activity of HMP. The greatest difference between the degradation products and HMP was the reduction of the triple helix structure, which might be the reason of the gastroprotective activity was less than that of HMP. Moreover, nSiO2 might interact with HMP through hydrogen bonding to enhance its activity.

The protective effect and crucial biological pathways analysis of Trametes lactinea mycelium polysaccharides on acute alcoholic liver injury in mice based on transcriptomics and metabonomics

Trametes lactinea mycelia polysaccharides (TLMPS) have a wide range of bioactivities. The potential mechanisms of action of TLMPS against acute alcohol-induced liver injury in vivo were investigated by analyzing the physical and chemical properties of TLMPS and its protective effects on a mouse model of alcoholic liver injury. TLMPS protected the liver against alcohol-induced injury, as evidenced by the reduced alcohol-induced elevation of the liver index, serum biochemical indices, and maintenance of hepatic morphology. Potential mechanisms were analyzed using transcriptome and metabolome analyses. The transcriptome data revealed the involvement of many differentially expressed genes in chemical carcinogenesis, drug metabolism, and metabolism of xenobiotics by cytochrome P450. The metabolome analysis revealed that TLMPS significantly regulated specific metabolites in the liver, including organic acids, lipids, nucleosides, and organic oxygen compounds. KEGG enrichment analysis revealed the significant involvement of different metabolites in choline metabolism, ATP-binding cassette transporters, and glycerophospholipid metabolism. Assessment of the changes in gene expression and metabolites revealed the significantly different expression of several genes encoding key enzymes and metabolites in choline metabolism pathway. The collective findings confirmed that choline metabolism plays an important role in the protective effects of TLMPS against acute alcoholic liver injury.

ARTP Mutagenesis to Improve Mycelial Polysaccharide Production of Grifola frondosa Using a Mixture of Wheat Bran and Rice Bran as Substrate

Mycelial polysaccharides from Grifola frondosa have shown potential for the prevention of chronic diseases. Atmospheric and room temperature plasma (ARTP) technology was used to enhance the ability of G. frondosa to efficiently utilize a mixture of rice bran and wheat bran in the production of mycelial polysaccharides. The ARTP-mutant G. frondosa GFA2 had an improved growth rate of 6.0 mm/d and polysaccharide yield of 2.65 g/L and showed stable genetic characteristics. Uniform design experiments showed that polysaccharide yield could be increased to 5.90 g/L using the optimized conditions of 10.0 g/L rice bran and 110.0 g/L wheat bran while omitting KH2PO4 and MgSO4·7H2O. Gas chromatography demonstrated that GFA2 polysaccharides were composed of the monosaccharides rhamnose, arabinose, fucose, xylose, mannose, glucose, and galactose. This study provides an effective strategy for improving polysaccharide production in edible fungi while proposing the added-value utilization of rice and wheat brans.

Carbon Source Affects Synthesis, Structures, and Activities of Mycelial Polysaccharides from Medicinal Fungus Inonotus obliquus.

The effects of various carbon sources on mycelial growth and polysaccharide synthesis of the medicinal fungus Inonotus obliquus in liquid fermentation were investigated. After 12-d fermentation, mycelial biomass, polysaccharide yield, and polysaccharide content were significantly higher in Glc+Lac group (glucose and lactose used as combined carbon source) than in other groups. Crude polysaccharides (CIOPs) and the derivative neutral polysaccharides (NIOPs) were obtained from mycelia fermented using Glc, fructose (Fru), Lac, or Glc+Lac as carbon source. Molecular weights of four NIOPs (termed as NIOPG, NIOPF, NIOPL, and NIOPGL) were respectively 780.90, 1105.00, 25.32, and 10.28 kDa. Monosaccharide composition analyses revealed that NIOPs were composed of Glc, Man, and Gal at different molar ratios. The NIOPs were classified as α-type heteropolysaccharides with 1→2, 1→3, 1→4, 1→6 linkages in differing proportions. In in vitro cell proliferation assays, viability of RAW264.7 macrophages was more strongly enhanced by NIOPL or NIOPGL than by NIOPG or NIOPF, and proliferation of HeLa or S180 tumor cells was more strongly inhibited by NIOPG or NIOPGL than by NIOPF or NIOPL, indicating that immune-enhancing and anti-tumor activities of NIOPs were substantially affected by carbon source. qRT-PCR analysis revealed that expression levels of phosphoglucose isomerase (PGI) and UDP-Glc 4-epimerase (UGE), two key genes involved in polysaccharide synthesis, varied depending on carbon source. Our findings, taken together, clearly demonstrate that carbon source plays an essential role in determining structure and activities of I. obliquus polysaccharides by regulating expression of key genes in polysaccharide biosynthetic pathway.

Structural characterization and immunomodulatory activity of mycelium polysaccharide from liquid fermentation of Monascus purpureus (Hong Qu)

Alkaline extracted endopolysaccharides (MPS) from Monascus purpureus (Hong Qu) mycelium were successfully separated into four sub-fractions, namely MPS-1 (18.0 %), MPS-2 (27.1 %), MPS-3 (12.6 %) and MPS-4 (14.7 %), by DEAE-Cellulose column chromatography. By combining monosaccharide composition analysis, methylation analysis and 1D & 2D NMR, the structure of sub-fractions was systematically characterized. Both MPS-1 and MPS-2 were comprised of mannose, glucose and galactose in the molar ratio of 1.5:1.6:1.0 and 10.6:1.0:13.8, respectively. The backbone of them both consisted of 2-α-Manp with several different branched chains. However, MPS-1 contained glucose based sugar residues such as 3-Glcp and 4-Glcp which were not shown on MPS-2. The proposed structures of MPS-3 and MPS-4 were not obtained due to the fairly complex molecular structure and relatively low yield. Moreover, based on the RAW 264.7 cells model, MPS-2 could significantly promote cytokines secretion including IL-6, TNF-α, and IL-10 and improve expression levels of the related mRNA.

Comparison of Polysaccharides Extracted from Cultivated Mycelium of Inonotus obliquus with Polysaccharide Fractions Obtained from Sterile Conk (Chaga) and Birch Heart Rot.

The polysaccharides of the sterile conk of Inonotus obliquus (Chaga) have demonstrated multiple bioactivities. The mycelium of this basidiomycete, obtained after submerged cultivation, has been considered a feasible alternative to the sterile conk for the production of polysaccharides. However, previous research has paid little attention to the differences in the structures of polymers obtained from the different resources. Moreover, the birch wood colonized by I. obliquus has never been investigated as a source of bioactive polysaccharides. In the present study, polysaccharide fractions produced from cultivated mycelium, sterile conks of different geographical origins, and birch heart rot were investigated. High amounts of phenolic compounds, possibly lignans, were bound to the sterile conk polysaccharides. Mycelial polysaccharides were rich in α- and β-glucans and had high (105 Da) and low (104 Da) molecular weight populations. On the other hand, sterile conk polysaccharides were mainly β-glucan of lower and monodispersed molecular weight (103 Da). Heart rot polysaccharides were comprised mainly of low molecular weight (103 Da) hemicelluloses. Nevertheless, fungal polysaccharides were identified in the extracts. The differences in structure and molecular properties among the polysaccharide fractions of mycelium, heart rot, and sterile conk are likely associated with differences in bioactivities and, therefore, in nutraceutical potential.

Effects of nitrogen from different sources on mycelial biomass and polysaccharide production and pellet morphology in submerged cultures of Grifola frondosa

The effects of nitrogen in the medium on the production of mycelial biomass, extracellular polysaccharides (EPS), and intracellular polysaccharides (IPS) was investigated in submerged cultures of Grifola frondosa. In addition, the effects on pellet morphology were examined. The maximum production levels of mycelial biomass (2.32 g/L), EPS (1.58 g/L), and IPS (29.1 mg/L) were obtained when the nitrogen sources in the medium were yeast extract, malt extract, and peptone, respectively. Using yeast extract as the nitrogen source yielded the maximum mycelial biomass, and morphological characterization revealed a composition of 47% large pellets (fraction L), 20% small pellets (fraction S), and 33% adhesive mycelia (fraction A). The maximum circularity value and the minimum roughness value of the pellets were observed using yeast extract cultures. Both the compactness (0.53) and circularity (0.15) of the pellets were the lowest among the seven types of nitrogen sources, but the roughness (2.86) was the highest in malt extract, which was the nitrogen source that resulted in maximum polysaccharide production. The results revealed that the production levels of mycelial biomass, EPS, and IPS of G. frondosa were associated with changes in pellet morphology due to the source of nitrogen in the medium.

Effect of the heme oxygenase gene on mycelial growth and polysaccharide synthesis in Ganoderma lucidum

The heme oxygenase gene has antioxidant and cytoprotective effects in organisms, but no related research has been conducted in Ganoderma lucidum. For the first time, we cloned the HMX1 gene in G. lucidum. The CDS is 1092 bp in length and encodes 363 amino acids. The HMX1 protein was prokaryotically expressed and purified, and the enzyme activity of the purified protein was measured. The value of Km was 0.699 μM, and Vm was 81.9 nmol BV h-1 nmol-1 protein. By constructing the silencing vector pAN7-dual-HMX1i, the transformants HMX1i1 and HMX1i2 were obtained. Compared with the wild-type (WT), the average growth rate of HMX1i1 and HMX1i2 decreased by 31% and 23%, respectively, and the mycelium biomass decreased by 53% and 48%, respectively. Compared with the WT, the extracellular polysaccharide content of HMX1i1 and HMX1i2 increased by 59% and 51%, and the intracellular polysaccharide content increased by 24% and 22%, respectively. These results indicate that the HMX1 gene affects mycelial growth and polysaccharide synthesis in G. lucidum.

Antioxidation, anti-inflammation and anti-fibrosis effect of phosphorylated polysaccharides from Pleurotus djamor mycelia on adenine-induced chronic renal failure mice

The mycelia polysaccharides (MPS) from Pleurotus djamor were prepared and purified by anion exchange column chromatography, and the phosphate content of phosphorylated MPS (PMPS) was 15.22 ± 0.37%. FT-IR spectra, HPLC and 1H and 13C-NMR results showed the PMPS contained α-pyranose structure and the peak area percentage composition of galacturonic acid and glucose were 13.01% and 85.82%, respectively. Animal experiment investigated the antioxidant, anti-inflammation, anti-fibrosis effects of PMPS on kidney in adenine-induced chronic renal failure (CRF) mice. All results including serum biochemical indices, histopathological observation, qRT-PCR, western blotting, immunohistochemical staining manifested the kidney injury could be remitted by PMPS interventions. This experiment suggested that PMPS could remit CRF and other kidney injury related diseases as one kind of dietary supplements and functional foods without toxic side effects.

Impact of different fermentation characteristics on the production of mycelial biomass, extra-cellular polysaccharides, intra-cellular polysaccharides, and on the antioxidant activities of Cordyceps militaris (L.) Fr. (strains AG-1, PSJ-1)

The mycelial biomass, antioxidant activity and production of extra- and intra-cellular polysaccharides production [EPS, IPS] of Cordyceps militaris strains AG-1, PSJ-1 were evaluated under different submerged liquid culture (SLC) conditions. At 24 0C mycelial biomass and polysaccharide production of AG-1, PSJ-1 was optimal using PVC media and static culture conditions; (AG-1: 21.85 ± 1.00; PSJ-1: 18.20 ± 1.84 g l-1 ), and oven drying at 40 oC (AG-1: 25.95 ± 0.84, PSJ-1: 23.55 ± 0.69 mg g-1) compared with hot water extraction (AG-1: 7.07 ± 0.15, PSJ-1: 7.39 ± 0.61 mg g-1). Maximum biomass, EPS and IPS production were observed when the initial pH was 6.7: AG-1: 12.92 ± 0.33, 209.70 ± 1.56, 32.62 ± 0.87; PSJ-1: 9.03 ± 0.24 g l-1 , 198.16 ± 0.85 mg g-1, 30.63 ± 1.96 mg g-1, respectively. The use 3.5 % coconut oil improved biomass, EPS, IPS production, which were 8.27 ± 0.09, 8.01 ± 0.01 g l-1 ; 1208.00 ± 8.60, 1110.40 ± 7.20 mg g-1; 32.43 ± 0.49, 29.74 ± 0.44, for AG-1 and PSJ-1, respectively. Both culture condition and oven drying methods had significant effects on H2O2 and radical scavenging activity, ABTS.+ radical activity, lipid peroxidation, and also had effects on total flavonoid and, total phenolic contents. The use of crude submerged liquid culture and oven drying on strains AG-1, PSJ-1 led to extracts with potent antioxidant activity, suggesting the therapeutic use of polysaccharides from strains AG-1, PSJ-1.

The role of Rho1 gene in the cell wall integrity and polysaccharides biosynthesis of the edible mushroom Grifola frondosa

Grifola frondosa polysaccharides, especially β-glucans, showed the significant antitumor, hypoglycemic, and immune-stimulating activities. In the present study, a predominant regulatory subunit gfRho1p of β-1,3-glucan synthase in G. frondosa was identified with a molecular weight of 20.79 kDa and coded by a putative 648-bp small GTPase gene gfRho1. By constructing mutants of RNA interference and over-expression gfRho1, the roles of gfRho1 in the growth, cell wall integrity and polysaccharide biosynthesis were well investigated. The results revealed that defects of gfRho1 slowed mycelial growth rate by 22% to 33%, reduced mycelial polysaccharide and exo-polysaccharide yields by 4% to 7%, increased sensitivity to cell wall stress, and down-regulated gene transcriptions related to PKC-MAPK signaling pathway in cell wall integrity. Over-expression of gfRho1 improved mycelial growth rate and polysaccharide production of G. frondosa. Our study supports that gfRho1 is an essential regulator for polysaccharide biosynthesis, cell growth, cell wall integrity and stress response in G. frondosa.