Saccharification of sunflower stalks using lignocellulases from a fungal consortium comprising Pholiota adiposa and Armillaria gemina.[Pubmed: 25924967]

Lignocellulases from Armillaria gemina and Pholiota adiposa are efficient in hydrolyzing aspen and poplar biomass, respectively. In the present study, lignocellulosic enzymes obtained from a fungal consortium comprising P. adiposa and A. gemina were used for the saccharification of sunflower stalks. Sunflower stalks were thermochemically pretreated using 2 % NaOH at 50 °C for 24 h. The saccharification process parameters including substrate concentration, enzyme loading, pH, and temperature were optimized using response surface methodology to improve the saccharification yield. The highest enzymatic hydrolysis (84.3 %) was obtained using the following conditions: enzyme loading 10 FPU/g-substrate, substrate 5.5 %, temperature 50 °C, and pH 4.5. The hydrolysis yield obtained using the enzymes from the fungal consortium was equivalent to that obtained using a mixture of commercial enzymes Celluclast and Novozyme β-glucosidase. Addition of up to 500 ppm of heavy metal ions (As, Cu, Fe, Mn, Ni, Pb, and Zn) during saccharification did not significantly affect the saccharification yield. Thus, the biomass grown for phytoremediation of heavy metals can be used for the production of reducing sugars followed by ethanol fermentation.

Differences in the activities of eight enzymes from ten soil fungi and their possible influences on the surface structure, functional groups, and element composition of soil colloids.[Pubmed: 25398013]

How soil fungi function in soil carbon and nutrient cycling is not well understood by using fungal enzymatic differences and their interactions with soil colloids. Eight extracellular enzymes, EEAs (chitinase, carboxymethyl cellulase, β-glucosidase, protease, acid phosphatase, polyphenol oxidase, laccase, and guaiacol oxidase) secreted by ten fungi were compared, and then the fungi that showed low and high enzymatic activity were co-cultured with soil colloids for the purpose of finding fungi-soil interactions. Some fungi (Gomphidius rutilus, Russula integra, Pholiota adiposa, and Geastrum mammosum) secreted 3-4 enzymes with weak activities, while others (Cyathus striatus, Suillus granulate, Phallus impudicus, Collybia dryophila, Agaricus sylvicola, and Lactarius deliciosus) could secret over 5 enzymes with high activities. The differences in these fungi contributed to the alterations of functional groups (stretching bands of O-H, N-H, C-H, C = O, COO- decreased by 11-60%, while P = O, C-O stretching, O-H bending and Si-O-Si stretching increased 9-22%), surface appearance (disappearance of adhesive organic materials), and elemental compositions (11-49% decreases in C1s) in soil colloids. Moreover, more evident changes were generally in high enzymatic fungi (C. striatus) compared with low enzymatic fungi (G. rutilus). Our findings indicate that inter-fungi differences in EEA types and activities might be responsible for physical and chemical changes in soil colloids (the most active component of soil matrix), highlighting the important roles of soil fungi in soil nutrient cycling and functional maintenance.

Characterization of a β-1,4-mannanase from a newly isolated strain of Pholiota adiposa and its application for biomass pretreatment.[Pubmed: 24590240]

A highly efficient β-1,4-mannanase-secreting strain, Pholiota adiposa SKU0714, was isolated and identified on the basis of its morphological features and sequence analysis of internal transcribed spacer rDNA. P. adiposa β-1,4-mannanase was purified to homogeneity from P. adiposa culture supernatants by one-step chromatography on a Sephacryl gel filtration column. P. adiposa β-1,4-mannanase showed the highest activity toward locust bean gum (V max = 1,990 U/mg protein, K m = 0.12 mg/mL) ever reported. Its internal amino acid sequence showed homology with hydrolases from the glycoside hydrolase family 5 (GH5), indicating that the enzyme is a member of the GH5 family. The saccharification of commercial mannanase and P. adiposa β-1,4-mannanase-pretreated rice straw by Celluclast 1.5L (Novozymes) was compared. In comparison with the commercial Novo Mannaway(®) (113 mg/g-substrate), P. adiposa β-1,4-mannanase-pretreated rice straw released more reducing sugars (141 mg/g-substrate). These properties make P. adiposa β-1,4-mannanase a good candidate as a new commercial β-1,4-mannanase to improve biomass pretreatment.

First report on isolation of methyl gallate with antioxidant, anti-HIV-1 and HIV-1 enzyme inhibitory activities from a mushroom (Pholiota adiposa).[Pubmed: 24572641]

In this study, a compound with antioxidant and anti-HIV activities designated as HEB was first isolated from the edible mushroom Pholiota adiposa by extraction with ethanol and ethyl acetate. HEB was then purified by high performance liquid chromatography (HPLC) and identified to be methyl gallate (C8H8O5, 184.1 Da) based on data from its mass spectrum (MS) and nuclear magnetic resonance (NMR) spectrum. HEB displayed strong antioxidant potency in inhibiting, at 1.36 mM concentration, erythrocyte hemolysis and scavenging DPPH radicals and superoxide anion (O2(-)) by 82.4%, 85.6% and 71.4%, respectively. Besides exhibiting a low cytotoxicity, compound HEB demonstrated significant anti-HIV activity in that it inhibited HIV-1 replication in TZM-BL cells infected by pseudovirus with an IC50 value of 11.9 μM. Further study disclosed that HEB inhibited the viral entry process and activities of key enzymes essential for the HIV-1 life cycle. HEB inhibited HIV-1 reverse transcriptase and integrase activities with an IC50 value of 80.1 μM and 228.5 μM, respectively, and at 10 mM concentration inhibited HIV-1 protease activity by 17.1% which was higher than that achieved by the positive control pepstatin A. Interestingly, this study first revealed that H2O2 stimulation not only activated cell oxidative stress responses, but also accelerated HIV-1 long terminal repeat (LTR) promotion in TZM-BL cells, which was significantly reduced by HEB from 18.2% to about 2%. It implied a direct relationship between the antioxidant and anti-HIV activities of the natural active constituent HEB. Nuclear transcription factor kappa B (NF-κB) signal pathways plays an important role in oxidative stress responses. Meanwhile, there is κB target sequence in HIV promoter LTR which is significant for virus replication and gene expression. In this study, Western Blot assay showed that HEB could inhibit the activation of NF-κB signal pathway stimulated by H2O2 in mouse spleen cells through suppressing NF-κB (p65) translocation into nucleus and NF-kappa-B inhibitor (IκB) degradation in cytoplasm. In summary, the antioxidant HEB from P. adiposa could inhibit HIV-1 replication through multiple target sites. The data suggest that natural antioxidant compounds might have a potential for treatment of AIDS.

Effects of adenosine extract from Pholiota adiposa (Fr.) quel on mRNA expressions of superoxide dismutase and immunomodulatory cytokines.[Pubmed: 23434863]

Pholiota adiposa is a kind of edible mushroom which has long been known for its health care applications. To reveal the exact mechanism of its protective functions in humans, in this study we isolated and identified the active compound PB3 of P. adiposa for the first time by a combination of chromatography techniques, including NKA macroporous resin and Sephadex G-15. PB3, with molecular mass of 267.2 Da and molecular formula of C₁₀H₁₃N₅O₄ discovered by mass spectrum (MS) was identified to be adenosine. Mice were injected intraperitoneally with purified fraction PB3. Seven days after injection, we found a 1.5-fold increase of IL10 at the mRNA level, while a down regulated expression of IL-2, IL-6 and IFN-γ to 49.0%, 56.9% and 73.4%, respectively, was detected in spleen by real-time quantitative PCR. What's more, SOD expression level was significantly increased by 1.6-fold compared to control. Fraction PB3 displayed anti-inflammatory potency and heightened SOD activity on the transcriptional level, which could be considered of further pharmaceutical or medication value.

Saccharification of poplar biomass by using lignocellulases from Pholiota adiposa.[Pubmed: 22831905]

A basidiomycetous fungus, identified as Pholiota adiposa SKU0714 on the basis of morphological and phylogenetic analyses, was found to secrete efficient lignocellulose degrading enzymes. The strain showed maximum endoglucanase, cellobiohydrolase and β-glucosidase activities of 26, 32 and 39 U/mL, respectively and also secreted xylanase, laccase, mannanase, and lignin peroxidase with activities of 1680, 0.12, 65 and 0.41 U/mL, respectively when grown with rice straw as a carbon source. Among the various plant biomasses tested for saccharification, poplar biomass produced the maximum amount of reducing sugar. Response surface methodology was used to optimize hydrolysis parameters. A maximum saccharification yield of 83.4% (667 mg/g-substrate), the highest yield from any plant biomass, was obtained with Populus biomass after 24h of hydrolysis. P. adiposa was proven to be a good choice for the production of reducing sugars from cellulosic biomass.

Isolation and purification of polysaccharides with anti-tumor activity from Pholiota adiposa (Batsch) P. Kumm. (higher Basidiomycetes).[Pubmed: 22577977]

Pholiota adiposa is a mushroom with excellent medicinal and nutritional properties. After culture in fermentation medium, Ph. Adiposa mycelia were filtered, lyophilized, and powdered. A crude polysaccharide (PAP) of Ph. Adiposa was prepared from the mycelial powder with hot water, centrifuged, and the resulting supernatant lyophilized. PAP was fractionated by 30%, 60%, and 80% ethanol precipitation steps to yield PAP30, PAP60, and PAP80. Subsequently PAP30-1 and PAP30-2, PAP60-1 and PAP60-2, and PAP80-1 and PAP80-2 were isolated from PAP30, PAP60, and PAP80, respectively, by ion-exchange chromatography on a DEAE-Sepharose column. Polysaccharide content increased from 43.8% in PAP to 50.54%~73.19% in PAP30-1~PAP80-2. The protein content was 4.92% at minimum in these polysaccharide products. In order to identify the chemical composition, the six polysaccharides (PAP30-1, PAP30-2, PAP60-1, PAP60-2, PAP80-1, and PAP80-2) were further purified by gel filtration on Sephacryl S-100-500. Finally, three water-soluble polysaccharides (PAP30-2a, PAP60-2b, and PAP80-2a) were obtained. HPLC analysis revealed that PAP30-2a, PAP60-2b, and PAP80-2a exhibited a molecular weight of 6.6 × 105 Da, 8.4 × 103 Da, and 3.5 × 103 Da, respectively. The glucose content in PAP80-2a, PAP60-2b, and PAP30-2a was 57.8%, 72.7%, and 68.9%, respectively. PAP30-2a, PAP60-2b, and PAP80-2a demonstrated significant differences in anti-tumor activity in mice. PAP80-2a is the optimal bioactive constituent with anti-tumor and T-lymphocyte proliferation stimulating effects.

Immobilization of Pholiota adiposa xylanase onto SiO₂ nanoparticles and its application for production of xylooligosaccharides.[Pubmed: 22421976]

Enhanced yields of different lignocellulases were obtained under statistically-optimized parameters using Pholiota adiposa. The k (cat) value (4,261 s(-1)) of purified xylanase under standard assay conditions was the highest value ever reported. On covalent immobilization of the crude xylanase preparation onto functionalized silicon oxide nanoparticles, 66 % of the loaded enzyme was retained on the particle. Immobilized enzyme gave 45 % higher concentrations of xylooligosaccharides compared to the free enzyme. After 17 cycles, the immobilized enzyme retained 97 % of the original activity, demonstrating its prospects for the synthesis of xylooligosaccharides in industrial applications.

Extraction and in vitro antioxidant activity of intracellular polysaccharide by Pholiota adiposa SX-02.[Pubmed: 20801714]

Response surface methodology (RSM) was used to optimize the extraction parameters for Pholiota adiposa SX-02 intracellular polysaccharide (IPS) produced during submerged culture. The optimum conditions of IPS extraction were predicted to be, ultrasonic power at 564.93 W, precipitation time 30.34 h and pH 8.28, and IPS yield was estimated at 19.75%. The actual value of IPS under these conditions was 20.51%. The in vitro antioxidant results showed that the inhibition effects of IPS at a dosage of 250 mg/l on superoxide anion, hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical were 74.66 ± 5.31%, 69.20 ± 5.13%, and 75.20 ± 6.73%, respectively, which were 27.51 ± 2.23%, 16.58 ± 1.33%, and 9.46 ± 0.72% higher than that of butylated hydroxytoluene (BHT), respectively. The reducing power of IPS was 0.32 ± 0.02 (absorbance at 700 nm), 39.13 ± 3.47% higher than that of BHT. The results provide a reference for large-scale extraction of IPS by P. adiposa SX-02 in industrial fermentation and the IPS can be used as a potential antioxidant which enhances adaptive immune responses.

A novel lectin with antiproliferative activity from the medicinal mushroom Pholiota adiposa.[Pubmed: 19636442]

Little was known about biological activities of compounds from the medicinal mushroom of the genus Pholiota. A lectin from the Pholiota adiposa has now been isolated and its properties tested. The isolation procedure included ion exchange chromatography on DEAE-cellulose and CM-cellulose, and fast protein liquid chromatography-gel filtration (FPLC) on Superdex 75. The lectin was composed of two identical subunits, each with a molecular mass of 16 kDa. Its N-terminal amino-acid sequence showed little similarity to sequences of other Agaricales lectins. The hemagglutinating activity of the lectin was stable at temperatures up to 50 degrees C, and in NaOH and HCl solutions with concentrations less than 25 mM. It was inhibited by inulin (12.5-200 mM), but enhanced by Cu(2+) (6.25-25 mM), Fe(2+) (12.5-25 mM), and Al(3+) (6.25-25 mM) ions. The lectin showed antiproliferative activity toward hepatoma Hep G2 cells and breast cancer MCF7 cells with an IC(50) of 2.1 microM and approximately 3.2 microM, respectively. It exhibited HIV-1 reverse transcriptase inhibitory activity with an IC(50) of 1.9 microM. When compared with P. aurivella lectin, the only Pholiota lectin published to date, P. adiposa lectin differs in chromatographic behavior, molecular mass, N-terminal sequence, and effect of cations on hemagglutinating activity. In the case of the lectin from P. aurivella, its antifungal, antiproliferative, and HIV-1 reverse transcriptase inhibitory activities have not been determined.