• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.131-131
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• 1998

In the course of screening for new natural compounds having antioxidant activity from microbials, mushrooms as well as plants. We have isolated novel sesquiterpenoid and officinalic acid from methanolic extracts of Stereum ostrea. The dried fruit body( 450 g) of Stereum ostrea was extracted with methanol, then methanolic extract was partitioned between water and hexane, chloroform, and ethyl acetate, subsequently. The chloroform extract was subjected on silica gel, Sephadex LH-20 and RP-18 column chromatography, successively. And two compounds were isolated and identified as new triterpenoids and officinalic acid using $^1$H - NMR, $\^$13/C - NMR as well as Mass spectra.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1540-1548
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• 2012

Manganese peroxidase (MnP) was isolated from the culture filtrate of the wood log mushroom Stereum ostrea (S. ostrea), grown on Koroljova medium, and then purified by ammonium sulfate [70% (w/v)] fractionation, DEAE-cellulose anion exchange chromatography, and Sephadex G-100 column chromatography, with an attainment of 88.6-fold purification and the recovery of 22.8% of initial activity. According to SDS-PAGE the molecular mass of the MnP was 40 kDa. The optimal pH and temperature were found to be 4.5 and $35^{\circ}C$, respectively. The enzyme was stable even after exposure to a pH range of 4.5 to 6.0, and at temperatures of up to $35^{\circ}C$ at a pH of 4.5 for 1h. The $K_m$ and $V_{max}$ values for the substrate phenol red were found to be $8{\mu}m$ and 111.14 U/mg of protein, respectively. The MnP also oxidized other substrates such as guaiacol, DMP, and veratryl alcohol. Sodium azide, EDTA, SDS, $Cu^{2+}$, and $Fe^{2+}$, at 1-5 mM, strongly inhibited enzyme activity, whereas $Ca^{2+}$ and $Zn^{2+}$ increased enzyme activity. The participation of the purified enzyme in the decolorization of dyes suggests that S. ostrea manganese peroxidase could be effectively employed in textile industries.

• The Korean Journal of Mycology
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• v.27 no.5 s.92
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• pp.349-353
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• 1999

The genus Stereum is consisted of species having smooth, binucleate amyloid spores, pseudocystidia and dimitic basidiocarps without clamps. There are five recorded species of Stereum in Korea. Through the specimen examination of Seoul National University Fungal Collection, five more species of Stereum, S. subtomentosum, S. peculiare, S. sanguinolentum, S. striatum and S. complicatum, were confirmed as unrecorded species to Korea. They are registered here with Korean names as well as English descriptions and a key to Korean Stereum species is attached together.

• Mycobiology
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• v.35 no.4
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• pp.210-214
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• 2007

Antibacterial and antifungal activities of liquid culture filtrate, water and ethanol extract (solid culture) of Stereum ostrea were evaluated against 5 bacteria and 3 plant pathogenic fungi. To determine the minimal inhibitory concentration (MIC), we studied $5{\sim}300\;mg/ml$ concentrations against bacteria and fungi separately. The MIC was 10 mg/ml for Bacillus subtilis and 40 mg/ml for Colletotrichum gloeosporioides and Colletotrichum miyabeanus. Liquid culture filtrate was more effective against Gram positive than Gram negative bacteria, and Staphylococcus aureus was the most inhibited (20.3 mm) bacterium. Water and ethanol extracts were effective against both Gram positive and Gram negative bacteria, and water extract was better than ethanol extract. In water and ethanol extract, inhibition zones were 23.6 and 21.0 mm (S. aureus) and 26.3 and 22.3 mm (Pseudomonas aeruginosa), respectively. For plant pathogenic fungi, the highest and lowest percent inhibition of mycelial growth (PIMG) was found 82.8 and 14.4 against C. miyabeanus and Botrytis cinerea in liquid culture filtrate, respectively. In water extract, the PIMG was found to be the highest 85.2 and lowest 41.7 for C. miyabeanus and C. gloeosporioides, respectively. The inhibitory effect of ethanol extract was better against C. miyabeanus than C. gloeosporioides and B. cinerea. Among 3 samples, water extract was the best against tested pathogenic fungi. This study offers that the extracts isolated from S. ostrea contain potential compounds which inhibit the growth of both bacteria and fungi.

• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.301-306
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• 2003

Twenty-one different fungi were tested for their ability to decolorize a wide range of structurally different dyes. Twenty fungal strains were isolated from fruiting bodies which were collected at the Kwangneung National Arboretum, Korea. One fungal strain were isolated from a rotting wood at Soongsil University, Korea. Nine kinds of dyes were used: three anthraquinone dyes and six azo dyes. The five fungal strains, Laetiporus sulphureus, Polyporus arcularius. Auricularia polytricha, Stereum ostrea, and Bjerkandera sp. UK-l showed decolorization ability. Except Auricularia polytricha, the four fungal strains were wood rotting fungi, and belonged to Aphyllophorales. Bjerkandera sp. UK-I, which was a white rot fungus, could decolorize all kinds of dyes tested in this study, indicating this fungus is one of candidates for applying in biological methods of dye waste treatment.

• Mycobiology
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• v.40 no.2
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• pp.134-137
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• 2012

Mushrooms collected from Deogyu mountain, Korea, in 2011, were identified as four classes, four orders, 13 families, 22 genera, and 33 species. In particular, agaricales was most abundant and comprised more than 70%. Their antioxidant activities were estimated using three different bioassay methods, the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical scavenging assay, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, and reducing power assay. As a result, the methanol extracts of Stereum ostrea, Laetiporus sulphureus var. miniatus, and Tyromyces sambuceus exhibited potent antioxidant activity in all bioassays tested.

• Journal of Forest and Environmental Science
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• v.32 no.2
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• pp.158-163
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• 2016

Mushroom surveys and collections were conducted in the western and eastern forest areas in Cambodia, and then fungal biodiversity was analyzed by identifying mushrooms. One thousand and three hundreds eighty three specimens were identified by morphological and genetical characteristics, and were classified into 238 species, 160 genera, 52 families, 15 orders, and 3 phylums. The collected mushrooms were immersed in 70% ethyl alcohol for DNA extraction, and the rest of them were dried in the portable mushroom dryer for 12 hrs. Among these mushrooms, the genera Mycena (8.7%), Ganoderma (5.6%), Microporus (5.3%), Marasmius (4.2%), Marasmiellus (3.0%), Phellinus (2.5%), Trametes (2.5%), Hygrocybe (1.9%) and Pycnoporus (1.5%) were dominant. In the western Cambodia, 1,061 specimens were collected from Koh Kong forests, while 263 specimens were collected from the eastern Cambodia, Seima and Mondulkiri forests. Elevations of surveyed sites were ranged from 0 to 750 m above sea level. The number of species observed in the elevation of 251-500 m was the highest as compared to the other ranges of elevation. Daldinia concentrica, Microporus vernicipes, Microporus xanthopus, Pycnoporus coccineus, Stereum hirsutum, and Stereum ostrea were commonly distributed in all ranges of elevation, while the distribution of Ceratomyxa fruticulosa, Panus fulvus, Schizophyllum, Trametes versicolor, and Tyromyces chioneus were limited under 500 m. One hundred and forty one species including Amauroderma sp., Bjerkandera adusta, Trichaptum abietinum, and Tyromyces chioneus were collected only in Cardamom, while 20 species including Auricularia auricula-judae, Coriolopsis sanguinaria, Rigidoporus microporus, and Xylaria polymorpha were collected only in Seima. Ganoderma sp., Mycena sp., Marasmius sp., Microporus xanthopus, Phellinus sp., and Russula sp. were dominant species in both the western and eastern Cambodia. Species diversity indices in the eastern and western survey sites were 1.83 and 1.77, respectively, while evenness indices were 0.92 and 0.90. The species similarity index between two survey sites was 0.42.

• Mycobiology
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• v.36 no.2
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• pp.114-120
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• 2008

This study was conducted to evaluate the degradation of aromatic dyes and the production of ligninolytic enzymes by 10 white rot fungi. The results of this study revealed that Pycnoporus cinnabarinus, Pleurotus pulmonarius, Ganoderma lucidum, Trametes suaveolens, Stereum ostrea and Fomes fomentarius have the ability to efficiently degrade congo red on solid media. However, malachite green inhibited the mycelial growth of these organisms. Therefore, they did not effectively decolorize malachite green on solid media. However, P. cinnabarinus and P. pulmonarius were able to effectively decolorize malachite green on solid media. T. suaveolens and F. rosea decolorized methylene blue more effectively than any of the other fungi evaluated in this study. In liquid culture, G. lucidum, P. cinnabarinus, Naematoloma fasciculare and Pycnoporus coccineus were found to have a greater ability to decolorize congo red. In addition, P. cinnabarinus, G lucidum and T. suaveolens decolorized methylene blue in liquid media more effectively than any of the other organisms evaluated in this study. Only F. fomentarius was able to decolorize malachite green in liquid media, and its ability to do so was limited. To investigate the production of ligninolytic enzymes in media containing aromatic compounds, fungi were cultured in naphthalene supple mented liquid media. P. coccineus, Coriolus versicolor and P. cinnabarinus were found to produce a large amount of laccase when grown in medium that contained napthalene.

• The Korean Journal of Mycology
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• v.42 no.4
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• pp.322-327
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• 2014

Subculture is the most common method for preservation fungi, but has a disadvantage of accumulation of spontaneous mutations during the repeated subculture. To reduce the subculture frequency, the effect of preservation period at $4^{\circ}C$ in a slant culture was examined on the mycelia growth and lignocellulolytic enzyme activities of various basidiomycetes. Mushrooms, including Stereum ostrea, Coprinellus micaeus, Trametes versicolor, Hypholoma fasciculare, Wolfiporia extensa, Pleurotus pulmonarius, Piptoporus betulinus and Ganoderma applanatum were not affected by the preservation period more than two years, indicating that they can be maintained by subculture every two years. Some other tested fungal strains showed a significant decrease in both viability and enzyme activity when they were maintained for two years, suggesting that they should be subcultured at least once in a year. A little correlation was found between the recovery of mycelial growth and extracellular enzyme activity. In conclusion, mycelial activity and enzyme activity according to storage period is expected to be a way of deciding on subculture times for fungal preservation.