• The Korean Journal of Mycology
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• v.13 no.3
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• pp.169-177
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• 1985

The studies were carried out to obtain the basic data for maximizing the protoplast yields from the mycelia of P. ostreatus and P. sajor-caju. Some factors affecting the regeneration of the protoplast of both species and the productivity of their reversion were also examined. The maximum yields of protoplasts were obtained from four days cultured mycelia of both species on cellophan membrane placed on the surface of PSA or MCM media in a petri dish. The optimal concentration of lytic enzyme Novozym 234 for protoplast releasing was 5 mg per ml of 0.5 M phosphate buffer solution with 0.6 M sucrose or 0.6 M $MgSO_4$ at pH 6.0. The greatest number of protoplasts was released 3 hours after incubation of the mycelia of P. ostreatus and after 4 hours for the P. sajor-caju in the lytic enzyme solution. Among the osmotic stabilizer solutions tested 0.6 M sucrose and 0.6 M KCl showed the best regeneration rates of the protoplasts of both species. When 0.75 % agar solution was over-layed on the regeneration media immediately after inoculation of the protoplast the regeneration rates were greatly enhanced. The ampicillin added to the agar solution prevented bacteria from infection. The reverted isolates produced the sporophores and basidial spores just like their parents without any mutations when they were cultivated in a broad mouth bottle with sawdust substrates.

• The Plant Pathology Journal
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• v.20 no.3
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• pp.200-205
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• 2004

The partial nucleotide sequences of the genomic dsRNA mycovirus infecting Pleurotus ostreatus isolates ASI2223 and Suhan were determined and compared with those of mycoviruses belonging to partitiviruses and totiviruses. Partial nucleotide sequences of the purified dsRNA from ASI2223 and Suhan showed RNA-dependent RNA polymerase sequences that are closely related to those of partitiviruses, including Fusarium poae virus 1, Fusarium solani virus, Rhizoctoniasolani virus, Discula destructiva virus 2, and Oyster mushroom isometric virus 2. Specific primers were designed for RT-PCR detection of dsRNA viruses from the P. ostreatus isolate ASI2223 and Suhan. Two virus specific primer sets were found to specifically detect each virus among six sets of designed oligonucleotide primers. Collectively, these results suggest that dsRNA mycoviruses from P. ostreatus isolates ASI2223 and Suhan belong to the family Partitiviridae, although, they are not the same virus species. Our results also suggest that these virus-specific primer sets can be employed for the specific detection of each viral sequence in infected tissues.

• Mycobiology
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• v.39 no.1
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• pp.12-19
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• 2011

Cellular damage caused by reactive oxygen species has been implicated in several diseases, thus establishing a significant role for antioxidants in maintaining human health. Acetone, methanol, and hot water extracts of Pleurotus citrinopileatus were evaluated for their antioxidant activities against ${\beta}$-carotene-linoleic acid and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, reducing power, ferrous ion-chelating abilities, and xanthine oxidase inhibitory activities. In addition, the tyrosinase inhibitory effects and phenolic compound contents of the extracts were also analyzed. Methanol and acetone extracts of P. citrinopileatus showed stronger inhibition of ${\beta}$-carotene-linoleic acid compared to the hot water extract. Methanol extract (8 mg/mL) showed a significantly high reducing power of 2.92 compared to the other extracts. The hot water extract was more effective than the acetone and methanole extracts for scavenging DPPH radicals. The strongest chelating effect (92.72%) was obtained with 1.0 mg/mL of acetone extract. High performance liquid chromatography analysis detected eight phenolic compounds, including gallic acid, protocatechuic acid, chlorogenic acid, ferulic acid, naringenin, hesperetin, formononetin, and biochanin-A, in an acetonitrile and hydrochloric acid (5 : 1) solvent extract. Xanthine oxidase and tyrosinase inhibitory activities of the acetone, methanol, and hot water extracts increased with increasing concentration. This study suggests that fruiting bodies of P. citrinopileatus can potentially be used as a readily accessible source of natural antioxidants.

• The Korean Journal of Mycology
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• v.20 no.3
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• pp.234-239
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• 1992

The experiment was performed to find out the possibilities to detect virus infection in oyster mushrooms, Pleurotus species by analysis of doublestranded ribonucleic acid (ds RNA). Ds RNA segments were extracted from virus infected isolates which grew abnormally. But virus free isolates didn't show any ds RNA segments. The ds RNA was consisted of one large segment of 8100 base pairs (bp) and 4 smaller segments with 2170, 2120, 1980 and 1984 bp. Whereas, cell free virus particles showed only one larger ds RNA segment. The ds RNA was dissolved by RNase A in low salt, 0.1 M SSC and melted at $85^{\circ}C$. It was possible to use the ds RNA analysis for detecting virus infection directly from the host cells.

• The Korean Journal of Food And Nutrition
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• v.30 no.3
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• pp.525-530
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• 2017

King oyster mushroom (Pleurotus eryngii), an improved species of oyster mushroom, is a popular ingredient in Asian cuisine. Spleen cells were treated with various concentrations (0, 5, 10, 50, 100, 250, 500, and $1,000{\mu}g/mL$) of king oyster water extracts (KOWE); then, the proliferation of the cells was measured 24, 48, and 72 h after each treatment. Also, type 1 T helper cytokine productions ($TNF-{\alpha}$, $IFN-{\gamma}$, and IL-2) were measured in activated macrophage by KOWE in seven concentrations. Under the condition of its 50, 100, 250, and $1,000{\mu}g/mL$ for 48 h, the proliferation of cells was increased. However, there was no significant fluctuation in the spleen cells proliferation for 24 and 72 h-long KOWE exposure. To determine cytokine ($TNF-{\alpha}$, $IFN-{\gamma}$, IL-2) productions of type 1 T helper cells, macrophage was stimulated by KOWE for 48 h. Treatment of KOWE gave a rise to the levels of $TNF-{\alpha}$ and $IFN-{\gamma}$, but not in that of IL-2 productions. These results suggest that king oyster mushroom water extracts may be beneficial for enhancing immune functions in its high concentration.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.12
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• pp.1681-1688
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• 2004

Soaked and pasteurised wheat straw was inoculated with five species of Pleurotus fungi (coded P-21, P-30, P-41, P-60 and P-90), packed in polyethylene bags and incubated in a fermentation chamber for 21 days. The chemical composition, in vitro digestibility and in sacco degradability of the treated and untreated straw were estimated using a complete randomised design consisting of six treatments and four replicates. In a feeding trial, in vivo digestibility and voluntary intake were determined in bulls, using a $3{\times}3$change over design. Dietary treatments were: 1) untreated wheat straw (UWS) as control; 2) fungal treated (P-41) wheat straw before mushroom formation (FTWS); 3) spent wheat straw (SPWS) after mushrooms were harvested. Apart from P-90, fungal treatment significantly (p<0.05) increased the crude protein (CP) and reduced the cell wall components of the straw. The in vitro dry mater and organic mater digestibility significantly (p<0.05) increased in the treated straw particularly with the treatments of P-41 and P-60. The in situ degradability and in vivo digestibility of DM and OM were significantly (p<0.05) increased in treated straws with the highest values observed for treatment P-41. The intake of DM, OM and digestible organic mater (DOM) were significantly (p<0.05) increased in cows fed FTWS.

• Mycobiology
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• v.36 no.4
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• pp.266-269
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• 2008

Twenty isolates of Bacillus species obtained from livestock manure composts and cotton-waste composts were tested for their antagonistic effects in vitro against three green mold pathogens of mushrooms (Trichoderma harzianum, T. koningii, and T. viridescens). However, there exists a possibility Bacillus species may have antagonistic effects against mushrooms themselves, and thus the same 20 isolates were tested in vitro against three species of mushrooms (Flammulina velutipes, Lentinus edodes, and Pleurotus ostreatus). Of the 20 Bacillus species isolates tested, two inhibited mycelial growth of T. harzianum, seven that of T. koningii, and eight that of T. viridescens. Importantly, the bacterial isolates M27 and RM29 strongly inhibited mycelial growth of all the Trichoderma spp. isolates tested. The isolate M27 was subsequently identified as the most effective in inhibiting mycelial growth of all the Trichoderma species. Interesting results of the effect Bacillus isolates had upon the mushroom species followed. It was found that most Bacillus isolates except 5T33 at least somewhat inhibited mycelial growth of the three mushroom species or some of the mushrooms. Furhermore, the antagonistic effects of the bacterial isolates against the three species of mushrooms varied depending on the mushroom species, suggesting a role for mushroom type in the mechanism of inhibition. The bacterial isolates M27 and RM29 were identified as having the most antagonistic activity, inhibiting mycelial growth of all the Trichoderma spp. as well as mycelial growth of the three species of mushrooms. These results suggest that the bacterial isolates and their antagonistic effects on green mold pathogens should be further studied for their practical use for biological control of green mold in the growing room of the mushrooms.

• Journal of environmental and Sanitary engineering
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• v.2 no.3 s.3
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• pp.7-11
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• 1987

A Comparison on the fatty acid composition of 7 species of Korean edible mushroom(Agaricus bisporus, Tricholoma matsutake, Lentinus edodes, Pleurotus ostreatus, Ramaria botrytis, Sarcodon asparatus, Calocybe gambosa) were investigated by gasliquid Chromatography. The results were obtained as follows: 1) The major fatty acid in all samples were linoleic $(77.33-35.53\%)$, oleic $(39.69-1.58\%)$ and palmitic$(22.51-7.31\%)$ acid, 31 2) The content of linoleic acid was the highest in Agaricus Bisporus, Pleurotus ostreatus and Lentinus edodes meanwhile, the content of oleic acid of these mushrooms was significantly low compared with others. 3) Quantity of myristic acid was higher in comparison with fatty acid composition from common lipid source.

• Korean Journal Plant Pathology
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• v.14 no.2
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• pp.177-183
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• 1998

A DNA fragment which is involved in tolassin production was cloned to obtain a molecular marker of Pseudomonas tolaasii, a casual agent of bacterial brown blotch disease of oyster mushroom (Pleurotus ostreatus). Tolaasin is a lipodepsipeptide toxin and known as a primary disease determinant of the P. tolaasii. It is responsible for formation of white line in agar when P. tolaasii were cultured against white line reacting organisms (WLROs). White line negative mutants (WL-) were generated by conjugation between rifampicin resistant strain of P. tolaasii and E. coli carrying suicidal plasmid pSUP2021 : : Tn5. The ability of tolaasin production of the WL- mutants was examined by hemolysis test, pathogenicity test, and high pressure liquid chromatography (HPLC) analysis of culture filtrate. All of the WL- mutants were lost the ability of tolaasin production (Tol-). Genomic library of the Tol- mutant was constructed in pLAFR3 and the cosmid clone containing Tn5 was selected. DNA fragment fro franking region of Tn5 was cloned from the plasmid and used as a probe in Southern blot. DNA-DNA hybridization with the probe to total DNA from group of bacteria ecologically similar to P. tolaasii including WLORs, fluorescent Pseudomonads isolated from oyster mushroom, P. agarici, P. gingeri, and some of other species of Psedomonas showed that some of the tested bacteria do not have any hybridized band and others have bands sowing RFLP. The cloned DNA fragment or its nucleotide sequence will be useful in detection and identification of the P. tolaasii.

• Journal of Microbiology and Biotechnology
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• v.19 no.8
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• pp.743-748
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• 2009

Fungal diversity during composting was investigated by culture-independent rDNA sequence analysis. Composting was carried out with pig manure and mushroom cultural waste using a field-scale composter (Hazaka system), and samples were collected at various stages. Based on partial sequence analysis of large subunit (LSU) ribosomal RNA (rRNA) and sequence identity values, a total of 12 different fungal species were found at six sampling sites; Geotrichum sp., Debaryomyces hansenii, Monographella nivalis, Acremonium strictum, Acremonium alternatum, Cladosporium sphaerospermum, Myriangium durosai, Pleurotus eryngii, Malassezia globosa, Malassezia restricta, Rhodotorula glutinis, and Fusarium sporotrichioides. Geotrichum sp. of the class Saccharomycetes was the most predominant fungal species throughout the composting process (185 out of a total of 236 identified clones, or 78.4%), followed by Acremonium strictum (7.6%), Monographella nivalis (5.1%), and Pleurotus eryngii (3.8%). The prevalence of Geotrichum sp. was the lowest (61.1%) at the beginning of composting, and then gradually increased to 92.5% after 10 days of composting.