• The Korean Journal of Mycology
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• v.16 no.2
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• pp.95-100
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• 1988

Isozyme band patterns were investigated by isoeletric focusing Esterase and Leucine amino peptidase of Pleurotus spp. in Korea. Esterase patterns of mycelia and fruitbody were distinquished. However, those of primordia, cap and stem were similar. Interspecies differences of Pleurotus ostreatus, P. cornucopiae and P. florida of Esterase zymogram were found. Species identification by electrophoretic zymogram may be a role as an additional taxonomic tool.

• The Korean Journal of Mycology
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• v.13 no.2
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• pp.75-78
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• 1985

Mutagenesis of protoplast could serve a great potential tool for improvement of strains and genetics in higher fungi. For the isolation of auxotrophic mutants from protoplasts of Pleurotus ostreatus and Pleurotus florida, viability levels of ultraviolet lights were determined. Seven auxotrophs were obtained from protoplasts irradiating UV to give $0.83{\sim}15%$ survival. The mutants showed a single requirement for each of Arg, Ribo-l, Ribo-2 or Phen for growth. Some of them showed two or three kinds of requirements, Gly Ser, Ade Hypo or Ala Om Tryp for growth.

• The Korean Journal of Mycology
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• v.13 no.2
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• pp.79-82
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• 1985

The experiment of protoplast regeneration and reversion were undertaken to provide a basic techniques for protoplast manipulation. Protoplasts of Pleurotus florida and Pleurotus ostreatus were reverted to normal hyphal growth and the reversion frequency of both fungal protoplasts were $0.24{\sim}3.19%$. Reversion medium stabilized with 0.6 M potassium chloride and sucrose was better than the other stabilized one. The protoplast reversion frequency was increased when various amino acid and vitamin compounds were added to the hypertonic mushroom complete agar medium.

• Journal of Microbiology
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• v.34 no.1
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• pp.37-37
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• 1996

The internal regions of nuclear small subunit rRNA from 6 plaeurotus species and 5 Pleurotus ostreatus strains were amplified by PCR and sequenced. The DNA sequences of 8 Pleurotus strains (P. ostreatus NFFA2, NFFA4501, NFFA4001, KFFA4001, KFCC11635, P florida, P. florida, P. sajor-cuju, P. pulmonarius, and P. spodoleucus) were idential, but P. cornucopiae differed from them in two bases out of 605 bases. However, p[hylogenetic analysis of the sequences by DNA-distance matrix and UPGMA methods showed that P. ostreatus NFFA2m1 and NFFA2m2, known as mutants of P. ostreatus NFFA2, belonged to anther group of Basidiomycotina, which is close to the genus Auricularia. The difference of the SSU rDNA sequences of P. cornucopiae from other Pleurotus species tested corresponds to the difference of mitochondrial plasmid type present in Pleurotus species as observed by Kim et al. (1993, Korean J. Microbiol. 31, 141-147).ishement of silencing at the HMR/hsp82 locus can occur in G1-arrested cells. Cell cycle arrest at G1 phase was achieved by treatment of early log a cell cultures with .alpha.-factor mating pheromone, which induces G1 arrest. The result suggests that passage through S phase (and therefore DNA replication) is nor required for re-establishing silencer-mediated repression at the HMNRa/HSP82 locus. Finally, to test whether de nono protein synthesis is required for re-establishment of silencer-mediated repression, cells were pretreated with cycloheximide (500 /.mu.g/ml) 120 min. It was apparent that inhibiting protein synthesis delays, but does not prevent, re-establishment of silencer-mediated repression. Altogether, these results indicate that re-establishment of silencer-mediated repression is not dependent on the DNA replication and has no requirement for protein synthesis.

• The Korean Journal of Mycology
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• v.47 no.4
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• pp.337-346
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• 2019

To develop a new antidementia acetycholinesterase (AChE) inhibitor from edible mushrooms, the inhibitory effects on AChE of water and ethanol extracts from various edible mushrooms were measured. Among the tested compounds, 70% ethanol extracts from Tremella fuciformis showed the highest AChE inhibitory activity, at 25.3% (IC₅₀: 9.9 mg). Water extracts from the fruiting body of Pleurotus ostreatus (Heuktari) showed AChE inhibitory activity of 20.2% (IC₅₀: 12.4 mg). However, the yield (40.8%) from Pleurotus ostreatus (Heuktari) was higher than that from Tremella fuciformis (5.0%). Therefore, we selected Pleurotus ostreatus (Heuktari) as the most promising candidate for a mushroom containing anti-dementia AChE inhibitors. The AChE inhibitor from Pleurotus ostreatus (Heuktari) was optimally extracted when its fruiting body was treated with water for 6 h at 30℃. The anti-dementia effects of the partially purified AChE inhibitor from Pleurotus ostreatus (Heuktari) were observed in PC12 nerve cells.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.1
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• pp.24-34
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• 2020

Objective: The effects of Pleurotus ostreatus on the feed utilization of broad bean stalks (BBS), rape straw (RS), paddy straw (PS), and corn stalk (CS) was examined. Methods: The four roughages were co-cultured with Pleurotus ostreatus. The chemical composition; enzyme activities of laccase, carboxymethylcellulase (CMCase) and xylanase; carbohydrate and protein fractions (based on The Cornell Net Carbohydrate and Protein System [CNCPS]) were assessed at different days after inoculation (7, 14, 21, 28 d) and un-inoculated roughages (control, 0 d). The digestibility of nutrient components and the gas production of roughage with various incubation times were monitored at 0, 2, 4, 6, 9, 12, 24, 36, 48, 60, and 72 h using an in vitro ruminal fermentation method. Results: A higher CMCase activity (0.1039 U/mL) and earlier time to peak (14 d) were detected in Pleurotus ostreatus cultured with CS (p<0.05). Significantly, the incubation length-dependent responses of cumulative gas production were observed from 24 to 72 hours post fermentation (p<0.05), and these incubation length-dependent effects on cumulative gas production of PS and CS appeared earlier (24 h) for PS and CS than those (48 h) for BBS and RS (p<0.05). The fast-degradable carbohydrate (CA) content for all four roughages significantly increased over time (p<0.05). Nonetheless, increased degradation efficiency for CA treated with Pleurotus ostreatus was detected at both 21 and 28 days of incubation (p<0.05). With the exception of PS (p<0.05), there were no significant difference among the roughages (p>0.05) in slowly-degradable carbohydrate (CB2) at different incubation times (p<0.05). Conclusion: Assessment of the alterations in chemical composition, CNCPS system fractions, and the fermentation kinetics after biological pretreatment may yield a valuable database for evaluating the biological pretreatment of Pleurotus ostreatus in ruminant feed.

• Journal of Mushroom
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• v.19 no.4
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• pp.310-315
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• 2021

We investigated the effect of sodium chloride-associated abiotic stress on the development of Pleurotus ostreatus. We examined the growth characteristics of fruiting bodies, constituent amino acids, and fragrance pattern to determine the effect of culturing Pleurotus ostreatus on a sawdust substrate supplemented with sodium chloride in a dose-dependent manner. Pleurotus ostreatus fruiting bodies exhibited an increasing tendency towards augmented yields when grown in the presence of 0.5% sodium chloride as compared with that grown in the control group. However, increasing the supplementation of sodium chloride from 1.0 % to 2.0% resulted in significantly decreased yields of Pleurotus ostreatus fruiting bodies in these groups as compared with that in control groups. Further assessment revealed the presence of 14 types of amino acids in the fruiting bodies, including aspartate, threonine, serine, glycine, alanine, methionine, valine, isoleucine, leucine, phenylalanine, tyrosine, lysine, histidine, and arginine, at lower levels in all the sodium chloride-treated groups than in the control group; except for glutamic acid and proline. Similarly, fragrance pattern analysis of the Pleurotus ostreatus fruiting body by chromatography confirmed that the intensity of the substances presumed to be octane compounds, to which the unique flavor of mushrooms is attributed, was lower in all the sodium chloride-treated groups than in the control group.

• The Korean Journal of Mycology
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• v.20 no.2
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• pp.149-153
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• 1992

This study aimed to investigate possible cause of slow and abnormal growth of oyster mushrooms, Pleurotus florida and P. ostreatus collected from bad crop farms. Spherical virus particles of 30 nm in diameter from P. florida, 23 nm particles from P. ostreatus, and both 23 and 30 nm particles were also found from interspecies mated culture between P. florida and P. osreatus. The virus particles might be associated with the bad crop of Pleurotus species.

• Journal of Mushroom
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• v.11 no.2
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• pp.87-91
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• 2013

When No. 42 strain of Pleurotus ostreatus was cultivated at five different media, MnP and Lac but no LiP activity was detected throughout the culture period in the media. The production of MnP and Lac by No. 42 strain of Pleurotus ostreatus were correlated with wheat bran composition in the medium. In the liquid culture, maximum production of MnP and Lac were observed in the medium contained glucose-peptone- yeast-wheat bran(GPYW). However, in solid medium, maximum production of MnP was observed in wood meal-wheat bran(WMW) medium, but that of Lac was observed in wheat bran(W) medium.

• Journal of Mushroom
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• v.18 no.2
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• pp.141-144
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• 2020

In this study, we attempted to find alternative materials to replace Cotten seed meal(CM) using the wastes of bean sprouts by-product in bottle cultivation of Pleurotus ostreatus. In Proximate analysis, the protein content of BW was slightly lower than that of CM, but the growth characteristics of mushrooms were similar to those of control when byproduct of bean sprouts was used. In addition, the amino acid composition of fruit body did not show a significant difference in the treatment section. Therefore, it is judged that BW could be a suitable substitute for CM in the cultivation of Pleurotus ostreatus.