• Korean Journal of Microbiology
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• v.27 no.4
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• pp.348-356
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• 1989

An extracellular peroxidase found in culture broth of Pleurotus ostreatus was induced by syringic acid. This enzyme was fractionated by DEAE Sephadex A-50 ion exchange chromatography and gel filtration chromatogrphy on Sephadex G-150. The enzyme is a glycoprotein containing 35.7% carbohydrate. The results of SDS-linear polyacrylamide gradient gel electrophoresis and gel filtration indicate that the enzyme is a dimer consisted of identical subunits (Mr=72,400). The absorption spectrum of the enzyme indicates the presence of one mole of iron protoporphyrin IX per one mole of subunit. Isoelectric point of the enzyme is 4.26 and $K_m$ values for $H_2O_2$ is $7.2{\mu}M$. The enzyme showed its optimal activity at pH 3.5-4.0 and at $40^{\circ}C$. The Km values of this enzyme for ferulic acid and sinapic acid are 2.4 and 12.3 times higher than those of horseradish peroxidase, respectively.

• Journal of Mushroom
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• v.12 no.3
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• pp.171-180
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• 2014

The primary objective of the present study is the characterization of the hybrids of monokaryon- monokaryon (mono-mono) crosses in mushroom breeding. We employed this technique for developing superior strains from Pleurotus species strains with 85 mono-mono intraspecific hybrids of 7 combinations between six Pleurotus ostreatus strains and one Pleurotus florida strain. In this study, the results of analysis on hybridization rate, nuclear DNA patterns, and colors and yields of fruit-bodies, are presented as follows. The crossability between mono-mono crossing ranges between 50 and 93.75%. The results of the analysis on the nuclear DNA patterns of 85 hybrid strains of mono-mono crosses share the nuclei of both parents, but their genetic similarities were predominated by either parent. The hybrid strain between P. florida and P. ostreatus showed patterns more similar to P. florida, while the hybrid strain between P. ostreatus and P. ostreatus either had patterns predominated by either parent strain. The fruiting body colors of the mono-mono crosses mostly had combined colors of both parents but showed the tendency of being more similar to that of either parent. 82% of the hybrid strain indicated similar fruiting body yields compared to both parent strains, while 0% was higher and 18% were lower than both parents. The present study was able to find out and suggest superior hybrid trains by identifying the nuclear DNA patterns of hybrids between Pleurotus species as well as the characteristics of their fruiting bodies. This study expects that the advantages of the mono-mono crossing are needs to be fully utilized in mushroom breeding and it is better to develop superior strains of Pleurotus species strains together with the mono-mono crossing.

• Journal of Mushroom
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• v.14 no.4
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• pp.197-201
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• 2016

During cultivation of Pluerotus ostreatus, there were happened several problems by mushroom flies. Many mushroom farms were faced with the problem that mushroom production periods became shorter by mushroom fly. In this study, we examined effect of Lycoriella ingenua on the production of P. ostreatus. When we used 10 adult flies at the time of inoculation, mushroom production decreased by 10.8% as compared to that of the control. And when L. ingenua used more than 20 adult flies, contamination occurred in all treatments. And when L. ingenua used at the time of P. ostreatus mycelium cultured during 14 days, it was confirmed that the yield of P. ostreatus decreased in proportion to the number of L. ingenua.

• The Korean Journal of Mycology
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• v.9 no.1
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• pp.19-24
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• 1981

The mycelial growth of Agaricus bitorquis and Pleurotus ostreatus in synthetic media were carried out by ordinary methods. The optimum pH and temperature for mycelial growth were from pH 6.0 to 6.5 and 25 to $30^{\circ}C$, and from pH 5.0 to 6.5 and $25^{\circ}C$ in A. bitorquis and P. ostreatus, respectively. Among the carbon and nitrogen sources, glucose, starch, and peptone showed the good result for the mycelial growth of A. bitorquis, and glucose, fructose, starch and peptone were good for the mycelial growth of P. ostreatus. The yield of mycelium decreased under lower or higher C/N ratio. Also, at the same C/N ratio, the higher the concentration of glucose and peptone, the more the yield was increased. Among various vitamins thiamine, Ca-pantothenate and folic acid were suitable for the mycelial growth of A. bitorquis, and thiamine, folic acid and ino­sitol for the mycelial growth of P. ostreatus. Although pH, total nitrogen and glucose contents of media decreased gradually during culture period the yield of mycelium increased.

• Journal of Food Hygiene and Safety
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• v.31 no.2
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• pp.119-125
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• 2016

Antioxidative components and activities of the extracts from Pleurotus ostreatus extracted at different ethanol concentration were analyzed and their correlation were investigated. Ergothioneine, total phenolic compounds, and flavonoid contents of the extracts from P. ostreatus extracted with hot water (0% ethanol) were the highest ($2.98{\pm}0.05$, $9.51{\pm}0.45$, and $2.83{\pm}0.03mg/g$, respectively) and the contents were decreased according to increase of ethanol concentration for extraction. DPPH and ABTS radical scavenging activities of the extracts from P. ostreatus extracted with hot water were the highest ($80.41{\pm}0.56$ and $91.47{\pm}0.11%$, respectively). FRAP value also showed the highest reducing power by $8.86{\pm}0.33\;FeSO_4\;eq$. mM in hot water extracts. Positive correlations were found between ergothioneine contents and antioxidative active components and antioxidant activity of the extracts from P. ostreatus. Results indicate that hot water extraction was most efficient for the extracts with high antioxidative activities from P. ostreatus.

• Journal of Mushroom
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• v.2 no.1
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• pp.10-14
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• 2004

Effect of solid grain media on the mycelial growth of Pleurotus ostreatus and its biofunctional activities were investigated using seven kinds of grains. Foxtail millet and barley were good for growth of hypha of P. ostreatus. However, growth of the mycelium was very slow in the solid grain media containing wheat, corn and brown rice. Mycelial growth of P. ostreatus according to water content of solid grain media was good at 25% to 30%. Mycelial growth of P. ostreatus according to heating-time and temperature of solid grain media was good for 30 min at $121^{\circ}C$. Anticancer activities against lung cancer cell line of the myceial extracts from P. ostreatus grown on several grain media were strong in the corn, defatted soybean, brown rice, barly and black bean in order. Fibrinolytic activities of the myelial extracts were strong in order defatted soybean, wheat, foxtail millet, barley, brown rice and black bean. The mycelial extracts were showed good antibacterial activities against Pseudomonas aeroginosa and Staphylococcus aureus.

• The Korean Journal of Mycology
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• v.24 no.3 s.78
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• pp.186-205
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• 1996

This study was carried out to obtain data concerning the genetic variability of Pleurotus ostreatus. Monospores of P. ostreatus were isolated and cultured to estimate differences in the rate of mycelial growth and genetic similarity among the isolates. Although the overall growth rates were slow compared to their parental dikaryon except 2-MI 4, significant differences in the rate of mycelial growth were observed among isolates. Random amplified polymorphic DNA (RAPD) analysis using twenty six random primers showed 345 polymorphic DNA bands from 35 monospore isolates and their parental dikaryon. DNA bands ranged from 0.1 to 4.0 Kb in size. Most various polymorphic DNA bands within monospore isolates were obtained when we used J (OPA-01) or W (OPB-04). The 36-MI 103 showed totally different band patterns from those of the others. RAPD analysis revealed that there is approximatly 75% genetic similarity between monospore isolates and their parental dikaryon except 36-MI 103, which showed only 49% genetic similarity. In addition, genetic similarity degrees were classified into four groups: I (parental dikaryon), II (fast growing type), III (moderate growing type), and IV (slow growing type). However, there is no correlation between mating type and mycelial growth rates.

• Journal of Mushroom
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• v.20 no.3
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• pp.102-106
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• 2022

This study was conducted to investigate the growth and antioxidant activity of Pleurotus ostreatus mycelia grown in medium supplemented with Aronia. The diameter and dry weight of the mycelia were increased in the medium supplemented with Aronia compared with the untreated medium. The total polyphenol content of mycelia grown in medium supplemented with Aronia and untreated medium was 6.54 mg GAE/g and 5.77 mg GAE/g, respectively. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of mycelia grown in medium supplemented with Aronia and untreated medium was 61.81% and 49.65%, respectively. Moreover, the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity of mycelia grown in medium supplemented with Aronia and untreated medium was 59.83% and 52.66%, respectively. These results confirmed that P. ostreatus mycelial growth and antioxidant activity were increased when Aronia was added to the culture medium.

• Journal of the Korean Society of Food Culture
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• v.16 no.5
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• pp.463-469
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• 2001

This study was to investigate the effect of ultraviolet rays, soaking, boiling and baking to ergocalciferol ($Vit.D_2$) and riboflavin($Vit.B_2$) contents of mushrooms, Lentinus edodes, Pleurotus ostreatus and Agaricus bisporus. The results were as follow: 1. Mushrooms were exposed to ultraviolet rays Lentinus edodes : $10J/cm^2$, Pleurotus ostratus : $2J/cm^2$ and Agaricus bisporus : $2J/cm^2$. 2. Before exposing to ultraviolet rays, the ergocalciferol contents of mushrooms were all $0{\mu}g/g$ dry base, but after exposing to it , those of Lentinus edodes, Pleurotus ostreatus and Agaricus bisporus were $222.50{\pm}5.30{\mu}g/g$ dry base, $150.90{\pm}6.60{\mu}g/g$ dry base and $23.98{\pm}1.20{\mu}g/g$ dry base, respectively 3. Before and after exposing to ultraviolet rays, the riboflavin contents of Lentinus edoes, Pleurotus ostreatus and Agaricus bisporus were $18.22{\pm}0.71{\mu}g/g$ dry base and $11.72{\pm}0.50{\mu}g/g$ dry base, $4.57{\pm}0.20{\mu}g/g$ dery base and $3.26{\pm}0.15{\mu}g/g$ dry base, and $37.42{\pm}1.20{\mu}g/g$ dry base and $27.33{\pm}2.10{\mu}g/g$ dry base, respectively. 4. The ergocalciferol contents of mushrooms according to boiling time were not significantly different but the riboflavin contents of them were decreased according to the increase of boiling time. 5. The ergocalciferol and riboflavin contents of mushrooms were decreased according to the increase of NaCl concentration and baking temperature. 6. The ergocalciferol content of Lentinus edodes after a short time soaking at $80^{\circ}C$ was higher than a long time soaking at $20^{\circ}C,\;40^{\circ}C$ and $60^{\circ}C$.

• The Korean Journal of Mycology
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• v.14 no.1
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• pp.31-36
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• 1986

The volatile aroma concentrates were isolated from Pleurotus ostreatus by simultaneous distillation-extraction and analyzed by gas chromatography and combined gas chromatography-mass spectrometry. The aroma concentrates obtained had a typical raw or slightly cooked mushroom-like odor, and the yield was 123 ppm. Of 27 components identified, the major components were 3-octanone, 3-octanol, 2-octenal, n-octanol and 2, 4-decadienal, including 1-octen-3-ol contributing 67.06% of the total volatiles, and the $C_8$ compounds comprised about 80% of the total volatiles. On the other hand, the $C_6$ and $C_8$ alcohols in mushroom increased gradually with increase of standing time after homogenation, while aldehydes, ketones, and linoleic acid decreased, and also $C_6$ and $C_8$ compounds were significantly increased when linoleic and linolenic acid were added in homogenates. It appears that most of volatile aroma components in Pleurotus ostreatus were probably produced enzymatically from unsaturated fatty acids containing cis, cis-1, 4-pentadiene moiety.