• Journal of Mushroom
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• v.14 no.4
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• pp.142-154
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• 2016

Worldwide production of mushrooms has been increasing by 10-20% every year. Recently, Pleurotus eryngii and P. nebrodensis have become popular mushroom species for cultivation. In particular, China exceeded 8.7 million tons in 2002, which accounted for 71.5% of total world output. A similar trend was also observed in Korea. Two kinds of mushrooms-Gumji (金芝; Ganoderma) and Seoji-are described in the ancient book 'Samguksagi' (History of the three kingdoms; B.C 57~A.D 668; written by Bu Sik Kim in 1145) during the Korea-dynasty. Many kinds of mushrooms are also described in more than 17 ancient books during the Chosun-dynasty (1392~1910) in Korea. Approximately 200 commercial strains of 38 species of mushrooms were developed and distributed to cultivators. The somatic hybrid variety of oyster mushroom, 'Wonhyeong-neutari,' was developed by protoplast fusion, and distributed to growers in 1989. Further, the production of mushrooms as food was 199,829 metric tons, valued at 850 billion Korean Won (one trillion won if mushroom factory products are included) in 2015. In Korea, the major cultivated species are P. ostreatus, P. eryngii, Flammulina velutipes, Lentinula edodes, Agaricus bisporus, and Ganoderma lucidum, which account for 90% of the total production. Since mushroom export was initiated in 1960, the export and import of mushrooms have increased in Korea. Technology was developed for liquid spawn production, and automatic cultivation systems led to the reduction of production cost, resulting in the increase in mushroom export. However, some species were imported owing to high production costs for effective cultivation methods. In academia, RDA scientists have conducted mushroom genome projects since 1997. One of the main outcomes is the whole genome sequencing of Flammulina velutipes for molecular breeding. With regard to medicinal mushrooms, we have been conducting genome research on Cordyceps and its related species for developing functional foods. There are various kinds of beneficial substances in mushrooms; mushroom products, including pharmaceuticals, tonics, healthy beverages, functional biotransformants, and processed foods have also became available on the market. In addition, compost and feed can likewise be made from mushroom substrates after harvest.

• Journal of Mushroom
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• v.13 no.1
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• pp.68-73
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• 2015

Hypocrea disease is the most severe disease of oyster mushroom cultivation in Korea. Physiological and ecological studies were performed on the pathogens (Hypocrea spp.) to obtain basic information for developing the integrated disease management system. Fourteen isolates of Hypocrea were collected from oyster mushroom house in five areas. Pathogenic fungi causing disease of oyster mushroom were identified as Hypocrea sp. based on morphological characteristics and pathogenicity. Two isolates (H-1, H-12) showed the fastest growth at $15^{\circ}C$ but four isolates (H-8, H-9, H-13, H-14) showed slower growth than those of other isolates at $20^{\circ}C$ and $25^{\circ}C$. Stroma with ascocarps and ascospore were produced on PDA under fluorescent light. The five isolates produced stroma with ascocarps and ascospores. Formation of fruiting body of strains H-14 of Hypocrea were the best out of all the strains on the potato dextrose agar (PDA). Also, fruiting bodies and ascospores were completely produced under fluorescent light. The growth of the isolates was correlated with total carbon content. The stroma of the isolates was formed mainly in histidine and asparagine treatment and especially in histidine-70 and asparagine-100 treatment. In the test of pathogenicity, after and before spawning showed very fast incidence of disease.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.10
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• pp.1447-1452
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• 2011

Polyphenol oxidase (PPO) isoforms were partially purified from oyster mushroom (Pleurotus ostreatus) using various chromatography techniques, and their characteristics of heat stability, substrate affinity, optimum pH, and optimum temperature were investigated. Three PPO isoforms named PO-I, PO-II-1, and PO-II-2 were partially purified from oyster mushroom. The molecular weight of PO-II-1 was 70 kDa and PO-I and PO-II-2 were less than 6 kDa each. Characterization was carried out using a PPO isoform partially purified by hydrophobic interaction chromatography. Optimum temperature was $55^{\circ}C$ and optimum pH 5.0. However, the PPO was inactivated at neutral pH or by heating at $80^{\circ}C$ for 30 min, while the 40% PPO still remained active after heating at $60^{\circ}C$ for 45 min. The PPO isoform showed the highest substrate affinity to chlorogenic acid and pyrogallol, in which KM values were 1.01 and 2.06 mM, respectively. Therefore, these results suggested that the mushrooms should be stored at a pH higher than 7.0 and at a low temperature to prevent enzymatic browning.

• Korean Journal of Food Science and Technology
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• v.41 no.2
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• pp.191-195
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• 2009

We assessed the effect of surimi gel, which is prepared from the king oyster mushroom (pleurotus eryngii) and cuttlefish meat paste (KCP) on lipid metabolism and antioxidant activity in high-cholesterol-fed rats. Three groups of 3-week-old male Sprague-Dawley rats were fed on a diet containing 1 g cholesterol/kg for 6 weeks. We administered only a high-cholesterol diet to the control group, one group was fed on surimi gel containing cuttlefish paste and king oyster mushrooms, and another group was fed with general boiled fish meat paste (GFP), which is commonly sold in marketplaces. Plasma and hepatic lipid profiles were measured, and the antioxidant status of the liver was assessed. The plasma triglyceride concentration did not differ significantly among the groups. Supplementation with KCP resulted in lower plasma and hepatic cholesterol concentrations and atherogenic index as compared to the control group and GFP, whereas the plasma high-density lipoprotein-cholesterol concentration was elevated. Moreover, the KCP-supplemented animals evidenced greater bile acid excretion. The KCP groups evidenced significantly lower plasma and hepatic levels of thiobarbituric acidreactive substances as compared to the control group. Besides, hepatic antioxidant enzyme activities, including catalase and superoxide dismutase, were significantly higher in the KCP group. In conclusion, KCP was quite effective in improving the lipid metabolism and reducing oxidative stress by upregulating the hepatic antioxidant enzymes in high-cholesterol-fed rats.

• Journal of Mushroom
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• v.11 no.3
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• pp.149-153
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• 2013

The oyster mushroom is a wide cultivar among cultivated edible mushrooms in Korea. But, due to the excess of domestic production, the price has been falling. This study has been conducted to develope new variety oyster mushroom(Pleurotus ostreatus) which have a long term storage to export in foreign market as well as domestic. 'Gonji-7ho', a new variety of oyster mushroom, for the bottle culture, was bred by mating with monokaryons isolated from 'Nongmin-59ho' and 'MT07156'. In the characteristics of fruit body, pilei were round type and gray and stipes were white color and soft. The fruit body growth was vital and uniform. When fruit-body was stored at 4 degrees after packing with plastic vinyl, storage period was extended 7 days longer than 28 day of chunchu-2ho. The yield was 166 g per a bottle(￠65, 900 ml).

• Journal of Mushroom
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• v.21 no.3
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• pp.173-178
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• 2023

In this study, the characteristics and taste components of six different oyster mushroom cultivars (Gonji-7ho, Santari, Baekseon, Chunchu, Suhan, and Heuktari) were analyzed and compared. The Heuktari mushroom pileus had the lowest brightness index (32.8) and remained dark (brightness index: 30.5) even after blanching. The moisture content of the mushrooms was approximately 90%. The salinity and sugar contents were highest in Heuktari (5.7% and 7.1%, respectively). Gonji -7ho had the highest contraction rates, with a length contraction rate of 16.4% and thickness contraction rate of 23.9%. The total amino acid content was highest in Heuktari (537.8 mg/100 g), but the glutamine content contributing to umami taste was highest in Santari (59.4 mg/100 g) and the aspartic acid content was highest in Baekseon (33.1 mg/100 g). Among the 5?-nucleotide components, guanosine monophosphate, which enhances umami taste, was highest in Baekseon (0.7 mg/g). Baekseon was also calculated to have the highest umami taste concentration based on amino acid and nucleic acid contents (12.7 g/100 g). The results of this study serve as valuable basic data on the physicochemical characteristics of oyster mushroom cultivars grown in Korea.

• Journal of Mushroom
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• v.12 no.4
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• pp.341-349
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• 2014

The composition and content of amino acid and free amino acid were separately compared in cap and stipe of fruitbody obtained from different color strains in winter mushroom and oyster mushroom strains. The result showed different kinds and amount of amino acids according to the mushroom parts, strains and kinds. Tryptophane was not detected in any mushrooms. Alanine was also not detected in all oyster mushroom strains. The content of glutamic acid was the highest and that of methionine, phenylalanine and cysteine were very low in all mushroom strains. When compared by parts, the ratio of amono acids showed similar tendency in composition. Generally the content of amono acids showed higher in caps than in stipes. The profile and content of free amino acid showed a lot of variation between cap and strip in the intra and inter mushrooms.

• Journal of Mushroom
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• v.15 no.4
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• pp.190-194
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• 2017

Oyster mushrooms are one of the most popular edible mushrooms in Korea. The 'Santari' cultivar bred in this study, which belongs to the species Pleurotus pulmonarius, is a new oyster mushroom cultivar for bottle culture. It was bred by mating monokaryons isolated from 'GMPO20404' and 'Hosan'. The optimum temperature for 'Santari' mycelial growth was $26-29^{\circ}C$ on PDA medium, and the temperatures for primordium formation and for growth of the fruit body on sawdust medium were $22^{\circ}C$ and $20^{\circ}C$, respectively. It took 34 days to complete the spawn run, 3 days to form primordia, and 3 days to finish fruit body growth in the bottle culture. The fruit body pilei were round in shape and brownish, whereas the stipes were long, thick, and white. The yield per bottle of 'Santari' was 172 g/1,100 mL, which was 43% higher than that of the reference cultivar ('Hosan'). The springiness, cohesiveness, gumminess, and brittleness of the stipe tissue were 87%, 82%, 193 g, and 16 kg, respectively. These physical property values of 'Santari' were lower than those of the control cultivar, except for the cohesiveness.

• The Korean Journal of Mycology
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• v.42 no.3
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• pp.247-252
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• 2014

The study was conducted to investigate the effect of shading treatment on the uniform primordium formation and development of fruit body during incubation of major cultivated oyster mushrooms (Pleurotus ostreatus). Oyster mushrooms cultivars Suhan No. 1 and Gonji No. 7 were incubated while shading during different times in the incubation room wherein temperature of $20^{\circ}C$ was maintained. Substrate temperature during incubation was increased to $24{\sim}25^{\circ}C$ in 11~12 days for Suhan No. 1 and to $25{\sim}26^{\circ}C$ in 11~12 days for Gonji No. 7 regardless of shading times. The $CO_2$ generation was the highest as 9~11% for Suhan No. 1 and 9~10% for Gonji No. 7 at the time of temperature increase the highest, while $O_2$contents became decreased, thus constructed good environment for the growth of hyphae. Therefore, ratio of ununiformal primordia formation was reduced by 20% as against control for Suhan No. 1 and by 13% for Gonji No. 7 when shading was applied from $10^{th}$ day of inoculation with no difference in fruit body yield.

• Journal of Mushroom
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• v.12 no.3
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• pp.154-162
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• 2014

Oyster mushrooms including of P. ostreatus, P. eryngii, P. pulmonarius and P. cornucopiae are one of the famous mushrooms for foods in Korea. RAPD were carried out using 14 of oligoprimers to analyze the phylogenetic relationship among 57 strains of 32 Pleurotus species. Most of species formed the minimum clade with strains within species and was divided respectively species. Therefore clade was separated well in accordance species. Pleurotus species formed again clade to be added in close related to other species, and were discriminated by sixteen clades with each representative species including high similarity groups. Sixteen clades were composed representative species according to each clade. There were clade I of P. pulmonarius(P. sajor-caju, P. opuntiae, P. sapidus), clade II of P. eryngii(P. fuscus var. ferulae, P. fossulatus), clade III of P. ostreatus(P. ostreatus var. columbinus, P. spodoleucus, P. floridanus), clade IV of P. florida, clade V of P. djamor(P. flabellatus, P. incarnates, P. salmoneo-stramineus), clade VII of P. populinus(P. subareolatus), clade VIII of P. cystidiosus(P. cystidiosus var. formosensis), clade X of P. dryinus(P. dryinus var. pometi), clade XIV of P. cornucopiae(P. citrinopilieatus, P. euosmus), and clade XV of P. australis. These species were representative species each clades. Five species, P. ulmarius(clade VI), P. griseus(clade IX), P. calyptratus(clade XI), P. lampas(clade XII), P. smithii(clade XIII)and P. serotinus (clade XVI) were used each one strain in analysis, so they were clustered other groups.