• The Korean Journal of Mycology
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• v.39 no.2
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• pp.141-144
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• 2011

Short-preservation of basidiomycetes is generally being conducted in slant tubes containing solid medium based on agar. In this study, we investigated the vitality of 28 species and 76 strains preserved on potato dextrose agar (PDA) at $4^{\circ}C$ for 2~7 years. The survival rates of the fungi were 82%, 86%, 94%, 96%, 94%, and 94% for seven, six, five, four, three, and two years old preservation, respectively. The volume of medium in Lentinula edodes showed decrease after 2 years preserved. The pH of preserved medium was 5.42 in 2007 (two years old), but it became nearly neutral as increasing preservation term.

• Journal of Mushroom
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• v.19 no.3
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• pp.115-125
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• 2021

Mushroom consumption causes changes in the immune system and gut microbiota via the actions of mushroom probiotic components. β-Glucan structure-related substances suppress secretion of inflammatory mediators, and induce macrophage activation, enhancing immunity and immune function. Substances other than directly useful components can be metabolized into short-chain fatty acids by gut microbiota. These short-chain fatty acids can then induce immunity, alleviating various diseases. Substances used to stimulate growth of health-promoting gut bacteria, thereby changing the gut microbiota community are defined to be probiotics. Probiotic altered intestinal microflora can prevent various types of bacterial infection from external sources, and can help to maintain immune system balance, thus preventing diseases. Research into beneficial components of Pleurotus eryngii, Lentinula edodes, Pleurotus ostreatus, Flammulina velutipes, Auricularia auricula-judae, and Agaricus bisporus, which are frequently consumed in Korea, changes in microbiota, changes in short-chain fatty acids, and correlations between consumption and health contribute to our understanding of the effects of dietary mushrooms on disease prevention and mitigation.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.117-117
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• 2022

표고(Lentinula edodes (Berk.))는 담자균강 주름버섯목 느타리과 잣버섯속에 속하는 식용버섯으로 봄에서 가을에 걸쳐 주로 재배하며, 예부터 식용 및 약용으로 널리 이용되어져 왔다. 우리나라를 비롯하여 일본, 중국 등의 동남아시아 지역뿐만 아니라 최근에는 미국, 캐나다 및 네덜란드 등의 서구 나라에서도 관심이 높으며, 전 세계적으로 중요한 식용 버섯으로써 주목을 받고 있다. 표고는 혈중 콜레스테롤 수준의 감소, 항당뇨, 혈압조절, 면역증강, 간 보호 및 비만 억제 등의 다양한 생리활성이 밝혀져 있어 현대인의 식생활에서 수요가 더욱 증가되고 있는 추세에 있다. 버섯의 생육은 크게 균사의 생장과 자실체의 생육으로 구분되는데, 표고 균사의 배양 기간이 86~123일 정도 소요되며, 자실체의 생육 기간은 10~20일 정도로, 균사의 배양 기간이 훨씬 긴 것으로 나타났다. 버섯의 생육 단계에서 영양, 생식, 생장은 모두 수분으로부터 비롯되며, 생육 조건, 조도, 환기 정도 등에 따라 버섯의 품질은 상당한 차이를 보일 수 있다. 일반적으로 봄에 수확한 표고는 대가 짧고 단단하며 감칠맛이 풍부하며, 가을에 수확한 표고는 대가 길고 육질이 부드럽고 비교적 강수량이 높아 수분함량이 높은 것으로 알려져 있다. 이러한 현상은 표고의 수확 시기에 따라 기후, 온도, 강수량 등의 차이가 이화학적 특성에 큰 영향을 미치는 것으로 생각되어, 본 연구에서는 봄과 가을에 각각 표고를 수확하여 이화학적 특성 및 기능성성분을 비교하였다. 분석결과 가을에 수확한 표고가 봄에 수확한 표고에 비해 수분, β-glucan, ergosterol 그리고 ergothioneine 함량이 유의적으로 높게 나타나, 소재 개발 시에 경제적 경쟁력을 고려했을 때 가을에 수확한 표고 활용이 유리할 것으로 고려된다.

• Journal of Mushroom
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• v.21 no.4
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• pp.200-208
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• 2023

This study was conducted to investigate the reasons for the decreased importation of fresh Shiitake mushrooms into Korea after implementation of the Korea-China Free Trade Agreement (FTA). Monthly time-series data from January 2009 to December 2022 were analyzed using regression analysis and vector autoregression (VAR) models to determine the relationship between the amounts of fresh and spawn Shiitake mushrooms imported. The analysis revealed that a major reason for the decreased importation of fresh Shiitake mushrooms was an increase in mushroom spawn imports after Korea-China FTA implementation. The same results were obtained from the VAR model analysis. However, in terms of the dynamic changes in amount of fresh shiitake mushrooms imported, it was confirmed that the impact of the change in mushroom spawn imports could increase the amount of Shiitake mushrooms imported.

• Journal of Food Hygiene and Safety
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• v.31 no.5
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• pp.386-392
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• 2016

This study investigated the isoflavone content, total phenol content, antioxidant activities (DPPH radical scavenging and oxygen radical absorbance capacity) and ${\beta}$-glucan content of defatted soybean extracts by bioconversion. Soybean was fermented with Lentinula edodes using submerged liquid fermentation system. Defatted soybean powder prepared by hexane (HDS; hexane defatted soybean) and ethanol (EDS; ethanol defatted soybean). The major components of non-fermented HDS (NFHDS) and EDS (NFEDS) were glucoside, such as daidzin, glycitin and genistin. During the bioconversion processing, isoflavone glucoside converted into aglycone such as daidzein, glycitein and genistein. The highest total isoflavone contents of fermented HDS (FHDS) were $2577.96{\mu}g/mL$, and the lowest total isoflavone contents of NFEDS were $428.27{\mu}g/mL$. The highest total phenol contents of fermented EDS (FEDS) was 42.34 mg GAE/g. DPPH radical scavenging and ORAC value were 31.30 to 59.92% and 247.48 to $786.36{\mu}M\;TE/g$ in non-fermented defatted soybean and fermented soybean, respectively. ${\beta}$-Glucan contents were 0.09 to 0.11% in non-fermented defatted soybean and fermented soybean, respectively. These results indicate that fermented soybean could be used as natural antioxidants for the development of functional foods.

• 한국균학회소식:학술대회논문집
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• 2014.05a
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• pp.13-13
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• 2014

Two kinds of mushrooms, Gumji (金芝; Ganoderma) and Soji, were described in old book of Samguksagi (History of the three kingdoms; B.C 57~A.D 668; written by Bu Sik Kim in 1145) in Korea-dynasty. Many kinds of mushrooms were also described in more than 17 kinds of old books during Chosun-dynasty (1392~1910) in Korea. Nowadays, mushroom cultivation has been increased through out the world last decade years. Production of mushrooms has also been increased 10-20% and many varieties have been cultivated. Similar trends were also observed in Korea. Approximately two hundred commercial strains of 37 species in mushrooms were developed and distributed to cultivators. Somatic hybrid variety of oyster mushroom 'Wonhyeong-neutari' were developed by protoplast fusion, and distributed to grower in 1989. The fruiting body yield index of somatic hybrids of Pleurotus ranged between 27 and 155 compared to parental values of 100 and 138. In addition, more diverse mushroom varieties such as Phellinus baumi, Auricularia spp., Pleurotus ferulae, Hericium erinaceus, Hypsizigus marmoreus, Grifola frondosa, Agrocybe aegerita and Pleurotus cornucopiae have been attempted to cultivate in small scale cultivation. Production of mushrooms as food was 190,111 metric tons valued at 800 billion Korean Won (one trillion won if include mushroom factory products; 1dollar = 1,040 Won) in 2011. Major cultivated species are Pleurotus ostreatus, Pleurotus eryngii, Flammulina velutipes, Lentinula edodes, Agaricus bisporus, and Ganoderma lucidum, which cover 90% of total production. Since mushroom export was initiated from 1960 to 1980, the export and import of mushrooms have been increased in Korea. Technology developed for liquid spawn production and automatic cultivation systems lead to the reduction of the production cost resulting in the increasement of mushroom export. However some species were imported because of high production cost for these mushrooms requiring the effective cultivation methods. Developing of effective post-harvest system will be also directly related to mushroom export. In academic area, RDA scientists have been conducting mushroom genome projects. One of the main results is the whole genome sequencing of Flammulina velutipes for molecular breeding. An electrophoretic karyotype of of F. velutipes was obtained using CHEF with 7 chromosomes, with a total genome size of approximately 26.7 Mb. The mususcript of the genome of F. velutipes was published in PLOS ONE this year. For medicinal mushrooms, we have been conducting the genome research on Cordyceps and its related species for developing functional foods using this mushroom. In 2013, Korea Food and Drug Administraion (KFDA) approved Cordyceps mushroom for its value as an immune booster.

• The Korean Journal of Mycology
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• v.47 no.4
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• pp.385-392
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• 2019

Currently, plastic bags are being used for sawdust cultivation of shiitake mushroom. However, due to serious environmental problems caused by the use of plastic bags, we studied the efficacy of bottle cultivation method to replace the sawdust bag method. Small detachable plastic bottles (400 g capacity) filled with Quercus spp. sawdust and wheat bran (4:1 w/w) media were incubated for 80 and 120 days. The weight loss (%) of the media was higher for the NIFoS 2464 strain at an approximate light intensity of 300 Lux than light intensity of 500 Lux; the light intensity was associated with the loss of sawdust medium-weight during the cultivation period. The highest yield was observed when the strain was cultivated for 80 days under dark conditions, 40 days under 500 Lux light, and air circulation fan speed of 30 rpm. When incubated for 120 days, mushroom yield in the bottle media was higher at 40 days of light exposure than 20 days of light exposure. In the bottle media incubated for 80 days under dark conditions, the mushrooms fruited due to repetitive water spraying on the top of the media and light stimulation during the fruiting period. The media could be separated from the bottles because the media shrank after the first harvest. These separated plastic bottles could be re-used for mushroom cultivation, thereby reducing the amount of plastic waste.

• Journal of Mushroom
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• v.15 no.4
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• pp.206-209
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• 2017

In this study, the morphology and antioxidant content of shiitake mushrooms (Lentinula edodes) cultivated in smart farms and general farms have been compared. With regard to morphology, mushrooms produced in the smart farm system exhibited a slightly thicker and wider pileus and thicker and longer stipe than those in the general farm system. The stipe in the mushrooms from moderate-sized farms was harder, because the low relative humidity of cultivation rooms could induce mushroom tissue to harden. With regard to the antioxidant content, the free radical scavenging activity was evaluated by the DPPH assay. Among the various treatments, hot water extracts of freeze-dried shiitake produced from smart farms exhibited the highest DPPH value of 37.8%. In contrast, the lowest activity of 12.2% was observed in a 70% fermented alcohol extract of shiitake that was dried by hot air. The polyphenol content was higher in hot water extracts than in 70% fermented alcohol extracts. Additionally, the polyphenol content was higher in the freeze-dried samples than in hot-air dried ones. The smart-farm system was preferred over the general cropping system for cultivating shiitake mushrooms, because the antioxidant activity and polyphenol content of mushrooms from the smart-farm system was better; the functionality of this system was more improved than that of the general cropping system, and it enables mushrooms to be cultivated more efficiently. The antioxidant content is represented as the $mean{\pm}SD$ of three replicates. Different letters indicate significant differences among samples, i.e., p<0.05.

• Journal of Mushroom
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• v.15 no.1
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• pp.31-37
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• 2017

In this study, we investigated the amino acids content of shiitake mushrooms grown in eight different media and under three different temperature conditions. The sawdust media were supplemented with 4 kinds of nutrients - rice bran, barley, bean curd refuse, and red ginseng refuse in an 8:2 ratio with or without 0.5% calcium chloride, and the fruiting temperature was set to low ($13-15^{\circ}C$), medium ($18-20^{\circ}C$), or high temperatures ($24-26^{\circ}C$). Seventeen amino acids were detected, and the content varied depending on the compositions of the media. The highest total amino acid content (209.7 mg/g) was measured in mushrooms from the media with red ginseng refuse, and the glutamic acid content was the highest (51.3 mg/g) in mushrooms from the media with barley. In terms of fruiting temperature, the amino acid content was the highest (38.2%) at medium temperature followed by the content at low (32.5%) and high temperature (29.3%). The amino acid composition of shiitake mushrooms was similar between the medium and low temperature conditions.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.533-540
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• 1999

We observed that the thick outer bark layer of Quercus variabilis hindered oak longicorn beetle (Moechotypa diphysis) from laying its eggs in inner bark (secondary phloem tissues). The outer bark thickness of Q. variabilis was average of 7.4mm, while those of Q. mongolica. Q. serrata and Q. acutissima were average of 1.1mm, 1.3mm and 2.0mm, respectively. Inner bark thickness was 4.8mm in Q. acutissima and 3.6-3.9mm in the other oak species. The outer shape of ovipositional holes on the bark by the longicorn beetle was $8-12mm{\times}6-8mm$ wide oval in Q. variabilis, whereas $5-9mm{\times}1-5mm$ narrow fusiform in the other oak species. Oak longicorn beetle drilled average of three ovipositional holes per a 1.2m-long log in a few Q. variabilis logs and its ovipositional rate was 15%. Compared to this, the longicorn beetle preferred Q. mongolica. All the 32 investigated logs of this oak species were drilled to have 20 ovipositional holes per a log and ovipositional rate was 56%. One third of the eggs laid already hatched in early June to damage the inner bark. It seems that oak longicorn beetle prefers oak species with smooth, thin and stable outer bark surface.