Oyster mushroom is one of the most widely cultivated and consumed mushrooms in Korea, and mechanization and automation of cultivation systems have enabled mass production. Many cultivars have been developed to replace the old ones such as ‘Suhan‘ and ‘Chunchuneutari 2 ho,‘ which have been cultivated for over 20 years. Among these, ‘Soltari‘ was developed in 2015. Although it has excellent quality, its cultivation is challenging and the productivity is somewhat lower. To address these issues, the Mushroom Division at the National Institute of Horticultural and Herbal Science selected the genetic resource KMCC05165 and attempted hybridization between monokaryons from KMCC05165 and ‘Soltari(KMCC04940)’. Through repeated cultivation tests and evaluation of fruiting body characteristics, the superior strain ‘Po-2019-smj22’ was selected and finally named ‘Otari‘. The optimal mycelial growth temperature of ‘Otari’ was between 25 and 30°C and optimal fruiting body growth temperature was between 13 and 18°C. Mycelial growth on PDA medium was best at 25°C, and at the same temperature, mycelial growth was similar across four media: PDA, MEA, MCM, and YM. In 1,100 mL bottle cultivation, the yield was approximately 174 g, which is about 5% higher than the control cultivar ‘Soltari‘, and the number of valid individuals was also higher at about 25. The diameter and height of the pileus were 29.8 mm and 17.6 mm, respectively, slightly smaller than ‘Soltari‘, and the stipe was thin and long with a thickness of 12.2 mm. Additionally, the pileus’ lightness index (L index) was 30.7, indicating a darker brown color compared to 'Soltari.' With excellent mycelial growth, ease of cultivation, and high yield, the new cultivar ‘Otari‘ is expected to be widely adopted by domestic oyster mushroom farms.

Recently, active research in Korea and worldwide has begun to focus on gene function and cultivar development using gene editing tools. This research, in addition to studies on edible mushroom, aims to enhance the physical and biochemical characteristics of mushrooms for applications in materials and substance production. For these studies, efficient isolation of protoplasts from the target mushroom is critical. However, several commercial cell wall-lysing enzyme cocktails, including Novozyme234, Glucanex, and Lysing enzymes, have recently been discontinued. In this study, we aimed to identify alternative enzyme systems to replace the discontinued cell wall-lysing enzymes for stable isolation of protoplasts from Ganoderma lucidum. To select an optimal osmotic buffer, enzyme function in 0.6 and 1.2 M Sorbitol, Sucrose, Mannitol, and KCl was assessed. The effect of reaction time was also evaluated. Protoplast isolation efficiency of each alternative enzyme was tested using lysing enzymes from Trichoderma harzianum, Chimax-N, and Yatalase, either individually or in combination. This matrix of studies identified enzymes and optimal conditions that could replace the discontinued lysing enzymes.

We aimed to develop outstanding domestic varieties suitable for both columnar and cylindrical-shape substrates, aiming to replace foreign varieties. and bred a high-quality new strain named ‘Charmjon’, using genetic resources collected from Japan and China. The optimal cultivation temperature for Charmjon’s mycelial growth was found to be 25°C, and its mycelial growth at 15°C and 25°C was superior to the control variety. In terms of mycelial growth characteristics based on the substrate, Charmjon exhibited excellent mycelial strength on PDA medium compared to the control variety. Through columnar and cylindrical-shape substrates cultivation, we assessed the quantity and morphological characteristics of the fruiting bodies. The results confirmed that Charmjon can be produced stably using both cultivation methods, and it showed higher yields and individual weights than the control variety. In addition, the color of the pileus was notably darker, and the shape of the pileus varied depending on the cultivation method. The test of genetic diversity revealed that Charmjon has distinct genetic characteristics compared to the control varieties.

Flammulina velutipesis a popular edible mushroom in South Korea, accounting for approximately 30% of the total mushroom export in the country. Despite its significant position in the domestic mushroom industry, approximately 65% of the cultivated F. velutipes are foreign varieties. To secure variety rights and enhance competitiveness in the export market, there is a need to develop domestic varieties with stable production and excellent shelf life. We focused on breeding a new variety called 'Baekwoon' through mon–mon crossing, using 'Baekseung' and an international collection strain (KMCC02260) as parents. Baekwoon exhibited faster mycelial growth rates at 15 °C and 25 °C and higher mycelial growth across four tested media compared to that of the control variety. Under bottle cultivation, Baekwoon had a mycelial cultivation period that was shorter by approximately 2 days compared to that of the control. The yield of Baekwoon was 228.0±10.9 g, 8.3% more than that of the control. Furthermore, Baekwoon displayed distinct morphological features characterized by a larger pileus and thicker stipe compared to that of the control variety. Genetic tests confirmed that Baekwoon is genetically different from both parental strains and the control variety. It is expected that the newly developed F. velutipes variety, Baekwoon, will be evaluated for its adaptation in different regions and actively promoted in the field, ultimately increasing the market share of domestic varieties.

Mushrooms have a unique taste and aroma, so in the processing of mushroom products with other ingredients, a separate pre-processing step is often taken to eliminate the mushroom aroma. In this study, we analyzed the changes in the concentration of volatile compounds according to drying conditions to promote the activation of processing using the fruiting bodies of yellow oyster mushrooms(Pleurotus citrinopileatus) and pink oyster mushrooms(P. djamor). The caps and stipes of yellow oyster and pink oyster mushrooms were separated and freeze-dried at -70oC for 120 hours. Subsequently, they were hot air-dried at temperatures of 40, 50, 60, and 70oC for 24, 24, 16, and 12 hours, respectively. The dried samples were pulverized and quantitatively analyzed by SPME-GC-MS. In the case of yellow oyster mushrooms, the concentration of t-2-nonenal in caps and stipes during freeze-drying was 164.43 g/g d.w. and 174.80 g/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 0.35~3.41 g/g d.w. and 0.98~59.88 g/g d.w. In a similar manner, for pink oyster mushrooms, the concentration of 1-octen-3-ol during freeze-drying in caps and stipes was 31.05 g/g d.w. and 176.17 g/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 1.59~9.66 g/g d.w. and 1.96~15.77 g/g d.w. Furthermore, most volatile compounds showed a tendency to decrease in concentration as the temperature during hot air-drying increased.

Radioactive waste is typically disposed of using standard 200 and 320 L drums based on acceptance criteria. However, there have been no cases evaluating the disposal and suitability of 200 L steel drums for RI waste disposal. There has been a lack of prior assessments regarding the disposal and suitability of 200 L steel drums for the disposal of RI waste. Radioactive waste is transported to disposal facilities after disposal in containers, where the drums are loaded and temporarily stored. Subsequently, after repackaging the disposal drums, the repackaged drums are transported to disposal facilities by vehicle or ship for permanent disposal. Disposal containers can be susceptible to damage due to impacts during transportation, handling, and loading, leading to potential damage to the radiation primer coating during loading. Additionally, disposal containers may be subject to damage from electrochemical corrosion, necessitating the enhancement of corrosion resistance. Metal composite coatings can be employed to enhance both abrasion resistance and corrosion resistance. The application of metal composite coatings to disposal containers can improve the durability and radiation shielding performance of radioactive waste disposal containers. The thickness of radioactive waste disposal containers is determined through radioactive shielding analysis during the design process. The designed disposal containers undergo structural analysis, considering loading conditions based on the disposal environment. This paper focuses on evaluating the structural improvements achieved through the implementation of metal composite coatings with the goal of enhancing corrosion and abrasion resistance.

목적 : 천연 항균, 항산화 물질인 망고스틴의 크산톤 화합물로 코팅된 콘택트렌즈를 제조하여 안과적 질환 예 방을 위한 기능성 콘택트렌즈의 물리·화학적 특성을 연구하였다. 방법 : 콘택트렌즈를 제조하여 IPN기술을 통해 감마망고스틴을 코팅하였다. 제조된 렌즈를 ISO와 식약처기준 을 참고하여 광투과율, 함수율, 산소투과율(Dk/t), 항균, 항산화성 실험을 진행하였다. 결과 : 감마망고스틴 코팅 콘택트렌즈의 가시광선투과율은 93%이다. 자외선은 70% 이상 청광은 30% 이상 차 단한다. 항균 실험에서는 감마망고스틴 코팅 콘택트렌즈의 항균성이 일반렌즈에 비해 5배 이상 효과 있고, 항산화 는 시험별 17.49, 28.46, 36.99%의 항산화율을 보였다. 결론 : 감마망고스틴으로 코팅된 콘택트렌즈는 UV와 청광의 차단율이 일반렌즈에 비해 매우 뛰어나다. 또한, 일반렌즈에 없는 항균, 항산화 활성을 보여 안과적 질환을 예방할 수 있을 것으로 보인다.

The development of automated bottle cultivation systems has facilitated the large-scale production of Pleurotus ostreatus, a commonly cultivated oyster mushroom species in South Korea. However, as the consumption of this product is decreasing and production quantities are exceeding demand, farmers are seeking various other mushroom types and cultivars. In response to this, we have developed a new oyster mushroom cultivar named 'Sena'. This high-yielding cultivar has a white pileus and excellent quality. The white oyster mushroom cultivars 'Goni' and 'Miso' were selected as parental strains from the genetic resources of the National Institute of Horticultural and Herbal Science’s Mushroom Division. By crossing their monokaryons, hybrids were developed and subjected to cultivation trials and characteristic evaluations to select the superior cultivar. The optimal temperature for 'Sena' mycelial growth is 25–30°C, with inhibition occurring at temperatures above 30°C, whereas the temperature for mushroom growth is 14–18°C. The mushrooms grow in clusters, with the white pileus having a shallow funnel shape. Optimal mycelial growth occurs in malt extract agar medium. When cultivated in 1,100 cc bottles, the 'Sena' cultivar had 35 available individuals, surpassing the number 16 available from the control cultivar 'Goni'. The yield per bottle also increased by approximately 157 g, a 24% increase over the control cultivar amount. When 300 g samples of harvested mushrooms were packed and stored at 4°C in a cold storage facility for 28 days, the weight loss rate of ‘Sena’ was approximately 4.22%, lower than that of 'Goni'. Moreover, the changes in pileus and stipe whiteness (measuring 6.99 and 8.33, respectively) were also lower than those of the control cultivar. Since the appearance of a white cap is crucial for quality assessment, the 'Sena' cultivar is superior to the 'Goni' cultivar in terms of both weight and quality after undergoing lowtemperature storage.

Recently, with the increasing global demand for Ganoderma lucidum as a material for functional beverages, varieties with enhanced functionality are needed. As part of this effort, 10 strains were selected from a collection of 160 G. lucidum strains, based on their quantity and fruiting body characteristics. These included four strains collected in Korea, three in Japan, and three of unknown origin. Approximately 44% of the 1,290 hybrid strains were secured. After two rounds of bag cultivation in oak sawdust, three strains (G-20-4, G-20-5, and G-20-7) were ultimately selected for single-timbered cultivation. Among these, G-20-4 demonstrated the earliest harvesting with a large size and a bright cap. Additionally, this strain exhibited the highest levels of total glucan, β-glucan, total triterpenoid, total polyphenol, and total flavonoid content.

Pleurotus species are the most consumed and cultivated mushrooms in Korea. Although oyster mushrooms (P. ostreatus) can be cultivated automatically, their storability is slightly lower than that of king oyster mushrooms (P. eryngii) and winter mushrooms (Flammulina velutipes); therefore, the export proportion of oyster mushrooms is very low. Since Korean mushrooms are highly preferred across Southeast Asian, the export of oyster mushrooms in the form of complete substrates is expected to be more promising than that of fresh mushroom. Here, 1 and 2.5 kg complete substrates of P. ostreatus ‘Soltari’ and P. sajor-caju ‘Sambok’ were prepared and stored at different temperature from 0 to 15°C for 10 days. Thereafter, the formation of fruiting bodies was induced. Since the 2.5 kg complete substrates required 70 days of incubation, their mycelia were at an advanced age and their fruiting bodies did not grown normally. When 70%-incubated complete substrates were stored at 5–10°C, the growth was faster and more uniform and stable fruiting bodies were formed. Export test of complete substrates to Vietnam using distribution containers set at 0°C and 15°C revealed that the growth period was shortened by 1–2 days when the distribution containers were set at 15°C and the yield of ‘Soltari’ increased by approximately 10%. In addition, even though the yield of ‘Sambok’ was similar between treatments at 0°C and 15°C, the quality of fruiting bodies from 15°C-distributed complete substrates was much better than that of those from 0°C-distributed substrates.

Flammulina velutipes, known as winter mushroom in the family of Physalacriaceae, is the main edible and export mushroom with the third highest production after oyster and king oyster mushroom in Korea. However, as normal consumers regard F. velutipes as a simple subsidiary material, there is a limitation to increasing mushroom demand. In order to overcome the consumption limit and increase the differentiation of new varieties, it is necessary to breed varieties with enhanced functionality in consideration of consumer preferences. Therefore, the study was performed to analyze nutrient components and several useful functional substances with 26 genetic resources of F. velutipes. Analyses of inorganic compound(Ca, K, Mg) and 15 amino acids revealed that Strain 4148 had the highest content among the 26 strains. Beta-glucan, which increases immune activity and polyphenol, which exert antioxidant effects were higher in non-white strains than in white strains with a small number of exceptions. Among the five fatty acids, linoleic acid(an omega-6 fatty acid) and α-linolenic acid(an omega-3 fatty acid), were detected in six mushroom strains. α-linolenic acid, which was not found in five major mushrooms including oyster mushrooms, was identified in F. velutipes. The results of HPLC analysis showed that ‘Auram’ (Strain 4232) and ‘Baekseung’(Strain 4230) had the highest content of the stabilizing neurotransmitter GABA(15.38 μg/ml and 20.56 μg/ml, respectively) among non-white and white strains, respectively. Our findings provide useful information for breeding F. velutipes to obtain strains with enhanced functionality.

Despite the long history of mushroom use, studies examining the genetic function of mushrooms and the development of new varieties via bio-molecular methods are significantly lacking compared to those examining other organisms. However, owing to recent developments, attempts have been made to use a novel gene-editing technique involving CRISPR/Cas9 technology and genetic scissors in mushroom studies. In particular, research is actively being conducted to utilize ribonucleoprotein particles (RNPs) that can be genetically edited with high efficiency without foreign gene insertion for ease of selection. However, RNPs are too large for Cas9 protein to pass through the cell membrane of the protoplasmic reticulum. Furthermore, guide RNA is unstable and can be easily decomposed, which remarkably affects gene editing efficiency. In this study, nanoparticles were used to mitigate the shortcomings of RNP-based gene editing techniques and to obtain transformants stably. We used Lentinula edodes (shiitake mushroom) Sanjo705-13 monokaryon strain, which has been successfully used in previous genome editing experiments. To identify a suitable osmotic buffer for the isolation of protoplast, 0.6 M and 1.2 M sucrose, mannitol, sorbitol, and KCl were treated, respectively. In addition, with various nanoparticle-forming materials, experiments were conducted to confirm genome editing efficiency via the formation of nanoparticles with calcium phosphate (CaP), which can be bound to Cas9 protein without any additional amino acid modification. RNPs/NP complex was successfully formed and protected nuclease activity with nucleotide sequence specificity.