• Natural Product Sciences
• /
• v.27 no.3
• /
• pp.187-192
• /
• 2021

Cordycepin is a characteristic bioactive compound of Cordyceps militaris with various beneficial effects. Cordyceps grows on both grains and insects, and the content of cordycepin varies depending on the cultivation conditions. In this study, the effect of culture conditions on the cordycepin content was analyzed and the extraction conditions were optimized. Analysis of cordycepin content in Pupae-Cordyceps found that it was highly affected by temperature in culture conditions. In the case of mycelium, it grows well at 20 and 25 ℃, but not at 30 ℃. However, the content of cordycepin was highest at 30℃ and less at 20 ℃. The fruiting body also showed a similar tendency: growth was 20 ℃ > 25 ℃ > 30 ℃, but the cordycepin content was 30 ℃ > 25 ℃ > 20 ℃. The content of cordycepin decreased after the fruiting bodies were produced. Next, extraction conditions such as solvent and time were optimized for maximum cordycepin content using response surface methodology (RSM). There was a large difference in the content of cordycepin according to the content of ethanol and the extraction temperature. Through RSM, it was confirmed that the optimum condition for extraction of cordycepin was 48.9 ℃ using 49.0% ethanol, and 160.9 mg/g extract could be obtained under this condition. In conclusion, this study suggested the optimized conditions for the cultivation and extraction of Pupae-Cordyceps for maximizing the content of cordycepin, and this may be applied to the discovery of materials using cordycepin.

• The Korean Journal of Mycology
• /
• v.35 no.2
• /
• pp.85-95
• /
• 2007

This study was carried out to investigate the physiological activities of the ethanol extract from Gymnopilus spectabilis mycelium (EGM) and of the supernatant obtained from fermentation broth (SGB). The contents of polysaccharides, phenol compounds and total ${\beta}-glucans$ of EGM were found to be 80.14%, 3.5 mg/ml and 5.91%, respectively and those for SGB were 78.68%, 3.32 mg/ml and 3.28%, respectively. Both EGM and SGB exhibited dose-dependent nitrate-scavenging abilities at pH 1.2. In addition, both EGM and SGB on the autoxidation rate of the linoleic acid demonstrated powerful antioxidant activities at 1 mg/ml level. With respect to fibrolytic activity, EGM showed 1,180 unit/g, which was the same activity as streptokinase, while SGB was 1,011 unit/g. The angiotensin converting enzyme inhibition activity of EMG determined by both the normal and pretreatment methods were estimated to be 8.2% and 10.2%, respectively. However, SGB showed no corresponding activity. The growth inhibitory effects of EGM on AGS, A549, HeLa and NCTC cells were over 58.88%, respectively. And the growth inhibitory effects of the SGB on HeLa and NCTC cells were 44.92 and 76.76%, respectively. Also, EGM and SGB activated the components of the alternative complement pathway from 51 and 62% at the concentration of 100 mg/ml, The xanthine oxidase inhibition activities of EGM and SGB (1 mg/ml) were 9.53 and 16.92%, respectively.

• Research in Plant Disease
• /
• v.25 no.3
• /
• pp.114-123
• /
• 2019

QD LED has an ideal light source for growing crops and can also be used to control plant pathogenic microorganisms. The mycelial growth inhibition effect of QD LED light on Rhizoctonia solani, Phytophthora drechsleri, Sclerotinia sclerotiorum, Sclerotinia minor, Botrytis cinerea, Fusarium oxysporum, Pectobacterium carotovorum, and Xanthomonas campestris were investigated. According to the results, BLUE (450 nm) light, suppressed S. sclerotiorum by 16.7% at 50 cm height from the light source, and 94.1% mycelial growth at 30 cm height. Mycelial growth of Sclerotinia minor was inhibited by 80.4% at 50 cm height and 36.3% at 50 cm height in B. cinerea. S. minor, and B. cinerea was inhibited by 100% mycelial growth at a height of 30 cm from the light source. At 15 cm height, all three pathogens (B. cinerea, S. minor, and S. sclerotiorum) was inhibited by 100%. QD RED (M1) and QD RED (M2) light suppressed mycelial growth of S. minor and B. cinerea by 100% at 30 cm and 15 cm height from the light source. For S. sclerotiorum, QD RED (M1) and QD RED (M2) showed 75.2% and 100% inhibition, respectively. Further experiment was conducted to know the suppression effect of lights after inoculating the fungal pathogens on lettuce crop. According to the results, QD RED (M2) suppressed the S. sclerotiorum by 59.9%. In addition, Blue (450 nm), QD RED (M1), and QD RED (M2) light reduce the infestation by 59.9%. In case of B. cinerea, disease reduction was found 84% by BLUE (450 nm) light. Results suggest that the growth inhibition of mycelium increases by Quantum dot LED light.

• Journal of Ginseng Research
• /
• v.10 no.1
• /
• pp.11-20
• /
• 1986

The potential effects of ginseng saponin on the growth, aflatoxin production, and physicochemical characteristics of Aspergillus parasiticus R-716 were investigated and the results obtained were summarized as follows. The pH values of culture filtrate were increased with an increase of addition amount of saponins, the amount of mycelium was increased up to l19% by the addition of 0.01% protopanaxatriol saponin (triol). Amount of aflatoxin was increased in proportion as the bright yellow color of chloroform extract of culture filtrate was intensified. There was no difference in sporulation by the addition of 0.02% saponins, however, the sporulation was gradually decreased as the addition concentration of saponins increased. Aflatoxin production was reduced to the level of 8% by the addition of crude saponin, but production of aflatoxin B1 and B2 were inhibited by 56% and 8% with the addition of 0.5% pure saponin. The production of aflatoxin B. was increased by the addition of 0.5% trios saponin, and by the addition of 0.02% biol saponin, aflatoxin G, production reached to the maximum and thereafter it was decreased.

• The Korean Journal of Pesticide Science
• /
• v.19 no.3
• /
• pp.272-278
• /
• 2015

Colletotrichum gloeosporioides is one of the most serious pathogens of persimmon in Korea. In 2013, 67 isolates of C. gloeosporioides were isolated from infected fruits, leaf and twigs of persimmon (Diosprosi kaki) at Sangju, Gyeongsangbukdo and fungal responses against five fungicides (prochloraz manganese complex, tebuconazole, mancozeb+myclobutanil, fluquinconazole+prochloraz, and tebuconazole+tolyfluanid) were evaluated by their growth on the fungicide-medium. All isolates were inhibited mycelium growth on the medium with each recommended application concentration of flied. $EC_{50}$ (${\mu}g/ml$) of tebuconazole was from 0.02 to 1.04 and average was 0.31. $EC_{50}$ (${\mu}g/ml$) of prochloraz manganese complex was 0.02~0.23 average was 0.078. Average $EC_{50}$ values (${\mu}g/ml$) of Fluquinconazole+Prochloraz (FP) was 0.029. On the basis $EC_{50}$ (${\mu}g/ml$), the correlation coefficient (r) between tebuconazole and prochloraz manganese complex, prochloraz manganese complex and FP, tebuconazole and FP were 0.42, 0.44 and 0.27, respectively.

• Korean Journal of Microbiology
• /
• v.51 no.3
• /
• pp.221-230
• /
• 2015

Ground bed cultivation method for shiitake mushroom (Phogo; Lentinula edodes) has been advanced to use the oak-sawdust composted by microorganisms. This method has some advantages in saving the labors and improving productivity. The aim of this study is to analyze microbial community in oak sawdust and to provide the information for efficient cultivation of shiitake mushroom. In process of composting, the proportions of thermophiles increased from 10% to 80%. This results show the microbial community succession from mesophilic bacteria to thermophilic bacteria. T-RFLP analysis and nucleotide sequencing of 16S rRNA gene demonstrated that the change of dominant bacteria coupled with shifts in each stages. The family of Enterobacteriaceae as a mesophilic bacteria were dominant (100%) in oak sawdust sample, but Amycolatopsis (49.0%) and Saccharopolyspora (26.5%) as a thermophilic Actinomycetes were dominant in the last day of composting. In hyphal growth stage, Leuconostoc (psychrophilic bacteria) was dominant (75.0%). The composting process of sawdust is very important for growth of mushroom mycelium. Therefore, there is need for the further study for the Amycolatopsis as thermophilic Actinomycetes.

• Korean journal of applied entomology
• /
• v.56 no.2
• /
• pp.195-201
• /
• 2017

The entomopathogenic fungus Zoophthora radicans (Entomophthorales: Entomophthoraceae) was found to infect Cnaphalocrocis medinalis, Plutella xylostella, Myzus persicae and one unidentifed species. Samples of the fungus were collected from three areas (Jinan, Gimje, and Iksan) in Jeollabuk-do, Korea. Infected insects appeared in July and September, during which time population infection rate of Z. radicans on C. medinalis reached up to 46%. Zoophthora radicans hyphal bodies are rod-like to hyphoid, and primary conidia are bullet-shaped to long ovoid. The fungus was isolated from the surfaces of larvae and cultured in Sabouraud dextrose agar with yeast extract (SDAY). The optimal temperature range for mycelial growth was $20{\sim}28^{\circ}C$. Mycelium growth on SDAY supplemented with egg yolk and milk (SDAY-EM) was higher than on SDAY alone. Zoophthora radicans may play an important role in controlling insect population density using naturally induced epizootics.

• Journal of Mushroom
• /
• v.7 no.4
• /
• pp.156-162
• /
• 2009

These experiments were carried out to determine the optimal culture conditions for nine strains of collected Hatakeshimeji, Lyophyllum decastes (Fr.:Fr.) Sing. SPA 202 and SPA 205 strains were selected because mycelium grew fast and showed fine density. All strains showed fast mycelial growth and mycelial density on BC(Burke compost) media for 20 days of incubation. The optimal sawdust species for the mycelial growth were the fermented sawdusts of Quercus aliena and Populus deltoides. Spawn running period on the fermented sawdust substrate required 50 days at 20 to $25^{\circ}C$ and additional 7 days after soil casing. Cultivation period and temperature forprimordia formation and fruitbody development appeared from 10 to 11 days and from 7 to 8 days at 17 to $18^{\circ}C$ respectively. The length of pilei and stipes of SPA 202 harvested in optimal stage showed 60mm and 67mm, respectively. Yield of SPA 202 strain grown on fermented sawdust substrate was 130g per 1,100ml in bottle cultivation. The length of pilei and stipes of SPA 205harvested in optimal stage showed 51mm and 81mm, respectively. Yield of SPA 205 strain grown on fermented sawdust substrate was 129g per 1,100 ml in bottle cultivation. SPA 202 strain and SPA 205 strain in artificial bottle cultivation of Lyophyllum decastes used in fermented sawdust substrate were selected as themost appropriate strain in yield.

• Research in Plant Disease
• /
• v.25 no.4
• /
• pp.220-225
• /
• 2019

During the year 2018, the symptoms of bunch rot on Shine Muscat (Vitis vinifera L.) were observed in Kimcheon-si, Gyeongbuk province in Korea. The disease appears on the Shine Muscat as a black rot due to prolific fungal sporulation after it has invaded into the Shine Muscat which look completely empty and dryness. Colonies of these fungi are present on the Shine Muscat skin from fruit setting and increase in amount from early season to harvest, while become peak at ripening stage. To isolate the causal agent, small fragments (2 to 3 mm) of decayed tissue from the lesion margin were placed onto potato dextrose agar (PDA) plates. Fungal colonies on PDA produced dense white aerial mycelium and then covered with dark black conidial heads. These heads were large and radiate, and vesicles were globose (2.12-32.0×2.0-3.1 ㎛). Based on morphological and cultural characteristics, this fungus was identified as Aspergillus tubingensis. To confirm its identity, the internal transcribed spacer, β-tubulin, and RNA polymerase II was sequenced for molecular identification. BLAST search indicated 99% identity with A. tubingensis. The pathogenicity test on healthy grape of Shine Muscat produced bunch rot, as the original symptoms. To select effective fungicides for the control of brunch rot, an in vitro antifungal activity of seven fungicides were evaluated against the growth of A. tubingensis. Five fungicides (dipenoconazole, tebuconazole, metconazole, iminoctadine, and captan) exhibited significantly strong suppression of the mycelial growth of A. tubingensis.

• Journal of Mushroom
• /
• v.11 no.1
• /
• pp.1-8
• /
• 2013

In this study, twelve of Lepista nuda were collected from various localities in Korea. Also thirteen exotic L. nuda species were collected from Japan, France, Switzerland and Portugal. Spores were isolated under optical microscope. These spores were placed on the surface of YM medium for inducing to germination. Eleven mating-groups were selected by morphological characters of fruit body such as size, color and stipe patterns. Intra-isolate crosses were made between two single-spore isolates derived from mating-groups. Also, dikaryotic crossing using the isolates from L. nuda were carried out to evaluated tetrakaryon formation. Cross-mating compatibility tests also verified its dikaryotic state by microscopic or molecular genetic observation of clamp connection and Random Amplified Polymorphic DNA (RAPD) band pattern. To analyze the growth rate of hybrids and parents mycelium in dikaryons obtained from compatible mating groups were placed on PDA medium. Intra-isolate crosses determined eleven mating-groups within L. nuda. The typical clamp connection were mostly observed in mating-groups of Korean L. nuda in $K1{\times}K2$, $K1{\times}K3$, $K1{\times}K4$, $K1{\times}K6$, $K1{\times}K5$, $K2{\times}K4$, $K2{\times}K3$, $K2{\times}K6$, $K3{\times}K4$, $K4{\times}K5$, and $K4{\times}K6$. Korean L. nuda type of dikaryon, shown to cross-incompatibility with L. sordida, it seemed that mating induce more rapidly than wild types in a view of growth rate. In conclusion, it would be useful to improve mass production with better morphological characteristics through a special mating of L. nuda.