• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.402-409
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• 2002

The effects of protein-bound polysaccharides (A-PBP and L-PBP) that were extracted from the mycelia of two edible mushrooms, namely Agaricus blazai and Lentinus edodes, on serum cholesterol and body weight were investigated in mice and female volunteers. Six groups of Male Balb/c mice were fed six kinds of diet supplement- solutions composed of L-PBP, A-PBP, chitosan, and other fiber constituents, for 30 days under the normal diet. Ninety female volunteers were also supplemented for 8 weeks with six kinds of capsules including control and five test groups as the same manners (two times a day, 4 capsules). From 12 days after feeding of L-PBP (Group I) and A-PBP (Group II), the weight of mice began to reduce as compared with control, whereas that of Group III fed chitosan was decreased 15 days after feeding. Group W and Group V which were fed mixture of L-PBP, A-PBP, chitosan, and other dietary fiber, were more significant in lowering weight. After 4 weeks of the supplementation in women, their serum LDL-cholesterol level and body weights in Group I and II were reduced, but Croup 111 taken with chitosan capsule showed weaker effect than Group I and II. After 8 weeks, LDL-cholesterol content in the sera of Group I (132.5 mg/dL) and II(131.5 mg/dL) was decreased to ideal level (125.4 and 122.8 mg/dL) for healthy blood vessel. In the case of Group W supplemented with mixture of L-PBP, A-PBP, and chitosan, the weight-reduction effect (11.8%) and hypocholesterolemic effect (11.0%) was most significant, indicating their synergistic action. These data suggested that the weight-controlling and hypolipidemic effect of L-PBP and A-PBP was involved, at least in part, in absorption of cholesterol as their role of dietary fiber, as well as cholesterol metabolism.

• Journal of the Korean Wood Science and Technology
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• v.42 no.4
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• pp.428-438
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• 2014

Functional effects of cauliflower mushroom (Sparassis latifolia) have been magnified by various media and internal and external research papers, recently. So, optimum condition of wood chip particle size and cultivation method of high ${\beta}$-glucan content for bulk cultivation generalization of cauliflower mushroom farms researched. As a result, T7 (1~2 mm 25%, 2~4 mm 50%, over 4 mm 25%) media as mixed media of certain ratio of particle size, showed excellent growth at $11.5{\pm}1.0$ cm / 44 days. Also, production of fruit body found higher than control and marketable pileus part took 85% ratio. The ${\beta}$-glucan content at media composition condition showed 1.4~2.4 times higher content in stipe part than pileus part. Also, PCF300 medium found 59.5% highest ${\beta}$-glucan content in stipe part. While ${\beta}$-glucan content showed 33.0% low content in pileus part. Therefore it needed additional study that ${\beta}$-glucan content improved in pileus part. In conclusion, production of high ${\beta}$-glucan content cauliflower mushroom was possible by T7 condition (wood chip particle size: 1~2 mm 25%, 2~4 mm 50% and over 4 mm 25%, composition: corn powder, flour and 300 ppm yeast).

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.220-229
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• 2009

Strain improvement and morphology investigation in bioreactor cultures were undertaken in suspended cultures of Phellinus linteus mycelia for mass production of protein-bound polysaccharides(soluble ${\beta}$-D-glucan), a powerful immuno-stimulating agent. Phellineus sp. screened for this research was identified as Phellinus linteues through ITS rDNA sequencing method and blast search, demonstrating 99.7% similarity to other Phellinus linteus strains. Intensive strain improvement program was carried out by obtaining large amounts of protoplasts for the isolation of single cell colonies. Rapid and large screening of high-yielding producers was possible because large numbers of protoplasts ($1{\times}10^5{\sim}10^6\;protoplasts/ml$) formed using the banding filtration method with the cell wall-disrupting enzymes could be regenerated in relatively high regeneration frequency($10^{-2}{\sim}10^{-3}$) in the newly developed regeneration medium. It was demonstrated that the strains showing high performances in the protoplast regeneration and solid growth medium were able to produce 5.8~6.4%(w/w) of ${\beta}$-D-glucan and 13~15 g/L of biomass in stable manners in suspended shake-flask cultures of P. linteus mycelia. In addition, cell mass increase was observed to be the most important in order to enhance ${\beta}$-D-glucan productivity during the course of strain improvement program, since the amount of ${\beta}$-D-glucan extracted from the cell wall of P. linteus mycelia was almost constant on the unit biomass basis. Therefore we fully investigated the fungal cell morphology, generally known as one of the key factors affecting cell growth extent in the bioreactor cultures of mycelial fungal cells. It was found that, in order to obtain as high cell mass as possible in the final production bioreactor cultures, the producing cells should be proliferated in condensed filamentous forms in the growth cultures, and optimum amounts of these filamentous cells should be transferred as active inoculums to the production bioreactor. In this case, ideal morphologies consisting of compacted pellets less than 0.5mm in diameter were successfully induced in the production cultures, resulting in shorter period of lag phase, 1.5 fold higher specific cell growth rate and 3.3 fold increase in the final biomass production as compared to the parallel bioreactor cultures of different morphological forms. It was concluded that not only the high-yielding but also the good morphological characteristics led to the significantly higher biomass production and ${\beta}$-D-glucan productivity in the final production cultures.

• Journal of Mushroom
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• v.3 no.3
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• pp.109-114
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• 2005

Attempts were made to control Diatrype stigma occurred on the bed-log of shiitake by resistant shiitake strains. In selection test of resistant shiitake strains, 67 out of 77 strains tested were proved to be resistant to D. stigma. Among them, 13 strains including KFRI 5 were effective to inhibit the access of D. stigma, and 7 strains including KFRI 180 remarkably invaded the territory of D. stigma. Among 31 shiitake strains made by hybridization of resistant strains for D. stigma, 8 strains including KFRI 537 inhibited the access of D. stigma, and 4 strains including KFRI 545 invaded the territory of D. stigma. The effects of temperatures and inoculation orders to the resistance were confirmed in PDA plates and test tubes filled with sawdust of Quercus acutissima. Four kinds of temperature treatments as follows were tested: (1) continuous incubation at $14^{\circ}C$, (2) continuous incubation at $25^{\circ}C$, (3) changing of incubation temperature from $14^{\circ}C$ to $25^{\circ}C$ as soon as mycelia of both shiitake and D. stigma meet together, (4) changing of incubation temperature from $25^{\circ}C$ to $14^{\circ}C$ as soon as mycelia of both shiitake and D. stigma meet together. Three kinds of inoculation procedure were tested: (1) inoculation of shiitake 3 days ahead of D. stigma inoculation, (2) inoculation of D. stigma 3 days ahead of shiitake inoculation, (3) simultaneous inoculation of both fungi. In PDA plate test, the strain KFRI 137 showed outstanding ability to inhibit mycelial growth of D. stigma and the strain KFRI 180 invaded into the territory of D. stigma in most of treatments. Hybrid strains, KFRI 545, 546, and 547 were more resistant than their parent strains, KFRI 488 and 405. In test tube examinations, all the strains of shiitake showed high resistance at the treatment of change in temperature from $14^{\circ}C$ to $25^{\circ}C$ when mycelia of both shiitake and D. stigma meet together. On the other hand, resistance of all the strains growing at $25^{\circ}C$ decreased when the temperature was changed into $14^{\circ}C$ after mycelia of both fungi. In these cases, the resistance reached to 7~20% of the highest resistance. The strain KFRI 259 invaded the territory of D. stigma, contrary to PDA plate test. Among the strains, KFRI 393 strain was the most resistant under the continuous incubation at $25^{\circ}C$.

• Korean Journal Plant Pathology
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• v.3 no.2
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• pp.114-119
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• 1987

Banana blast was frequently encountered in greenhouses of Jeju province during a local survey of plan diseases from 1985 to 1986. The disease incidence on banana was very severe up to $100\%$ in a greenhouse. The causal fungus was identified as Pyricularia angulata Hashioka based on mycological characteristics and Path genicity of the fungus. The symptom of blast produced on leaves of banana was circular to oval, dark brow spots with yellow margins which measured 1-10mm in diameter, and the symptom on fruits was circular to oval reddish brown or dark brown, depressed spots which measured up to 20mm in diameter. The symptoms were scattered not only on leaves and fruits of banana but. also on petioles, leaf sheaths, bunch stalks and crowns The pathogen was characterized that conidia were hyaline, 2 septated, ovate to pyriform with a small hilum solitary at ends of den tides of conidiophores, and measured $16.0-34.0\times7.0-12.0{\mu}m$ (average $22.5\times9.0{\mu}m$) and conidiophores were mostly 2 septated, occasionally 2 or 3 branched, denticulate at the tips, and measured $7.5-100.0\times3.0-5.0{\mu}m$(average $90.0\times4.0{\mu}m$). The optimum temperature range for mycelial growth of the fungus on PDA was $26-28^{\circ}C$. The result of pathogenicity tests revealed that P. angulata had pathogenicity only on banana. On the other hand Pyricularia grisea (Cke.) Sacc. isolated from Digitaria sanguinalis(L.) Scopo. was not pathogenic to banana. It was revealed that the leaves were the most susceptible to P. angulata among several parts of banana in inoculation tests. Thirty-day-old fruits of banana were more susceptible to the fungus than 60-day-old fruits, and bunch stalks were more susceptible than the fruits.

• Journal of Mushroom
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• v.2 no.1
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• pp.15-20
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• 2004

Pleurotus ostreatus, the oyster mushroom, is one of the most widely cultivated and important edible mushrooms in the world. In order to study the developmental process of P. ostreatus and its regulatory mechanism, a new culturing method needs to be established for inducing the fruiting body and sporulation in the laboratory. In this study, we have examined whether the fruiting body of P. ostreatus can be formed on the plastic petri dish which are commonly used for cell culture in the laboratory. The strain was cultured on $60{\times}15mm$ plastic petri dish with potato dextrose agar media at $28^{\circ}C$ for mycelial growth and then at $18^{\circ}C$ for the formation of primordia and fruiting bodies within plant growth chamber. The development of primordia into fruiting bodies was achieved on cultured dishes under air ventilation. At the primordia stage, the normal formation of fruiting body was blocked by sealing the plastic dish with parafilm. The periods requiring for the formation of primordia and fruiting bodies were examined on the dish culture. About 96% and 76% of cultured samples formed primordia and fruiting bodies under the optimal conditions during ten weeks of culture, respectively. These culturing periods, however, were changed by the mechanical injury treatment to mycelia. As other factors affecting the fruiting body formation, the effects of light and cold shock have been tested. No fruiting formation was observed on the cultured dishes under the dark. The cold shock treatment by storing cultured dishes for one day at $4^{\circ}C$ did not have any significant effects in the fruiting body formation. Spores of fruiting bodies acquired from the petri dishes could be germinated on culture media at $28^{\circ}C$. These results suggest that the fruiting bodies of P. ostreatus can be formed on the experimental petri dish and this dish-culturing method is useful for understanding of the developmental process of P. ostreatus in the laboratory. Furthermore, the dish-culturing method is able to shorten the life cycle of P. ostreatus without requiring large area and expensive device.

• Journal of Mushroom
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• v.6 no.2
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• pp.47-51
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• 2008

The Oyster mushroom is saprophytic fungus. The pileus is stemmed at the side and later depressed. It grows to 5-15 cm, and is of grey, grey-lilac, blackish-grey, steel grey, grey-brown, and blue-blackish. Various kinds of Oyster mushrooms such as golden, pink, brown, grey, white, and blue make marketing an interesting challenge depending upon the market niche. A new commercial strain "Chung" of oyster mushroom was developed by hyphal anastomosis. It was improved with hybridization between monokaryotic strain derived from Pleurotus ostreatus ASI 2194 and ASI 2487. The pileus of parental strain ASI 2194 and ASI 2487 was grey and light blue-grey, respectively. Most of intra-specific hybrids between strain ASI 2194 and ASI 2487 were showed similar pileus color of parents. By the way, the pileus color of variety 'Chung' was blue to bluish grey. The optimum temperatures of mycelial growth and fruiting body development was $25{\sim}30^{\circ}C$ and $12{\sim}16^{\circ}C$, respectively.

• Journal of Mushroom
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• v.15 no.3
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• pp.129-133
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• 2017

Oyster mushroom is a type of mushroom that is commonly cultivated and consumed in Korea. P. ostreatus 'Suhan' is a preferred cultivar for many mushroom farmers because it has a dark pileus and thick stipe. However, as it is very sensitive to environmental conditions, farmers consistently demand an alternative cultivar. To develop a new cultivar, the parental strains KMCC01680 ('Suhan') and KMCC00478 ('Gosol') were selected from various collected P. ostreatus strains by cultivating genetic resources. P. ostreatus 'Heuksol' was developed by the method of Mon-Mon crossing between monokaryotic strains derived from 'Suhan' and 'Gosol'. Thirty strains of 174 crossed strains were initially selected by cultivation experiments. After bulk cultivation tests, 'Heuksol' was selected. The nuclear DNA profile of 'Heuksol' was similar to those of the parental strains, 'Suhan' and 'Gosol', when RAPD (random amplified polymorphic DNA) primers and UPF (Universal PCR Fingerprinting) 2, 3, and 4 were used. The optimum temperature for mycelial growth was $30^{\circ}C$ for 'Heuksol', but medium-high temperatures were also appropriate, especially $13-20^{\circ}C$. The fruiting body production per bottle (1,100 mL) was approximately 140.8 g. When compared to the control strain 'Suhan', the thickness of the stipe of 'Heuksol' was greater than that of 'Suhan' (13.5 mm vs 9.4 mm). The pileus diameter of 'Heuksol' was similar to that of 'Suhan' and the pileus thickness of 'Heuksol' and 'Suhan' was 19.7 mm and 21.8 mm, respectively. 'Heuksol' had more a productive stipe number than 'Suhan' and the pileus of 'Heuksol' was dark gray, even at high temperatures. Therefore, it was suggested that this new cultivar, 'Heuksol', could provide an alternative to 'Suhan' and contribute to the profit of oyster mushroom farms.

• Journal of Mushroom
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• v.16 no.3
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• pp.203-207
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• 2018

'Daebak', a new cultivar of Grifola frondosa, was bred by mating two monokaryotic strains isolated from 'F14309' and 'GMGF44062' at the Mushroom Research Institute, Gyonggi-Do ARES in 2017. The optimum temperature for mycelial growth of 'Daebak' was $25^{\circ}C$ on PDA medium. In bottle cultivation, the culture period of 'Daebak' was 57 days, which was 2 days shorter than that of 'Cham' (control). The pinheading rate of 'Daebak' was 98.4%, which was 24.8% higher than that of 'Cham' and its CV (Coefficient of variation) was 0.6%, 5.3% lower than that of 'Cham'. Regarding the growth characteristics of 'Daebak', the diameter and thickness of the pileus were 27.7 mm and 1.73 mm, respectively, and the diameter and height of the fruiting bodies cluster were 132 mm and 87.2 mm, respectively. The pileus was thinner but the fruiting bodies cluster was larger than that of 'Cham'. Fruiting bodies weighed 139 g per 1,100 ml bottle of 'Daebak', which was 28% higher than that for 'Cham', with a CV of 2.5%, which was 6.2% lower than that of 'Cham'. The yield per 10,000 bottles (used for cultivation) of 'Daebak' was 1,376 kg, 70% higher than that of 'Cham', with a CV of 3.0% that was 11.5% lower than that of 'Cham'. With respect to physical characteristics, the strength and brittleness of the fruiting body of 'Daebak' was less than that of 'Cham'. When considering the period available for sale, the shelf life of 'Daebak' was 42 days, which was 6 days longer than that of 'Cham'.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.230-238
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• 1998

This study was conducted to compare the regeneration of the seedlings under different vegetation types and to identify the presence of allelopathy in Abies koreana(Ak) natural forest in Banyabong Peak(elevation, 1715m), of Mt. Chiri. Twenty quadrats($10m{\times}10m$) were placed in May, 1996 to classify vegetation structure using TWINSPAN. Water-soluble extracts from leaves and soil humus of different vegetation types were collected to test their effects on both seed germination of Ak and mycelial growth of ectomycorrhizal fungi. Phenolic compounds from soil humus were quantified using HPLC. Among the four vegetation types, Sasa borealis(Sb) was found in both Ak-Quercus mongolica(Qm) and Ak-Rhododendron schlippenbachii(Rs) communities. Natural seeding of Ak was $230,000{\pm}90,000seeds/ha$ in 1995 and their germination rate was 25% in an ideal laboratory condition. Density of Ak seedlings less than 5cm in height was 52,000/ha in 1996, while that of seedlings taller than 5cm in height was only 4,000/ha. In the case of Ak-Qm community, density of Ak seedlings with Sb understory was only 7% of the density of seedlings with Rs understary, suggesting the inhibitory effect of Sb. The germination rate of Ak seeds was significantly reduced by leaf extracts of Sb, and Rhododendron mucronulatum var. ciliatum(Rm) and Ak. Soil humus extract of Ak-Qm-Sb subcommunity reduced germination of Ak seeds by 81% and also reduced by 19% the respiration of mycelia of ectomycorrhizal fumgus, Lactarius sp. Among the seven phenolic compounds identified from the soil humus, extract, Ak-Qm-Sb subcommunity contained significantly high content of p-hydroxybenzoic acid, vanillic acid, and syringic acid. Particularly, p-hydroxybenzoic acid was present at 4.2ppm in the Sb roots and at 16.5ppm in the Sb humus, suggesting that it could be the primary allelopathic compound in Abies koreana forests with Sasa borealis understory.