• Korean Journal of Microbiology
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• v.37 no.4
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• pp.239-244
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• 2001

We isolated a Myxobacteria strain from a soil sample obtained from Mt. Daedoon located in Choongnam, Korea. This strain, ARJ, secreted slime while swarmed on the surface of CT medium. It produced greenish yellow pigment in liquid or solid media, and the swarming edge showed green florescence under U. V. at 366 nm. It formed fruiting bodies when nutrient was exhausted, which is one of the most imkportant characteristics of Myxobacteria. The fruiting bodies did not have a stalk and consisted of naked myxospores when examined under the scanning electron microscope. These traits lead us to believe that this strain is very close to Myxococcus virescens. It showed antimicrobial activity, especially against Gram positive bacteria. Culture filtrate showed the activity but this was not due to protein. The culture filtrate also had proteolytic activity in which at least two enzymes are involved.

• 한국균학회소식:학술대회논문집
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• 2015.11a
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• pp.35-35
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• 2015

Pleurotus eryngii has recently become a major cultivated mushroom; it uses tetrapolar heterothallism as a part of its reproductive process. Sexual development progresses only when the A and B mating types are compatible. Such mating incompatibility occasionally limits the efficiency of breeding programs in which crossing within loci-shared strains or backcrossing strategies are employed. Therefore, understanding the mating system in edible mushroom fungi will help provide a short cut in the development of new strains. We isolated and identified pheromone and receptor genes in the B3 locus of P. eryngii and performed a functional analysis of the genes in the mating process by transformation. A genomic DNA library was constructed to map the entire mating-type locus. The B3 locus was found to contain four pheromone precursor genes and four receptor genes. Remarkably, receptor PESTE3.3.1 has just 34 amino acid residues in its C-terminal cytoplasmic region; therefore, it seems likely to be a receptor-like gene. Real-time quantitative RT-PCR (real-time qRT-PCR) revealed that most pheromone and receptor genes showed significantly higher expression in monokaryotic cells than dikaryotic cells. The pheromone genes PEphb3.1 and PEphb3.3 and the receptor gene PESTE3.3.1 were transformed into P5 (A3B4). The transformants were mated with a tester strain (A4B4), and the progeny showed clamp connections and a normal fruiting body, which indicates the proposed role of these genes in mating and fruiting processes. This result also confirms that PESTE3.3.1 is a receptor gene. In this study, we identified pheromone and receptor genes in the B3 locus of P. eryngii and found that some of those genes appear to play a role in the mating and fruiting processes. These results might help elucidate the mechanism of fruiting differentiation and improve breeding efficiency.

• Mycobiology
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• v.36 no.1
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• pp.13-18
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• 2008

Eight distinct bacteria were isolated form diseased mycelia of the edible mushroom, Pleurotus eryngii. 16S rDNA sequence analysis showed that the isolates belonged to a variety of bacterial genera including Bacillus (LBS5), Enterobacter (LBS1), Sphingomonas (LBS8 and LBS10), Staphylococcus (LBS3, LBS4 and LBS9) and Moraxella (LBS6). Among them, 4 bacterial isolates including LBS1, LBS4, LBS5, and LBS9 evidenced growth inhibitory activity on the mushroom mycelia. The inhibitory activity on the growth of the mushroom fruiting bodies was evaluated by the treatment of the bacterial culture broth or the heat-treated cell-free supernatant of the broth. The treatment of the culture broths or the cell-free supernatants of LBS4 or LBS9 completely inhibited the formation of the fruiting body, thereby suggesting that the inhibitory agent is a heat-stable compound. In the case of LBS5, only the bacterial cell-containing culture broth was capable of inhibiting the formation of the fruiting body, whereas the cell-free supernatant did not, which suggests that an inhibitory agent generated by LBS5 is a protein or a heat-labile chemical compound, potentially a fungal cell wall-degrading enzyme. The culture broth of LBS1 was not inhibitory. However, its cell-free supernatant was capable of inhibiting the formation of fruiting bodies. This indicates that LBS1 may produce an inhibitory heat-stable chemical compound which is readily degraded by its own secreted enzyme.

• The Korean Journal of Mycology
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• v.39 no.3
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• pp.185-188
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• 2011

To develop health food and alternative medicine, water and ethanol extracts from Hypsizygus marmoreus (white cultivar) fruiting body were prepared, and its physiological functionalities were investigated. Antihypertensive angiotensin I-converting enzyme (ACE) inhibitor activity from water extract was showed higher of 60.5% than ethanol extract and SOD-like activity and xanthine oxidase inhibitory activity were also showed 24.1% and 23.0%, respectively. The other functionalities were very low or not detected. The maximal ACE inhibitory activity (80.5%) was obtained when the fruiting body of Hypsizygus marmoreus was extracted with distilled water (dilution 1 : 30) at $50^{\circ}C$ for 12 h.

• The Korean Journal of Mycology
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• v.39 no.3
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• pp.231-234
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• 2011

This study was performed to develop new Hypsizygus marmoreus cultivars that have enhanced functional materials and improved physiological characteristics with mutagenesis by gamma ray irradiation. Protoplasts of H. marmoreus brown strain HYM-056 were irradiated by gamma ray for mutagenesis, and then 2,000 clones of mutants were randomly selected and the fruiting bodies were induced by bottle culture. Among them, 157 isolates with fast-growing, heavy and many fruiting body-producing were selected. The isolates were cultured in plastic bottle containing rice bran, barley hulls and fir sawdust to form the fruiting bodies. About 100 days after inoculation, characteristic of fruiting bodies were investigated. The isolates were divided into 6 groups based on color, shape and size of pileus, and length, diameter, number and weight of stipe. In addition, the genetic variation of the isolates was analyzed by URP-PCR fingerprinting.

• Journal of agriculture & life science
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• v.43 no.4
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• pp.33-36
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• 2009

Globose to clavate base-ball sized, pear shaped, fruiting bodies were found under the Himalayan cedar, Cedrus deodora at less fertile and poor sandy poor soil in the campus of Gyeongsang National University in Jinju, Korea. The fruiting body was at first, round to club-shaped, usually with a narrow, rooting base with yellowish rhizomorphs attached to it and lack a volva and a sterile base. The peridium of fruiting body was tough and crusty. The peridioles were white pea-like capsules in a blackish matrix. The color change to darker tints of brown at the top of the exterior peridium reflected the gradual ripening of the interior gleba and peridioles, which proceeded from the top downward to become a mass of spore dust, appearing as cinnamon brown at the apex of the vertical section. At around this stage, the peridium cracked open linearly, exposing the gleba with powdery spores mass released from overmatured peridioles. Spores were more or less round, warty or spiny, 10 to $12{\mu}m$; globose, cinnamon brown in powdery mass, with spines up to $2{\mu}m$ long. The thin peridium ruptured further in response to the disintegration of the peridioles, releasing the powdery spores, which proceeded until whole fruiting body disappeared leaving the dry spore dust coats in the vicinity. The absence of a capillitium is a distinctive characteristic that distinguishes the specimen from other puff-ball fungi and from most of earthballs. Based on the above characteristics, the specimen was identified as Poslithus tinctorius.

• Mycobiology
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• v.46 no.4
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• pp.382-387
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• 2018

The entomopathogenic fungus Cordyceps militaris is a valuable medicinal ascomycete, which degenerates frequently during subsequent culture. To avoid economic losses during industrialized production, scratching stimuli of mycelia was introduced to improve the fruiting body production. The present results indicated that higher yields and biological efficiency were obtained from two degenerate strains (YN1-14 and YN2-7) but not from g38 (an insertional mutant in Rhf1 gene with higher yields and shorter growth periods). Furthermore, the growth periods of the fruiting bodies were at least 5 days earlier when the mycelia were scratched before stromata differentiation. Three ROS-scavenging genes including Cu/Zn superoxide dismutase (CmSod1), Glutathione peroxidase (CmGpx), and Catalase A (CmCat A) were isolated and their expression profiles against scratching were determined in degenerate strain YN1-14 and mutant strain g38. At day 5 after scratching, the expression level of CmGpx significantly decreased for strain g38, but that of CmSod1 significantly increased for YN1-14. These results indicated that scratching is an effective way to promote fruiting body production of degenerate strain, which may be related at least with Rhf1 and active oxygen scavenging genes.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.339-343
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• 2021

This study was conducted to compare the shoot development and fruit characteristics on fruit bearing branch (FBB) according to the fruiting level (FLs: FL-Low, -Middle, -High) of peach 'Cheonhong'. The number of shoots per FBB according to the FLs were most distributed in 1-2 (42%) of FL-Low, 1 (47%) of FL-Middle and 1 (42%) of FL-High. And fruit weight and soulable solide content were 210-270g (50%) and 10-12Brix (44%), 180-240g (60%) and 10-12Brix (59%), 180-240g (60%) and 11-13Brix (48%), respectively. In addition, only FL-High showed a linear regression correlation between fruit weight and number of shoots. And a linear regression equation of y=0.0126x+8.1857 (R²=0.1964, P≤0.01) is shown between the souble solid content (y) and the fruit weight (x).

• Journal of Mushroom
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• v.22 no.3
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• pp.112-116
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• 2024

We developed a new oyster mushroom cultivar named 'Dawon-tari', which has a longer stipe and higher yield than those of 'sootari'.'Dawon-tari' was crossed by mating monokaryons isolated from 'Sootari' and 'Daejang2ho'. The optimal temperature for mycelial growth was determined to be 20~25℃ on potato dextrose agar medium, while the optimal temperatures for primordia formation and fruiting body growth were 15~17℃ on a sawdust substrate. During bottle cultivation, the mycelial growth phase required approximately 26 days. Additionally, primordia formation required 5 days, and fruiting body growth took 4 days. The fruiting bodies exhibited a shallow funnel shape; were grayishbrown; and the stipes were characterized by a long, thin structure. The yield of fruiting bodies was 185 g per 1,100 mL bottle, which was 5% higher than that of 'Sootari'.

• Journal of Mushroom
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• v.3 no.4
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• pp.133-139
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• 2005

Fruiting bodies of Cordyceps have been regarded as popular folk and effective medicines to treat human diseases such as asthma, bronchial and lung inflammation, and kidney disease. Cordyceps pruinosa (Clavicipitaceae; Hypocreales; Ascomycotina) has received special attention for medicinal purpose due to its various physiological activites. The nucleoside derivative N6-(2-hydroxyethyl) adenosine (HEA) isolated from it showed a $Ca^{2+}$ antagonistic effect and negative inotropic response. The artificial production of fruiting body of C. pruinosa has not been tried successfully yet by using living silkworm substrate. To develop techniques for the production of C. pruinosa stromata on a large scale, the infection of Bombyx mori with C. pruinosa and the growth characteristics of stroma of C. pruinosa were investigated. Also, studied about biological activities of fruiting body formed on silkworm. Infection rate of the silkworm pupae with C. pruinosa was the highest in injection inoculation. The formation of the fruiting body of C. pruinosa was quite good in the room controlled at $21{\sim}25^{\circ}C$, over 91% of relative humidity and over 1500 lx. Glucose concentration was high in the fruiting bodies of the silkworm pupae infected with C. pruinosa on a dry weight basis. The most abundant amino acid in the fruiting bodies was arginine and phenylalanine. The fruiting bodies of silkworm pupae infected with C. pruinosa was rich in oleic acid. The high amount of citric acid was found in the fruiting bodies of silkworm pupae infected with C. pruinosa.