• BMB Reports
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• v.40 no.1
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• pp.113-118
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• 2007

Tolaasin, a pore-forming peptide toxin, is produced by Pseudomonas tolaasii and causes brown blotch disease of the cultivated mushrooms. P. tolaasii 6264 was isolated from the oyster mushroom damaged by the disease in Korean. In order to isolate tolaasin molecules, the supernatant of bacterial culture was harvested at the stationary phase of growth. Tolaasin was prepared by ammonium sulfate precipitation and three steps of chromatograpies, including a gel permeation and two ion exchange chromatographies. Specific hemolytic activity of tolaasin was increased from 1.7 to 162.0 HU $mg^{-1}$ protein, a 98-fold increase, and the purification yield was 16.3%. Tolaasin preparation obtained at each purification step was analyzed by HPLC and SDS-PAGE. Two major peptides were detected from all chromatographic preparations. Their molecular masses were analyzed by MALDI-TOF mass spectrometry and they were identified as tolaasin I and tolaasin II. These results demonstrate that the method used in this study is simple, time-saving, and successful for the preparation of tolaasin.

• The Plant Pathology Journal
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• v.21 no.4
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• pp.343-348
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• 2005

The partial nucleotide sequences of the genomic dsRNA mycoviruses infecting Pleurotus ostreatus (isolates ASI2596, ASI2597, and Bupyungbokhoe) and Agaricus blazei Murrill were determined and compared with those of the other dsRNA mycoviruses. Partial nucleotide sequences of the purified dsRNA from ASI2596 and ASI2597 revealed RNA-dependent RNA polymerase sequences that are closely related to Oyster mushroom isometric virus 2, while nucleotide sequences and the deduced amino acid sequence from dsRNA mycovirus infecting Agaricus blazei did not show any significant homology to the other dsRNA mycoviruses. Specific primers were designed for RT-PCR detection of these dsRNA viruses and were found to specifically detect each dsRNA virus. Northern blot analysis confirmed the homogeneity of RT-PCR products to each purified dsRNA. Altogether, our results suggest that these virus-specific primer sets can be employed for the specific detection of each dsRNA mycovirus in infected mushrooms.

• Mycobiology
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• v.36 no.3
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• pp.157-160
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• 2008

This study was carried out to determine the possibility of bottle cultivation utilizing recycled oyster mushroom culture waste as a cultivating substrate for P. ostreatus. Total nitrogen percentage was 0.76%, 1.13%, 1.16%, 1.36%, and 1.38% in the 1-, 2-, 3-, 4-, and 5-time mixed substrate, respectively; 0.95%, 1.04%, 1.34%, 1.36%, and 1.25% in the 1-, 2-, 3-, 4-, and 5-time postharvest substrate, respectively; and 0.72% and 0.68% in the 2- and 3-time nonadditive substrate, respectively. Weight of the fresh fruiting body harvest was 115 g, 120 g, 117 g, 118 g, and 114 g on 1-, 2-, 3-, 4-, and 5-time mixed substrate, respectively; and 105 g and 45 g on 2- and 3-time nonadditive substrate, respectively. The first mixed substrate (fresh) and recycled substrates generated no significant difference in the weight of fresh fruiting bodies harvested.

• Journal of Microbiology and Biotechnology
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• v.17 no.8
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• pp.1271-1283
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• 2007

A fibrinolytic protease (PoFE) was purified from the cultured mycelia of the edible oyster mushroom Pleurotus ostreatus, using a combination of various chromatographies. The purification protocol resulted in an 876-fold purification of the enzyme, with a final yield of 6.5%. The apparent molecular mass of the purified enzyme was estimated to be 32 kDa by SDS-PAGE, fibrin-zymography, and size exclusion using FPLC. The optimal reaction pH value and temperature were pH 6.5 and $35^{\circ}C$, respectively. PoFE effectively hydrolyzed fibrinogen, preferentially digesting the $A{\alpha}$-chain and the $B{\beta}$-chain over the ${\gamma}$-chain. Enzyme activity was enhanced by the addition of $Ca^{2+},\;Zn^{2+},\;and\;Mg^{2+}$ ions. Furthermore, PoFE activity was potently inhibited by EDTA, and it was found to exhibit a higher specificity for the chromogenic substrate S-2586 for chymotrypsin, indicating that the enzyme is a chymotrypsin-like metalloprotease. The first 19 amino acid residues of the N-terminal sequence were ALRKGGAAALNIYSVGFTS, which is extremely similar to the metalloprotease purified from the fruiting body of P. ostreatus. In addition, we cloned the PoFE protein, encoding gene, and its nucleotide sequence was determined. The cDNA of cloned PoFE is 867 nucleotides long and consists of an open reading frame encoding 288 amino acid residues. Its cDNA showed a high degree of homology with PoMEP from P. ostreatus fruiting body. The mycelia of P. ostreatus may thus represent a potential source of new therapeutic agents to treat thrombosis.

• Journal of Mushroom
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• v.10 no.2
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• pp.49-56
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• 2012

Two strains which have good traits in quality and speedy growing were selected based on previous report(Ryu, 2007) to breed a new strain carrying the traits in it. KNR2322 carrying high quality and KNR2503 carrying a speedy growing trait were cultivated to harvest monokaryons. The monokaryotic mycelia were characterized in growth rate, color, and stability. Selfing of monokaryons from KNR2322 and crossing between KNR2322- and KNR2503-derived monokaryons were performed. Two parental lines, $KNR2322-4{\times}37-6{\times}12(B)$ showing thremmatological values in weight and quality, 68.5g and 6.5 and $KNR2322-30{\times}KNR2503-60(A)$ was harvested in 13.5 days after scraping old medium were selected. Crossing between A and B resulted in two high quality and speedy growing strain, A8B8 and A8B10. Their days for harvest after scraping, weight, and quality were 14.0 days, 88.8g and 92.7g, 7.0 and 7.1. Originality tests were conducted with genomic DNAs of A8B8 and Keuneutari 3ho(commercial strain) by DNA fingerprinting a confrontation culture. The results showed polymorphism and a inhibition line between them. It suggested that the new strain have originality from the commercial strain. A8B8 have been registered in Korea Seed and Variety Service with as "Saesongi 1ho".

• Journal of Mushroom
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• v.10 no.2
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• pp.63-67
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• 2012

This study of afterripening conditions during oyster mushroom (Suhanneutari 1ho) cultivation in bottles was investigated. Medium materials were used poplar-sawdust (68%), cotton seed peel (16%), Beet pulp (8%) and cotton seed cake (8%). Mix of materials was used as a percentage of the volume and to adjust moisture content (67%). Autoclaved mediums were placed in low temperature storage ($20^{\circ}C$) and then moved in inoculation room and conducted mechanical inoculation. Mycelial culture temperature was maintained at $20{\sim}21^{\circ}C$ and cultured during 18 days. The afterripening period were 6days, 9days, 12days and 15 days at $25{\sim}27^{\circ}C$. The yield of fruit body was higher for 9 days (163.1g/bottle) and 12 days (160.7g/bottle) than that of other afterripening period. Second, in the changes in moisture content of the medium according to the afterripening period, no significant changes were observed during mycelial grwoth. The longer afterripening period was showed slightly lower weight of media. The moisture content of media after harvest at afterripening for 9 days had the biggest reduction than any other treatments. In addition, weight of media and yield of afterripening for 9 days were the lowest and highest, respectively.

• Journal of Mushroom
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• v.7 no.4
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• pp.141-149
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• 2009

The sexual incompatibility system was investigated in the new strain Pleurotus ostreatus 'Miso'. Matings among monosporous progeny collected from fruiting bodies revealed that the new oyster mushroom is heterothallic and has a tetrapolar mating system. Single basidiospore isolates that did not have clamp connections were determined to be monokaryotic. Compatible parings of monokaryons were distinguishable macroscopically by the rapid growth and gross morphology to some extent but they were distinguished obviously by the presence of clamp connections from incompatible pairings under microscopic examination. Rarely dikaryotization was unidirectional with clamp connections only at the margin of one side of mating. In tetrapolarity of matings, four kinds of patterns, A1B1, A1B2, A2B1, and A2B2, were decided depending on compatibility tests in a parental strain with a mating factor of A1A2B1B2. The mating tests with the tester strains were performed for the detection of mating types on the rest of selected monokaryons.

• The Korean Journal of Mycology
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• v.27 no.2 s.89
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• pp.132-137
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• 1999

This study was carried out to develop the molecular marker for the detection of Pseudomonas tolaasii, a causative agent of bacterial brown blotch disease of oyster mushroom (Pleurotus ostreatus). When several primers designed from repetitive sequences and pectin lyase genes of bacteria were used to produce DNA polymorphism from different Pseudomonas spp. isolated from edible mushrooms, PEU1 primer derived from pectin lyase gene produced polymorphic bands differentiating P. tolaasii strains from other Pseudomonas species. Two bands, 1.0kb and 0.4kb, found commonly in 6 isolates of P. tolaasii were cloned into pGEM-T vector which were designated as pPTOP1 and pPTOP2, respectively, to use as probe. The 0.4 kb insert of pPTOP2 hybridized to only 6 isolates of P. tolaasii, but did not to the other Pseudomonas species. As few as $1.5{\times}10^3$ colony forming unit (cfu) of P. tolaasii could be detected by dot blot hybridization with the cloned 0.4kb DNA in pPTOP2.

• Journal of Mushroom
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• v.5 no.1
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• pp.34-38
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• 2007

The white-colored and the dark gray-colored mutants were frequently happened in cultivated areas of Pleurotus ostreatus (Wonhyeong-neutari). These caused conflicts between farmers and spawn companies. Our studies were conducted to elucidate the mechanism of mutagenesis. The results from the studies would provide valuable informations that could be used to prevent the color-related mutation, and also will be applied in breeding programs of P. ostreatus. Oyster mushroom variety, Wonhyeong-neutari, is somatic hybrid of Pleurotus and has genetic makers for arginine, ornithine, proline, riboflavine. Genetic markers analysis of monospore isolates derived from color mutants show identical tendency with that of Wonhyeong-neutari, these results indicate that color mutants were derived from Wonhyeongneutari. Twenty-one and four homokaryons were selected from the white-colored mutant MGL 2205 and gray-colored ASI 2029. All 34 F1 hybrids derived from the white-colored mutant MGL 2205 produce white-color fruiting bodies, indicating that the white color trait is heritable. In the first generation hybrids between the white-colored MGL 2205 and the gray-colored ASI 2029, all 16 hybrids produced pigmented fruiting bodies. Homokaryons isolated from the hybrid MGL 2205 X ASI 2029 were mated with homokaryon tester strains derived from MGL 2205. By these result, we could assumed that white color trait is a heritable character which is controlled by more than one recessive gene.

• Korean journal of applied entomology
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• v.43 no.3 s.136
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• pp.233-239
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• 2004

The potential of five entomopathogenic nematodes, Steinernema carpocapsae Pocheon strain, S. logicaudum Nonsan strain, S. glaseri Dongrae strain, Heterorhabditis bacteriophora Hamnyang strain, and Heterorabditis sp. Gyeongsan strain were evaluated as biological control agents against a mushroom fly, Mycophila speyeri in the mushroom, Pleurotus ostreatus cultivation house. Control effect of M. speyeri was significantly different according to nematode species. Heterorhabditis was more effective than Steinernema. H. bacteriophora Hamnyang strain showed the highest control effect representing $49.0\%$ (7 days), $89.5\%$ (14 days) and $89.1\%$ (21 days post-treatment) at the rate of $1\times10^6$ and $46.5\%$ (7 days), $76.6\%$ (14 days) and $85.4\%$ (21 days post-treatment) at the rate of $1.0\times10^5$ Ijs/$1.5 m^2$ in Changnyoung, Gyeongnam, respectively. In Jinju, Gyeongnam, control effects of the sa me species were $54.0\%$ (7 days), $74.5\%$ (14 days), and $79.8\%$ (21 days post-treatment) at the rate of $1\times10^6$ and $49.0\%$ (7 days), $76.6\%$ (14 days), and $61.1\%$ (21 days post-treatment) at the rate of $1.0\times10^5$ Ijs/$1.5 m^2$, respectively.