• Journal of Food Hygiene and Safety
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• v.19 no.4
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• pp.209-216
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• 2004

Dry rehydratable film methods were compared to conventional methods for the enumeration of microorganisms in Korean traditional foods. Kimchi, doenjang, kochujang, kanjang, takju, sujeongkwa and sikhe were used as Korean traditional foods. $Petrifilm^{TM}$ aerobic count plate, $Petrifilm^{TM}$ coliform count plate, $Petrifilm^{TM}$ E. coli/coliform count plate, $Petrifilm^{TM}$ yeast and mold count plate and $Petrifilm^{TM}$ staph express count plate were compared to plate count agar, most probable number (MPN) for coliform, MPN for E. coli, potato dextrose agar and coagulase test, respectively. Regression analysis indicated that correlation coefficient values were 0.974-0.998, 0.913-0.995, 0.955-0.978, 0.968-0.986 and 0.998-0.999 for total aerobic bacteria, yeast and mold, coliform, E. coli and S. aureus, respectively. There were no significant differences between two methods, suggesting that $Petrifilm^{TM}$ plates can be used as an alternative to conventional method for the determination of microorganisms in Korean traditional foods.

• The Korean Journal of Food And Nutrition
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• v.25 no.3
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• pp.637-643
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• 2012

This study was performed to increase the utilization of rice and improve the productivity of jochung, traditional food in Korea. Two kinds of jochung products were prepared from steamed rice(SR) and wet-milled rice flour(WRF) by rice cultivated from 2006 to 2010. It is common to add a liquefying enzyme for rice liquefaction(4 $m{\ell}$/1,000 g rice, at $90{\sim}95^{\circ}C$, 3 h) and saccharogenic enzyme with malt(45 g/1,000 g rice, at $55{\sim}57^{\circ}C$, 6 h). In order to evaluate the quality characteristics of jochung, producing rate, pH, solidity, reducing sugar, dextrose equivalence(D.E.), viscosity, total phenolic compound, color value and sensory evaluation were carried out. In terms of the producing rate of jochung, WRF jochung was produced about 7.4% much more than SR jochung. There was no difference in producing rate between the jochung cultivated from 2006 to 2010 rice. The pH varied from 4.86~5.66, solidity was 79.48~82.28%. Color L value was 25.82~27.92, a value of 1.28~2.81, b value were 2.98~4.33. The results of sensory evaluation for jochung, as a whole, received higher score than for the commercial product(Daesang Co., Ltd, Seoul, Korea), overall acceptability score was the highest in the 2008SR. Reducing sugar, dextrose equivalence(D.E.) and total phenolic compounds were determined to be higher WRF jochung than SR jochung, while viscosity was lower WRF jochung than SR jochung. These results are thought to be due to increased surface area of rice by milling. SR jochung manufacturd by wet-milled rice flour will increase the producing rate for jochung, thereby saving manufacturing time and costs.

• Journal of Mushroom
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• v.16 no.3
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• pp.162-170
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• 2018

To improve the productivity of Pleurotus ostreatus, different conditions of liquid spawn culture were tested. The optimum culture conditions were potato dextrose broth, incubation temperature of $22^{\circ}C$, and pH 6. Fifteen different media ('A' to 'O') containing 0.3% soybean meal (SM) were prepared by varying sugar and glucose contents. The cultures were propagated in SM media for 14 days, at $22^{\circ}C$, and pH 6. Their absorbances were higher after 14 days of incubation in the media containing both sugar and glucose. In particular, the absorbance of media containing 5 to 20% of glucose alone ('C', 'D', 'E', and 'F') tended to increase in the incubation period. Dry cell weight was lower in media containing less than 20% sugar or glucose alone than in media containing 30% sugar ('A') or 30% glucose ('B') alone. In sawdust media, in 900 mL-bottle, the optimum inoculation volume of liquid spawn was 15 to 20 mL. The texture of the mushroom cultivated with the liquid spawn was superior to that cultivated in the solid spawn.

• The Korean Journal of Mycology
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• v.16 no.2
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• pp.70-78
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• 1988

To obtain basic information for the genetic analysis and breeding of Flammulina velutipes, some factors affecting the release of protoplasts from the fungus were studied. Potato Dextrose peptone Agar medium was suitable for the growth of the mycelium and the protoplast formation of F. velutipes. The culture age for the high yields of protoplast was 5 days on PDPA. Few protoplasts were formed from the mycelium cultured on Mushroom minimum Media. The highest yield of protoplasts was obtained in enzyme solution containing Novozyme 234 plus cellulase CP at 10 mg $ml^{-1}$ concentration, while a half amount of protoplasts was obtained in enzyme solution containing Novozyme 234 only. The optimal reaction time of the mycelium in the Iytic enzyme mixtures was 3 hours. The best osmotic stabilizer for the protoplast formation of the mycelium was 0.6M sucrose without buffer at pH 6.2.

• Research in Plant Disease
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• v.15 no.3
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• pp.217-221
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• 2009

Fludioxonil is derived from the antifungal compound pyrrolnitrin produced by Pseudomonas pyrrocinia and classified as a reduced-risk fungicide by the US EPA. The efficacy of fludioxonil for the control of lettuce gray mold caused by Botrytis cinerea was evaluated under several conditions such as growth stages of host, inoculum concentrations, and amounts of potato dextrose broth (PDB) included in spore suspension of B. cinerea. At 4-leaf stage of lettuce plants, fludioxonil applied at 2 ${\mu}g$/ml was more effective for the control of gray mold than at 5- and 6-leaf stages. However, fludioxonil at more than 10 ${\mu}g$/ml provided similar control activity in all growth stages of lettuce tested. The fungicide (10 and 50 ${\mu}g$/ml) also gave excellent control of gray mold on lettuce seedlings inoculated with spore suspensions of B. cinerea ($2.5{\times}10^5$ to $2{\times}10^6$ spores/ml). But, control efficacy of fludioxonil (2 ${\mu}g$/ml) was negatively correlated with inoculum concentration. Addition of PDB in spore suspension of B. cinerea resulted in higher disease severity than non-treated control. By inoculating spore suspension including 0.5% PDB, the fungicide gave the most control activity on the disease, followed by 1% and 2% PDB. The results suggest that fludioxonil has potential to control gray mold of lettuce, but the fungicide at a concentration having moderate activity may represent low control efficacy on the disease under some conditions.

• Korean Journal Plant Pathology
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• v.13 no.4
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• pp.200-204
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• 1997

The effect of water potential ($\psi_W$) and temperature on mycelial growth and sclerotial production of Sclerotium cepivorum was determined in potato dextrose agar(PDA) and potato dextrose broth (PDB) adjusted to different $\psi_W$ with NaCI, KCI, sucrose or polyethylene glycol (PEG) at 15, 20 and $25^{\circ}C$. the growth of mycellium was not significantly af. fected by $\psi_W$ values between -1,970 and -2,240J/Kg, but severely decreased lower than -2,240J/Kg. Dry weight was slightly increased at $\psi_W$values between -450 and -2,240 J/Kg. The reduction of dry weight wasslower than the reduction of mycelial growth as the $\psi_W$ decreased. The mycelial growth and dry weight were more severely influenced on PEG amended media than on other osmotica amended media. About 50% reduction of mycelial growth and dry weight was occurred about -1,000 and -2240 J/Kg, respectively. The production of sclerotion of sclerotial production occurred between -450 and -810 J/Kg. Sclerotium was not produced lower than -2,240 J/Kg. Mycelial growth and sclerotial production was better at $25^{\circ}C$ as the $\psi_W$ decreased than at $20^{\circ}C$ which is optimal temperaturein the undmended media. The influence of $\psi_W$ on mycelial growth and sclerotial production of S. cepivorum adjusted with NaCl, KCI sucrose or polyethylene glycol showed similar patterns.

• Applied Biological Chemistry
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• v.49 no.4
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• pp.259-265
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• 2006

Effect of the fungicide mepanipyrim on the resistant and sensitive isolates of Botrytis cinerea was studied in vitro and also tested to control Botrytis rot of strawberry, cucumber and grape in the field. These isolates were selected by relative mycelial growth and spore germination on potato dextrose agar(PDA) incorporated with $100{\mu}g\;a.i./ml$ of benomyl and procymidone, respectively, compared to the unamended PDA. Mycelial growth of the selected resistant isolates was significantly inhibited by mepanipyrim but the inhibition rate was similar to other fungicides belong to benzimidazole or dicarboximide, although spore germination was not inhibited even by the higher concentration of mepanipyrim. When the benomyl and procymidone resistant isolates were inoculated to cucumber leaves, lesion development was significantly inhibited with application of $250{\mu}g\;a.i./ml$ of mepanipyrim but not with that of benomyl and procymidone. In addition, when $250{\mu}g\;a.i./ml$ of mepanipyrim was applied to strawberry, cucumber, and grape in the field, the control of Botrytis rot was significantly different from that of the untreated control(Duncan's multiple range test, p<0.05). The results suggested that mepanipyrim might be an alternative fungicide for the control of benomyl- and procymidone-resistant pathogens of Botrytis rot.

• Applied Biological Chemistry
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• v.47 no.4
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• pp.379-383
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• 2004

For the elucidation of substrate specificity to the brown copra meal by Bacillus sp. ${\beta}-mannanase.$, the enzymatic hydrolysate after 24 hr of reaction was heated in a boiling water bath for 10 min, and then centrifuged to remove the insoluble materials from hydrolysates. The major hydrolysates composed of D.P 5 and 7 galactosyl mannooligosaccharides. For the separate of galactosyl mannooligosaccharides, the supernatant solution of 150 ml was put on a first activated carbon column. The column was then washed with 5 l of water to remove mannose and salts. The oligosaccharides in the column were eluted by a liner gradient of $0{\sim}30%$ ethanol, at the flow rate of 250 ml per hour. The sugar composition in each fraction tubes was examined by TLC and FACE analysis. The combined fraction from F3 was concentrated to 30 ml by vacuum evaporator. Then put on a second activated carbon column. The oligosaccharides in the column were eluted by a liner gradient of $0{\sim}30%$ ethanol (total volume: 5 l), at the flow rate of 250 ml per hour. The eluent was collected in 8 ml fraction tubes, and the total sugar concentration was measured by method of phenol-sulfuric acid. The major component of F2 separated by 2nd activated carbon column chromatography were identified $Gal^3Man_4(6^3-mono-{\alpha}-D-galactopyranosyl-{\beta}-mannotetraose)$. To investigate the effects of brown copra meal galactomannooligosaccharides on growth of Bifidobacterium longum, B. bifidum were cultivated individually on the modified-MRS medium containing carbon source such as $Gal^3Man_4$, compared to those of standard MRS medium.

• The Korean Journal of Mycology
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• v.24 no.3 s.78
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• pp.214-222
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• 1996

This study was carried out to obtain the basic data on artificial culture of Phellinus linteus. The optimum condition for the mycelial growth was $25{\sim}30^{\circ}C$ and pH $6.0{\sim}7.0$. The carbon sources such as D-glucose, D-mannose and Dextrose were favorable to mycelial growth. As nitrogen sources, peptone, cassamino acid and glutamic acid appeared to be favorable. The optimum C/N ratio was about 20:1, when 2% of glucose was provided as a carbon source. The better organic acids and vitamin among tested ones were gallic, silicic acids and biotin. The mineral nutrients of $KH_2PO_4,\;FeSO_4{\cdot}7H_2O,\; MgSO_4{\cdot}7H_2O,\;ZnSO_4{\cdot}7H_2O$ were effective and the optimum concentrations were 0.05, 0.001, 0.02 and 0.003%, respectively.

• The Korean Journal of Mycology
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• v.39 no.2
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• pp.91-98
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• 2011

Oudemansiella mucida, an edible and medicinal mushrooms belonging to Tricholomataceae of Basidiomycota, has been known to produce antifungal substances to inhibit the mycelial growth and spore germination of the plant pathogenic fungi. To produce good amount of antifungal substances from culture media, the optimal culture conditions of O. mucida were investigated. The most favorable conditions for the mycelial growth were $25^{\circ}C$ and pH 5 in potato dextrose agar. The most favorable carbon and nitrogen sources promoting mycelial growth were maltose and calcium nitrate, respectively. The optimum C/N ratio was about 20 : 1 in case that 3% glucose was supplemented to the basal medium as a carbon source. The optimal mycelial growth of O. mucida was found in the Hennerberg medium. The crude extract from submerged culture of potato dextrose broth exhibited inhibition of mycelial growth of Colletotrichum acutatum, Botrytis cinerea and Pyricularia oryzae but, fungicidal activity is not good enough to compared with commercially available fungicides tested. Therefore, the antifungal substances extracted from submerged culture of O. mucida might have a potential to be used for biocontrol agent of fungal diseases of plants.