• Korean Journal of Microbiology
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• v.12 no.4
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• pp.159-179
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• 1974

In order to investigate morphological and cultural characteristics of strains in species, Flammulina velutipes, the author collected isolates of Flammultina velutipes at 49 locations in Korea and cultivated these isolates on the various kinds of solid media. After investigating the cultural characteristics, appeared on the various media, he obtained the following results : 1. The variation of colors in the fruit bodies is connected with the variation of climatic environments(composite effects between mean temperature in January and number of rain days of 1mm and over precipitation). The author, therfore, can find out the trend that brown type is distributed in the midland climatic region and yellow type in the southern climatic regoin. 2. Two types can be classified into several strains respectively : the strain of abundant or insufficient productivity, and strain of selectivity or non-selectivity of media. 3. According to the results of mutual comparison of soluble mycelial proteins by disc electrophoresis using polyacrylamide gels, each type has special common protein fractions(brown type : band located at 26..5mm position from surface of gel, yellow type : band located at 24.5mm position from surface of gel), and each strain has special protein fractions too. Therefore this phenomenon seems to support the results obtained by the above-stated morphological and cultural studies. 4. In the adaptability of strains to the temperature, every strain has the nature of growing in lower temperature(the optimum temperature of 20.deg.C to 25.deg.C) except that YI-1 strain has the optimum temperatue of $25^{\circ}C$-26^{\circ}C. And mycelial growth of every strain is discontinued at $35^{\circ}C.$ 5. In the adaptability of strains to the H-ion concentration, every strain has wide adaptable range of H-ion concentration, and has optimum range of pH 5.5 to 6.6 in mycelial growth excepting YA01, BI-2 and YI-1. 6. In the utility of carbon sources, the mycelial growth of every strain is very poor on the media containing xylose(average diameter of mycelial growth : 18mm), and most strains utilize favorably sucrose(39mm), maltose(37mm) and dextrose(35mm) in mycelial growth. In the utility of nitrogen sources, every strain utilizes favorably organic nitrogens(36 mm)more than inorganic nitrogens (25 mm), and utilizes fully peptone nad asparagine in organic nitrogens. Especially BA-1, BIK-2 and YA-1 strains grow vigorously on each media containing various carbon and nitrogen sources. 7. The characteristic tests of the number of days required for mycelial growth, the number of days requried for sprout of young bodies, the length of stipe and the number of fruit bodies formation seem to be useful methods in the early selection of the strain of the abundant productivity.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.346-353
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• 2010

This study was conducted to determine cleaning effects of environmental-friendly washing detergent on milking installation in dairy farms. Milking machine, cooling machine and milking liner were washed by alkaline detergent and acid detergent for first three weeks and alkaline detergent and environmental~friendly detergent for next three weeks and the results get through microorganism and physico-chemistry analysis at the five district dairy farms different from environment. E-coli, coliform, fecal coliform, staphylococcus aureus, fecal streptococcus, prsudomonas aeruginosa and yersinia were not found in all of the dairy farms, and total colony counts were no difference compared with chemical detergent. The water for washing exceeded the determining acceptable level of nitrate nitrogen in the Anseong, Onyang and Cheonan and the remaining substance of washed water was also high levels. The cause of the result was that the level of nitrate nitrogen of water is basically high. Therefore, this study indicated that washing effect is no differences between environmental-friendly detergent and chemical detergent by washing for milking machine and cooling machine. Above all, producing high quality milk is to manage the water quality as well as using detergent.

• Journal of Food Hygiene and Safety
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• v.33 no.5
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• pp.412-415
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• 2018

The objective of this study was to establish a quantitative count method of Vibrio vulnificus cells. Plate count method is often used to count the number of V. vulnificus cells using thiosulfate citrate bile salts sucrose (TCBS) agar plate. However, this method is unsuitable for counting V. vulnificus cells due to growth inhibition and cell injuries in TCBS medium. In this study, we suggested a most probable number-polymerase chain reaction (MPN-PCR) method using alkaline peptone water medium for the quantification of V. vulnificus. This MPN-PCR method showed 2 log higher cell number than TCBS agar plate method. Similar results were also found in the control using, Luria-Bertani agar containing 2% NaCl. Thus, this MPN-PCR method can be used a sensitive method for quantitative count of viable V. vulnificus cells in fish and shellfish samples.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.120-126
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• 1984

The effects of heat treatment of soy protein and of various nutrients added to soy protein isolate (SPI)-based yogurt on the growth of Lactobacillus acidophilus were investigated. The sensory evaluation of the yogurt beverage prepared from SPI was also performed. Soy milk was prepared from SPI (4.2% as protein) and various nutrients, such as glucose, lactose, sucrose, yeast extract, peptone and tryptone. Mild $(60^{\circ}C)$ or medium $(95^{\circ}C)$ heat treatment of soy protein did not inhibit the growth of L. acidophilus and the optimum degree of heat treatment was approximately $95^{\circ}C$ for 20 min. Glucose and lactose enhanced the growth and acid production by L. acidophilus. The optimum concentration of these two sugars in the medium was approximately 3% each. Yeast extract of approximately 0.5% stimulated the acid production by L acidophilus. Concentration of soy protein did not affect the growth of L. acidophilus, whereas it affected the viscosity of SPI-based yogurt markedly.

• The Korean Journal of Mycology
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• v.43 no.2
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• pp.99-103
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• 2015

We prepared supernatants and cell-free extracts of yeasts isolated from wild flowers in Korea, and their antioxidant activity and inhibitory activities of xanthine oxidase and tyrosinase were investigated. Among them, cell-free extracts of Kuraishia capsulata UL40-2 and Sporobolomyces ruberrimus 121-Z-3 showed significantly high xanthine oxidase inhibitory activity of 46.4% and 48.3%, respectively. Starmerella bombicola 80-J-1 also showed tyrosinase inhibitory activity of 36.2% in the cell-free extract. Other antioxidant activities and tyrosinase inhibitory activities were not detected or were below 20%. Maximal production of the xanthine oxidase inhibitors were observed when Kuraishia capsulate UL40-2 and Sporobolomyces ruberrimus 121-Z-3 were cultured in the yeast extract-peptone-dextrose media at $30^{\circ}C$ for 24 hour, respectively.

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.348-351
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• 1988

The production of extracellular $\alpha$-amylase by Bacillus thuringiensis 19 serotypes was examined by the hydrolysis test of starch. Thirteen serotypes produced the amylase. B. thuringiensis serovar thuringiensis alesti, kurstaki, sotto, kenya, israelensis, morrisoni, entomocidus, tolworthi, thompsoni, toumanoffi, pakistani, and indiana produced tee enzyme. The amylase produced by B. thuringiensis serovar israelensis showed highest activity around pH 6.7 to 7.2 and 55$^{\circ}C$ to $65^{\circ}C$. The high production medium of the amylase was composed of 1% bactopeptone, 0.3% beef-extract, 0.3% yeast ex-tract, 0.5% NaCl, 0.3% $K_2$HPO$_4$, 0.1% KH$_2$PO$_4$, 0.2% Soluble Starch, 0.012% CaCl$_2$.2$H_2O$$_2$, 0.005% MnCl$_2$, and 0.03% MgCl$_2$.7$H_2O$. The highest production of the enzyme was observed at 4 hours culture in the soluble starch (0.6 units/$m\ell$) or glucose (0.43 units/$m\ell$) substrate.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.402-406
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• 2014

Six kinds of newly recorded yeasts such as Rhodosporidium diobovatum SY4-2, Cryptococcus bestiolae SY7-1, Kazachstania unispora SY14-1, Kazachstania servazzii SY14-3, Pichia holstii SY20-2 and Cryptococcus tephrensis SY26-1 were screened from sixty one yeasts derived from wild flowers found in Seonyudo, Gogunsanyeoldo, Jeollabuk-do, Korea. All of them grew in 50% glucose-containing yeast extract-peptone-dextrose (YPD) broth and Pichia holstii SY20-2 was also halophile, growing in 20% NaCl-containing YPD broth. All of them, except Cryptococcus tephrensis SY26-1, were assimilated to glucose. Cell-free extract from Kazachstania servazzii SY14-3 showed the highest 98.6% of ${\alpha}$-glucosidase inhibitory activity and maximal production of the ${\alpha}$-glucosidase inhibitor was obtained with 24h incubation at $30^{\circ}C$. The antihypertensive angiotensin I-converting enzyme inhibitory activity of the unrecorded yeasts were showed 58.6-80.4% in their supernatants.

• Korean Journal of Food Science and Technology
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• v.7 no.2
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• pp.61-68
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• 1975

This study was conducted (1) to isolate the film-forming yeast from the commercially available soy sauce, (2) to identify the state of soy sauce fermentation by the use of yeasts, (3) to confirm characteristics of yeasts. The result were as follows. 1. These yeast strains in the soy sauce fermentation test showed full fermentation of whole sugar content, reduction of the pure extract and relative reduction in total nitrogen. Soy sauce color was somehow faded to lower the stability of soy sauce. 2. In anti-fungal activity test butylparaben at a higher level 60 ppm., sodium propionate 2,400 ppm, sodium benzoate 800 ppm., menadion 165 ppm, showed their anti-fungal effect, while alcohol did not show the effect in the 3% additive group. 3. The optimum sodium chloride concentration for these strains in the 2% G.Y.P. medium was 5% and optimum temperature was $30^{\circ}C$. The extinction temperature was $62^{\circ}C$ for strain No-1 and No-3, and was $65^{\circ}C$ for No-2 and No-4. 4. The film-forming soy sauce turned out in the gas chromatogram to possess much flavor of low boiling point as compared with the standard. These flavors were considered due to flavor spoilage of the soy sauce. 5. These isolated yeasts were identified Saccharomyces rouxii (film-forming yeast) in the Lodder's taxanomic study.

• Korean journal of applied entomology
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• v.27 no.3
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• pp.149-158
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• 1988

Nematophagous fungi were successfully isolated by baited plating, centrifugation technique of soil, and direct isolation from naturally ingested nematodes. Predominant seven fungi isolated were identified as Artheobotrys arthroboteyides, A.conoides, A. oligospora, Dactylella lobata, Fusatium oxysporum, Monacrosporium ellopsoporum and Harposporium anguillu-lae. Of these, six fungi were tested for cultural characteristics except. H, anguillulae, extre-mely fastidious fungus in artificial media. Among 14 media tested in this experiment, Corn-meal Agar (CMA) and Oatmeal Agar (OMA) were the most suitable media for growing all six nematophagous fungi. Weakly saprophytic M. ellipsospoyum also grew vigoroualy on these two media. The radial growth, dry weight and sporulation of the fungi tested were quite diverse depending on the culture media. D. lobata revealed good growth and abundantly sporulated on Glucoes Peptone Agar (GPA). Although over-all growth of F, oxysporum was not satisfactory on Sucrose Nitrate Agar (SNA), the sporulation was best on this medium. Optimum conditious for mycelial growth and sporulation of nematophagous fungi ranged pH 5-8 and 20-$30^{\circ}C$ on SNA. D. lobata and F, oxysporum grew vigorously and most profusely sporulated on all media tested. They turned out an most promising biocontrol agents for their aggressive growth and sporulation over the ranges of temperature and pH ranges.

• The Korean Journal of Mycology
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• v.19 no.1
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• pp.79-84
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• 1991

Fruit bodies of Ganoderma lucidum have been used for most pharmacological studies, but pharmacological effects are likely variable because the habitats and strains of Ganoderma lucidum are different. Therefore, their fermentation is required to produce constant and reliable pharmacolo­gical constituents from Ganoderma lucidum. During the studies of medium for industrial application. it was found that ginseng root residues, remaining after being extracted with ethanol, were a good carbon source for a fermentation of Genoderma lucidum and a corn steep liquor was also economical for the nitrogen source. Yield of the mycelial cultured in ginseng root residues and corn steep liquor was 2.5 times higher than that in glucose and peptone, known as a conventional medium of Ganoderma lucidum. The polysaccharide content of the extracts from the cultured mycelia was higher than that from fruit bodies, but protein content was vice versa. Extracts of the cultured mycelia were more effective and lasting than extracts of the fruit bodies in decreased hypertention of spontaneously hypertensive rats (SHR).