• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.4
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• pp.443-450
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• 1995

Listeria monocrogenes has been increasingly recognized as an important food poisoning and pathogenic bacterium which is Gram positive, non spore forming and facultative anaerobic rod shape. Bacteriological and physiological characterization of L. monocytogenes YM-7 isolated from a patient was performed. Optimum growth condition of 1. monocytogenes YM-7 was at $37^{\circ}$, pH 8.0 and $0\%$ sodium chloride in tryptic soy broth, and then it grew pretty well in the range of $8-40^{\circ}C,\;pH 5.0-10.0\;and\;up\;to\;7\%$ of sodium chloride in the medium. The highest hemolysin activity of hemolysin produced by L. monocytogenes YM-7 was shown in the stationary phase of its growth. Hemolysin produced by the isolated strain was stable at $4^{\circ}C\;and\;pH\;6.0-8.0, while it was gradually unstable by increasing the storage temperature.

• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.325-333
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• 2007

One bacterium with high proteinase production and spore-forming ability was isolated from korean traditional soybean paste(doenjang). The isolated strain was identified as Bacillus subtilis, based on gram-staining, biochemical properties and l6S rRNA gene sequencing, and designated as B. subtilis DJI. Its growth rate was very fast, and it reached its stationary phase within 9 h, and then started to form spores. Bacterial-koji and doenjang were prepared using B. subtilis DJI. Chemical components of the doenjang were determined after 2 months of aging period: amino nitrogen 507 mg%, crude protein 14.3%, crude fat 4.8% and water 54.9%. The composition of total and free amino acids and their ratios of doenjang were changed during the aging period. Among total amino acids in DJI doenjang, glutamic acid, aspartic acid, leucine and arginine were the major amino acids. The fibrinolytic activities of DJI doenjang and traditional doenjangs were 909.7 units/ml and $363.3{\sim}618.6\;units/ml$, respectively. Flavor compounds of DJI doenjang and traditional doenjang were extracted by SDE(simultaneous steam distillation and extraction), and analyzed by GC/MS; DJI doenjang possessed the typically favorable flavor compounds in traditional korean doenjang, with reduced off-flavor compounds.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.84-92
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• 2020

To supply a stable amount of standard material to detect paralytic shellfish toxin (PST), we examined possible increases in toxic content in Alexandrium catenella and A. pacificum using a light emitting diode (LED), which is one of the most eco-friendly and economical lighting method. When comparing the growth rates of organisms and wavelengths of light used, the half saturation constants (Ks) of red wavelength were higher than those of other wavelengths. In contrast, the Ks of blue wavelength were lower than those of other wavelengths. Moreover, when comparing the toxic contents and wavelengths of light used, red wavelength produced approximately 8 times more toxic content in A. catenella and approximately 3.2 times more toxic content in A. pacificum than other wavelengths. Thus, the toxic content present in the organism might be closely related to the Ks of light. The optimum light source to be used to ensure economically ef ective and productive growth in an Alexandrium culture system (photo-bioreactor) would likely consist of a two-phase culture, wherein a blue LED is used during the lag and exponential phases to increase growth rates, followed by the use of a red LED during late exponential and stationary phases to achieve increased PST yields.

• Journal of Life Science
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• v.25 no.11
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• pp.1273-1279
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• 2015

Agarase from a novel agar-degrading bacterium isolated from seawater in Namhae at Gyeongsangnamdo province of Korea was characterized. The SH-1 strain was selected from thousands of colonies on Marine agar 2216 media. Almost full 16S rRNA gene sequence of the agarolytic SH-1 strain showed 99% similarity with that of bacteria of Simiduia genus and named as Simiduia sp. SH-1. Agarase production was growth related, and activity was declined from stationary phase. Secreted agarase was prepared from culture media and characterized. It showed maximum activity of 698.6 units/L at pH 7.0 and 30℃ in 20 mM Tris-HCl buffer. Agarase activity decreased as the temperature increased from an optimum of 30℃, with 90% and 75% activity at 40℃ and 50℃, respectively. Agarase was not heat resistant. Slightly lower agarase activity was observed at pH 6.0 than at pH 7.0, without statistical difference, and 80% and 75% activity were observed at pH 5.0 and 8.0, respectively. Neoagarotetraose and neoagarobiose were the main final products of agarose, indicating that it is β-agarase. Simiduia sp. SH-1 and its β-agarase would be useful for the industrial production of neoagarotetraose and neoagarobiose, which have a whitening effect on skin, delaying starch degradation, and inhibiting bacterial growth.

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.806-813
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• 1996

Five strains of psychrotrophic lactic acid bacteria which had been isolated from kimchi were inoculated as kimchi starters, and then their effects were investigated during fermentation at $8^{\circ}C$. The initial numbers of Gram negatives and coliforms in no-starter-inoculated kimchi were $4.0{\times}10^{6}CFU/ml\;and\;3.2{\times}10^4CFU/ml$ respectively, while these of lactic acid bacteria were only $1.6{\times}10^3CFU/ml$. Starter-inoculated kimchi showed sharp decreases in Gram negatives and coliforms from initial stage, but no-starter-inoculated kimchi showed slow increases in those bacteria in the early stage, and sharp decreases after 10 days. It took 10 days in no-starter-inoculated kimchi, $4{\sim}6$ days in Leuconostoc-inoculated kimchi and 2 days in Lactobacillus-inoculated kimchi for lactic acid bacteria to reach stationary phase of growth. No-starter-inoculated kimchi required 10 days to reach optimum ripened state, while all starter-inoculated kimchi samples required 4 days. The inoculations of all these starters did not cause over acidifications. Remarkable softening occurred in Leu. dextranicum-inoculated kimchi in 6 days, but did not in the rest. Except the Leu. paramesenteroides-inoculated kimchi, the qualities of Leuconostoc-inoculated kimchi were as good as those of no-starter-inoculated kimchi, but those of Lactobacillus-inoculated kimchi were not so good.

• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.47-53
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• 1994

The effects of light on the production of anthocyanin and betacyanin in cell suspension cultures of Vitis vinifera and Phytolacca americana were investigated. The cell growth of V.vinifera was little affected by exposure to light, but that of P.americana was markedly increased by light than in the dark In suspension cultures of V vinifera maximum accumulation of anthocyanin was observed during the stationary phase in continuous light By contrast, in suspension cultures of R americana, accumulation of betacyanin occured in parallel with cell division which showed two peaks after 4 days and 8 days of culture in continuous light whereas in continuous dark accumulation of anthocyanin and betacyanin did not occured However treatment of light interrupting for l, 12, and 24 h after 4 days in cell suspension. cultures of remarkably showed a slight anthocyanin accumulation, but after 8 days of culture remarkably accumulated by light interrupting for more than 12 h. In cultures of P. americana, the light treatment was more effective at 4th day than at 7th day after culture, but betacyanin accumulation was decreased again in the dark after light treatment These result indicate that the difference of light responses exist between the V.vinifera and the betacyanin of P. americana though cell suspension culture systems.

• Food Science of Animal Resources
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• v.33 no.6
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• pp.772-780
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• 2013

The aim of this study was to investigate the effect of season and location on activities of enzyme produced by psychrotrophic bacteria isolated from raw milk located in Kyunggi region of South Korea. Agar diffusion and colorimetric methods were used for the lipase and protease activities of psychrotrophic bacteria. Intensities of dark blue and transparent ring around colony were compared for activity measurement. Nutrient agar with 1% skim milk added was employed for measuing protease activity. 14 strains of Arthrobacter russicus with lipase activity and 19 strains of Chryserobacterium shigense with protease activities were found to be present. It was found that Acinetobacter genomospecies 10 (match %: 99.90) isolated from B region in fall was the most lipolytic species, whereas Serratia liquefaciens (match %: 99.39) isolated from the same region in spring was the most proteolytic species. Growth curve of Acinetobacte and Serratia liquefaciens was a typical sigmoidal form. Lipase activity increased with incubation time, but its activity began to drop at stationary to motality phase. Optimum condition for incubation time, pH and temperature for extracellular lipase from Acinetobacter genomospecies 10 (match %: 99.90) was 12 h, 8.5, and $45^{\circ}C$, respectively. Extracellular protease from Serratia liquefaciens (match %:99.39) had the same optimum incubation time and pH as extracellular lipase, but optimum temperature was $35^{\circ}C$.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.358-364
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• 2006

This study was conducted to develop optimal solid culture medium for Tricholoma matsutake. As the solid matrix, granitic soil, perlite, vermiculate, pine sawdust and peat moss were compared regarding their effected on mycelial growth. Ergosterol content which is a fungal wall component was used as the growth index of the mycelia. Among the various solid matrixes, the granitic soil, perlite and mixture of the two supported the growth most. Barely flour appeared to be very effective on the stimulating of the mycelial growth when added to the solid matrix. An mixture of the matrix contained an even (1:1:1:1, v/v/v/v) mixture of granitic soil, perlite, vermiculate and pine sawdust. T. matsutake started growth 2 weeks after inoculation and reached stationary growth phase after 8th weeks in the solid matrix mixture. The mycelial density in the solid matrix was 7 times higher than that in fairy-ring soil. In addition, 30~70% water content and 10% humus soil in the solid matrix also supported good growth suggesting that T. matsutake needs humus soil for a nutrient sources. The solid matrix developed in the present study could be used to study physiological characteristics of T. matsutake as well.

• Microbiology and Biotechnology Letters
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• v.41 no.1
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• pp.33-43
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• 2013

A bacterium producing a fibrinolytic enzyme was isolated from Cheonggukjang. The bacterium was identified as a strain of Bacillus amyloliquefaciens by 16S rDNA analysis and designated as B. amyloliquefaciens HC188. The optimum culture medium appeared to be one containing 0.5% (w/v) maltose and 0.5% (w/v) soytone. Bacterial growth in the optimal medium at $37^{\circ}C$ reached the stationary phase after 27 h of incubation and the fibrinolytic enzyme showed optimum activity at 24 h. The enzyme was purified by 20-80% ammonium sulfate precipitation, CM Sepharose fast flow ion exchange chromatography, and Sephacryl S-200HR column chromatography. Its specific activity was 38359.3 units/mg protein and the yield was 5.5% of the total activity of the crude extracts. The molecular weight was 24.7 kDa and the amino acids of the N-terminal sequence were AQSVPYGVSQIKAPA. The fibrinolytic enzyme activity had an optimum temperature of $40^{\circ}C$ and an optimum pH of 8.0, and the enzyme was stable in the ranges $20-40^{\circ}C$ and pH 6.0-8.0. Enzyme activity was increased by $Ca^{2+}$ and $Co^{2+}$ but inhibited by $Cu^{2+}$, EDTA, and PMSF. It is suggested that the purified enzyme is a metallo-serine protease.

• Journal of Plant Biotechnology
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• v.32 no.3
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• pp.209-215
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• 2005

Lactoferrin is an iron-binding glycoprotein with many biological roles, including the protection against microbial and virus infection, stimulation of the immune system. We developed the transgenic Siberian ginseng (Acanthopanax senticosus) cell cultures producing the human lactoferrin (hLf) protein following Agrobacterium tumefaciens-mediated transformation. A construct containing a targeting signal peptide from tobacco endoplasmic reticulum fused to hLf cDNA under the control of an oxidative stress-inducible SWPA2 promoter was engineered. Transgenic Siberian ginseng cultured cells to produce a recombinant hLf protein were successfully generated and confirmed by PCR and Southern blot analysis. ELISA and western blot analysis showed that full length-hLf protein was synthesized in the transgenic cells. The production of hLf increased proportionally to cell growth and reached a maximal (up to 3% of total soluble proteins) at the stationary phase. These results suggest that the transgenic Siberian ginseng cultured cells in this study will be biotechnologically useful for the commercial production of medicinal plant cell cultures to produce hLf protein.