• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.1
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• pp.59-69
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• 2013

Temporal and spatial variation in the freshwater region, created by river runoff, of a small bay, caused by the passage of typhoons was examined using a three-dimensional primitive equation model (the Princeton Ocean Model, POM). Numerical experiments were implemented focusing on temporal evolution in the freshwater region in association with typhoon tracks. The model domain covered most of the estuary around the Nakdong River, including Noksan Bay, where river water is periodically released from upstream (Noksan dam). The model showed that the extension of the freshwater region outside of the bay depended strongly on the tracks of typhoons, specifically the associated wind directions and inner flow fields that are accompanied by new clockwise eddies. The model also showed that entrainment from typhoon passage frequently creates salt wedges in the estuary, indicating that organisms in the bay are biologically and chemically influenced with variation in the freshwater region.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1559-1563
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• 2002

The ovarian follicular fluid was found to contain steroidogenesis stimulatory protein similar to albumin from human and buffalo. Therefore, the albumins from various species, commercial and purified, were studied for their steroidogenic effect on progesterone secretion by granulosa cells from buffalo ovaries, during culture. A dose of $20{\mu}g$ of bovine serum albumin was optimum to exhibit maximum progesterone secretion on day 6 of culture, in medium ($350{\mu}l$) containing $10^5$ cells. Among commercial albumins, chicken albumin showed highest effect on progesterone secretion, which was followed by albumins from goat, bovine, human, sheep and rat, respectively at day 6 of culture. The albumins were also purified from blood serum of buffalo, goat and rat using salt fractionation, ion-exchange chromatography, gel filtration and SDS-PAGE. The highest stimulatory effect on progesterone secretion was shown by albumin purified from buffalo blood serum and lowest by that from rat blood. Comparatively the buffalo and goat albumins were more biologically active than commercial albumins. The presence of some active molecules conjugated with freshly purified albumins may be responsible for better stimulatory effect.

• Korean Journal of Clinical Laboratory Science
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• v.44 no.4
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• pp.216-221
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• 2012

The fruiting body of Cordyceps is derived from the pupa or larva of insects infected by the entomopathogenic fungi Cordyceps. The fruiting body has been used as an anti-cancer and anti-inflammatory ingredient in traditional Chinese medicine. The biochemical characteristics of protease isolated from Cordyceps nutans were investigated in this study. The culturing period for production of protease by C. nutans was 10days. The acidity was pH 7.0, and the temperature was $25^{\circ}C$. The carbon and nitrogen sources for the production of the protease were glucose and yeast extract, respectively. The ratio of C/N was 2% glucose and 0.6% yeast extract. 0.06% $CuSO_4$ was used as the inorganic salt. The investigation into the acidity of the protease produced by C. nutans revealed that the optimal pH and temperature were pH 7.0 and $30^{\circ}C$. The stability of the protease was shown as pH 6.0~9.0 and $30{\sim}50^{\circ}C$. The investigation into the influence of the metal ions on the enzyme activation of C. nutans revealed that it was inhibited in $ZnSO_4$ and activated in $FeSO_4$.

• Korean Journal of Microbiology
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• v.12 no.3
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• pp.115-130
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• 1974

Searches for the nutrition requirements of three strains of Brevibacterium ammoniagenes reported in the previous paper were carried out with an aim of achieving the striking accumulation of L-glutamic acid and the large multipication of cells. It was recognized that all three strains required both biotin and thiamine, together with amino acids such as histidine or cysteine, for their good growth and extracellular L-glutamic acid accumulation. The quantity of biotin required for remarkable growth of these microorganisms was quite different from that for the maximum production of L-glutamic acid. This result, however, did not apply in the case of thiamine. It was also confirmed that, of 18 amino acids, histidine and cysteine were the msot effective organic nitrogen sources, while the most available inorganic ammonium salt resulting in a large amount of L-glutamic acid-production and considerable cell gorwth was found to be only urea. Maximum accumulation of extracellular L-glutamic acid, more than 50%(w/w) of the initial sugar content, could be obtained from fermentation in the medium containing wheat-bran extract(Brev. ammoniagenes T-1 and Brev.ammoniagenes Y-2) or rice-bran extract(Brev. ammoniagenes YR-2), which confirmed us a possibility that these bacteria might be employed for industrial fermentation of L-glutamic acid.

• Korean Journal of Microbiology
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• v.29 no.1
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• pp.56-62
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• 1991

Extremely halophilic bacteria isolated from salterns at Mado, Kyunggido, Korea, were identified and investigated on their salt requirements. The results have shown that six strains were identified to be belonged to the genus Halobacterium and three strains identified as the fenus Halococcus. Among them, the optimal NaCl concentration for growth of Halobacterium sp. EH10 was at 4.2M and no growth occurs below 2.0M NaCl. The strain, EH10, is nonmotile and showed acid production from glucose, fructose and maltose while H. salinarum is motile and does not produce acid from any carbohydrates. On the other hand, the strain EH10 does not utilize readily glucose while a number of sugars are readily utilized for growth with acid production by H. saccharovorum. Thus, the isolate, EH10, was classified into the genus Halobacterium and could be a novel species of the genus by its main morphological and physiological features including G+C content. The optimal temperature for growth of the isolate, EH10, was 50.deg.C. But this strain did not grow when NaCl was replaced with KCl.

• Journal of Microbiology and Biotechnology
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• v.23 no.2
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• pp.149-155
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• 2013

Heterologous expression of a putative $K^+/H^+$ antiporter of Streptomyces coelicolor A3(2) (designated as sha4) in E. coli and Streptomyces hygroscopicus JCM4427 showed enhanced tolerance to $K^+$ stress, acidic-pH shock, and/or geldanamycin production under $K^+$ stress. In a series of $K^+$ extrusion experiments with sha4-carrying E. coli deficient in the $K^+/H^+$ antiporter, a restoration of impaired $K^+$ extrusion activity was observed. Based on this, it was concluded that sha4 was a true $K^+/H^+$ antiporter. In different sets of experiments, the sha4-carrying E. coli showed significantly improved tolerances to $K^+$ stresses and acidic-pH shock, whereas sha4-carrying S. hygroscopicus showed an improvement in $K^+$ stress tolerance only. The sha4-carrying S. hygroscopicus showed much higher geldanamycin productivity than the control under $K^+$ stress condition. In another set of experiments with a production medium, the secretion of geldanamycin was also significantly enhanced by the expression of sha4.

• Food Science and Preservation
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• v.10 no.4
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• pp.554-559
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• 2003

The optimal culture conditions on bacteriocin producing of Lactobacillus sp. FF-3 isolated from Korean Dongchimi, were studied for enhancing its production with regard to environmental and nutritional factors. The optimal cultivation time, initial pH and temperature were 21 hours, pH 7.0 and 30∼37$^{\circ}C$ respectively. Optimal compositions of culture medium for bacteriocin production were glucose 3% as carbon source, tryptone 4% as nitrogen source, and manganese sulfate 0.005% as inorganic salt with other basal components. The maximum antimicrobial activity was 484 BU/mL under the optimal culture condition.

• The Korea Journal of Herbology
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• v.23 no.3
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• pp.163-173
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• 2008

Objectives : Imyosan (IMS), a drug preparation comprised of Phellodendri Cortex (PC) and Atractylodis Rhizoma (AR), is commonly used as a traditional herbal medicine in Korea and China for the treatment of various inflammatory diseases. However, little is known about the effect of IMS and its component herbs on inflammatory mediators in RAW 264.7 cells. Therefore, in this study, methanol extracts of IMS and its component herbs were examined to determine if they inhibited inflammatory effects in RAW 264.7 cells. Methods : Cytotoxic activity of IJHT and its components on RAW 264.7 cells was using 5-(3-carboxymethoxyphenyl)-2H-tetrazolium inner salt (MTS) assay. The nitric oxide (NO) production was measured by Griess reagent system. And proinflammatory cytokines were measured by ELISA kit. The levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression were detected by western blot. Results : Methanol extract of IMS and its component herbs were significantly reduced iNOS and COX-2 expression as well as NO, PGE2, $IL-1{\beta}$ and IL-6 production in RAW 264.7 cells. Conclusions : The results of this study indicated that the anti-inflammatory effect of Imyosan extract is more potent than that of extracts of its component herbs in macrophages.

• Journal of Environmental Science International
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• v.11 no.3
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• pp.177-182
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• 2002

A biosurfactant-producing microorganism was isolated from activated sludge by enrichment culture when grown on a minimal salt medium containing n-hexadecane as a sole carbon source. This microorganism was identified as Pseudomonas sp. and it was named Pseudomonas sp. EL-G527. It's optimal culture condition is 2% n-hexadecane, 0.2% NH$_4$NO$_3$, 0.3% KH$_2$PO$_4$, 0.3% $K_2$HPO$_4$, 0.02% MgSO$_4$ㆍ7$H_2O$, 0.0025% CaCk$_2$ㆍ6$H_2O$, 0.0015% FeSO$_4$ㆍ7$H_2O$ in 1$\ell$ distilled water and initial pH 7.0. Cultivation was initiated with a 2% inoculum obtained from starter cultures grown in 30 $m\ell$ of the same medium in 250 $m\ell$ flask. They were cultivated at 3$0^{\circ}C$ in reciprocal shaking incubator and the highest biosurfactant production was observed after 4 days.

• Food Science of Animal Resources
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• v.30 no.3
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• pp.359-364
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• 2010

Lactobacillus acidophilus A12 was isolated from chicken feces for use as an immunostimulating livestock probiotic. The purpose of this study was to optimize the production of L. acidophilus A12 using response surface methodology (RSM). Initially, the influence of growth medium was studied in terms of carbon sources (glucose, fructose, lactose, glycerol, sucrose, ethanol, and mannitol), nitrogen sources (beef extract, yeast extract, malt extract, and tryptone), and inorganic salts ($CaCl_2$, $MgSO_4$, $KH_2PO_4$, $(NH_4)_2SO_4$, $FeSO_4$, and NaCl). Through one factor-at-a time experiment, lactose, yeast extract, and $CaCl_2$ were determined to be the best sources of carbon, nitrogen, and inorganic salt, respectively. The optimum composition was found to be 17.7 g/L lactose, 18.6 g/L yeast extract, and 0.9 g/L $CaCl_2$. Under these conditions, a maximum cell density of 9.33 Log CFU/mL was produced, similar to the predicted value.