• Korean Journal of Environmental Biology
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• v.22
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• pp.54-62
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• 2004

We examined the impacts of anthyopogenic pollutant (benzo〔a〕pyrene) on the growth and photosynthesis of five marine phytoplankton species (Skeletonema costatum, Heterosigma akashiwo, Prorocentrum dentatum, P. minimum, Aknshiwo sanguinea), which are dominant in Korean coastal water. After the 72 h exposure to benzo〔a〕pyrene, the dramatic decrease in cell numbers was observed in the range of 1 to 10 $\mu\textrm{g}$ L$^{-1}$ for S. costatum, P. minimum, P. dentatum, whereas for A. sanguinea and H. akashiwo at the low concentrations 0.1 to 1 $\mu\textrm{g}$ L$^{-1}$ . Among the 5 phytoplankton species, the highest growth inhibition concentration ($IC_{50}$/) was 6.20 $\mu\textrm{g}$ L$^{-1}$ for P. minimum, followed by 2.14 $\mu\textrm{g}$ L$^{-1}$ for P. dentatum, 1.68 $\mu\textrm{g}$ L$^{-1}$ for S. costatum, 0.74 $\mu\textrm{g}$ L$^{-1}$ for H. akashiwo, 0.10 $\mu\textrm{g}$ L$^{-1}$ for A. sanguinea. The five species exposed to the low concentration of 1 $\mu\textrm{g}$ L$^{-1}$ were recovered after transferring to new media, but the species exposed to the high concentrations of 10 and 100 $\mu\textrm{g}$ L$^{-1}$ were not recovered, with the exception of P. minimum. Those results indicate that the thecate dinoflagellate P. minimum is most tolerant to the chemical and the athecate dinoflagellate A. sanguinea is not. Geneyally, the cell-specific photosynthetic capacity of H. akashiwo exposed to the low concentrations of 0.1 and 1 $\mu\textrm{g}$ L$^{-1}$ was higher than that of the cells in the control, whereas the cells exposed to the high concentrations of 5 and 10 $\mu\textrm{g}$ L$^{-1}$ showed the negligible photosynthetic level by the first few days of the experiment. In the case of the cells exposed to the concentration of 5 $\mu\textrm{g}$ L$^{-1}$ , after 12 days of the experiment the photosynthetic capacity was increased toward the end of the experiment. This indicates that H. akashiwo may utilize the benzo〔a〕pyrene as a carton source for its growth when exposed to low concentrations. Results suggest that anthropogenic pollutants such as benzo〔a〕pyrene may have significant influence on the succession of phytoplankton species composition and the primary production in coastal marine environments.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.449-455
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• 1993

Vibrio vulnificus is a recentry recognized halophilic organism that may cause human infections. Patients infected with Vibrio vulnificus often have a history of exposure to the sea, suggesting that the organism may be common inhabitant of marine environment. In this studies 314 samples were collected from 9 sites of Chonnam coastal area, from April to Jun, 1993. Isolation rates of V. vulnificus were 7.1% in total samples, 33.3% in sea water, 55.5% in sediment, 1.7% in fish and shellfish, 6.3% in kitchen environment. In each areas of Chunnam V. vunificus were isolated from 3.6% to 11.4%. The isolation rates of V. vulnificus was correlated positively with organic matter and COD in sea warer and sediment. In sea water, Microorganism population were $4.5{\times}10^3{\sim}3.5{\times}10^5\;CFU/ml$, Vibrio strains were $1.8{\times}10^l4.6{\times}10^3\;CFU/ml$, Coliform bacteria were $1.9{\times}10^1{\times}3.7{\times}10^2\;CFU/100ml$. In sediment, Microorganism population were $4.8{\times}10^3{\sim}5.2{\times}10^5\;CFU/ml$. Vibrio strains were $1.9{\times}10^2{\sim}8.4{\times}10^4\;CFU/ml$, Coliform bacteria were $7.2{\times}10^1{\sim}9.9{\times}10^2\;CFU/100ml$.

• Journal of Marine Life Science
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• v.5 no.2
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• pp.35-42
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• 2020

17β-estradiol (E₂) is a natural hormone secreted by ovary, and continuously discharged from household and livestock wastewater into aquatic environment. Due to its strong estrogenic activity, it has adverse effects on development and reproduction in crustacean as an endocrine disrupting chemical. Although ecdysteroid signaling pathway play a key role in development in crustacean, little information on transcriptional modulation of ecdysteroid-related genes in response to E₂ is available in small crustacean. Here, we investigated the acute toxicity of E₂ to obtain 24-h LC_x values in the brackish water flea Diaphanosoma celebensis. Time-dependent expression patterns of seven ecdysteroid pathway - related genes (CYP314a1, EcRA, EcRB, USP, ERR, Vtg, VtgR) were further examined using quantitative real time reverse transcriptase polymerase chain reaction (qRT-PCR). As results, 24-h LC₅₀ and LC₁₀ values were 9.581 mg/l and 4.842 mg/l, respectively. The mRNA expression of CYP314a1, EcRA, USP, VtgR was significantly up-regulated at 12 or 24 h after exposure to E₂. These findings indicate that E₂ can affect their molting and reproduction by modulating the expression of ecdysteroid pathway - related in D. celebensis. This study will be useful for better understanding of molecular mode of action of endocrine disrupting chemicals on molting process in small crustacean.

• Journal of Life Science
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• v.19 no.2
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• pp.264-270
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• 2009

We investigated the effect of black soybean and doenjang with black soybean on production of cytokines including interleukin-2 (IL-2), interleukin-6 (IL-6) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) compared with yellow soybean and doenjang with yellow soybean. We also determined inhibitory effect of two types of soybeans and doenjang on tumor metastasis produced by colon 26-M3.1 carcinoma cells. The cytokine productions of mouse splenocytes increased by the exposure of lipopolysaccharide (LPS, 1 ${\mu}g$/ml) compared to without treatment of LPS. The LPS-induced IL-2 production was highest in the black soybean methanol extract, while the methanol extract from black soybean doenjang fermented for 2 mo showed the higher levels of IL-2 without LPS (p<0.05). In case of LPS-induced IL-6 production, the methanol extracts from control, yellow soybean, black soybean doenjang fermented for 2 and 7 mo showed higher levels of IL-6 compared to those of black soybean, and yellow soybean doenjang fermented for 2 mo (p<0.05). The methanol extract of black soybean doenjang fermented for 2 mo showed significantly higher levels of TNF-${\alpha}$ in both with and without LPS (p<0.05). In experiment of tumor metastasis, the treatment (1 mg/mouse) of methanol extract from black soybean doenjang fermented for 7 mo inhibited tumor metastasis by 50% and had the highest inhibitory effect among other samples (p<0.05). From these results, doenjang manufactured with black soybean modulated the production of cytokine and showed anticancer effect, suggesting that this effect was increased with increased periods of fermentation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.118-126
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• 1986

Vibrio vulnificus is a recently recognized halophilic organism that nay cause serious human infections. Patients infected with V. vulnificus often have a history of exposure to the sea, suggesting that the organism may be common inhabitant of marine environment. The purpose of this experiment is to investigate the distribution and bacteriological characteristics of V. vulnificus. The strain used in this experiment was isolated from sea water and sea products such as common octopus (Octopus variabilis), ark shell (Anadara broughtonii), blue crab (Ericheir japonica), and sea squirt (Synthia roretzi) collected in Pusan area from July to October in 1985. V. vulnificus was frequently isolated in August when temperature of sea water was around $26^{\circ}C$ and rarely isolated in October when temperature of sea water was around $18.5^{\circ}C$. The distinctive biochemical characteristics of V. vulnificus were ONPG hydrolysis positive and fermented lactose and not grown in peptone water contained $8\%$ NaCl. The optical density at 660 nm of the growth of V. vulnificus was reached maximum level after 8 hours of culture at $35^{\circ}C$ in brain heart infusion broth but that of V. vulnificus was little increased at $15^{\circ}C$ for 14 hours. Optimum temperature and pH for the growth of V. vulnificus were around $35^{\circ}C$ and 8.0. The specific growth rate and the generation time of V. vulnificus isolated from the samples were $1.21\;hr^{-1}$, 34 min at $35^{\circ}C$ and $0.61\;hr^{-1}$, 69 min at $25^{\circ}C$, respectively. V. vulnificus did not grow on eosin-methylene-blue agar, salmonella-shigella agar, deoxycholate agar but grew well on Endo agar, xylose-lysine-deoxycholate agar and hektoen enteric agar. On Endo agar, the colonies of V. vulnificus were red and achieved a diameter of 2 to 4 mm as a feature enabling differentiation of V. vulnificus from other Vibrio spp. V. vulnificus grow well on TCBS agar forming green colonies. V. vulnificus refrigerated at $4^{\circ}C$ exhibited a linear decline of its viablity as 1 log cycle in every 16 hours storage, while V. vulnificus freezed at $-18^{\circ}C$ almost became extinct.

• Journal of Preventive Medicine and Public Health
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• v.19 no.1 s.19
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• pp.16-30
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• 1986

In order to prepare the fundamental data for the improvement of noisy working environments and the effective hearing conservation program on workers exposed to industrial noise, the authors surveyed the working processes and evaluated the noise levels on 56 manufacturing industries in Pusan area from April to July in 1985. The results were summarized as follows : 1. The noise level was the highest in shipbuilding and repairing(95.6 dBA), and followed by steel rolling(94.0 dBA), manufacture of motor vehicles(93.1 dBA), manufacture of fishing nets(92.9 dBA), manufacture of testiles(92.5 dBA), iron and steel foundries(89.3 dBA), manufacture of metal products(89.1 dBA), preserving and processing of marine foods(87.0 dBA), manufacture of rubber products(85.3 dBA), manufacture of plywood(84.9 dBA) and manufacture of paints(84.5 dBA). 2. Among fifty surveyed working processes, the noise level of twenty-one processes (42%) exceeded the threshold limit value for 8 hours per day. 3. As the allowable exposure times by governmental threshold limit values to industrial noise level(dBA), cocking of shipbuilding and repairing and plating(CGL) of steel rolling were the shortest(30 minutes), and followed by assembling(rivet) of manufacture of motor vehicles(1 hour) weaving of manufacture of textiles and shot, machine, pipe laying of shipbuilding and repairing(2 hours). 4. By the result of octave band analysis on noisy working processes in excess of 90 dBA, the sound level was the highest at 2,000 Hz or 4,000 Hz. 5. It was recognized that the measurement of overall sound pressure level was also effective as octave band analysis in evaluating the industrial noise.