• Ocean and Polar Research
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• v.33 no.1
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• pp.21-34
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• 2011

We determined potential meso-scale benthic-pelagic ecosystem coupling in the north equatorial Pacific by comparing surface chl-a concentration with sediment bacterial abundance and adenosine triphosphate (ATP) concentration (indication of active biomass). Water and sediment samples were latitudinally collected between 5 and $11^{\circ}N$ along $131.5^{\circ}W$. Physical water properties of this area are characterized with three major currents: North Equatorial Current (NEC), North Equatorial Count Current (NECC), and South Equatorial Current (SEC). The divergence and convergence of the surface water occur at the boundaries where these currents anti-flow. This low latitude area ($5{\sim}7^{\circ}N$) appears to show high pelagic productivity (mean phytoplankton biomass=$1266.0\;mgC\;m^{-2}$) due to the supplement of high nutrients from nutrient-enriched deep-water via vertical mixing. But the high latitude area ($9{\sim}11^{\circ}N$) with the strong stratification exhibits low surface productivity (mean phytoplankton biomass=$603.1\;mgC\;m^{-2}$). Bacterial cell number (BCN) and ATP appeared to be the highest at the superficial layer and reduced with depth of sediment. Latitudinally, sediment BCN from low latitude ($5{\sim}7^{\circ}N$) was $9.8{\times}10^8\;cells\;cm^{-2}$, which appeared to be 3-times higher than that from high latitude ($9{\sim}11^{\circ}N$; $2.9{\times}10^8\;cells\;cm^{-2}$). Furthermore, sedimentary ATP at the low latitude ($56.2\;ng\;cm^{-2}$) appeared to be much higher than that of the high latitude ($3.3\;ng\;cm^{-2}$). According to regression analysis of these data, more than 85% of the spatial variation of benthic microbial biomass was significantly explained by the phytoplankton biomass in surface water. Therefore, the results of this study suggest that benthic productivity in this area is strongly coupled with pelagic productivity.

• Journal of Applied Biological Chemistry
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• v.54 no.1
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• pp.21-25
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• 2011

A lactic acid bacterial strain showing high acid production in saccharified-rice suspension was isolated from Kimchi. This strain was analyzed by API 50 CHL kit and 16S rRNA sequencing analysis and identified as Leuconostoc mesenteroides 310-12. Saccharified-rice suspension was fermented using L. mesenteroides 310-12 strain at $30^{\circ}C$ for 15 h. The changes of pH, titratable acidity and viable cell number during fermentation were determined. The pH and titratable acidity were reached to pH 3.57 and 0.40% after 15 h fermentation, respectively. The viable cell population of L. mesenteroides 310-12 was rapidly increased to $8.9{\times}10^8$ CFU/g during the 15 h of cultivation. The contents of lactic acid and acetic acid were determined to be 0.077% and 0.065% after 15 h fermentation, respectively. The rice-based fermented beverage was manufactured by blending L. mesenteroides 310-12 fermented broth and some food additives. When this beverage was stored at $4^{\circ}C$, the viable cells population was decreased to $1.0{\times}10^7$ CFU/g and pH was nearly maintained for 25 days.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.4
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• pp.583-588
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• 2002

Two microorganisms isolated from soybean curd residue (biji) were identified as Enterococcus faecium (51% homology) and Lactobacillus rhamnosus (99.5% homology) by using gram positive identification (GPI) card and API 50 CHL kit, respectively. Ent. faecium grew well in micronized full-fat soyflour (MFS) milk, indicating pH 4.9, 0.38% acidity and 1.8$\times$10$^{9}$ CFU/$m\ell$ of viable cell counts after fermentation for 20 hr. L. rhamnosus LL showed pH 6.5 and 4.6$\times$10$^{8}$ CFU/$m\ell$ viable cell counts, but enhanced acid production in MFS milk mixture fortified with skim milk or by the addition of 1% of glucose and lactose. On the other hand, Ent. faecium LL did not show increased acid production in MFS/skim milk and MFS milk fortified with sugar. The MFS/skim milk fermented by L. rhmnosus LS and Ent. faecium LL showed 600 mg% and 350 mg% lactic acid, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.6
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• pp.397-404
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• 1991

The steady state and decay characteristics of primary fluorescenece of phytoplanktons including Cyanophyceae and Cryptophyceae were investigated in vivo. At 580-640 nm region, fluorescence emission spectra were obtained from all algae examined. The observed fluorescence emission maxima were similiar$(\pm3\;nm)$ except Synechocorcus sp. (SYN). Considered $\lambda_{max}$ of emission spectra of phycobiliproteins and the excitation spectra with $\lambda_{max}=540-560nm$, it seems to be originated from biliproteins. Fluorescence lifetimes $(\tau)$ and decay curves were compared with standard solution of candidate organic compounds, b-phycoerythrin. The $\tau$ values obtained for phytoplankton with $\lambda_{max}=580nm$ were different depending upon the species of algae. The observed $\tau$ values were ranged from 1.39 ns to 1.95 ns. These are considerably shorter than $\tau(3.23\;us)$ for standard solution of b-phycoerythrin. The reduction of $\tau$ for phycoerythrin in vivo seems to be originated from effective energy transfer system between Chl. a and phycobiliprotein in intact cell. There are subtantial differences in fluorsecence spectra and lifetimes at the class level. At the species level, differences seems to be much smaller. The result of experiment suggests that measurement of fluorescence lifetimes may be helpful in the rapid characterization of algae. Direct application will likely be found in combination with the measurement of other luminescence parameters.

• Applied Biological Chemistry
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• v.50 no.2
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• pp.87-94
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• 2007

A bacterium which has high enzymatic activities such as amylase, cellulase and protease was isolated from Korean traditional soybean food, doenjang. The isolated bacterium was identified to Bacillus subtilis HS25 by the test of morphological and biochemical properties according to Bergey's Manual of Systematic Bacteriology and API 50 CHL kit, and by the 16S rDNA sequence. The isolated B. subtilis HS25 had a potent antibacterial activity against food born causative or pathogenic bacteria. B. subtilis HS25 is endospore forming cell and contained flagella and abundant viscous material at the out layer of cell wall. It was rod type bacterium $(0.5{\sim}0.8{\times}3{\sim}5{\mu}m)$ having biochemical characteristics such as gram staining(+), catalase(+), oxidase(-) and hydrolysis of esculin(+). The optimal medium compositions for production of antibacterial substance in the B. subtilis HS25 were 1% of soluble starch, 0.5% of yeast extract, 0.5% of peptone and 0.05% of MgCl$_2{\cdot}6H_{2}O$. The optimum temperature and pH of the growth of the B. subtilis HS25 was 35$^{\circ}C$ and pH 7.5, respectively. The antibacterial activity was more high in neutral to a little alkaline pH (6.5-10.5) than in acidic pH. The optimal shaking speed to grow and to produce antibacterial substance of the B. subtilis HS25 was 160${\sim}$200 rpm. The optimal culture time for antibacterial activities of the bacterium were shown to be in the range of 12-36 hr.

• Environmental Mutagens and Carcinogens
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• v.26 no.4
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• pp.119-124
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• 2006

There are $10{\sim}30%$ polyphenol and $2{\sim}4%$ caffeine in green tea. Caffeine is a kind of alkaloid containing nitrogen which cause stimulation, impatience, headache, insomnia, low birth weight infant. Because of these negative effect, decaffeined beverage came out and decaffeined coffee already have a big market since 1970s. Having proving the physiologic functions of green tea, high consumption of coffee is shifting to green tea. Because of the carcinogenic effect of the organic solvents, decaffeine processing with supercritical carbon dioxide has industrialized and have an advantage in environment-friendly and minimized flavor loss. Decaffeined green tea using supercritical carbon dioxide is considered to be safe but there are not enough study. We investigated the chromosome aberration test with mammalian cell line, CHL. When the cells were treated with 5000, 2000, 1000 ${\mu}g/ml$ and compared with the negative controls, there were no significant(P>0.05) increased chromosome aberration. Same results was observed when adding S9 mixture or not. As a result, water extract of decaffeined green tea using supercritical carbon dioxide does not induce chromosome aberration.

• Korean Journal of Environmental Biology
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• v.17 no.4
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• pp.481-492
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• 1999

The observations on the spatio-temporal distribution and seasonal fluctuations of phytoplankton community were carried out in Deukryang Bay of the Korean Southwestern Sea from June 1992 to April 1993. A total of 75 species of phytoplankton belonged to 47 genera was identified. In Deukryang Bay seasonal succession in dominant species; P. alata, G. flaccida, S. costatum, L. danicus and N. longissima in summer, St. palmeriana, Ch. curvisetus and B. paxillifera in autunm, S. costatum, Ch. curvisetus, E. zodiacus and Pn. pungens in winter, and As. glacialis, As. kariana, N. pelagica, Th. nitzschioides and S. costatum in spring, were very marked, that is to say, the communities structure of phytoplankton in Deukryang Bay appeared to be various species composition and it was occupied with diatoms all the year round. Phytoplankton standing crops fluctuated with an annual mean of $1.4{\times}10^5 cells/1 between the lowest value of 2.6{\times}10^3 cells/1 in July and the highest value of 1.0{\times}10^6 cells/1$ by S. costatum in January. Densities of the phytoplankton cell number by the samples of Deukryang Bay ranged from $2.6{\times}10^3cells/1 to 1.2{\times}10^5 cells/1 with the mean value of 3.6{\times}10^4cells/1 in summer, from 6.0{\times}10^3cells/1 to 2.6{\times}10^5 cells/1 with mean of 1.5{\times}10^5 cells/1 in autumn, from 1.3{\times}10^4cells/1 to 1.0{\times}10^6 cells/1 with mean 3.5{times}10^5 cells/1 in winter, and from 4.8{\times}10^3cells/1 to 6.0{\times}10^5 cells/1 with mean of 1.6{\times}10^5 cells/1$ in autumn. That is to say, phytoplankton standing crops was large in low temperature seasons, on the other hand small in high temperature seasons. Chlorophyll $\alpha$ concentration fluctuated between 0.l9 $\mu$g/l and 12.3 $\mu$g/l in March. in Deukryang Bay seasonal flucturation in chi-$\alpha$ concentration was not marked. Especially, chl-$\alpha$ concentration in the water around Deukryang Island located in the middle part of Deukryang Bay showed patchy distributions with a very high concentration. And chl-$\alpha$ concentration was high during a year. Therefore, phytoplankton production in Deukryang Bay could be very high year-round.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.6
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• pp.669-676
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• 2017

To understand the relationship between environmental factors and phytoplankton community structures and why early outbreaks of Cochlodinium polykrikoides occur in the inner bay of Korea, short-term investigations were conducted at 17 stations in the eastern part of the South Sea of Korea, with sessions every two weeks from July 7 to August 24, 2016. The water temperature increased from $22.3^{\circ}C$ in the first survey to $28.4^{\circ}C$ in the fourth survey, which was a rise of about $6.01^{\circ}C$. Salinity was relatively high at Stns. 8 13 in the inner bay. In the first survey, rainfall of about 150 mm was observed, so nutrients were supplied at a high level and a high concentrate of Chl. a was observed. Cryptophyta (Crpytomonas spp.) represented 58.3 % of the community, followed by Bacillariophyta at 33.8 %. In particular, at Stn. 5, Dinophyta Prorocentrum spp. accounted for a very high percentage, 32.2 %. In the second survey, low phytoplankton populations were observed, and Bacillariophyta (Chaetoceros spp.) accounted for 61.0 %. At Stn. 4, Skeletonema spp. showed high populations but did not appear at other stations even at a low density. In the third and fourth surveys, phytoplankton populations were very low. Bacillariophyta represented 78.0 % in the third study and 73.3 % in the fourth. Interestingly, although the appearance of C. polykrikoides was investigated at the beginning of the red tide in the coastal area, they were not observed inshore, implying that the likelihood of inflow by the germination of resting cysts was low for the inner bay during this study period. In addition, environmental characteristics such as salinity and nutrient presence were significantly different between sampling stations due to the existence of a semi-closed bay in the southern sea, resulting in dominant phytoplankton species and community composition differing in these short-term investigations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.1
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• pp.43-50
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• 2000

The obseuations on the seasonal fluctuations of phytoplankton community in Haechang Bay of the Korean southern sea were carried out during four seasons from 1997 to 1998. A total of 77 species of phytoplankton including 10 freshwater species, belonging to 51 Benera was identified. Seasonal succession of dominant species was evident in Haechang Bay; Chaetoceros cunisetus, Skeletonema costatum, Eurampia zodiacus, Dictyocha fibula and Ceratium furca in summer, C. curisetus in autunm, C. cunisetus Rhizosoienia setigera and E. zodiacus in winter and S. costatum in spring. The phytoplankton community in Haechang Bay showed various species composition and was occupied with centric diatoms all the year round, Densities of the phytoplankton cell number by the samples of Haechang Bay ranged from $8.4{\times}10^3\;cells/l\;to\;2.0{\times}10^5\;cells/l$ with the mean value of $9.2{\times}10^4\;cells/l$ in summer, from $3.2{\times}10^3\;cells/l\;to\;4.6{\times}10^6\;cells/l$ with mean of $6,2{\times}10^4\;cells/l$ in autumn, from $8.4{\times}10^3\;cells/l\;to\;4.3{\times}10^4\;cells/l$ with mean $2.2{\times}10^4\;cells/l$ in winter and from $1.0{\times}\;10^3\;cells/l to\;4.6{\times}10^4\;cells/l$, with mean of $1.1{\times}10^4\;cells/l$ in spring. Phytoplankton standing crops fluctuated with an annual mean of $4.7{\times}10^4 cells/l$ between the lowest value of $1.0{\times}10^3\;cells/l$ in spring and the highest value of $4.6{\times}10^5 cells/l$ in autumn, That is, phytoplankton standing crops was high in summer and autumn, while it was very low in winter and spring.

• Journal of Food Hygiene and Safety
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• v.16 no.2
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• pp.145-151
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• 2001

EpoxidiBed soy bean oil (ESBO) is a plasticizer of PVC which is being widely used as a gaskets for the lid of glass jars including baby food. Using reverse mutation assay, chromosome aberration test and micronucleus test, ESBO were evaluated the mutagenicity. In the reverse mutation test, ESBO did not induced mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, TA1537, TA102 with and without metabolic activation. In the chromosome aberration test using CHL cells, the results showed no increased structural and numerical aberrations in the concentration of sample producing cytotoxicity with and without metabolic activation. The in vivo induction of micronuclei was measured in polychromatic erythrocytes of bone marrow of young (3weeks old) and adult (6 weeks old) ddY mice of both sex. At 24 hours after treatment with ESBO 20, 10, 5, 2.5 g/B.W. kg/corn oil 10 ml by oral route animals were sacrificed and bone marrow cells were prepared for smear slides. The results showed no increased micronucleated polychromatic erythrocytes regardless of sex and age. It was concluded that water soluble ESBO did not show certain genotoxicity within our studies conducted.