• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.1
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• pp.27-38
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• 2011

The distributions of phytoplankton assemblages and environmental factors in Jinhae Bay and their relationships were investigated to estimate the potential limiting nutrient for phytoplankton growth and community structure. In situ algal bioassay experiments were also conducted to assess the species-specific characteristics in phytoplankton responses under different nutrient conditions (control, N(+) and P(+) treatment). During the study periods, bacillariophyceae and cryptophyceae occupied more than 90% of total phytoplankton assemblages. Phytoplankton standing crops in the inner part of Masan Bay were higher than that of Jinhae Bay. The DIN:DIP ratio, pH and transparency showed the significant positive correlation with phytoplankton biomass. According to cluster and multidimensiolnal scaling (MDS) analysis based on phytoplankton community data from each station, the bay was divided into three groups. The first group included stations from the south-western part of Jinhae bay where cryptophyta species were dominated. The second group was distinguished from inner stations in Masan Bay. These stations showed low transpancy and high DIN:DIP ratio. The other cluster included the stations from the eastern part and central part of Jinhae Bay, which was characterized by the high DSi:DIP ratio and dominant of diatom species. Phosphorous (P) was limited in Masan Bay due to significantly increases in the phytoplankton abundances. Based on stoichiometric limitation and algal bio-assay in Jinhae Bay, nitrogen (N) was a major limiting factor for phytoplankton production. However, silicate (Si) was not considered as limiting factor, since Si/DIN and Si/P ratio and absolute concentration of nutrient did not create any potential stoichiometric limitation in the bay. This implies that high Si availability in winter season contributes favorably to the maintenances of diatom species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.4
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• pp.466-475
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• 2005

Docosahexaenoic acid (22:6n-3, DHA) is highly enriched in membrane of brain and retina, and plays an important role in maintaining an optimal function of the central nervous system. We investigated the effect of n-3 fatty acid deficiency on rat brain, retina and liver fatty acyl composition at two different ages (3 wks and 15 wks) under DHA deficient condition. Rat pups born to dams fed a diet with $3.1\%$ of total fatty acids as $\alpha-linolenic$ acid (LNA) were fed using an artificial rearing system either an n-3 deficient (n-3 Def) or n-3 adequate (n-3 Adq) diet. Both diets contained $17.1\%$ linoleic acid (LA) but the n-3 Adq diet also contained $3.1\%$ LNA. Rats consuming the n-3 Def diet showed a lower brain $(50\%\;in\;13\;wks\;and\;70\%\;in\;15\;wks,\;p<0.05)$ and retinal $(50\%\;in\;13\;wks\;and\;63\%\;in\;15\;wks,\;p<0.05)$ DHA than those on the n-3 Adq diet, which was largely compensated for by an increase in docosapentaenoic acid (22:5n-6, DPAn-6). In the liver of the n-3 Def group, the percentage of DHA decreased by $97\%$ at 3 wks of age with an apparent increase in DPAn-6 relative to the n-3 Adq group (p<0.05), while there was a $65\%$ lower liver DHA in n-3 Def group at 15 wks of age than the n-3 Adq group (p<0.05). Liver arachidonic acid (20:4n-6, AA) was increased at 3 wks of age but decreased at 15 wks of age in the n-3 Def group compared with n-3 Adq group (p<0.05). In conclusion, the replacement of DHA by DPAn-6 in brain and retina fatty acid composition may be related to the suboptimal function in spatial learning, memory and visual acuity. This artificial rearing method presents a first generation model for n-3 deficiency that is similar to the case of human nutrition that commonly employed two generation model.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.1
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• pp.75-82
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• 1999

The hydrolysate of desalinated tuna boiled extract (TBE) were prepared by continuous hydrolysis of TBE using a membrane reactor. TBE and tuna boiled extract hydrolysate (TBEH) were isolated depending on molecular weights. The major molecular weight distributions of TBEH-l0K, TBEH-5K and TBEH-lK were 9,800Da, 3,000Da and 990Da, respectively. The amounts of nucleotides and their related compounds of TBE were 3.47 $\mu$mole/g AMP, 23.75 $\mu$mole/g IMP, 9.07 $\mu$mole/g inosine and 1.89 $\mu$mole/g hypoxanthine. Total content of amino acids having desirable taste (glycine, glutamic acid, alanine, proline, aspartic acid, serine) was about $63\%$ of total amino acid from TBE and about $62\%$ from TBEH. The natural seasoninings were prepared with TBE and TBEH. From the results of sensory evaluations, complex seasoning containing TBEH-1K was almost equal to the shellfish complex seasoning obtained from the market. The mixed sauce which was made by mixing of $50\%$ TBEH sauce and $50\%$ fermented soy sauce was similar to the tradition soybean sauce in product quality and it showed the possibility to be used for the substitute product for acid hydrolyzed soysauce.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.431-438
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• 2000

To clarify the annual reproductive cycle in a rockfish, Sebastes schlegeli, monthly changes in gonadosomatic index (GSI), hepatosomatic index (HSI) and histological feature of gonads and plasma levels of sex steroid hormones ($estradiol-l7{\beta},\;17{\alpha},\;20{\beta}-dihydroxy-4-pregnen-3-one,\;testosterone\;and\;11-ketotestosterone$) were investigated. The annual reproductive cycle in females could be divided into 5 periods as follows: 1) recovery period (June to September): serum level of $estradiol-l7{\beta}$ increased gradually; 2) vitellogenesis period (Septemer to february) : vitellogenic oocytes were obsewed, GSI sustained high value, and serum level of $estradiol-l7{\beta}$ increased; 3) gestation period (February-April): developing larva showed in the ovary, and serum levels of $17{\alpha},\;20{\beta}-dihydroxy-4-pregnen-3-one$ and testosterone increased; 4) partrition period (April to May) : larva were delivered, and value of GSI and serum levels of hormones decreased rapidly; 5) resting period (May to June) : value of GSI and serum levels of $estradiol-l7{\beta}$ and testosterone remained low. The annual reproductive cycle in males could be divided into 6 periods; 1) early maturation period (April to June): value of GSI and serum levels of hormones incresed gradually, cyst of spermatogonia incresed in number, and a small number of cyst of spermatocyte was observed; 2) mid-maturation perid (June to September); value of GSI and serum levels of hormones increased, and germ cells in many cysts were undergoing active sperrnatogenesis; 3) late maturation period (September to November) : value of GSI and serum levels of hormones remained high and spermatozoa were released into the lumina of the seminal lobules; 3) spermatozoa dischaging period (Nobember to December) : the lumina of the seminal lobules were enlarged and filled with mature spermatozoa; 4) degeneration period (December to Februauy)i value of GSI decresed and cyst of spermatocyte were decresed in number; 5) resting period (December to April) : no histological changes of testes were observed, and value of GSI and serum levels of hormones remained low. In November, the lumina of the seminal lobules were filled with mature spermatozoa and sperm masses were present in the ovarian cavity. Thus, copulation in this species occurred in November and December.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.276-281
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• 2008

Extracts from Rododendron mucronulatum Turcz. flowers were tested for antioxidant and their inhibitory activities of ${\alpha}$-amylase, ${\alpha}$-glucosidase and angiotensin converting enzyme (ACE). Total contents of phenolics were found as $30.6{\pm}0.14mg/g$ (60% EtOH extract) and $23.2{\pm}0.21mg/g$ (water extract). Electron donation ability (EDA), ABTS [2,2azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] radical decolorization, Antioxidant protection factor (PF) and thiobarbituric acid reactive substance (TBARs) were measured for the antioxidative activity of the extracts from Rododendron mucronulatum Turcz. flowers. The water extract were determined as 97.5% at ethanol extract showed 83.2% and 60% EtOH extract were 89.7% in EDA. The water extract showed higher antioxidant activity than 60% EtOH extract when evaluated by ABTS radical decolorization and antioxidant PF. The TBARS of water extracts and 60% EtOH extracts were shown as $0.29{\times}10^2{\mu}M\;and\;0.28{\times}10^2{\mu}M$, respectively, and were lower than control. ACE inhibitory activity in water extract (67.6% inhibition) was higher than that of 60% EtOH extract (46.7% inhibition) at $200{\mu}g/mL$. Water extracts had higher inhibitory activities on ${\alpha}$-amylase and ${\alpha}$-glucosidase than 60% EtOH extracts. The result suggests that the water extract from Rododendron mucronulatum Turcz. flowers will be useful as natural antioxidants and functional foods.

• Food Science and Preservation
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• v.20 no.2
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• pp.234-241
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• 2013

The phenolic compounds of water extracts from Prunella vulgaris were highest at 9.25 mg/g, respectively, when various extraction solvents were used. The optimum condition for extracting phenolic compounds from Prunella vulgaris was extraction in water for 18hr. The DPPH-scavenging activities of Prunella vulgaris were highest at the water extracts. The ABTS radical cation decolorization was higher than 40% in the range of 0~100% ethanol extract section. The antioxidant protection factor on the lipophilic phenolic metabolites was shown to be 1.1 PF in the water extracts from Prunella vulgaris. The TBARS was lower than the control ($0.53{\mu}M$) in all the sections. The tyrosinase inhibitory effect, which is related to skin whitening, was above 40%, and for the anti-wrinkle effect, the elastase inhibition activity was above 40% at 0.2 mg/mL. The astringent effect of the Prunella vulgaris 40% ethanol extracts was 98.1% at 1 mg/mL. As a result, it can be concluded that Prunella vulgaris has the potential to be used as a cosmetic material.

• Journal of Life Science
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• v.22 no.10
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• pp.1295-1306
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• 2012

A microorganism producing carboxymethylcellulase (CMCase) was isolated from seawater and identified as Bacillus atrophaeus. This species was designated as B. atrophaeus LBH-18 based on its evolutionary distance and the phylogenetic tree resulting from 16S rDNA sequencing and the neighbor-joining method. The optimal conditions for rice bran (68.1 g/l), peptone (9.1 g/l), and initial pH (7.0) of the medium for cell growth was determined by Design Expert Software based on the response surface method; conditions for production of CMCase were 55.2 g/l, 6.6 g/l, and 7.1, respectively. The optimal temperature for cell growth and the production of CMCase by B. atrophaeus LBH-18 was $30^{\circ}C$. The optimal conditions of agitation speed and aeration rate for cell growth in a 7-l bioreactor were 324 rpm and 0.9 vvm, respectively, whereas those for production of CMCase were 343 rpm and 0.6 vvm, respectively. The optimal inner pressure for cell growth and production of CMCase in a 100-l bioreactor was 0.06 MPa. Maximal production of CMCase under optimal conditions in a 100-l bioreactor was 127.5 U/ml, which was 1.32 times higher than that without an inner pressure. In this study, rice bran was developed as a carbon source for industrial scale production of CMCase by B. atrophaeus LBH-18. Reduced time for the production of CMCase from 7 to 10 days to 3 days by using a bacterial strain with submerged fermentation also resulted in increased productivity of CMCase and a decrease in its production cost.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.287-301
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• 2014

In order to understand environment condition and phytoplankton community before and after coastal upwelling, the influences of upwelling events on phytoplankton community were studied at 18 stations located the Southern part of East Sea, Korea from May to August 2013. The surface water masses showed low temperature and high salinity due to upwelling events at coastal stations (A1, B1, C1). Correlation between temperature and nutrients (DIP, r=-0.218, p<0.01; DIN, r=-0.306, p<0.01; silicate, r=-0.274, p<0.01) was significantly negative. This result could be explained that nutrients were supplied to surface water by the upwelling of bottom water. Phytoplankton communities were composed of 186 species. Phytoplankton abundance were relatively high in May (C1, $726{\times}10^3cells\;L^{-1}$) and July (A1, $539{\times}10^3cells\;L^{-1}$). Total chlorophyll a and micro-size fraction ($&gt;20{\mu}m$) increased at coastal stations in July and August, while phytoplankton abundance and total chl. a was much low in June. Dominant species in June was Pseudo-nitzschia spp. of which the cell size was $309{\mu}m^3$. Cell size of Pseudo-nitzschia spp. was smaller than dominant species in other period. Therefore, the increase in total chloro-phyll a and the size of phytoplankton was resulted in the sufficient supply of nutrients. In contrast, these tendencies were not observed at outside stations. These results suggested that coastal upwelling was an important influencing factor to determine the species composition and standing stock of phytoplankton community in the coastal waters of the Southern part of East Sea, Korea.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.938-946
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• 2017

This study was conducted to examine the changes in serum lipid components and blood glucose by krill (Euphausia superba) meal and sodium fluoride (NaF) in rats fed on experimental diets and administered orally to NaF 10 mg for 5 weeks. Body weight of rats decreased as the amount of krill meal diet increased, it was observed the basal diet plus NaF group (BF group) compared to the lower basal diet group (BD group). The serum concentrations of total cholesterol, LDL (low-density lipoprotein) cholesterol, free cholesterol, triglyceride (TG), phospholipid (PL) and blood glucose in serum were higher in the BF group than the 10% krill meal group plus NaF 10 mg (KF10 group) or BD group, the 20% krill meal plus NaF 10 mg group (KF20 group), the 30% krill meal plus NaF 10 mg group (KF30 group). Conversely depending on the content of krill meal for the HDL (high-density lipoprotein) cholesterol level, it showed higher results. The concentration of total protein was no significant difference among the groups (p<0.05). The results indicate that a krill meal diet effectively inhibited increases in lipid elevation and blood glucose level in the sera of rats.

• Journal of Applied Biological Chemistry
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• v.62 no.2
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• pp.173-179
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• 2019

The aim of this study is to investigate the biological activities of Hericium erinaceus. 1,1-Diphenyl-2-picrylhydrazyl radical scavenging activity of H. erinaceus extract was higher than positive control. The inhibitory activities of xanthin oxidase, ${\alpha}$-glucosidase, and hyaluronidase was measured as functional food activity, and inhibitory activities on collagenase, tyrosinase, and astringent effect as beauty food activity in water and ethanol extracts from H. erinaceus. In functional food activity, xanthin oxidase inhibitory activities at $50-200{\mu}g/mL$ phenolic concentration in ethanol extracts from H. erinaceus showed inhibitory activity in dose dependent manner. ${\alpha}$-Glucosidase inhibitory activities at $50{\mu}g/mL$ phenolic concentration showed high activity of higher than 80%. Inhibitory activities on hyaluronidase as anti-inflammation factor showed inhibition effect in dose dependent manner both in water and ethanol extracts. In beauty food activity, Inhibitory activities on collagenase at $200{\mu}g/mL$ phenolic concentration in water and ethanol extracts showed high activity to 65.09 and 58.38% dose dependently. Tyrosinase inhibitory activity in water extract showed 9.4-58.24%. Astringent activity as pore shrink effect in ethanol extracts also showed a very high activity of 18.94-100%. Antimicrobial activity on pathogenic bacteria was highly effective on Staphylococcus aureus, Salmonella enteritidis, Vibrio parahaemolyticus and Escherichia coli at 2.5 mg/mL or above. Therefore, the extracts from H. erinaceus can be used as a functional food and beauty food resources and natural antimicrobial agent on pathogenic bacteria in food.