• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.125-125
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• 2003

Recirculating aquaculture systems consist of different treatment compartments that maintain water quality within the ranges of commonly recommended for fish culture. This paper presents the common considerations in designing different treatment compartments as well as the engineering criteria in designing closed recirculating aquaculture system including a circular tank for fish culture, a sedimentation basin and a foam fractionator for solids removal, two styrofoam bead filters for TAN removal, a sand filter for nitrate removal, and aerators. The main purpose is to outline a common procedure in designing of closed recirculating aquaculture system for marine fish culture.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.254-255
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• 2017

As the number of ships and goods shipped by marine transportation increases, almost all shipping companies adopted foreign crews in order to overcome lack of seafarers and be competitive for manning cost. Thus, these days it is inevitable to work with foreign crews aboard ships, but there occur many marine accidents due to language barriers and communication problems under multicultural and multilingual shipboard environments. In order to resolve troubles resulting from different languages, reduce miscommunication risks, and make working on ships safe and efficient, this study recognized the current status of ships with mixed crews, analyzed marine accidents caused by communication problems not only in Korea but also in other countries using analytical methodologies. Additionally, existing hazards affecting miscommunication were identified and risk of miscommunication was quantitatively evaluated while offering suggestions and future forecasts. Consequently, in this study we suggested that fundamental dialogues are to be necessarily educated on the ships with foreign crews so as to reduce the language barrier and risk of miscommunication. Furthermore, a standard maritime Korean language program and manual targeting Korean coastal vessels would be developed in the next step.

• Journal of Microbiology and Biotechnology
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• v.26 no.8
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• pp.1420-1427
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• 2016

Geosmin and 2-methylisoborneol (2-MIB) are two of the most common taint compounds that adversely affect the quality of aquacultural animals. In the present study, 94% of geosmin and 97% of 2-MIB in suspended growth reactors producing bioflocs (SGRs) with aquaculture waste were removed after inoculation with Bacillus subtilis, significantly higher than that of control SGRs (70% of geosmin and 86.4% of 2-MIB). The lowest concentrations of geosmin and 2-MIB achieved in the effluent of the SGRs were 2.43 ± 0.42 ng/l and 2.23 ± 0.15 ng/l, respectively. The crude protein content of the bioflocs produced in the SGRs was 35 ± 4%. The NH₄⁺-N and NO₂^--N concentrations in the effluent of the reactors were 1.13 ± 0.21 mg/l and 0.42 ± 0.04 mg/l, respectively. These results suggest that inoculated with Bacillus subtilis, SGRs have a better performance to reuse the nitrogen in fish waste and to remove geosmin and 2-MIB from the culture water efficiently.

• Development and Reproduction
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• v.12 no.1
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• pp.51-56
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• 2008

To optimize the cell culture conditions of zebrafish embryonic cells, we compared the efficiency of three types of medium, DMEM, K-NAC and D-NAC. In this study, we showed that the cells grown in K-NAC have better plating efficiency than DMEM, especially in the case of low cell seeding density. However, cells grew slower in K-NAC than those in DMEM in confluent cultures. The effect of 0.1% zebrafish embryo extracts was minimal. The presence of 1% trout serum in culture medium significantly increased the growth rate of cells(p<0.05). No difference was found at $2{\sim}3{\times}10^5$ cell seeding density(p<0.05). At $4{\sim}5{\times}10^5$ cell seeding density, cells grew better in DMEM than K-NAC (p<0.1). The results suggest that supplementation of NAC and A2P in Keratinocyte SFM may improves plating efficiency when cells are plated at low population. No difference was found for cell growth in either medium with 5%, 10% or 15% FBS supplemented (p<0.05). Cells culture in D-NAC grew significantly better than those in DMEM(p<0.05). Our results clearly showed that the use of NAC and A2P in the culture medium has a positive effect on cell growth regardless of the amount of FBS added.

• Ocean and Polar Research
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• v.25 no.4
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• pp.493-501
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• 2003

Performance of a laboratory scale closed seawater recirculating aquaculture system was evaluated. Twenty-kg of korean rockfish (130 fish) with an average body weight of 153.8g was stocked. Over a 107-day culture period, fish reached final density of $51.7kg/m^3$ (initial density, $33.3kg/m^3$) on the basis of the culture tank volume. On a daily basis, added water amounted to 3.4% of the total water volume in the system. Total ammonia nitrogen (TAN) concentrations were below 1mg/l and nitrite nitrogen $(NO_2-N)$ concentrations were within the range of 1-3mg/l on most sampling days. TAN was removed from bead and sand filters and it was removed or produced in the sedimentation basin. Basically, $NO_2-N$ was removed in the bead and sand filters, while it was either removed or produced in the sedimentation basin. Nitrate nitrogen $(NO_3-N)$ was produced in the bead filters and removed from the sand filter and sedimentation basin. The foam fractionator performed well in the recirculating system. The maximal daily removal values for total suspended solids (755) and protein were 10.9g and 1.4g, respectively. Whole water quality parameters were within the levels commonly recommended for fish culture on most of the sampling days. However, further studies are needed to evaluate the commercial feasibility of this system because of the smallscale system used in present experiment. At least, the present study still provides some basic information for further studies of this kind of system.

• Journal of Microbiology and Biotechnology
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• v.17 no.8
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• pp.1403-1406
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• 2007

An antiproliferative agent, streptochlorin, was isolated from the fermentation broth of a marine actinomycete isolated from marine sediment. Phylogenetic analysis of the 16S rRNA gene sequence indicated that the strain belongs to the genus Streptomyces. Bioactivity guided fractionation of the culture extract by solvent partitioning, ODS open flash chromatography, and reversed-phase HPLC gave a pure compound, streptochlorin. Its structure was elucidated by extensive 2D NMR and mass spectral analyses. Streptochlorin exhibited significant antiproliferative activity against human cultured cell lines.

• Journal of Korea Port Economic Association
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• v.26 no.4
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• pp.269-288
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• 2010

21 C is called the age of Culture and it is underlined in all the Areas of Human lifes. Among all activities, Culture oriented Thinking and activities and strategies through and for Culture establishing are emphasized. As Sea may appear as a image of longing and challenge for the unknown world, Port is understood as a link which connect Sea and Land. Sea, Island and Port are the basis of human lifes, economic working areas and communication spaces with nature. Sea and Port have been changed in accordance with human History as the space of Life, Work, Play and Imagination. The Maritime activities has been developed as the type of a Culture, including various diversities according to the time and space. This Paper suggested a definition of Maritime Culture and Theoretical review and groped introduction and strategies and countermeasures for expansion of systematic Maritime Culture. Maritime Culture not only enhance the quality of Citizen life but also contribute the progress of National economy increasing the quality of Culture, Turism and Environment and the expectation of it has been enlarged. It is needed to introduce and expand Maritime Culture systematically through theoretical framework suggested by this paper, and additional research may be necessary for the detailed solutions and countermeasures.

• KSBB Journal
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• v.28 no.4
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• pp.217-224
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• 2013

A bacterium CGH18 exhibiting antioxidizing and chitin-degrading activities in the colloidal chitin culture medium was isolated from salt-fermented crab. This strain was identified as Bacillus idriensis based on 16S rDNA sequence homology search. Its crude extract was partitioned between n-BuOH and $H_2O$. The organic layer was further partitioned between $CH_2$ $Cl_2$ and $H_2O$. Antioxidant activities of crude extract and its solvent fractions were evaluated using five different bioassay methods, including the degree of occurrence of intracellular reactive oxygen species (ROS), peroxynitrite scavenging (ONOO), and oxidative damage of genomic DNA. All fractions exhibited significant antioxidant activity in bioassay systems used.

• Journal of Microbiology and Biotechnology
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• v.24 no.11
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• pp.1559-1565
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• 2014

Cellulase and xylanase are main hydrolysis enzymes for the degradation of cellulosic and hemicellulosic biomass, respectively. In this study, our aim was to develop and test the efficacy of a rapid, high-throughput method to screen hydrolytic-enzyme-producing microbes. To accomplish this, we modified the 3,5-dinitrosalicylic acid (DNS) method for microwell plate-based screening. Targeted microbial samples were initially cultured on agar plates with both cellulose and xylan as substrates. Then, isolated colonies were subcultured in broth media containing yeast extract and either cellulose or xylan. The supernatants of the culture broth were tested with our modified DNS screening method in a 96-microwell plate, with a $200{\mu}l$ total reaction volume. In addition, the stability and reliability of glucose and xylose standards, which were used to determine the enzymatic activity, were studied at $100^{\circ}C$ for different time intervals in a dry oven. It was concluded that the minimum incubation time required for stable color development of the standard solution is 20 min. With this technique, we successfully screened 21 and 31 cellulase- and xylanase-producing strains, respectively, in a single experimental trial. Among the identified strains, 19 showed both cellulose and xylan hydrolyzing activities. These microbes can be applied to bioethanol production from cellulosic and hemicellulosic biomass.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.05a
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• pp.266-266
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• 2002