• Journal of Life Science
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• v.18 no.1
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• pp.103-108
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• 2008

An agar-degrading marine bacterium, strain AS-1 was isolated from the seawater. The strain AS-1 was identified as Sphingomonas paucimobilis (90% probability) by VITEK. The optimum medium for agarase activity of the isolated strain was determined to be marine medium, marine broth 2216 containing 0.1% agar as carbon source. An extracellular agarase was purified 104-fold from the culture supernatant by ammonium sulfate precipitation, ion exchange chromatography and gel filtration methods. The molecular weight of the purified enzyme was estimated to be 80 kDa by SDS-PAGE. The optimum pH and temperature for activity were 7.0 and $40^{\circ}C$, respectively. Antioxidative activity of the strain AS- was 72% in the supernatant cultured for 12 h. The culture supernatant of the strain AS-1 showed antibacterial activity against bacteria causing putrefaction and food poisoning such as Escherichia coli, Staphylococcus aureus and Proteus vulgaris. However, the cell growth of the lactic aicd forming strain, Lactobacillus plantarium was promoted by the treatment of 10% culture supernatant of an agar-degrading strain.

• Journal of Life Science
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• v.18 no.3
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• pp.329-335
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• 2008

Korean Deep ground sea-like water (KDSW) has a similar mineral composition with deep sea water. KDSW has demonstrated its usefulness and attracted in the medical fields. KDSW and Danasoo (desalted deep ground sea-like water) intake improve antioxidant, antidiabetic activity and immunity. Antioxidant activities of KDSW and Dnansoo were measured by using 2,2-diphenyl-l-picryl-hydrazyl (DPPH) free radical, superoxide dismutase-like activity (SODA) and photochemiluminescence (PCL). DPPH radical scavenging and SOD-like activities of KDSW and Danasoo were remarkably increased in a dose-dependent manner. Antioxidant activities of KDSW and Danasoo 85.32 and 14.02 nmol of ascorbic acid equivalent/ml KDSW and Danasoo, respectively, using the PCL method. Lipopolysaccharide (LPS)-induced nitric oxide (NO) production in macrophages RAW264.7 cells was inhibited up to 30% by treatment with Danasoo (20%). NO is synthesized by the enzyme of nitric oxide synthase (NOS) and plays an important role tumor growth and angiogenesis. The anticancer effects of Danasoo on human gastric and lung cancer cells was performed by levels of inducible nitric oxide synthase (iNOS). Danasoo significantly reduced iNOS expression of human gastric cancer (SNU-l) and lung carcinoma (A549). The serum glucose level was significantly reduced by Danasoo (20%) diet in streptozotocin (STZ)-induced diabetic rats. These result suggest that KDSW has excellent biological activities and thus it has great potential as a source for natural health products.

• Ocean and Polar Research
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• v.29 no.4
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• pp.401-410
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• 2007

In Korea the study of marine heterotrophic protists started in the late 1980s, and since the early 1990s many studies have been conducted in various marine environments. In this article, studies on the distribution and abundance of protists and the biotic interactions(bacteria-protists, phytoplankton-protists) conducted in Korean coastal waters are reviewed, and a field study is reported and discussed. The field study in Masan Bay was carried out from February 2004 to November 2005 at seven selected stations representative of the bay. During the study, the mean abundance of heterotrophic bacteria and the mean concentration of chlorophyll-a were $2.1{\times}10^6\;cells\;mL^{-1}$ and $9.8{\mu}g\;L^{-1}$, respectively. Heterotrophic protists consisted of heterotrophic dinoflagellates, heterotrophic nanoflagellates(excluding dinoflagellates) and ciliates, and their abundances were means of $7.9{\times}10^4\;cells\;L^{-1}$, $1.2[\times}10^3\;cells\;mL^{-1}$, and $4.0{\times}10^4\;cells\;L^{-1}$, respectively. Generally, the chlorophyll-a concentra+CZ14tions and the abundances of heterotrophic bacteria and protists were higher in the inner zone of the bay, where there are high concentrations of organic matters, than in the middle and outer zones. Using the grazing rates of heterotrophic nanoflagellates on bacteria previously reported in this area, it can be calculated that about 69% of bacterial producton was removed by HNF grazing activity. About 24% of initial chlorophyll-a concentration was removed by microzooplankton grazing activity. In conclusion, this study suggests that in Masan Bay heterotrophic protists control the growth of bacteria and phytoplankton, and heterotrophic protists represent an important link of bacterial & microalgal biomass to higher trophic levels.

• Journal of the Korean earth science society
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• v.24 no.3
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• pp.216-233
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• 2003

This study delineates the phenomena related with global environmental changes such as global warming, ozone depletion, and El Ni${\tilde{n}}$o/Southern Oscillation (ENSO) noted in the Antarctic. Retreat of ice cliffs, glaciers, and calving of ice shelves indicate the effects of recently aggravated global warming. The ice cliff located at Marian Cove, King George Island, South Shetland Islands off the Antarctic Peninsula has been observed to be retreating faster in the last 7 years than in the previous 38 years since 1956. There are some indications of temperature and precipitation changes associated with ENSO around King Sejong Station. The regression analyses indicate significant trends such as a decrease in the total amount of ozone and an increase in ultraviolet radiation which was seen by a satellite (TOMS-EUV) in September and October which correspond to ozone-hole season over King Sejong Station. Increase of UV radiation due to the ozone depletion in the Antarctic has changed the growth rate of marine organisms. It may also result in changes to the productivity, biomass, and species composition of marine organisms which can affect the whole marine ecosystem. The recent ice-core drilling over Lake Vostok has been reviewed with emphasis on the four cycles of glacial stages over the past 420,000 years. It is time to show more interest in mainland Antarctica through investigations of the coring and vast ice sheet, terrestrial geology, and upper atmospheric sciences in order to understand the past environmental changes and to predict possible changes to the environment in the future.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.190-193
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• 2015

The current sea route sign system based on an electronic marine chart only has a data manufacture specification for uses at ECDIS. Therefore, it has a limitation in expressing various sea route data and falls short of productivity as it is frozen to prevent being changed for a long time. Also, it cannot satisfy requirements from high tech such as lattice structure data and time series information. Currently, although it builds each independent operation system based S-57, it has been found that it is the most important requirement from consumers that the entire monitoring system can mutually interwork by standardizing and uniting formats of all protocols. In addition, current status information and alarm system is using AIS, TRS, WCDMA telecommunication and processing all the data after saving it into each different server. Lighthouse lantern which currently has used was utilized to do a performance test of a developed system. All of created data was trasmitted through the RS-232, It is clear that the data was received by a situation monitoring system. In addition, when the data was transmitted after saving in a database, same data was ordinarily received. In this thesis, we will implemented the status information and alarm system of Marine transportation facilities which is a sea route sign system based on S-63 electronic marine chart, S/W, after uniting each different protocol and making combined system.

• Plant Journal
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• v.9 no.3
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• pp.38-42
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• 2013

Submarine gas fields have focused because of the increasing fuel cost, the environmental regulations, and the safety & NIMBY problems. LNG-FPSO which is available for acid gas removal, recovery of the condensate & LPG and Liquefaction in topside process is one of high technology offshore structures. On the other hands, it is necessary to verify the pre-treatment efficiency by the ship motion and to apply to the design for LNG-FPSO. This study is to develop the pre-treatment technology for LNG-FPSO as taking account to the process efficiency by ship motion effects and the area optimization. Based on the simulation results, it founds that hybrid process shows the low circulate rate, the low heat duty and the small size of column dimensions compared to typical amine process. It will be verified the process efficiency in the various conditions by sea states as performing the 6-DOF motion test and CFD simulation.

• Journal of Fisheries and Marine Sciences Education
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• v.18 no.3
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• pp.293-301
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• 2006

This study was undertaken to prolonging the freshness in Squid(Todarodes pacificus) on the effects of ice storage methods(tap water ice, electrolytic water ice) using stainless diaphragm electrolytic instrument and also test an efficiency of instrument. Basically, stainless diaphragm electrolytic instrument studied for changes of pH on difference water flow and ampere. The lower water flower and higher ampere made low pH on acid part of electrolytic instrument. Squid samples were stored in tap water ice, acid part of electrolytic water and base part of electrolytic water and used in studying the changes of VBN and skin color through storage. Acid water had strong sterilization effects and VBN was lower levels of acid water than the others. Base water had not sterilization effects. Tap water ice storage was more sterilizing effects than base water ice storage but less effects than acid water ice storage. Lightness of Squid skin showed getting decrease at storage of ice water of all storage methods but acid water ice storage showed more retarding than the other two storage. From these results, it could be suggested that acid electric water ice storage is effective in extendance the shelf-life of squid at chilled storage.

• Journal of Life Science
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• v.24 no.9
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• pp.995-1000
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• 2014

The studies of marine viruses in terms of viral isolation and detection have been limited due to the high mutation rate and genetic diversity of marine viruses. Of the modern methods currently used to detect marine viruses, serological methods based on enzyme-linked immunosorbent assay (ELISA) are the most common. They depend largely on the quality of the antibodies and on highly purified suitable antigens. Recently, a new experimental system for using viral capsid protein as an antigen has been developed using the yeast surface display (YSD) technique. In the present study, the capsid protein gene of the red-spotted grouper nervous necrosis virus (RGNNV) was expressed and purified via YSD and HA-tagging systems, respectively. Two regions of the RGNNV capsid protein gene, RGNNV1 and RGNNV2, were individually synthesized and subcloned into a yeast expression vector, pCTCON. The expressions of each RGNNV capsid protein in the Saccharomyces cerevisiae strain EBY100 were indirectly detected by flow cytometry with fluorescently labeled antibodies, while recognizing the C-terminal c-myc tags encoded by the display vector. The expressed RGNNV capsid proteins were isolated from the yeast surface through the cleavage of the disulfide bond between the Aga1 and Aga2 proteins after ${\beta}$-mercaptoethanol treatment, and they were directly detected by Western blot using anti-HA antibody. These results indicated that YSD and HA-tagging systems could be applicable to the expressions and purification of recombinant RGNNV capsid proteins.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.1
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• pp.42-45
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• 2014

Even though to discard the waste FRP (Fiber-Reinforced Plastic) is urgent and problematic, the way to do it has not been efficient. In our project team the FRP have been splitted into some layers which have different physical properties; mat and roving layers. Among those, the roving layer woven like a basket by bundles of glass fibers has been cut into reusable fibers called 'F-fiber'. F-fiber is 1 mm or 3 mm in width and 3 cm in length. It is used in fiber-reinforced concrete (FRC) with 0.5%, 0.7%, 1.0%, or 1.5% of volume ratio. Produced FRC was tested in compressive, tensile, and bending stress in contrast to the without-fiber (standard) concrete and 0.1% polypropylene reinforced concrete (PP-FRC). The tensile and bending stresses are more or less those of PP-FRC. The compressive stress, however, is similar (with 3 mm F-fiber) to or lower (with 1 mm F-fiber) than that of standard concrete. Conclusively the usage of the waste FRC in concrete is advised to be limited to the one where the compressive stress is not much critical.

• Journal of Life Science
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• v.26 no.2
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• pp.198-203
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• 2016

This study aimed to isolate a novel agarase-producing marine bacterium and characterize its agarase, as agarases are known to produce biofunctional agarooligosaccharides or neo-agarooligosaccharides. A novel agar-degrading bacterium, SH-2, was isolated from the seawater of Namhae in Gyeongnam Province, Korea, and cultured in Marine agar 2216 medium. The 16S rRNA gene sequence represented 99% identity with that of the members of the Marinomonas genus; hence, the isolated bacterium was named Marinomonas sp. SH-2. The crude agarase was prepared from a culture medium of Marinomonas. sp SH-2, and exhibited maximum agarase activity at 170.2 units/l. The optimum conditions were pH 6.0 and 30℃ in 20 mM Tris-HCl buffer. The agarase activity of the bacterium was highly elevated from 20℃(42% relative activity) to 30℃(100%), and 82% activity was shown at 40℃. Its relative activities were less than 40% at over 40℃ after a 0.5 hr exposure. Relative activity was 100% at pH 6.0, while it was 72% and 48% at pH 5.0 and pH 7.0, respectively. The enzyme from Marinomonas sp. SH-2 degraded agarose to neoagarohexaose and neoagarotetraose, indicating that the enzyme is β-agarase. Thus, Marinomonas sp. SH-2 and its enzyme could be practical for applications in food, cosmetic, and medical research.