• Journal of Microbiology and Biotechnology
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• v.25 no.4
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• pp.448-451
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• 2015

In a previous study, we isolated octaphlorethol A (OPA) from Ishige foliacea and evaluated its anti-melanogenesis activity in a murine melanoma cell line. However, the whitening effect and toxicity of OPA have not yet been examined in vivo. Therefore, in this study, we investigated the inhibitory effect of OPA on melanin synthesis and tyrosinase activity in an in vivo zebrafish model. More than 90% of subject embryos survived upon exposure to OPA concentrations below $25{\mu}M$, which was not significantly different from the finding in the control group. OPA markedly inhibited melanin synthesis and tyrosinase activity in a concentration-dependent manner.

• Journal of Microbiology and Biotechnology
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• v.26 no.11
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• pp.2006-2011
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• 2016

The marine sponges Hyrtios and Haliclona species, both of which are known to produce secondary bioactive metabolites, were used to extract 1304KO-327 and 1304KO-328. Such secondary metabolites are potentially antibacterial, antiviral, anti-inflammatory, antitumoral, antifungal, and antiplasmodial. In the present study, the effects of 1304KO-327 and 1304KO-328 were studied for their clinical and pathological importance. The cytotoxicity of 1304KO-327 and 1304KO-328 was assessed via MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay on HT-29, Caco-2, and Raw 264.7 cells. Rotavirus-infected Caco-2 cells were used to prove the antiviral effects of the marine sponge extracts. The test results cogently proved that the virus-inhibiting effects of the sponge extracts improved with extract concentration. Anti-inflammatory effects of the marine sponge extracts were tested on Lipopolysaccharide-treated Raw 264.7 cells. Nitric oxide and cytokine were produced by treatment of the cells with LPS and the inhibiting effects of the sponge extracts on $IL-1{\beta}$ formation were investigated. This study found that the NO production was decreased dose dependently, and $IL-1{\beta}$ formation was significantly reduced by the marine sponge extracts.

• Journal of Marine Bioscience and Biotechnology
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• v.8 no.1
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• pp.24-29
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• 2016

Microalgae are considered as superior biodiesel producers, because they could effectively produce high amount of lipid with fast growth rate. In this study, Chlorella vulgaris was exposed to various light wavelengths (${\lambda}_{max}$ 470 nm, ${\lambda}_{max}$ 525 nm, and ${\lambda}_{max}$ 660 nm) using light emitting diodes (LEDs) to examine effect of light quality on their growth and fatty acid production in 0.4-L bubble column photobioreactors. Fluorescent lamps were also used as polychromatic light sources (control). From the results, biomass productivity was varied by light wavelength from 0.05 g/L/day to 0.30 g/L/day. Maximum biomass productivity was obtained from red LED among tested ones. We also observed that contents of oleic acid and linolenic acid, which affect biodiesel properties, were significantly changed depending on supplied wavelength. These results indicated that production of algal biomass, and fatty acid content and productivity could be improved or controlled by supplying specific light wavelength.

• Journal of Marine Bioscience and Biotechnology
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• v.8 no.2
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• pp.54-66
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• 2016

Productivity of Saccharina japonica was evaluated by water layers in Gijang and Wando sea area to find the suitable farming areas for mass production of biomass. For this, S. japonica was cultivated at various depths (0.5, 1, 2, 3 m), respectively. As the result, the growths in Gijang were 225.1-261.5 cm in length, 18.5-21.3 cm in widths, 396.0-537.7 g in weights, 14.3-17.8 kg/cluster in biomass, and those in Wando were 332.0-435.7 cm in lengths, 24.6-32.5 cm in widths, 766.0-1,232.9 g in weights, 16.4-24.3 kg/cluster in biomass. It showed that the growths of blades in Wando were faster than those in Gijang. The growth rates of blades by the depths were faster at 0.5-1 m depth from January to June. After June, however, as the growth rates of blades were lower than the shedding rates of blades, it showed that the growth of S. japonica decreased at all depth conditions except 2 m depth. Productivity of S. japonica was better in Wando which is lower in the water temperature and nutrients than Gijang.

• Journal of Microbiology and Biotechnology
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• v.31 no.3
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• pp.456-463
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• 2021

In this study, the culture conditions for Porphyridium cruentum were optimized to obtain the maximum biomass and lipid productions. The eicosapentaenoic acid content was increased by pH optimization. P. cruentum was cultured with modified F/2 medium in 14-L photobioreactors using a two-phase culture system, in which the green (520 nm) and red (625 nm) light-emitting diodes (LEDs) were used during the first and second phases for biomass production and lipid production, respectively. Various parameters, including aeration rate, light intensity, photoperiod, and pH were optimized. The maximum biomass concentration of 0.91 g dcw/l was obtained with an aeration rate of 0.75 vvm, a light intensity of 300 μmol m-2s-1, and a photoperiod of 24:0 h. The maximum lipid production of 51.8% (w/w) was obtained with a light intensity of 400 μmol m-2s-1 and a photoperiod of 18:6 h. Additionally, the eicosapentaenoic acid and unsaturated fatty acid contents reached 30.6% to 56.2% at pH 6.0.

• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.384-390
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• 2021

A Gram-negative, aerobic, motile by gliding, and rod-shaped marine bacterium, designated CE67^T was isolated from the marine sponge Callyspongia elegans on Biyang-do in Jeju Island. The CE67^T strain grew optimally at 25℃, pH 7.5, and in the presence of 2-3% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain CE67^T was related to the genus Aureivirga and had the highest 16S rRNA gene sequence similarity to the Aureivirga marina VIII.04^T type strain (96.3%). The primary fatty acids (>10%) of strain CE67^T were iso-C_15:0 (35.3%) and iso-C_17:0 3OH (21.8%). The polar lipid profile of strain CE67^T contained phosphatidylethanolamine, unidentified aminolipids, and unidentified lipids. The predominant menaquinone was MK-6. The DNA G+C content was 29.1 mol%. Based on the polyphasic taxonomic analysis, strain CE67^T was determined to be a representative novel species of the genus Aureivirga for which we propose the name Aureivirga callyspongiae sp. nov., whose strain type is CE67^T (=KCTC 42847^T=JCM 34566^T).

• Journal of Marine Bioscience and Biotechnology
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• v.13 no.1
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• pp.48-57
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• 2021

Vibrio species are Gram-negative basophils that are ubiquitous in seawater, increasing in number as the water temperature increases. Humans are usually infected by the consumption of contaminated seawater or seafood. V. alginolyticus infection in humans is mainly associated with infections of the skin and ears, such as acute otitis media and cellulitis. In this study, the distribution of V. alginolyticus along the coast of Jeju Island, and its relationship with water temperature, salinity, DO, and pH was investigated. The antibiotic susceptibility of the bacteria isolated was also tested. In seawater, the Daejeong area had the highest detection rate, with 13 cases (21.7%), and the Hallim area showed the lowest detection rate, with eight cases (13.3%) in. In shellfish, the Daejeong area had the highest rate, with seven cases (23.3%), and the Seongsan and Hallim areas had the lowest detection rate, with four cases (13.3%). The overall detection rate was the highest in Daejeong area, with 20 cases (22.2%), and the lowest in the Hallim area, with 12 cases (13.3%). The detection rate was highest when the water temperature was highest.

• Journal of Marine Bioscience and Biotechnology
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• v.14 no.2
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• pp.143-154
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• 2022

We isolated marine actinomycetes, strain D-5 which produces anti-methicillin resistant Staphylococcus aureus (anti-MRSA) compound. Streptomyces sp. D-5 relatively grew well in the 20~25℃, pH 8.0, and NaCl 3.0%. The ethyl acetate extract of D-5 culture was separated by C₁₈ ODS open column and reverse phase HPLC to yield anti-MRSA compound. The molecular weight of this compound was determined to be 898 by a Liquid chromatograph-mass spectrometer (LC-MS). Compared with penicillin G, this compound showed significant anti-MRSA activity. It also exhibited an inhibition zone of 26 mm at a concentration of 64 ㎍/disk and an inhibition zone of 16 mm at a concentration of 16 ㎍/disk against the MRSA KCCM 40511. Furthermore, the co-treatment of HPLC peak 5 compound and vancomycin caused a more rapid decrease in MRSA cells than each compound alone. It showed 86.8% growth inhibition activity within 12 hours at a low concentration of 50 ㎍/mL during co-treatment, and 97.1% growth in-hibition activity within 48 hours against MRSA KCCM 40511. Taken together, our results suggest that Streptomyces sp. D-5 and its anti-MRSA compound could be employed as a potent agent in MRSA infection.

• Journal of Marine Bioscience and Biotechnology
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• v.14 no.1
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• pp.43-50
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• 2022

Squid is a sustainable source of long-chain omega 3 fatty acids. This study aims to assess the safety and triglyceride-lowering efficacy of refined oil derived from the squid(Todarodes pacificus) viscera. Male and female participants with elevated fasting serum lipids (i.e., total cholesterol of ≥5.2 mmol/L or fasting serum triglyceride of ≥1.65 mmol/L) were randomly allocated to the control (n = 52) or squid oil group (n = 52), and participants in the latter group were instructed to consume 3 g of squid oil daily for 60 days. None of the subjects reported adverse events associated with the consumption of squid oil. Baseline clinical chemistry and hematological parameter values and those toward the end of the treatment period were similar, and all values were within the normal range. Fasting cholesterol and triglyceride levels in the control and squid oil groups were similar; however, toward the end of the 60 day study period, these levels significantly reduced in the squid oil group relative to those in the control group (P< 0.01). However, high-density lipoprotein-cholesterol remained unchanged in both groups. Thus, it can be inferred that squid oil is a safe source of long-chain omega-3 fatty acids and has beneficial effects on the blood lipid levels. This is the first clinical study on squid oil usage, and suggests that it could be a sustainable source of omega 3 fatty acids.

• Journal of Marine Life Science
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• v.2 no.1
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• pp.7-11
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• 2017

Sulfated polysaccharides are known to be immune-stimulators in mammals and can be used as food additives to enhance immunity. In this study, the immune-stimulating activity of water-soluble anionic macromolecules F₂ fractionation isolated from Codium fragile using ion-exchange chromatography was tested in olive flounder, Paralichythys olivaceus, in vitro and in vivo. The gene expression of interleukin (IL)-1β was adopted to check the immune-affection. As a result, in vitro study revealed that the expression of IL-1β was significantly upregulated in head kidney cells by 1 and 5 ㎍/ml of polysaccharides 4 h and by 5 ㎍/ml of polysaccharides at 24 h. In vivo, IL-1β gene expression in head kidney was significantly upregulated by 20 and 100 ㎍ of the polysaccharides at day 1 post-i.p. injection, while downregulated at day 3 but not significant. Meanwhile, in peritoneal cells, it was upregulated by 20 ㎍ of the polysaccharides at day 1 but the upregulation was sustained until day 3 though it was not significant. These results indicate that the sulfated polysaccharides from C. fragile are an immune-stimulator and might be potential feed additives for olive flounder.