• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.94-100
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• 2016

Hydrogen production via steam reforming of bio-oil from algal biomass over fast pyrolysis with commercial catalysts was carried out. Aqueous bio-oil obtained by phase separation from a crude oil over fast pyrolysis was used as a reactant and comparison studies for activity over different catalysts (FCR-4-02, POS-7, Cat. A, RUA), reaction temperature, and steam/carbon (S/C) ratios were performed. Experimental results showed that different catalytic activities were observed with different S/C ratios and catalyst composition and the highest hydrogen yield of 70% was obtained with a POS-7 catalyst at a S/C ratio of 10 and 1073 K.

• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.352-358
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• 2020

In this study we investigated the immune effects of oral administration of anionic macromolecules extracted from Codium fragile (CFAM) and red ginseng extract mixture on the peritoneal macrophage cells in immune-suppressed mice. Cyclophosphamide (CY) induces the immune-suppressed condition. CY-treated mice were orally fed with different concentrations of CFAM supplemented with red ginseng extract and the peritoneal macrophages collected. CY treatment significantly decreased the immune activities of peritoneal macrophages, compared to the normal mice. The administration of CFAM mixed with red ginseng extract significantly boosted the viability of macrophage cells and nitric oxide production of peritoneal macrophages. Further, the oral administration of CFAM mixed with red ginseng extract up-regulated the expression of iNOS, COX-2, and TLR-4 as well as cytokines such as IL-1β, IL-6, TNF-α, and IFN-γ more than the red ginseng-treated group. This study showed that CFAM enhanced the immune activity of red ginseng extract in the peritoneal macrophage cells of immune-suppressed mice. Furthermore, CFAM might be used as a co-stimulant of red ginseng extract through the regulation of macrophage cells for the enhancement of human health and immunity.

• Journal of Marine Bioscience and Biotechnology
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• v.12 no.1
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• pp.20-28
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• 2020

Symbiodinium is a dinoflagellate genus that coexists with coral reefs and is known to provide ultraviolet (UV) protection in nature through the synthesis of mycosporin-like amino acids (MAA). In order to develop a natural and ecofriendly sunblock for use in summer resorts, the possibility of using a Symbiodinium microbiome extract or an MAA was investigated. Two sunblocks, one containing 7% Symbiodinium extract and the other containing MAA were prepared to be tested on hairless mice and human skin. In this clinical study, the sun protection factor (SPF) and Protection factor of UV A (PFA) values of the sunblock containing either Symbiodinium extract or MAA were determined. The SPF values of the sunblock containing Symbiodinium extract and MAA were 10.43 and 10.83, respectively, and the PFA values were 3.42 and 3.39, respectively. Based on their PFA values of ≥2, the UV A protection can be graded as PA+ (low) for both the sunblocks. In addition, the UV-blocking extract of Symbiodinium has a low phototoxicity and cytotoxicity, reducing the possibility of a heavy feeling to the skin or a foreign-body sensation caused by residue build-up. The low toxicity feature of the major sunblock component will also prevent side effects, such as allergic reactions. Although Symbiodinium extract or MAA alone do not provide effectiveprotection against UV irradiation, their protection capacity can be complemented by the addition of inorganic UV-protecting compounds.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.1
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• pp.8-12
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• 2015

Non-esterified bio-diesel fuel saves cost by no esterified process and its performance was more similar to diesel oil than esterified bio-diesel fuel when the fuel blended 95% diesel oil and 5% it was used on diesel engine with electronic control system. A performance optimization is necessary for application of non-esterified bio-diesel fuel blended with diesel oil 95% on the latest diesel engine. In this study, test using fractional factorial design was accomplished at 25% and 50% partial load in order to evaluate influence of controllable 6 factors on responses such as specific fuel consumption, nitrogen oxides and coefficiency of variation of indicated mean effective pressure as basic experiment for performance optimization of this fuel. It is cleared that the injection timing and common rail pressure of 6 factors are mainly effective and its effect level is different according to load.

• Ocean and Polar Research
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• v.38 no.2
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• pp.139-148
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• 2016

The activity concentrations of $^{210}Po$ and $^{210}Pb$ within phytoplankton-zooplankton-anchovy-mackerel in the coastal water of the Jeju Island were determined to understand their distribution and bio-accumulation along the trophic level. In the surface water, the total activity concentrations of $^{210}Po$ and $^{210}Pb$ were $0.83{\pm}0.004mBq\;kg^{-1}$ and $1.27{\pm}0.03mBq\;kg^{-1}$. And the dissolved activity concentration of $^{210}Po$ and $^{210}Pb$ were $0.75{\pm}0.06mBq\;kg^{-1}$ and $1.22{\pm}0.09mBq\;kg^{-1}$ respectively. In the phytoplankton, the concentration factor (CF) of $^{210}Po$ and $^{210}Pb$ were $1.5{\times}10^5$ and $2.6{\times}10^4$ shows $^{210}Po$ is 5 times higher compared to $^{210}Pb$. The similar CF factor in the zooplankton of $^{210}Po$ was derived as $1.4{\times}10^5$. The CF of $^{210}Po$ in anchovy was increased twice compared to that in plankton. This is the evidence that there is $^{210}Po$ bio-magnification in the trophic level of plankton-anchovy. However the $^{210}Po$ activity concentration in the muscle tissue of mackerel was one-hundred times lower than that in anchovy. This reflects that in the trophic level of anchovy-mackerel, the bio-accumulation of $^{210}Po$ is decreased. The activity concentrations of $^{210}Po$ in the internal organs of anchovy and mackerel were 8 to 38 times higher than those in muscle tissues. In phytoplankton-zooplankton-anchovy, the CF of $^{210}Pb$ was decreased five times along the trophic level in order. In anchovy-mackerel it was decreased by 30-70%.

• Journal of Microbiology and Biotechnology
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• v.32 no.2
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• pp.256-262
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• 2022

Panax ginseng C. A. Meyer is well known as traditional herbal medicine, and ginseng berries are known to exhibit potential immune-enhancing functions. However, little is known about the in vivo immunomodulatory activity of Korean ginseng berries. In this study, crude Korean ginseng berries polysaccharides (GBP) were isolated and their immunomodulatory activities were investigated using cyclophosphamide (CY)-induced immunosuppressive BALB/c mice. In CY-treated mice, oral administration of GBP (50-500 mg/kg BW) remarkably increased their spleen sizes and spleen indices and activated NK cell activities. GBP also resulted in the proliferation of splenic lymphocytes (coordinating with ConA: plant mitogen which is known to stimulate T-cell or LPS: endotoxin which binds receptor complex in B cells to promote the secretion of pro-inflammatory cytokines) in a dose-dependent manner. In addition, GBP significantly stimulated mRNA expression levels of immune-associated genes including interleukin-1β (IL-1β), IL-2, IL-4, IL-6, tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), toll-like receptor 4 (TLR-4), and cyclooxygenase-2 (COX-2) in CY-treated mice. These results indicate that GBP is involved in immune effects against CY-induced immunosuppression. Thus, GBP could be developed as an immunomodulation agent for medicinal or functional food application.

• Journal of Microbiology and Biotechnology
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• v.33 no.6
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• pp.840-847
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• 2023

Korean ginseng (Panax ginseng C. A. Meyer), a member of the Araliaceae family, is known as a traditional medicinal plant to have a wide range of health properties. Polysaccharides constitute a major component of Korean ginseng, and its berries exhibit immune-modulating properties. The purpose of this study was to investigate the immune effects of crude polysaccharide (GBPC) extracted from Korean ginseng berry on peritoneal macrophages in mice with cyclophosphamide (CY)- induced immunosuppression. BALB/c mice were divided into eight groups: normal control, normal control + CY, levamisole + CY, ginseng + CY, and four concentrations of 50, 100, 250, and 500 mg/kg BW/day of GBPC + CY. Mice were orally administered with samples for 10 days. Immunosuppression was established by treating mice with CY (80 mg/kg BW/day) through intraperitoneal injection on days 4 to 6. The immune function of peritoneal macrophages was then evaluated. Oral administration of 500 mg/kg BW/day GBPC resulted in proliferation, NO production, and phagocytosis at 100%, 88%, and 91%, respectively, close to the levels of the normal group (100%) of peritoneal macrophages. In CY-treated mice, GBPC of 50-500 mg/kg BW/day also dose-dependently stimulated the proliferation, NO production, and phagocytosis at 56-100%, 47-88%, and 53-91%, respectively, with expression levels of immune-associated genes, such as iNOS, COX-2, IL-1β, IL-6, and TNF-α, of about 0.32 to 2.87-fold, compared to those in the CY group. GBPC could be a potential immunomodulatory material to control peritoneal macrophages under an immunosuppressive condition.

• ALGAE
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• v.38 no.4
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• pp.295-306
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• 2023

Human coronavirus diseases, particularly severe acute respiratory syndrome coronavirus 2, still remain a persistent public health issue, and many recent studies are focusing on the quest for new leads against coronaviruses. To contribute to this growing pool of knowledge and explore the available marine natural products against coronaviruses, this study investigated the antiviral effects of fucoxanthin isolated from Sargassum siliquastrum-a brown alga found on Jeju Island, South Korea. The antiviral effects of fucoxanthin were confirmed in severe acute respiratory syndrome coronavirus 2-infected Vero cells, and its structural characteristics were verified in silico using molecular docking and molecular dynamic simulations and in vitro colorimetric method. Fucoxanthin inhibited the infection in a concentration-dependent manner, without showing cytotoxicity. Molecular docking simulations revealed that fucoxanthin binds to the angiotensinconverting enzyme 2-spike protein (binding energy -318.306 kcal mol^-1) and main protease (binding energy -205.118 kcal mol^-1). Moreover, molecular dynamic simulations showed that fucoxanthin remains docked to angiotensin-converting enzyme 2-spike protein for 20 ns, whereas it breaks away from main protease after 3 ns. Also, the in silico prediction of the fucoxanthin was verified through the in vitro colorimetric method by inhibiting the binding between angiotensinconverting enzyme 2 and spike protein in a concentration-dependent manner. These results indicate that fucoxanthin exhibits antiviral effects against severe acute respiratory syndrome coronavirus 2 by blocking the entry of the virus. Therefore, fucoxanthin from S. siliquastrum can be a potential candidate for treating coronavirus infection.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.2
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• pp.252-258
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• 2009

Engine bench tests has been done on a common-rail diesel engine with bio-diesel fuel to study effects of B100 and B20 on output power, fuel consumption and emissions. Test results show that B100 and B20 could reduce PM, HC, CO emission and smoke, but power decrease, fuel consumption increase and NOx increase obviously, B100 reduce PM and DS with $50%{\sim}70%$ and $80%{\sim}85%$ compared with diesel fuel, while B20 reduce PM and DS with $25%{\sim}35%$ and $30%{\sim}40%$. NOx of B100 and B20 increase $5%{\sim}20%$ compare to diesel.

• Korean Journal of Environmental Agriculture
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• v.35 no.2
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• pp.137-142
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• 2016

BACKGROUND: Identification of endophytic yeasts inhabiting the internal roots of the Mankyua chejuense tree requires techniques involving biotechnology. There is a need for a culture-based method to isolate and identify yeast strains associated with M. chejuense.METHODS AND RESULTS: We spread homogenized M. chejuense root samples onto glucose-peptone- yeast agar containing antibiotics, Triton X-100, and L-sorbose. A total of 152 yeast isolates were obtained and identified via phylogenetic analysis based on ITS gene sequencing. The results revealed that the root-associated yeast species included the genera Cyberlindnera (140 isolates), Candida (11 isolates), and Kluyveromyces (one isolate). Additionally, three yeast isolates showed high bioethanol production.CONCLUSION: We identified the specific yeast community associated with M. chejuense roots. These yeast isolates may have industrial applications as bioethanol producers. Our findings revealed that Cyberlindnera isolates included C. suaverolens and C. satumus, while Kluyveromyces isolates showed high bioethanol production.