• ALGAE
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• 제38권4호
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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.

• 한국해양바이오학회지
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• 제12권1호
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• pp.40-49
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• 2020

This article emphasized the physiological characteristics of the selected marine microalgal strains obtained from the culture collection of the National Marine Biodiversity Institute of Korea (MABIK). Therefore, in this study, 13 different marine microalgal strains belonging to the phylum Chlorophyta were analyzed for the composition of fatty acids, elements, photosynthetic pigments, and monosaccharides, as well as the lipid and protein contents. The results presented that the primary fatty acids were palmitic (C_16:0), palmitoleic (C_16:1 n-7), stearic (C_18:0), oleic (C_18:1 n-9), linoleic (C_18:2 n-6), and α-linolenic (ALA, C_18:3 n-3) acid in the evaluated microalgae. The lipid contents of heterotrophically grown strains ranged from 15.1% to 20.4%. The calorific values of the strains were between 17.4 MJ kg^-1 and 21.3 MJ kg^-1. The major monosaccharides were galactose, glucose, and mannose, while the primary photosynthetic pigments were chlorophyll-a (Chla), chlorophyll-b (Chlb), and lutein, respectively. Based on the results, the microalgal strains showed high potentials in the use of microalgae-based technologies to produce biochemicals, food, and renewable fuels as they are rich in sustainable sources of high-value bio-compounds, such as antioxidants, carbohydrates, and fatty acids.

• 해양환경안전학회지
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• 제21권1호
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• pp.103-108
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• 2015

최근 지구 온난화는 세계 경제발전으로 화석연료 사용이 주범으로 인식하고 있다. 이러한 화석연료를 감소하기 위한 연구는 여러 대체에너지 산업으로 발전하고 있으며, 그 중 우리나라에서 생산할 수 있는 연료는 바이오연료이다. 바이오연료는 화석연료에 의해서 발생하는 환경오염 문제를 줄이면서 경제적인 이익을 주는 지속 가능한 연료이다. 그래서 바이오연료를 친환경에너지로 전환시키는 재생에너지 등에 많은 연구가 진행되고 있다. 따라서 본 실험은 어선에서 사용했던 기관을 다시 리모델링하여 실험장치를 직접 제작 설치하였고, 여러 바이오연료를 사용하여 선박의 경제적이고 친환경적인 운항에 도움을 주고자 연구하였다. 유채유, 대두유, 폐유채유의 배기배출 물특성에 미치는 영향을 종합적으로 분석한 결과는 연료의 물리적, 화학적 성분이 비슷하여 선박용 엔진에 사용이 가능하고, 연료소비율과 NOx는 약간 증가하였으나, 매연은 많이 감소하는 경향이 확인되었다.

• 한국태양에너지학회 논문집
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• 제36권1호
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• pp.19-26
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• 2016

Biomass has been used for energy sources from the prehistoric age. Biomass are converted into solid, liquid or gaseous fuels and are used for heating, electricity generation or for transportation recently. Solid biofuels such as bio-chips or bio-pellet are used for heating or electricity generation. Liquid biofuels such as biodiesel and bioethanol from sugars or lignocellulosics are well known renewable transportation fuels. biogas produced from organic waste are also used for heating, generation and vehicles. Biomass resources for the production of above mentioned biofuels are classified under following 4 categories, such as forest biomass, agricultural residue biomass, livestock manure and municipal organic wastes. The energy potential of those biomass resources existing in Korea are estimated. The energy potential for dry biomass (forest, agricultural, municipal waste) were estimated from their heating value contained, whereas energy potential of wet biomass (livestock manure, food waste, waste sludge) is calculated from the biological methane potential of them on annual basis. Biomass resources potential of those 4 categories in Korea are estimated to be as follows. Forest biomass 355.602 million TOE, agricultural biomass 4.019 million TOE, livestock manure biomass 1.455 million TOE, and municipal organic waste 1.074 million TOE are available for biofuels production annually.

• 한국해양환경ㆍ에너지학회지
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• 제10권2호
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• pp.112-117
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• 2007

본 연구는 수산 폐기물, 폐어망 등 해양 유기성 폐기물을 유류와 같은 대체 에너지 자원으로 개발하기 위한 기초 연구로 수행되었다. 현재까지 폐플라스틱이나 폐타이어와 같은 석유공업을 기반으로 한 유기성 폐기물을 유류자원화 하여 대체연료로 사용하는 연구가 활발하고 상용화된 사례들은 많다. 그러나 주위에 쉽게 버려지는 음식물 쓰레기, 유기성 폐기물을 이용해 대체자원을 개발하는 연구는 미미한 실정이다. 따라서 본 연구에서는 동물성 유기 폐기물을 사용하여 고온고압 하에서 열분해를 이용해 오일을 얻었고, 오일의 성분과 특성을 조사하여 대체자원으로의 가능성을 평가하였다. $250^{\circ}C$, 40 atm에서 열분해한 바이오오일은 점도가 높아 불순물을 제거에 어려움이 있었고, 발열량이 중유(重油)보다 다소 낮았으며, 연료로 사용하기에는 부적합한 다양한 종류의 가스 생성물을 얻었다. 하지만 기존의 열분해 방법들이 $500^{\circ}C$ 이상의 고온에서 반응시키는 것과 달리 대상물질 자체의 수분을 이용해 증기압으로 가압하기 때문에 $250{\pm}5^{\circ}C$의 낮은 온도에서도 열분해 할 수 있었다. 그러나 바이오오일의 점도가 높아 액상연료로 사용하기에는 미흡하였다.

• 해양환경안전학회지
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• 제8권2호
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• pp.53-60
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• 2002

Marine biotechnology is one of the promising frontier of scientific exploration and commercial utilization for the next century. Compared with the terrestrial environment, the oceans of the world remain largely unexplored and include a major portion of bio-resources. Using the tools of biotechnology, the vast and diverse marine resources can be applied to produce new products and foods. Marine biotechnology has the characteristics of pro-environment, saying energy, and intensive knowledge. Therefore, we can take advantage of the marine biotechnology industry under our situation with the poor natural resources. The study focuses on the current status and administrative supports on marine biotechnology industry for upgrading the economic value of output. The status of our marine biotechnology industry is beginning stage in the economic aspects. Manpower and the level of most technologies are weaker than the ones of the advanced countries. More investment and recruiting skilled specialists are necessary because the improvement of marine biotechnology is depend on the technology and scientists. This study suggests the ways of administrative supports for domestic marine biotechnology: Efficient information network and supporting system for the development of marine biotechnology should be interrelated with other technical and scientific fields; The government should provide sustainable fund for the long-term research project and the infrastructure in the marine biotechnology.

• 한국수산과학회지
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• 제56권5호
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• pp.660-666
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• 2023

This study aimed to examine the effect of external pop-up satellite archival tags (PSATs) attachment and water temperature on the oxygen consumption rate (OCR) of the olive flounder (mean body weight 2281.7 g). The OCRs of fish were measured under conditions of three different water temperature conditions (15, 20, and 25℃) and two different tagging methods [non-tagging, control; bio-logger external attachment with a miniature PSAT (dummy mrPAT), BEA] using a closed flow-through respirometer. The OCRs of fish linearly increased with the increase in water temperature in both the control and BEA (P<0.001); however, the OCRs of BEA were approximately 1.8-1.9 times lower than those of the control at each water temperature (P<0.001). The Q₁₀ values of the control and BEA were the highest in the water temperature range of 15 to 20℃, but sensitivity to water temperature changes was higher in BEA than in the control. The metabolic energy loss rate (MEL) of fish increased with increasing water temperature regardless of external tagging, but the MEL of the control was higher than that of BEA (P<0.001). These results demonstrate that OCR, thermal sensitivity, and energy expenditure are all affected in adult olive flounder with external PSAT attachment.

• Fisheries and Aquatic Sciences
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• 제19권5호
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• pp.24.1-24.6
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• 2016

We determined the optimum dietary protein level in juvenile barred knifejaw Oplegnathus fasciatus in cages. Five semi-purified isocaloric diets were formulated with white fish meal and casein-based diets to contain 35, 40, 45, 50, and 60 % crude protein (CP). Fish with an initial body weight of $7.1{\pm}0.06g$ ($mean{\pm}SD$) were randomly distributed into 15 net cages (each size: $60cm{\times}40cm{\times}90cm$, $W{\times}L{\times}H$) as groups of 20 fish in triplicates. The fish were fed at apparent satiation level twice a day. After 8 weeks of feeding, the weight gain (WG) of fish fed 45, 50, and 60 % CP diets were significantly higher than those of fish fed 35 and 40 % CP diets. However, there were no significant differences in WG among fish fed 45, 50, and 60 % CP diets. Generally, feed efficiency (FE) and specific growth rate (SGR) showed a similar trend as WG. However, the protein efficiency ratio (PER) was inversely related to dietary protein levels. Energy retention efficiency increased with the increase of dietary protein levels by protein sparing from non-protein energy sources. Blood hematocrit content was not affected by dietary protein levels. However, a significantly lower amount of hemoglobin was found in fish fed 35 % CP than in fish fed 40, 45, 50, and 60 % CP diets. Fish fed 60 % CP showed the lowest survival rate than the fish fed 35, 40, 45, and 50 % CP diets. Broken-line analysis of WG showed the optimum dietary protein level was 45.2 % with 18.8 kJ/g diet for juvenile barred knifejaw. This study has potential implication for the successful cage culture of barred knifejaw.

• Journal of Advanced Marine Engineering and Technology
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• 제39권4호
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• pp.381-386
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• 2015

최근에 환경오염 문제와 대체에너지 문제에 많은 관심을 가지고 있다. 디젤기관은 세계적으로 연료의 경제성 때문에 사용이 증가할 것이다. 그러므로 선박용기관의 대기오염 문제도 여러 분야에서 큰 관심사가 되고 있다. 화석연료로 부터 배출되는 유해 배기가스를 줄이기 위하여 대체연료기술이 개발되고 있다. 이러한 신재생에너지의 바이오디젤연료는 기존 디젤연료를 대체할 친환경 에너지로 각광을 받고 있으며, 일정한 비율로 디젤연료와 혼합하면 기존 디젤기관에 개조 없이 사용가능하다. 본 연구에서 바이오디젤연료가 선박디젤기관의 연소특성에 미치는 영향을 분석하기 위하여 폐식용유로부터 제조된 바이오디젤유를 엔진에 적용하여 실험을 수행하였다. 폐식용 성분에는 세탄가와 점도가 높은 성분이 있고, 탄소함유량이 적으면서 산소함유량이 잔존하고 있다. 연구 결과 연료소비율은 증가하고, 압력, 압력상승율 및 열발생율은 감소하였다.

• 한국해양환경ㆍ에너지학회지
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• 제14권1호
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• pp.1-10
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• 2011

전남 서해 갯벌 연안경계부 수질특성을 파악하기 위하여 5개 해역(무안만, 탄도만, 함평만, 신안지도 및 영광해역)을 대상으로 2008년에서 2009년까지 2년 동안 한 달에 두 번씩 현장조사를 실시하였다. 수온은 $1.3{\sim}31.1^{\circ}C$로 연교차가 컸다. 염분은 비교적 32 내외로 균일하였으나 강우가 집중되는 시기에 염분 함량이 20 이하로 저염화가 나타났으며, 수온 변화에 따라 용존산소는 하계에 낮고 동계에 높았다. 수소이온농도는 용존산소와 비슷한 분포경향을 보였다. 부유물질의 경우 영광해역에서 100 mg/l 이상으로 높은 함량을 보였다. 화학적 산소요구량은 1 mg/l 내외로 큰 변화가 없었으며, 용존무기질소와 용존무기인은 담수유입이 증가하는 시기에 높은 함량을 보였다. 용존무기질소는 겨울과 초봄에 낮은 반면에 용존 무기인은 월별 변화 없이 균일한 분포를 보이다가 2009년 7월 이후 다소 증가하는 경향을 보였다. 엽록소a는 봄철에 $10\;{\mu}g/l$내외로 나타났으며 이후 대부분 비슷한 분포 경향을 보이나 특히 타 해역에 비하여 여름철에 영광해역에서 높게 나타났다. 해역별 수질특성을 비교하기 위하여 실시한 주성분분석 결과는 다음과 같이 뚜렷한 특징을 보였다. 무안만과 탄도만에서 제 1 주성분 요인은 담수유입 변동이었으며, 신안지도 해역과 영광해역에서는 수온의 변화로 나타났다. 함평만에서는 담수유입 변동과 수온변화의 영향이 제 1 주성분 요인으로 복합되어 나타났다.