• ALGAE
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• 제25권2호
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• pp.99-104
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• 2010

A psychrotolerant cyanobacterium, Nodularia spumigena KNUA005, was isolated from a cyanobacterial bloom sample collected near Dasan Station in Ny-${\AA}lesund$, Svalbard Islands during the Arctic summer season. To generate an axenic culture, the isolate was subjected to three purification steps: centrifugation, antibiotic treatment and streaking. The broad antibacterial spectrum of imipenem killed a wide range of heterotrophic bacteria, while the cyanobacterium was capable of enduring both antibiotics, the remaining contaminants that survived after treatment with imipenem were eliminated by the application of an aminoglycoside antibiotic, kanamycin. Physical separation by centrifugation and streaking techniques also aided axenic culture production. According to the cold-tolerance test, this mat-forming cyanobacterium was able to proliferate at low temperatures ranging between 15 and $20^{\circ}C$ which indicates the presence of cold-tolerance related genes in N. spumigena KNUA005. This suggests the possibility of incorporating cold-resistance genes into indigenous cyanobacterial strains for the consistent production of algae-based biofuel during the low-temperature seasons. Therefore, it is needed to determine the cold-tolerance mechanisms in the Arctic cyanobacterium in the next research stage.

• 수산해양기술연구
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• 제59권2호
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• pp.155-163
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• 2023

This study deals with the maximum thermal load analysis and optimal capacity determination method of tank culture system for applying seawater source heat pump to save energy and realize zero energy. The location of the fish farm was divided into four sea areas, and the heat load in summer and winter was analyzed, respectively. In addition, two representative methods, the flow-through aquaculture system and the recirculation aquaculture system were reviewed as water treatment methods for fish farms. In addition, the concept of the exchange rate was introduced to obtain the maximum heat load of the fish farms. Finally, power consumption for heat pumps was analyzed in the view point of sea areas, tank capacity, and exchange rate based on the calculated maximum thermal load.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2002년도 춘계 수산관련학회 공둥학술발표회
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• pp.203-204
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• 2002

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 1997년도 수산관련공동학술대회발표요지집
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• pp.359-359
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• 1997

• 환경생물
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• 제33권2호
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• pp.215-222
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• 2015

During our investigation of ciliates from Korea, four ciliates were isolated from the non-flood Petri dish culture of soil. They were cultured under laboratory condition and studied using standard methods morphologically, including living observations, protargol impregnations, and morphometrics. The four species are Metopus hasei Sondheim, 1929, Urosomoida agiliformis Foissner, 1982, Oxytricha proximata Shibuya, 1930, and Cladotricha sp. in Nie${\ss}$en (1984) respectively.

• Journal of Microbiology
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• 제41권3호
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• pp.183-188
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• 2003

We isolated and cultured bacteria that inhabited marine biofilms, and identified them by phylogenetic analysis using 16S rDNA sequences. In the marine environment, biofilms cover most subtidal and intertidal solid surfaces such as rocks, ships, loops, marine animals, and algae. The bacteria in most biofilms are embedded in extracellular polymeric substances that comprise mainly of exopolysaccharides. The exopolysaccharides are excreted from multiple bacterial species; therefore, biofilms are a good source for screening exopolysaccharide-producing bacteria. Thirty-one strains were cultured, and a total of 17 unique strains were identified. Phylogenetic analysis using 16S rDNA sequences indicated that the 17 strains belonged to ${\alpha}$-Proteobacteria (Ochrobactrum anthropi, Paracoccus carotinifaciens); ${\gamma}$-Proteobacteria (Pseudoalteromonas agarovorans, P. piscicida, Pseudomonas aeruginosa, Shewanella baltica, Vibrio parahaemolyticus, V. pomeroyi); CFB group bacteria (Cytophaga latercula, Tenacibaculum mesophilum); high GC, Gram-positive bacteria (Arthrobacter nicotianae, Brevibacterium casei, B. epidermidis, Tsukamurella inchonensis); and low GC, Gram-positive bacteria (Bacillus macroides, Staphylococcus haemolyticus, S. warneri).

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.481-484
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• 2006

This research compares oyster farming in Gamak Bay which Hiroshima Bay which has nearly similar marine environments. The marine environment of these two waters has similar variations of air temperature, sea surface temperature, precipitation and salinity. However Hiroshima Bay is higher than Gamak Bay in the sea surface temperature and Hiroshima Bay is also higher than Gamak Bay in the salinity. Their oyster farming method is basically similar but it is different in their facilities. We need to take some measures against high mortalities, and in addition, to enhance the rate of seed collection.

• Archives of Pharmacal Research
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• 제29권8호
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• pp.624-626
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• 2006

Four known butenolides were isolated from the ethyl acetate extracts of the culture broth of the marine-derived bacterium, Streptoverticillium luteoverticillatum, by bioassay-guided fractionation. The structures were identified on the basis of spectral data. The absolute configuration of compound (1) was determined by CD spectrum for the first time. Compounds 1-4 showed in vitro cytotoxicity against the murine lymphoma P388 and human leukemia K562 cell lines. This is the first report on the isolation of butenolides from the marine bacterium, Streptoverticillium luteoverticillatum, and their cytotoxic activities.

• Ocean and Polar Research
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• 제37권1호
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• pp.61-71
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• 2015

Eicosapentaenoic acid (EPA) produced from marine organisms is widely used in nutraceuticals. Monodus subterraneus and Nannochloropsis oceanica, which are representative freshwater and marine Eustigmatophyceae, respectively, are known to have a high content of protein and lipid, particularly, EPA. In this study, to compare the growth and nutritional composition of M. subterraneus and N. oceanica, they were cultured in autotrophic and mixotrophic conditions with JM and f/2 medium, respectively, at $25^{\circ}C$. In addition, $80{\mu}mol\;photons\;m^{-2}s^{-1}$ with 24-hour and 12-hour light was provided, with the addition of 2% glucose to the medium for the mixotrophic culture. With regard to growth, M. subterraneus showed 10 times higher biomass in a mixotrophic culture than in an autotrophic one. However, no significant difference was observed for N. oceanica between the two culture methods. With respect to nutritional composition, M. subterraneus cultured autotrophically had a higher protein and lipid content, particularly EPA, than that cultured mixotrophically, but no significant difference was found in the two cultures of N. oceanica. Furthermore, M. subterraneus cultured autotrophically with continuous light showed higher nutritional composition, particularly EPA, than N. oceanica. In conclusion, the mass culture of freshwater M. subterraneus is much easier and more economical than marine N. oceanica. In addition, production of EPA will be economically improved if mixotrophic culturing of M. subterraneus is first conducted to maximize the biomass, and then secondary autotrophic culturing is performed.

• 한국패류학회지
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• 제29권4호
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• pp.273-281
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• 2013

갯벌양식 굴의 생산성을 향상시키고자 2011년 9월부터 12월까지 어장환경이 서로 상이한 해면 가두리 중간육성장에서 성장과 폐사를 비교하고 2012년 1월 갯벌 수평망식 본양성장에 이식하여 7월까지 조간대 노출시간 별 갯벌양식 굴의 순응 결과를 조사하였다. 해면 가두리 중간육성장의 경우 각 양식장간에 수온과 영양 염류를 제외한 환경요소가 뚜렷한 차이가 없음에도 불구하고 참굴의 성장에 차이가 있었다. 해면 가두리 중간육성장의 수온은 원산도리에서 가장 높게 나타났고 염분은 세 지역 모두 안정적인 변화 양상을 보였으며 Chlorophyll-a 농도는 수온과 비례하는 경향을 보였다. 갯벌지역의 수온은 해면지역에 비해 변화 폭이 큰 것으로 나타났다. 해면 가두리 중간육성장 갯벌 양식 굴의 성장은 원산도리, 창리, 파도리 순으로 나타났으며 시간이 지남에 따라 성장이 감소하였다. 갯벌 수평망식 본양성장 갯벌양식 굴의 성장은 3시간, 1시간, 5시간 대기노출 순으로 나타났으며, 수온과 밀접한 관계가 있었다. 수온이 $5^{\circ}C$ 이하로 내려간 1월에는 성장이 크게 낮아졌으나 폐사율의 뚜렷한 경향은 보이지 않았고, 수온이 올라가는 3월부터 성장률이 증가하였으나 월평균 수온의 변동폭이 높았던 4-6월에 폐사율이 급증하였다. 한편, 해면 가두리 중간육성장에서 수용한 참굴은 각장 대비 각고가 길게 성장하는 경향을 보였으나 다시 갯벌 수평망식 본양성장에 이식 후 수용하면서 각고 대비 각장이 크게 성장하였다.