• KSBB Journal
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• 제25권3호
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• pp.223-229
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• 2010

Fucoidans, polysaccharides that are composed of fucose, uronic acids, galactose and xylose, are one of the main constituents of brown seaweeds. For the past decade algal fucoidans have been extensively studied due to their biological activities including anticoagulant, antiinflammatory, antitumor, contraceptive and antiviral activities. Even though fucoidan is known as a highly functionality derivative, its industrial applications have been limited because of low inclusion efficiency and high cost of manufacturing. Furthermore the sea-weed smell of fucoidan has been a limiting factor for the application especially in food and cosmetic area. The potential application of various extraction technology and deodorization of sea-weed smell is highly required for a wider application of fucoidan. As an alternative extraction process, enzymatic hydrolysis process or ultra-high pressure treatment has been investigated for the improvement of production yield and bioefficacy of fucoidan. More intensive research on the fucoidan production technology and its application in nutraceutical and cosmoceutical area is needed.

• ALGAE
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• 제27권4호
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• pp.269-281
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• 2012

Marado is a small rocky island located off the south coast of Jeju Island and acts as the first gateway of the Kuroshio Current to Korean coastal ecosystems. This island is one of the most unpolluted and well preserved sea areas around the Jeju coast. We extensively observed macroalgal assemblages of species and functional forms in the intertidal and subtidal zones through four seasons on Marado, Jeju Island, Korea to demonstrate the seasonality of vertical distribution patterns and biomass. A total of 144 species (14 Chlorophyta, 40 Phaeophyta, and 90 Rhodophyta) were identified in quadrats and were analyzed seasonally and vertically to define the variation patterns. The annual mean biomass of macroalgae was $2,932.3g\;wet\;wt\;m^{-2}$ and the highest value was recorded in spring and the lowest was in winter. The annual dominant species by biomass was Ecklonia cava followed by Sargassum fusiforme, S. macrocarpum, Amphiroa galapagensis, Chondria crassicaulis, and S. thunbergii. Obvious biomass zonation patterns of macroalgal species were detected in relation to tidal height and depth. Macroalgal biomass, diversity index (H'), and community dynamics were the highest in the shallow subtidal zone. Species number was higher in the subtidal than in the intertidal zone and similar throughout the entire subtidal zone. Our results provide revealing insights into the distribution patterns of macroalgal assemblages in an unpolluted sea area around Jeju Island.

• ALGAE
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• 제32권3호
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• pp.223-233
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• 2017

Kelp forests and the many vital ecosystem services they provide are threatened as the severity of climate change and other anthropogenic stressors continues to mount. Particularly in the North Pacific, sea surface temperature is warming and glacial melt is decreasing salinity. This study explored the resiliency of early life-history stages of these foundation species through a factorial laboratory experiment. The effects of rising sea surface temperature under low salinity conditions on kelp spore settlement and initial gametophyte growth in Eualaria fistulosa, Nereocystis luetkeana, and Saccharina latissima were investigated. Decreased settlement and growth were observed in these species at elevated temperatures and at low salinity. Eualaria fistulosa spores and gametophytes were the most negatively impacted, compared to the more widely distributed N. luetkeana and S. latissima. These results suggest that N. luetkeana and S. latissima could potentially outperform E. fistulosa under projected conditions. However, despite decreased performance among all species, our findings indicate that these species are largely resilient to temperature changes when exposed to a low salinity, even when the temperature changes are immediate and extreme. By exploring how early life-history stages of several key kelp species are impacted by dual stressors, this research enhances our understanding of how kelp forests will respond to projected and extreme changes in temperature when already stressed by low salinity.

• ALGAE
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• 제23권4호
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• pp.251-255
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• 2008

In Gamak Bay, Paralytic Shellfish Poisoning (PSP) was first detected from seafoods in 2003, however the toxin source is unknown yet. In this study, we report potential PSP producers of toxic dinoflagellates, describing morphology and abundance of cysts isolated from surface sediment of Gamak Bay. The most abundant type in these cysts was characterized with ellipsoidal and transparent wall identical to Alexandrium catenella and/or A. tamarense. Germination experiment of the cysts revealed that all motile cells germinated were morphologically identified as A. tamarense. This result suggests that A. tamarense may relate to PSP contaminations in Gamak Bay. Moreover, bottom water temperature in Gamak Bay is favorable for germination of A. tamarense cysts. Further studies are required to carry out the PSP monitoring for preventing the risk of PSP events that may outbreak in future at Gamak Bay.

• 한국수산과학회지
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• 제42권6호
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• pp.674-682
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• 2009

Recently, the occurrence of harmful algae blooms from the Chattonella group has been increasing and expanding in the southern and western seas of Korea. We investigated the relationship between growth kinetics and nutrients in the harmful algae Chattonella marina and Chattonella ovata of the South Sea, Korea. As a result; high concentrations of ammonium ($30\;{\mu}M$ and above) was not effective to the growth of C. ovata, while C. marina displayed good growth at concentration of $100\;{\mu}M$. The half-saturation constant ($K_s$) of C. marina for ammonium ($2.51\;{\mu}M$), nitrate ($5.36\;{\mu}M$) and phosphate ($0.75\;{\mu}M$) was higher than C. ovata (1.85, 4.01, and $0.61\;{\mu}M$, respectively). This indicates that C. ovata can achieve higher cell densities than C. marina under lower nutrient conditions. These $K_s$ values were comparatively higher than those of diatoms and other flagellates previously reported. Therefore, our results indicate that the growth of C. marina and C. ovata is less adapted to lower nutrient environments than other competition species, such as Skeletonema costatum and Cochlodinium polykrikoides.

• 한국수산과학회지
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• 제39권6호
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• pp.487-494
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• 2006

The effects of water temperature, salinity and irradiance on the growth of harmful algae Chattonella marina isolated from Gamak Bay in South Sea, Korea were investigated. C. marina was able to grow in temperatures of $15-30^{\circ}C$ and salinities of 10-35 psu. Maximum specific growth rate (0.64/day) was observed with combination of $25^{\circ}C$ and 25 psu. Optimal growth (${\ge}70%$ of maximum specific growth rate) was obtained with all salinities of the above $20^{\circ}C$. This result indicated that C. marina is a stenothermal of the high water temperature and euryhaline organism. C. marina was did not grow at irradiance ${\le} 10{\mu}mol$ photons/($m^2\;s$). Photoinhibition did not occur at $300{\mu}mol$ photons/($m^2\;s$), which was the maximum irradiance used in this study. The irradiance-growth curve was described as ${\mu}=0.78(I-11.4)/(I+34.1)$ at $25^{\circ}C$ and 25 psu. The half-saturation photon flux density (PFD) ($K_s$) was $56.9{\mu}mol$ photons/($m^2\;s$) and compensation PFD ($I_c$) was $11.4{\mu}mol$ photons/($m^2\;s$). The result of the present study indicate that C. marina has advantage physiological characteristic to the interspecific competition at the embayment and costal areas of South and West Sea, Korea in summer.

• 한국해양환경ㆍ에너지학회지
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• 제15권1호
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• pp.1-8
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• 2012

전남 거문도 바다숲 조성용 시설물의 효율적인 배치를 위하여 수치실험을 통하여 바다숲 조성해역의 조석류에 의한 해수유동을 분석하였으며, 분석된 해수유동을 바탕으로 하여 바다숲 조성해역 인근에 위치한 자연적인 해중림에서 발생한 해조류 포자의 거동을 파악하기 위하여 입자추적실험 및 부유사 농도변화 실험을 수행하였다. 수치실험에 사용된 수치모형은 EFDC(Environmental Fluid Dynamics Code)를 사용하였으며, 연직방향으로 총 10개층으로 나누어 실험을 수행하였다. 실험결과, 바다숲 조성해역의 해수유동패턴은 대상해역 바깥쪽의 주류에 비해 방파제의 역할을 하는 밖노루섬으로 인해 흐름이 약하고, 잔차류를 분석한 결과 주로 북서방향의 흐름이 형성되나 크기는 미약하였다. 인근에 위치한 자연 해중림은 크게 2곳으로, 이들 해역에 투하한 해조류 포자는 투하한 후 30시간이 경과하면 대부분 해저면에 안착하였다. 포자는 대상 해역의 미약한 흐름에 의해 발생지역에 대부분 안착하였다. 바람조건을 적용한 경우에는 적용하지 않은 경우에 비해 포자가 남동쪽으로 좀 더 이동하여 안착하나 그 차이는 미미하였다. 부유사 실험결과 부유사 농도는 조시별로 흐름에 따라 농도가 변화하며 표층보다 저층에서 높게 나타났다. 이러한 결과를 토대로 바다숲 조성용 시설물을 효율적으로 배치할 수 있을 것으로 사료된다.

• 한국수산과학회지
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• 제32권4호
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• pp.427-431
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• 1999

해조자원의 기능 특성을 밝혀 그 이용도를 증진시키기 위한 연구의 일환으로 일반 해조류의 단백질 함량 및 물추출물과 해조 가수분해물의 ACE 저해효과를 조사한 결과는 다음과 같다. 1 단백질 함량은 김이 $39.6\%$로 가장 높았으며, 파래 $22.1\%$, 미역 $21.1\%$, 우뭇가사리 $18.3\%$, 청각 $15.7\%$, 톳 $12.4\%$, 다시마 $8.2\%$의 순으로 나타났다. 2. 해조 물추출물의 ACE 저해효과는 $50^{\circ}C,\;70^{\circ}C,\;98^{\circ}C$의 세 조건에서 각각 추출한 결과 $70^{\circ}C$에서 추출시 시료 모두에서 가장 높게 나타났으며, ACE 저해율이 가장 높은 $70^{\circ}C$를 기준으로 비교했을 때 우뭇가사리 $10.9\%$, 김 $9.3\%$, 파래 $8.9\%$, 미역 $8.2\%$, 톳 $7.5\%$, 다시마 $7.1\%$, 청각 $7.0\%$로 나타났다. 3. maxazyme과 papain에 의한 해조 가수분해물의 ACE 저해효과는 김이 파래, 미역, 우뭇가사리에 비해 월등히 높았고 pep-tide-nitrogen함량 역시 매우 높았다. 김의 경우 가수분해 8시간에서 ACE 저해효과가 maxazyme $31.3\%$, papain $27.9\%$로 가장 높았고 peptide-nitrogen함량도 이 시간에서 가장 높게 나타났다. 파래의 ACE 저해효과 역시 8시간에서 maxazyme $9.6\%$, papain $8.5\%$로 다른 시간대에 비해 대체로 높았으며 peptide-nitrogen함량은 16시간까지 완만히 증가하였다.

• 한국식품위생안전성학회지
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• 제33권3호
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• pp.151-156
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• 2018

해양생물에는 육상생물자원에서는 존재하지 않는 다양한 화합물이 많이 존재하는데 이들 화합물은 새로운 치료제 및 대체 치료법을 개발하는데 유용하게 이용될 수 있다. 현재 해조류의 다양한 생리활성에 대한 연구가 진행되고 있으며 최근에는 여러 병원성 및 인체 감염균에 대한 항균효과를 나타내어 신약개발의 보고로 다양한 연구가 진행이 되고있다. 즉, 해조류는 천연물신약 또는 새로운 치료제 개발에 중요한 생물자원이다.

• Mycobiology
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• 제51권6호
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• pp.401-409
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• 2023

Nigrospora (Xylariales, Apiosporaceae) consists of species of terrestrial plant endophytes and pathogens. Nigrospora has also been reported in marine environments such as mangroves, sea fans, and macroalgae. However, limited research has been conducted on Nigrospora associated with macroalgae. Here, we isolated Nigrospora species from three types of algae (brown, green, and red algae) from Korean islands (Chuja, Jeju, and Ulleung) based on phylogenetic analyses of multigenetic markers: the internal transcribed spacers (ITS), beta-tubulin (BenA), and translation elongation factor 1 (TEF1-α). A total of 17 Nigrospora strains were isolated from macroalgae and identified as nine distinct species. The majority of Nigrospora species (seven) were found on brown algae, followed by red algae (three), and then green algae (two). To our understanding, this study represents the first account of N. cooperae, N. covidalis, N. guilinensis, N. lacticolonia, N. osmanthi, N. pyriformis, and N. rubi occurring in marine environments. Additionally, this study provides the first report of the occurrence of N. cooperae, N. covidalis, N. guilinensis, N. lacticolonia, and N. osmanthi in South Korea. This study will provide valuable insights for future research exploring the functions of fungi in macroalgal communities.