• ALGAE
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• 제23권4호
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• pp.269-276
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• 2008

We have conducted the study of distribution and inhabitation of the aerial algae from five stone cultural properties located in Gyeonggi-do. A total of 21 taxa were identified, among which 8 taxa of cyanophytes, 12 taxa of cholorophytes and one diatom species. Protococcus viridis, Ulothrix zonata, Synechocystis aquatilis and Chroococcus varius occurred in 15, 9, 8 and 7 study sites, respectively. These coccoid types appeared more frequently than filamentous types. In this study, Chlorococcum infusionum, Cylindrocystis gracilis, Klebsormidium crenulatum, Klebsormidium dissectum and Klebsormidium flaccidium newly recorded from Korea. We found that 80% of stone cultural properties had aerial algae and their 58-84% were grouped into Class 5 based on chlorophyll-a concentration.

• ALGAE
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• 제25권2호
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• pp.89-97
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• 2010

To test the feasibility of using chlorophyll ${\alpha}$ fluorescence to assess the establishment success of seagrass transplants, photosynthetic characteristics of eelgrass Zostera marina transplants were measured using a Diving-pulsed amplitude modulation fluorometer in Jindong Bay on the southern coast of Korea. Maximum quantum yield ($F_v/F_m$), photosynthetic efficiency ($\alpha$), saturating irradiance ($E_k$) and maximum electron transport rate ($ETR_{max}$) of transplants and reference plants in a nearby transplant site were measured using the fluorometer for 5 months. Additionally, shoot morphology, individual shoot weight and productivity of transplants and reference plants were also monitored. Shoot height, leaf weight and productivity of transplants were significantly reduced during the first two or three months after transplantation compared to those of reference plants, and then increased to the levels of reference plants Characteristics of chlorophyll a fluorescence, including $F_v/F_m$, $\alpha$, $E_k$ and $ETR_{max}$ of transplants were also significantly reduced in the initial period, but recovered slightly sooner than shoot morphology or leaf productivity. These results indicated that after transplantation, Z. marina transplant photosynthesis recovered faster than shoot morphology, biomass or productivity. Thus, chlorophyll a fluorescence can be used as an indicator for early assessment of the status of eelgrass transplants without destructive sampling.

• 한국해양환경ㆍ에너지학회지
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• 제19권2호
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• pp.87-98
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• 2016

2009년 7월 3일부터 7월 27일까지 러시아 조사선 R/V Lavrentyev를 이용하여 러시아 연안으로부터 4개의 Line(D, R, E, A)을 따라 표층 30 m 수심의 시료를 26개의 정점(울릉분지와 일본분지를 포함한 동해의 전 수역)에서 채수하여 영양염 및 엽록소-${\alpha}$의 농도를 분석하였다. 냉수역보다 난수역에서 1.4배 높은 질산염을 제외한 나머지 항목들은 모두 난수역보다 냉수역에서 높게 나타났다($NH_4$, $PO_4$ 각 1.8배, $Si(OH)_4$ 1.2배, 엽록소-${\alpha}$ 1.9배). 암모니아와 인산염, 엽록소-${\alpha}$의 수평분포는 매우 유사한 분포를 보이며, 한류와 저층수의 용승 영향권에 있는 러시아 근해에서 최대치를 보이고, 울릉분지에서 비교적 낮은 분포를 보인다. 반면, 질산염은 대마난류수의 직접적인 영향권에 있는 울릉분지에서 최대치를 보이며, 점차 북상할수록 감소한다. N/P 비는 한류수계보다 대마난류 중층수에서 가장 높은 값을 보이며, 대마난류수는 동해로 유입되는 질산염의 주요 공급원으로 작용하고 있다. 그러나 난수역에서 인산염의 평균 농도는 $0.2{\mu}M$ 이하로 식물플랑크톤 성장의 제한 요인으로 작용할 수 있는 반면, 냉수역에서의 높은 농도는 엽록소-${\alpha}$와 직접적인 상관성을 보이고 있다. 해양환경에 영향을 미치는 주요인을 분석하기 위한 주성분 분석결과 주성분 I은 수온에 의해 동해의 해양환경이 주로 영향을 받으며, 주성분 II는 영양염과 엽록소-${\alpha}$ 가 주요인으로 작용한다. 따라서 연구해역의 해양환경은 수온에 지배되며, 그에 따라 냉수역과 온수역으로 구분되는 특성을 보였다.

• 한국연초학회지
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• 제18권1호
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• pp.49-53
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• 1996

This experiment was carried out to study the effect of oxygen on chemical composition and physical properties of tobacco leaves during flue-curing. The results obtained were as follows: Starch content decreased and sucrose content increased with increasing oxygen supply during curing. Glucose and fructose of the cured leaves showed high content at the 5-10% oxygen supply. Amino-N and nitrate-N increased with increasing oxygen supply. Total nitrogen and NH4-N showed the lowest value at the 5-10% and 10-15% oxygen supply in the cutters and leaf, respectively. Chlorophyll and chlorogenic acid increased, and total volatile base decreased with increasing oxygen supply. The activity of α-amylase increased at the latter period of flue-curing, and the maximum activity point were delayed 12 hours with increasing oxygen supply. Shatter index of cured leaves decreased with increasing oxygen supply. It was desirable to supply oxygen during flue-curing for the improvement of chemical and physical properties such as starch, total sugar, chlorogenic acid, and shatter index of cured leaves.

• ALGAE
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• 제17권2호
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• pp.89-93
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• 2002

Seasonal changes of pigment compositionin two intertidal red algae, Gloiopeltis furcata (Postels et Ruprecht) J. Agardh, and Porphyra yezoensis Ueda, were investigated. Chlorophyll α and phycoerythrin levels were high during winter, but decreased in late spring or summer, with accompanying discoloration from deep red to green or yellow. This discoloation corresponded closely to the fluctuationof phycoerythrin content. Nevertheless, photosynthesis capacity was maintained by the increasing water temperature in the field, suggesting that large amounts of phycoerythrin are not necessary for photosynthesis. Phycoerythrin conten correlated significantly with nitrogen content in both species when the nitrogen level was greater than the level of critical content (1.30% DW in G. furcata, and 2.26% DW in P. yezoensis), indicating that phycoerythrin plays a more important role in the nitrogen status as a nitrogen pool than that of nitrogen critical content. Furthermore, the dependence level of the alage on phycoerythrin as a nitrogen pool was greater in P. yezoensis than in G. furcata because of the remarkable increase of phycoerythrin content in P. yezoensis with increasing jnitrogen content.

• 한국해양환경ㆍ에너지학회지
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• 제7권2호
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• pp.64-69
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• 2004

제주도 서남쪽 동중국해 해역에서 하계인 8월에 형성되는 외양 전선역의 특성을 알아보기 위해 1999년 8월 하순에 관측이 이루어 졌는데, 그 결과를 해 보면 A라인에서는 경도 124°,위도 31°30'에 위치한 정점 A5에서 표층부터 수심 50m까지의 밀도가 21.4에서 22.1의 범위로 비교적 균등한 분포를 보임으로써 중국연안쪽의 22.0과 외양역의 22.0의 값과는 구분되는 전선역이 형성된다. 또한 B라인에서는 경도 124°,위도 33°에 위치한 정점 B,6에서 A라인에서와 마찬가지로 중국연안쪽과 외양역의 밀도 20.0과 구분되는 전선역이 형성된다. 이 결과는 동중국해 해역에서 양자강 담수의 유출로 인한 외양역(에서)의 전선역이 양자강에서 정동방향으로는 동경 124°,동북쪽으로는 동경 124°30'에서 형성되고 있음을 보여주는 것이다. 전선역에서의 영양염 특성은 전선역을 중심으로 중국 연안쪽에서 높고, 외양역에서 표층과 저층간의 농도차가 뚜렷하게 나타나는 반면에 전선역에서는 상하 층이 거의 균일하며 낮은 농도 분포를 보인다. 엽록소 a의 농도도(는) 전선역을 중심으로 중국 연안쪽과 외양역에서 높으나 전선역 중심에서는 낮은 분포를 보인다. 이상과 같은 결과로 볼 때 전선역이 형성되는 해역은 상하혼합과정에서 흐름의 증대로 인해 식물플랑크톤의 활성이 낮아지기 때문에 생산력이 낮아지는 것으로 생각된다. 또한 여름철 동중국해 해역에서 형성된 외양전선역은 중국대륙 담수의 유출량에 따라 전선역이 제주도까지 밀려올 가능성을 가지고 있는 것으로 판단된다.

• 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.

• ALGAE
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• 제23권4호
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• pp.257-268
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• 2008

Species composition, standing crop and dominant species of phytoplankton were investigated at 6 sites of Galgok stream and Incheon river which run into Gomso Bay, Jeollanam-do in April, August and November 2007. Total of 210 taxa were found which were classified as 6 classes, 12 orders, 25 families, 66 genera, 177 species, 27 varieties, 5 forms and 1 unidentified species. These river and stream had lower concentration of T-N and T-P compared to that of others; however, the site 2 of Galgok stream in summer was hypertrophic in T-P and also near hypertrophic in TN, and the site 1 in Incheon river during fall appeared to be hypertrophic in T-N, and the site 3 in summer showed near hypertrophic level in T-P. Determining the trophic status of the water quality based on chlorophyll a (chl-a), the site 3 of Galgok stream in spring and the site 3 of Incheon river in fall were oligotrophic; moreover, 6 sites including the site 2 and 3 of Galgok stream in summer were mesotrophic, and 9 sites including all sites of Galgok stream in fall turned out to be eutrophic. Particularly, the site 1 of Galgok stream in summer was hypertrophic, having 58.19 mg chl-a m$^{-3}$. There was a conspicuous difference between two values of standing crops based on chl-a and cell counting. This discrepancy may have occurred because of abundant cyanophytes and exclusion of picoplankton cells in cell counting. In the study, 5 cyanophytes, Synechocystis aquatilis, Microcystis aeruginosa, M. flos-aquae, Oscillatoria angustissima, O. limnetica and 2 diatoms, Thalassiosira bramaputrae and Navicula viridula var. rostellata were abundant. Based on the T-N, T-P values, standing crops and cell counting in Galgok stream and Incheon river were between mesotrophic and eutrophic conditions.

• 한국식품과학회지
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• 제48권3호
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• pp.208-213
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• 2016

다래순 묵나물을 찬물에 16시간 불리고, 30분 삶은 후 1시간 찬물에 불리는 재수화 과정을 거친 후 다래순의 라디칼 소거 활성과 알파글루코시데이스 억제활성은 유의하게 감소하였으며 재수화된 다래순을 $180^{\circ}C$에서 10분 또는 20분 동안 가열 조리한 경우 들기름 첨가와 관계없이 라디칼 소거활성은 증가하였으나 알파글루코시데이스 억제 활성은 들기름을 첨가하고 가열 조리한 경우에만 증가하였다. 다래순의 라디칼 소거 활성과 알파글루코시데이스 억제 활성 변화는 색소보다는 산화방지제, 플라보노이드 또는 토코페롤보다는 폴리페놀 화합물 함량 변화와 더 유사한 경향을 보였다. 따라서 본 결과는 다래순 묵나물의 재수화 또는 가열 조리 시 산화 방지, 항당뇨 등 건강기능성 개선을 위해 폴리페놀 화합물의 손실을 줄이는 것이 바람직함을 시사하였다.

• 한국초지조사료학회지
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• 제43권2호
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• pp.109-115
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• 2023

Ammonium (NH₄⁺) serves as a nitrogen source, but its elevated levels can hinder plant growth and production. Excess NH₄⁺ with α-ketoglutarate is assimilated into glutamate, a precursor of proline and glutathione (GSH). This study aimed to investigate the effects of excessive NH₄⁺ on the regulation of proline and GSH synthesis. Detached leaves from oilseed rape (Brassica napus L.) were fed with 0, 50, 100, 500, and 1000 mM NH₄Cl for 16 h. As the NH₄⁺ concentrations increased, the leaves exhibited progressive wilting and yellowing. Furthermore, total carotenoid and chlorophyll concentrations declined in response to all NH₄⁺ treatments, with the lowest levels observed in 1000 mM NH₄⁺ treatment. Hydrogen peroxide (H₂O₂) concentration showed a minor increase at low NH₄⁺ concentration (50 and 100 mM) treatments but a significant increase at high NH₄⁺ (500 and 1000 mM), which was consistent with the localization of H₂O₂. Amino acid concentrations increased with increasing in NH₄⁺ concentration, while the protein concentration displayed the opposite trend. Proline and cysteine concentrations exhibited a gradual increase in response to increasing NH₄⁺ concentrations. However, GSH concentrations rose only in the 50 mM NH₄⁺ treatment and decreased in the 500 and 1000 mM NH₄⁺ treatments. These results indicate that excessive NH₄⁺ is primarily assimilated into proline, while GSH synthesis is adversely affected.