• ALGAE
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• 제21권1호
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• pp.149-156
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• 2006

The aim of the present study was to evaluate the antioxidant activity of red algae in Jeju Island. The algal extracts were obtained with MeOH and fresh water at 20 and 70°C, and screened for antioxidant activities using hydroxyl radical (HO·), superoxide anion (O2–), hydrogen peroxide (H2O2) and DPPH free radical scavenging assays. Among them, Gracilaria verrucosa methanolic extract at 20°C (20ME, 96.85%), G. textorii aqueous extract at 20°C (20AE, 88.01%), Grateloupia filicina 20AE (85.35%), and Polysiphonia japonica 20ME (94.92%) exhibited the highest scavenging activities against HO·, O2–, H2O2, and DPPH free radicals, respectively. Moreover, P. japonica (20ME and 70ME) is correlated between DPPH free radical scavenging activity and polyphenolic contents. These results indicate that some red algae in Jeju Island could be potential candidates for development of antioxidants.

• ALGAE
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• 제30권4호
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• pp.303-312
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• 2015

The intimate physical interaction between food algae and sacoglossan sea slug is a pertinent system to test the theory that “you are what you eat.” Some sacoglossan mollusks ingest and maintain chloroplasts that they acquire from the algae for photosynthesis. The basis of photosynthesis maintenance in these sea slugs was often explained by extensive horizontal gene transfer (HGT) from the food algae to the animal nucleus. Two large-scale expressed sequence tags databases of the green alga Bryopsis plumosa and sea slug Placida dendritica were established using 454 pyrosequencing. Comparison of the transcriptomes showed no possible case of putative HGT, except an actin gene from P. dendritica, designated as PdActin04, which showed 98.9% identity in DNA sequence with the complementary gene from B. plumosa, BpActin03. Highly conserved homologues of this actin gene were found from related green algae, but not in other photosynthetic sea slugs. Phylogenetic analysis showed incongruence between the gene and known organismal phylogenies of the two species. Our data suggest that HGT is not the primary reason underlying the maintenance of short-term kleptoplastidy in Placida dendritica.

• ALGAE
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• 제23권2호
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• pp.91-114
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• 2008

Fifty seven taxa of Cyanobacteria and 15 taxa of Chlorophyta were recorded from the exterior of buildings and rock surfaces of monuments in different regions in India. Four cyanobacteria, e.g. Chroococcidiopsis kashayi, Pseudophormidium indicum, Plectonema puteale and Scytonema geitleri, and the green alga Trentepholia abietina var. tenue occur on the sub-aerial habitats throughout the year. In addition, five other green algae: Chlorococcum infusionum, Scenedesmus arcuatus, Trentepholia aurea, Gloeocystis polydermatica and Printzina effusa, and 18 other cyanobacteria taxa of the genera Chroococcus (5), Asterocapsa (1), Cyanosarcina (2), Gloeocapsa (7), Gloeothece (2) and Scytonema (1) occur on the sub-aerial surfaces enduring extreme temperature and desiccation during summer months of the tropics. During the rainy season, the warm and humid climatic regime coupled with availability of moisture supported an additional ten green algae and 29 cyanobacteria in eight and 17 genera, respectively. The green algal genera Klebsormidium, Stichococcus and Trebouxia, which are dominant in temperate regions, did not occur on the sub-aerial habitats in India, however, species of Gloeocapsa, Chroococcus, Chroococcidiopsis, Phormidium, Leptolyngbya, Nostoc, Scytonema, Chlorella and Trentepholia showed global occurrence in similar habitats.

• ALGAE
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• 제22권1호
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• pp.45-52
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• 2007

An intertidal marine benthic algal vegetation and vertical distribution at Kangnung and it’s vicinity, the eastern coast of Korea was investigated to clarify the community structure and vertical distribution by quadrat method. Marine algae identified from the area were 116 species; 15 green, 31 brown and 70 red algae. The dominant species were Ulva pertusa, Codium fragile, Undaria pinnatifida, Dictyota dichotoma, Gelidium amansii, Corallina pilulifera, Carpopeltis affinis, Grateloupia filicina, Pachymeniopsis elliptica and Chondrus ocellatus at study sites. The vertical distribution of intertidal marine algae was divided into three distinct zones. They were characterized by Porphyra tenera at the upper, Enteromorpha spp. and Ulva pertusa at the middle, and Sargassum thunbergii, Hizikia fusiformis and Pachymeniopsis elliptica at the lower zones, respectively. The vertical distribution of subtidal zone algae were characterized by Laminaria spp. at 15m depth and Kjellmaniella crassifolia at 15 to 25 m depths, whereas Agarum cribrosum was dominant at the lower zone than 25 m depth.

• 한국해양학회지
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• 제10권2호
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• pp.51-56
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• 1975

Continued to the previous papers, the present investigation is carried out to clarify cesium-137 activities and potassium contents among 54 samples of edible marine algae collected along the coast of Korea during September, 1973 and April, 1974. The potassium contents are variable, 1.5-29.6%, and 11.36% on an average, while most of the members contain them about 10-16% generally. Among the algal phyla, they are 13.49% in green, 10.82% in brown and 16.46% in red algae, respectively. Cesium-137 activities are variable, 0.19-8.13 pCi$\^$137/ Cs/g K, and 2.35 pCi$\^$137/Cs/g K on an average in the samples investigated. Among the algal phyla they are 4.35 in green, 2.17 in brown and 0.89 pCi $\^$137/Cs/g K in red algae, respectively. Green algae contain especially higher activities compared with the other two groups. The brown alga, Myelophycus caespitosus shows the highest activities, 8.13 pCi$\^$137/Cs/g K, among the members investigated. Considering the concentration factor, this plant would be an indicator plant of cesium-137 among the marine algae along the coast of Korea.

• ALGAE
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• 제21권3호
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• pp.343-348
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• 2006

This study was conducted to screen in vitro angiotensin - I converting enzyme (ACE) inhibitory activities of methanol (MeOH) and aqueous extracts at 20°C and 70°C, respectively, prepared from twenty-six red algae obtained from the coast of Jeju Island in Korea. Among aqueous extracts at 20°C (20AE) from red algae Lomentaria catenata showed the strongest ACE inhibitory activity and Lithophyllum okamurae recorded the second highest activity. From MeOH extract at 20°C (20ME) Ahnfeltiopsis flabelliformis possessed the strongest ACE inhibitory activity. Remarkable activities from MeOH extracts at 70°C (70ME) were observed in Grateloupia filicina, Sinkoraena lancifolia and Grateloupia lanceolata. However, no significant activity was found in aqueous extracts at 70°C (70AE). The IC50 values, which are concentrations required to inhibit 50% activity of ACE, for ACE inhibitory activities of 20AE from Lithophyllum okamurae and L. catenata were 13.78 and 12.21 μg mL–1, respectively. The IC50 values of 20ME from A. flabelliformis and Laurencia okamurae were 13.84 and 106.15 μg mL–1. Those of the 70ME from Bonnemaisonia hamifera, Grateloupia filicina, Sinkoraena lancifolia, G. lanceolata, Gracilaria vermiculophylla and L. okamurae ranged from 25.82 to 124.69 μg mL–1.

• Ecology and Resilient Infrastructure
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• 제5권2호
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• pp.82-87
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• 2018

Proliferation of algae on the surface of concrete or mortar in aquatic habitat has a negative impact on maintenance of concrete-based structures. Growth of algae may decrease stability of structure by bio-deterioration. In this study, we developed a functional mortar for restraining bio-deterioration by using $Cu^{2+}$ ion. The mortar contains soluble glass beads made of $Cu^{2+}$ ion, which can dissolve into water slowly. Mortars prepared with different ratio of glass beads (0, 2, 5, 10, and 15%) were placed in a culture medium with algae and incubated over a month period. Water chemistry, chlorophyll-a, and extracellular enzyme activities were measured. The incubation was conducted in both freshwater and seawater conditions, to assess applicability to both aquatic conditions. Overall, mortar with Cu glass exhibited lower chlorophyll-a content, suggesting that the functional mortar reduced algal growth. DOC concentration increased because debris of dead algae increased. Cu glass also decreased phosphatase activity, which is involved in the regeneration of inorganic P from organic moieties. Since, P is often a limiting nutrient for algal production, algal growth may be inhibited. Activities of ${\beta}$-glucosidase and N-acetylglucosaminidase were not significantly affected because carbon and nitrogen mineralization may not be influenced by the Cu glass beads. Our study suggests that functional mortar with Cu glass beads may reduce the growth of algae on the surface, while it has little environmental impact.

• 펄프종이기술
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• 제44권1호
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• pp.16-23
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• 2012

Use of security papers for monetary papers, gift certificates, and lottery tickets increases every year. As the use of security papers increase, there are more possibility of counterfeits. In this study, we used unique fibers from the sea to increase the difficulties against counterfeiting. The red algae fibers give opacity as much as calcium carbonates, and have unique shape in length ($500{\sim}900\;{\mu}m$) and width ($1{\sim}4\;{\mu}m$) to be discerned from other natural fibers such as wood and cotton fibers. We mixed red algae fibers to wood fibers in a series of fixed ratios to make single and multiply papers for making security papers. Paper with dyed red algae fibers were also used. Paper made without fillers gave enough opacity for printing when red algae fibers were used more than 20% of the fiber furnish. Those properties may allow red algae fibers to be a potential candidate for fiber raw materials of security paper.

• 한국물환경학회지
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• 제30권1호
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• pp.25-30
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• 2014

This study is done to prove the premise that both alkalinity and hardness affect on the dissolved phosphorus concentration so that the growth of algae is also affected in water bodies like rivers and lakes. Statistical analysis of the water quality data of 13 reservoirs collected for the last decade shows the relations between alkalinity and chlorophyll-${\alpha}$ and between hardness and chlorophyll-${\alpha}$ are not linear but follow second order equation. This relation seems to be due to two antagonistic effects accompanying a simultaneous increase in alkalinity and hardness. The increase stimulates the growth of algae by supplying carbonates and $Ca^{2+}$ to algae and at same time it causes a decrease in soluble phosphorus which retards algae to grow. These opposing tendencies are confirmed by theoretical calculations with the MINTEQ model. There seems to be ranges of alkalinity and hardness that are in favor of algae growth; the ranges are less than 44 mg/L as $CaCO_3$ in alkalinity and also less than 63 mg/L as $CaCO_3$ in hardness. This finding will provide a solid base to develop an effective water quality management of water bodies.

• 분석과학
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• 제12권4호
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• pp.346-353
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• 1999

For the non-destructive multi-elemental analysis of environmental and biological materials, instrumental neutron activation analysis (INAA) was applied for the determination of toxic and trace elements in a set of three Algae samples provided by the International Atomic Energy Agency (IAEA). The analytical quality control was evaluated by comparing the analytical results of two standard reference materials of the National Institute of Standards and Technology (NIST); Oyster Tissue (SRM 1566a) and Citrus Leaves (SRM 1572). According to given analytical procedure, the concentration of 15-25 elements including spiked elements such as As, Cd, Cr and Hg in Algae samples were determined. To identify and validate these results, a data intercomparison program using more than 35 analytical methods in 150 laboratories was carried out and the estimated statistical data are summarized. Result of INAA is favorable, therefore, it is illustrated that can be applied for routine analysis of essential and toxic elements in algae samples as well as analytical quality assurance.