• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.5
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• pp.571-578
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• 2018

Seasonal variability in algal community structure of the subtidal zone was examined at four study sites on the southeastern coast of Korea from February to November 2016. A total of 81 species of algae (8 green, 12 brown, and 61 red) were indentified. During the study period, the greatest number of species was observed at Sinamri (57 species) followed by Daesongri (50 species), Dongbaekri (47 species) and Gangyangri (42 species). Of the six functional seaweed forms, the coarsely-branched form was the most dominant, accounting for about 43% of the total species at Daesongri. The annual average biomass in wet weight varied from $700.59g/m^2$ at Sinamri to $1,712.45g/m^2$ at Daesongri. The parameters of seaweed community structures were as follows: dominance index (DI), 0.30-0.54; richness index (R), 4.92-7.05; evenness index (J'), 0.54-0.72; and diversity index (H'), 2.05-2.91.

• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1080-1086
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• 2006

본 연구에서는 해조류의 항돌연변이 및 항암 생리활성물질을 검색하여 발암물질 생성 방지 및 생체 방어 물질로서의 이용 가능성을 검토하고자 Ames test를 이용하여 직접돌연변이원인 MNNG와 간접돌연변이원인 $AFB_1$에 대한 항돌연변이 효과 및 암세포 증식 억제 효과를 알아보고자 하였다. $AFB_1$에 대해서 괭생이모자반(S. horneri)이 실험에 사용된 다른 해조류들 중에서 가장 높은 돌연변이 억제 효과를 보였다. 첨가농도 1.25mg/plate일 때, 괭생이모자반의 acetone+methylene chloride 추출물과 methanol 추출물은 각각 96%, 91%로 실험에 사용된 다른 해조류들의 추출물들 중에서 가장 높았으며 양성 대조군인 다시마의 용매 추출물보다도 높은 돌연변이 억제 효과를 보였다. $AFB_1$과 같은 농도인 0.6mg/plate의 농도의 MNNG를 사용하여 S. typhimurium TA100 균주에 대한 해조류의 항돌연변이성 실험을 한 결과, 간접 돌연변이원인 $AFB_1$에 비해 직접 돌연변이원인 MNNG에 대해서는 다소 항돌연변이 효과가 떨어지지만, 여기서도 실험에 사용된 해조류들의 돌연변이 억제 효과를 살펴볼 수 있었으며 acetone+methylene chloride 추출물의 경우가 methanol 추출물보다 다소 높은 활성을 나타내었다. 항돌연변이 실험에서 효과가 뛰어난 괭생이모자반과 짝잎모자반을 중심으로 인체 암세포(위암세포, AGS 및 결장암 세포, HT-29) 증식억제효과를 살펴본 결과, 용매 추출물을 0.5%, 1% 및 2%의 농도별로 암세포에 처리했을 때 acetone+methylene chloride 추출물과 methanol 추출물은 둘 다 가장 낮은 농도인 0.5%에서부터 농도 의존적으로 암세포 증식 억제 효과가 증가하였다. 이상의 7종의 갈조류 추출물들은 Ames test에서 높은 항돌연변이 효과를 나타냈을 뿐만 아니라 괭생이모자반 및 짝잎모자반은 인체 암세포에 대해서도 높은 증식 억제 효과를 나타냄을 살펴 볼 수가 있었다.

• ALGAE
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• v.28 no.4
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• pp.371-378
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• 2013

Water and methanolic extracts of Ecklonia cava, a marine brown alga, were prepared by ultrasonic extraction (UE) and conventional extraction (CE) methods. The radical-scavenging activity and the inhibitory effects against hydrogen peroxide ($H_2O_2$)-induced DNA damage of the extracts were investigated. All extracts prepared by CE exhibited higher total polyphenolic content than that in the extracts prepared by UE. Extraction yield and total phenolic content increased as the UE time increased. The radical-scavenging activities increased as the UE time increased. All extracts prepared by CE exhibited higher 1,1-diphenyl-2-pricrylhydrazyl (DPPH) and hydroxyl radical-scavenging activities than did those prepared by UE. Extracts prepared by UE showed stronger scavenging activities on alkyl radical and $H_2O_2$ than those prepared by CE did. Methanolic extract with UE 12 h (100MEU-12h) and methanolic extract with CE 24 h (100MEC-24h) were selected and evaluated by comet assay for their inhibitory effect against $H_2O_2$-induced DNA damage. 100MEU-12h showed slightly greater protective effect against $H_2O_2$-induced DNA damage than 100MEC-24h. Thus, UE can be effectively used as a seaweed extraction technique, and there is potential for scale-up of the extraction process.

• Journal of Marine Bioscience and Biotechnology
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• v.15 no.2
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• pp.59-66
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• 2023

Dictyopteris divaricata, a type of marine brown algae, has been studied for its various biological properties, including anti-inflammatory, antidiabetic, and whitening effects. However, its potential antiobesity effects have not been extensively explored. This study aimed to examine the impact of D. divaricata ethanol extract (DDE) on adipocyte differentiation and adipogenesis using 3T3-L1 preadipocytes. Our results showed that when 3T3-L1 preadipocytes were treated with noncytotoxic concentrations of DDE there was a concentration-dependent decrease in fat accumulation rate and triglycerid production compared with the control. Furthermore, DDE significantly reduced the expression of transcription factors (PPARγ, C/EBPα, and SREBP-1) and fatty acid transport protein (FABP4), which are crucial for 3T3-L1 preadipocyte differentiation. These findings suggest that DDE may exhibit antiobesity effects by suppressing the expression of lipogenic transcription factors and fatty acid transport proteins. Therefore, DDE holds potential as a therapeutic agent for obesity.

• ALGAE
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• v.17 no.3
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• pp.135-144
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• 2002

Scytosiphonaceae is an acetocarpalean brown algal family, that is a recent focus of synstematics and marine biodiversity. We describe Petalonia zosterifolia and Scytosiphon gracilis from Korea for the first time. P. zosterifolia occurred on the East coast, and had flat, linear and solid thalli. S. gracilis was found in Jeju, and had cylindircal to flat and hol-low thalli. However, these two species are so similar that it is difficult to identify by morphology alone. In order to determine if the nuclear DNA reveals the distinctness of both species and to know their phylogenies, the ITS region sequences were newly detrmined in 22 samples of P. zosterifolia, Scytosiphon gracilis, and other three members of the genera from Korea. We found 0.12% variation among samples of P. zosterifolia from different locations, and no variation between S. gracilis samples from diferent years, but extensive interspecific divergences (13.62-22.83%) of each species to other members in Petalonia and Scytosiphon . The ITS sequence dta consistently showed a close relationship between P. zosterifolia and S. gracilis. This result is congruent with morphology and with the published data of plastid rbc and partial nrDNA large subunit gene sequences, and suggests that P. zosterifolia and S. gracilis might have diverged from the most recent common ancestor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.3
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• pp.209-215
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• 2024

Ishige foliacea belongs to class Phaeophyceae and family Ishigeaceae. This study investigated the physiological activities of the Korean marine algae I. foliacea. Its solvent extracts were prepared with 70% ethanol, 80% methanol, and distilled water. The ethanol and methanol extracts had higher α-glucosidase (half-maximal inhibitory concentration, IC₅₀: 0.67-0.73 mg/mL), xanthine oxidase (IC₅₀: 0.25-0.28 mg/mL), and angiotensin-converting enzyme (IC₅₀: 25.29-38.28 ㎍/mL) inhibitory activities than those of the water extract. The ethanol and methanol extracts possessed high acetylcholinesterase inhibitory activity (IC₅₀: 0.78c0.97 mg/mL). Conversely, the water extract exhibited the highest β-secretase inhibitory activity (IC₅₀: 0.48 mg/mL). These results indicate that I. foliacea may be useful as a functional substance in food and pharmaceuticals with anti-diabetic, anti-gout, anti-hypertension, and anti-dementia properties.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.1
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• pp.32-37
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• 2000

Silver-alginate (Ag-alginate) was prepared with Na-alginate extracted from marine brown algae. The antibacterial effect of Ag-alginate against Staphylococcus aureus and Escherichia coli was carried out by measuring optical density of liquid culture at 600 nm. The cell growth of S. aureus and E. coli was very active at pH 7, and was inhibited by adding Ag-alginate with more than $0.006 wt.{\%}$ of stiver content. The cell growth of S. aureus .and E. coli was also influenced by the characteristics of counter Jon of silver. The cell growth of S. aureus was less inhibitory than E. coli at the same concentration of Ag-a1ginate.

• Korean Chemical Engineering Research
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• v.53 no.5
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• pp.570-575
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• 2015

The green algae have cellulose as a main structural component of their cell wall and the cellulose content in green algae is much higher than other marine algae such as brown algae and red algae. Furthermore, green algae do not contain lignin in their cell wall and store starch as food in their plastids. Thus, it was investigated that the effect of hydrothermal pretreatment process utilizing microwave irradiation for Ulva pertusa Kjellman, a division of green algae, which is expected to be utilized for bioenergy production, on the enzymatic hydrolysis. The hydrothermal temperature have an effect on the pretreatment of Ulva pertusa Kjellman, but the effect of power of microwave irradiation is negligible. The rate of enzymatic hydrolysis was increased as the hydrothermal temperature increased until $140^{\circ}C$. The enzymatic hydrolysis of pretreated Ulva pertusa Kjellman under the optimum pretreatment conditions (50 W of microwave irradiation power and $150^{\circ}C$ of hydrothermal temperature) with cellulase, ${\alpha}$-amylase, and Novozyme 188 having ${\beta}$-glucosidase acitivity resulted in the saccharification of 96 wt% of total carbohydrate in Ulva pertusa Kjellman during 3 hrs, while it took 24 hrs for the enzymatic hydrolysis of untreated Ulva pertusa Kjellman. It confirmed that the hydrothermal pretreatment was effective on Ulva pertusa Kjellman for the enzymatic hydrolysis.

• Applied Biological Chemistry
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• v.14 no.3
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• pp.213-220
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• 1971

In order to investigate chemical components of edible marine algae in Korea, the present work is carried out with ten edible and two non-edible species of brown algae, collected from Cheju-island during October, 28-30 in 1970. Among the general components, water content is about 14-16% to dry weight and the crude protein about 16%, which are almost similar in content compared with several non-cultivate edible land plants. The content of crude fat is about 0.7-2.0%, and that of crude fiber about 3-8%, while the content of crude ash is 9.17-16.89%. The last one is more than two times in content compared with the land plants. The reducing sugar is about 0.27-2.49% in general. On the other hand, among the minerals Ca content is the most abundant, 1.73-2.51%, and the next is S, 1.0-1.8%. Mg and I are around 0.1-1%, while K and Na are about 1% in content. Among the micro-elements, Fe and Zn are about 0.01-0.03%, and Cu and Mn 0.001-0.005% in content. There is no special significant difference in chemical components between the edible and non-edible species of brown algae. Moreover, so far as the present investigation is concerned, there can be found no significant inter-species relationship on the taxonomical or phylogenetical points of view, considering their components.

• Journal of Plant Biology
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• v.34 no.2
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• pp.165-173
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• 1991

Subtidal algal communities of lnchon Dock, an enclosed artificial dock in the western coast of Korea, were investigated qualitatively and quntitatively. Assessments of species composition, biomass rlominant species, and vertical distribution were conducted from January to December, 1990. Duf"16 the study, benthic marine algal community was disturbed completely by water blooming in June, and was recolonized from July. Forty-five species of marine algae, 18 blue green. 13 green. 6 brown, and 8 red algae, were identified as results. Mean biomass was in ranges of $53.50-118.00\;g-dry\;wt/m^2$ in community before disturbance and $0.57-2.62\;g-dry\;wt/m^2$ after it. Dominant species determined by biomass and frequency were Polysiphonia m0\ulcorner7owii and Ceramium fastigiramosum before disturbance, while Lyngbya semiplena, Lyngbya lutea and Lyngbya rivulariarum after disturbance as pioneer colonizers.nizers.