• ALGAE
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• v.38 no.2
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• pp.151-157
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• 2023

Grateloupia turuturu is a red alga with a flat but firm slippery thallus. Throughout its lifetime, this alga experiences a wide range of environmental stresses in the intertidal rocky shores. The aim of this study is to investigate the effect of salinity and irradiance on the early developmental stages of G. turuturu tetrasporophytes. The released carpospores were cultivated at different salinities (S = 15, 25, and 35) and irradiances (50, 100, and 200 μmol photons m^-2 s^-1). Germination of carpospores and development of juvenile tetrasporophytes were observed every 5 days and recorded by a digital camera. Discoid crusts were formed at all conditions within 5 days. The discoid crusts at 200 μmol photons m^-2 s^-1 died within 20 days regardless the salinity. The discoid crusts at S = 35 also died at all irradiance conditions within 25 days. Except for those at S = 35 and 200 μmol photons m^-2 s^-1, the discoid crusts reached about 8,000-9,000 ㎛² by day 20. Regardless of irradiance, the upright thalli formation rate from discoid crusts was 85 and 10% at S = 15 and S = 25, respectively. These results suggest that salinity and irradiance are important factors influencing early developmental stages of G. turuturu.

• ALGAE
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• v.24 no.4
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• pp.231-238
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• 2009

The genus Grateloupia is the largest with more than 96 currently recognized species in the family Halymeniaceae, but morphological features of the genus are highly homoplasious making species identification difficult. In this study, we analyzed rbcL gene from 34 samples collected in Korea and compared the haplotypes of Korean species with those already published. The rbcL tree confirmed the occurrence of eight species in Korea: G. asiatica, G. catenata, G. divaricata, G. elliptica, G. imbricata, G. lanceolata, G. subpectina, and G. turuturu. All, except G. asiatica and G.catenata, been introduced from their native northeastern Asian waters to Australasian, European, and North American waters. The introduced haplotypes of G. lanceolata in Europe and North America were absent in Korea, while haplotype sharing of G. turuturu in Korea and Europe was common. Further sampling will show a source population of each introduced species and also provide a correct list of Grateloupia from Korea, including the other remaining 11 species of the genus.

• Journal of fish pathology
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• v.18 no.2
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• pp.147-156
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• 2005

To obtain antimicrobial algae against fish pathogenic bacteria, we screened 80% methanolic extracts of 30 algae using fish pathogenic bacteria, Staphylococcus sp., Streptococcus sp., Edwardsiella tarda and Vibrio anguillarum. Among them, Corallina officinalis, Dumontia simplex, Gloipeltis furcata, Grateloupia lanceolata and Grateloupia turuturu were effective for growth inhibition of a Gram-positive bacterium, Staphylococcus sp.. Sargassum thunbergii and Polysiphonia morrowii exhibited significant inhibitory effects against the growth of Gram-negative bacteria, both E. tarda and V. anguillarum. Moreover, antimicrobial activity-guided fractionation for P. morrowii extract yielded significantly active 90% methanolic fraction. This fraction significantly inhibited the growth of E. tarda exhibiting a MIC of 1 mg/ml. In addition, its antimicrobial activity was stable under various pH conditions.

• Natural Product Sciences
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• v.18 no.2
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• pp.130-136
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• 2012

In the present work, we have collected 19 species of macroalgae (9 Phaeophta and 10 Rhodophyta) f rom all around of Korea: Dictyopteris divaricata, D. prolifera, Myelophycus cavus, Papenfussiella kuromo, Petalonia zosterifolia, Petrospongium rugosum, Rugulopteryx okamurae, Sargassum fulvellum, S. muticum, Callophyllis japonica, Gloiopeltis tenax, Gracilaria longissima, Gracilaria vermiculophylla, Grateloupia asiatica, Grateloupia lanceolata, Grateloupia sparsa, Grateloupia turuturu, Grateloupia sp, and Polyopes affinis. The macroalgal species were extracted by 70% ethanol (EtOH) for 24 h and evaluated its inhibitory effects on ${\alpha}$-glucosidase. Among ethanol extracts, Myelophycus cavus showed the most effectively inhibitory activity ($IC_{50}$, 2.17 ${\mu}g/ml$) against ${\alpha}$-glucosidase, followed by Sargassum fulvellum (<$IC_{50}$, 8.13 ${\mu}g/ml$), Dictyopteris prolifera ($IC_{50}$, 16.66 ${\mu}g/ml$), Rugulopteryx okamurae ($IC_{50}$, 50.63 ${\mu}g/ml$), and Petrospongium rugosum ($IC_{50}$, 101.62 ${\mu}g/ml$). Furthermore, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay showed no cytotoxicity on mouse pre-adipocytes cell line (3T3-L1). These results suggest that some edible macroalgae merit further evaluation for clinical usefulness as anti-diabetic functional foods.