• ALGAE
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• v.22 no.2
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• pp.117-123
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• 2007

The seasonal change of algal flora and intertidal community structures of Bagryoungdo Island was investigated at Dumujin from February to November 2006. The description of subtidal algal community was made in October by Scientific SCUBA-diving. The total of 43 species, including 6 Chlorophytes, 6 Phaeophytes, 29 Rhodophytes and 2 sea grasses were identified in this survey. The occurrence of species according to season, listed as follows, 26 species in winter, 34 in spring, 18 in summer and 18 in autumn. Three species, Laminaria japonica, Neorhodomela aculeata and Ulva pertusa were dominant. The algal zonation of intertidal zone was figured out by Porphyra spp., Gloiopeltis furcata, Caulacanthus okamurae, Gelidium divaricatum - Neorhodomela aculeata, Enteromorpha compressa - Ulva pertusa, Dumontia simplex, Laminaria japonica from upper to lower zone. The zonation of subtidal zone was figured out by Ulva pertusa - Laminaria japonica - Zostera marina (sea grass), crustacean red algal population in autumn. The average of biomass of macroalgae was measured as 119.4 g∙dry wt/m2.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.496-500
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• 2000

Partial fragments of nuclear 185 rDNAs from morphologically wide and narrow thalli of the seaweed Porphyra pseudolineazis were amplified and sequenced to compare their DNA homology. Both sequences of 311 base pairs showed $100{\%}$ identical each other. They showed $97.7{\%}$ similarity with a wild strain collected at Sodol in Kangwondo, and $99.4{\%}$ similarity with the GenBank accession number AB013185 of the Japanese P. pseudolinearis. Thus the morphological difference of wide and narrow blades might not be a classification criterion for the sub-species level of P. pseudolinearis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.960-972
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• 2014

Marine algal flora and community structure were seasonally investigated at Oryukdo, on the southeast coast of Korea, from March 2011 to February 2014. A Total of 66 seaweed species including 6 green, 7 brown and 53 red algae were identified and 23 species were found throughout the survey period. Seaweed biomass was maximal during summer in 2012 (2276.2 g wet weight $m^{-2}$) and minimal in winter in 2012 (9.1 g wet weight $m^{-2}$). The dominant species in term of biomass were Undaria pinnatifida, Dictyopteris prolifera, Dictyota dichotoma, Sargassum horneri, Rhodymenia intricata, Acrosorium polyneurum, and Polyneura japonica during the suvery period. The flora could be classified into six functional groups: coarsely branched form (30.3%), filamentous form (24.2%), thick leather form (19.7%), sheet form (15.2%), jointed calcareous form (7.6%), and crustose form (3.0%). The numbers of marine algal species in the Oryukdo area were markedly reduced when compared with previous studies at Dongbaekseom in 1971. These results suggest possible future changes in the algal vegetation, considering the physical and chemical pollution loadings in the coastal marine environment of this area.

• ALGAE
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• v.34 no.3
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• pp.187-198
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• 2019

The exploration of seaweed diversity in poorly studied habitats has often led to the discovery of new species. Sand-covered rocks are an example, as they received less attention than sand-free rocky intertidal habitats during seaweed diversity surveys in Brazil. In sand-covered rocks from Espirito Santo and Rio de Janeiro we found an alga whose morphology was unique among rhodomelacean species previously reported in Brazil. With the aim to clarify the taxonomic identity of this species we studied its morphology, as well as its phylogenetic relationships. Molecular analyses resolved this species in the genus Alsidium (tribe Alsidieae) and differed from sequenced congeners with divergences ${\geq}2.5$ and 4.2% in the rbcL and cox1 genes, respectively. Morphological characters were in agreement with the genus Alsidium, and differed from other species currently recognized in the genus. The species consisted of a basal crust and scarcely branched erect axes with seven pericentral cells covered by a continuous layer of cortical cells. Reproductive structures were formed on clusters of short determinate branches. Therefore, the new species A. oliveiranum is proposed based on morphological and molecular evidence. Our findings contribute to better understand the diversity of the tribe Alsidieae, which is particularly diverse in the Americas.

• Ocean and Polar Research
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• v.34 no.4
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• pp.445-451
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• 2012

The EtOH extracts of red seaweeds (Symphyocladia latiuscula, Chondrus ocellatus and Carpopeltis affinis) and solvent partitioned fractions were investigated for their 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 1,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effects and the total phenolic contents were correlated with ABTS and DPPH radical scavenging activities. The EtOH extracts and their solvent partitioned fractions exhibited strong ABTS and DPPH radical scavenging activities. Among the solvent partitioned fractions obtained from n-Hexane (HX), methylenchloride (MC), ethylacetate (EA), and buthanol (BuOH), the HX fraction from C. affinis showed higher radical scavenging activities than other fractions. Total phenolic contents showed significant correlation ($r^2$ = 0.709) with ABTS radical scavenging activity. The results of this study suggest that the strong radical scavenging activity of HX fraction from C. affinis is a promising natural antioxidant for healthcare products.

• Preventive Nutrition and Food Science
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• v.15 no.3
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• pp.176-183
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• 2010

The hypoglycemic effects of red ginsgeng-chungkukjang plus seaweeds, green laver and sea tangle, in streptozotocin (STZ)-induced diabetic rats were investigated. Five groups of male Sprague-Dawley rats weighing $140\pm10$ g (10 animals/group) were fed for four weeks with the following: nondiabetic control (NC group); STZ-induced diabetic (D group); diabetic rats fed 3% red ginseng (20%, w/w)-chungkukjang (D-RC group); diabetic rats fed RC containing 10% (w/w) green laver powder (D-RCG group); diabetic rats fed RC containing 10% (w/w) sea tangle powder (D-RCS group). Partially normalized body weight gain, FER, and blood glucose levels were observed in the D-RC, D-RCG and D-RCS groups as compared to the D group. In these three groups, serum levels of triglycerides, total cholesterol, and LDL-cholesterol were found to be lower than in the D group, whereas HDL-cholesterol levels increased. Serum insulin level in D was significantly lower than that of NC, although D-RC, D-RCG, and D-RCS almost recovered to the NC. Serum ALT activity was markedly increased in the D group, while the serum ALT levels in the D-RC, D-RCG, and D-RCS were almost the same as the NC group. Due to diabetes, hepatic xanthine oxidase (XO) activity was significantly increased and administration of red ginseng-chungkukjang or seaweeds resulted in decreased levels of the XO activity. Activity of hepatic antioxidant enzymes (superoxide dismutase and glutathione peroxidase) were significantly decreased in the D group, but the activity in the D-RC, D-RCG, and D-RCS groups were similar to that of the NC group. Results of the present study indicate that supplementation of red ginseng-chungkukjang with seaweed after the onset of diabetes ameliorated hyperglycemia via an increase in serum insulin.

• Korean Journal of Environment and Ecology
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• v.28 no.1
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• pp.10-23
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• 2014

This study was carried out to examine seaweed community structure and distribution of crustose coralline algae at the intertidal and subtidal zones of Gallam, Samchuk, eastern coast of Korea. Total 112 species including 14 of green algae, 33 of brown algae, and 65 of red algae were collected and identified. Among these species, 29 species were found throughout the year. The dominant species which contributed significantly to the total biomass were Ulva pertusa, Colpomenia spp., Sargassum fulvellum, Sargassum fusiforme, Sargassum muticum, Sargassum thunbergii, Corallina pilulifera, and Gelidium elegans. Annual seaweed biomass in dry weight was 66.7 $gm^{-2}$ and maximum biomass was recorded seasonally in summer (107.5 $gm^{-2}$), while minimum was recorded in autumn (36.2 $gm^{-2}$). In seaweed functional group analyses, coarsely branched form was the most dominant functional group constituting from 40.0 to 48.6% of the total flora. Ecological state group ESG II, as an opportunistic species, including sheet form, filamentous form, and coarsely branched form, consisted of 46~61 species, constituting 76.7~82.4%. Crustose coralline algae was observed throughout all seasons. Species of the crustose coralline algae were largely classified into Lithothamnion lemoineae, Lithophyllum okamurai, Lithophyllum yessoense, and Hydrolithon gardineri. The coverage of crustose coralline algae seems to be lower than that of other studies from 36.8% to 11% on average.

• Microbiology and Biotechnology Letters
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• v.44 no.2
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• pp.145-149
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• 2016

Thermal acid hydrolysis pretreatment of Kappaphycus alvarezii was carried out with 12% (w/v) seaweed slurry and 180 mM H₂SO₄ at 140°C for 5 min. Utility of the thermotolerant yeast Kluyveromyces marxianus KCTC7150 was evaluated with respect to cell growth and ethanol fermentation at 40°C was close to optimal for enzymatic hydrolysis. This could lead to the integration of both the saccharification and fermentation processes. The levels of ethanol production by simultaneous saccharification and fermentation (SSF) with non-adapted and adapted K. marxianus KCTC7150 were 9.1 g/l with an ethanol yield (Y_EtOH) of 0.24 and 10.2 g/l with an ethanol yield (Y_EtOH) of 0.27 at 156 h, respectively. The two-phase SSF process was employed in this study to improve the efficiency of ethanol fermentation. Adapted K. marxianus KCTC7150 using the two-phase SSF process produced 13.5 g/l with an ethanol yield (Y_EtOH) of 0.35 at 96 h. Development of the two-phase SSF process could enhance the overall ethanol fermentation yields of the seaweed K. alvarezii.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.607-618
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• 2013

Marine macroalgal community structures and characteristics of ocean environmental factors were examined seasonally at four sites in Jeju Island, Korea, from March to November 2012. A total of 71 macroalgal species were identified, including 9 green, 7 brown, and 55 red algae. Peyssonnelia capensis occurred at all study sites and in all seasons. The average annual biomass of seaweed was 991.84 g wet $wt/m^2$, with seasonal variations from 543.80 g in autumn to 1,284.17 $g/m^2$ in summer. A green alga, Codium coactum, was the dominant species, occupying 21.31% (211.39 $g/m^2$) of the total algal biomass in Jeju Island. Subdominant species were Ecklonia cava and Lithophyllum okamurae, comprising 20.85% (206.75 $g/m^2$) and 19.64% (194.75 $g/m^2$), respectively, of the total algal biomass in Jeju Island. The vertical distribution of subtidal seaweeds was represented by L. okamurae at 5 m depth, C. coactum at 10 m depth, E. cava at 5-10 m depth and P. capensis at the 20 m depth level. In the present study, crustose coralline algae, which predominated on barren ground, were subdominant species at all study sites. Community indices varied between 0.51-0.63 for dominance index (DI), 5.53-8.14 for richness index (R), 0.51-0.63 for evenness index (J'), and 2.04-2.32 for diversity index (H'). On the basis of seaweed biomass and community indices, Sinchang was the best preserved coastal area, showing maximal values in biomass, and evenness- and diversity-indices, and minimal value in the dominance index, representing stable environmental conditions. In contrast, the Onpyung and Topyeong sites, located near tourist venues such as Udo and Seogwipo were relatively poor habitats based on community indices and biomass. The present results could imply that climate changes alter seaweed community structure, and long-term monitoring of the study sites is required.

• Microbiology and Biotechnology Letters
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• v.43 no.1
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• pp.9-15
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• 2015

The seaweed, Gracilaria verrucosa, was fermented to produce bioethanol. Optimal pretreatment conditions were determined to be 12% (w/v) seaweed slurry and 270 mM sulfuric acid at 121℃ for 60 min. After thermal acid hydrolysis, enzymatic saccharification was carried out with 16 U/ml of mixed enzymes using Viscozyme L and Celluclast 1.5 L to G. verrucosa hydrolysates. A total monosaccharide concentration of 50.4 g/l, representing 84.2% conversion of 60 g/l total carbohydrate from 120 g dw/l G. verrucosa slurry was obtained by thermal acid hydrolysis and enzymatic saccharification. G. verrucosa hydrolysate was used as the substrate for ethanol production by separate hydrolysis and fermentation (SHF). Ethanol production by Candida lusitaniae ATCC 42720 acclimated to high-galactose concentrations was 22.0 g/l with ethanol yield (Y_EtOH) of 0.43. Acclimated yeast to high concentrations of specific sugar could utilize mixed sugars, resulting in higher ethanol yields in the seaweed hydrolysates medium.