• Korean Journal of Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.134-138
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• 1969

Experiments were carried out to asses the impotance of environmental conditions upon the growth rate, length compositions seedling and spore liberation of a red alga Glacilaric verrucosa. The alga grown in water of low salinity mixed with fresh water shows better growth rate, lager length composition and excellent seedling, whereas the one vegetated in an area of tidal exposure shows a somewhat retarded growth rate and poor seedlings. The rate of growth Increases from August to October and begins to diminish from December continuing to diminish through February. Therefore the spore settling time extends from May to lune. Although the sun-drying method is the most eacient way of inducing spore liberation, further investigations are necessary in oiler to use this method for the application to artificial spore settling.

• Ocean Science Journal
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• v.42 no.3
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• pp.165-170
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• 2007

The structure of the nematodes communities has been studied in the sediments on two sites located outside and under the layer of Ahnfeltia tobuchiensis (Kanno and Matsubara 1932; Makijenko 1970). Bottom sediments at the stations were represented by sands with a different degree of silting. Specific structure of nematodes at the stations was significantly different under the similar environmental conditions (water depth, dissolved oxygen saturation, salinity, temperature of the bottom layer and organic carbon content inside of the sediment). Nematodes dominated (75.7 %) in meiobenthos community under the layer of A. tobuchiensis where concentration of silt particles was 12 %. Representatives of the family Comesomatidae were dominant. Low index of species diversity and high Simpson domination index were detected in this community. Under a layer of A. tobuchiensis with the thickness of 30 cm concentration of the silt particles was 5.39 %; nematodes density was low and made 32.1 % of the general density of meiobenthos. Species of the families Xyalidae and Monoposthiidae were dominant. Outside of A. tobuchiensis, field percentage of silt particles was minimal (3.1 %) and representatives of families Cyatholaimidae and Axonolaimidae dominated. The specific structure of nematodes in this type of the ground is characterized by high index of species diversity and low level of domination.

• 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.29 no.2
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• pp.101-109
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• 2014

Small red algae, especially those previously referred to as 'primitive' are often overlooked, but can be quite abundant. These 'primitive' red algae are now placed in several classes distinct from the Florideophyceae, for example the Stylonematophyceae. A brownish-red filamentous alga was collected from a sandy tide pool at Cape Tribulation, Queensland, Australia. Cultured specimens were identified as Bangiopsis and conformed to the morphological characters of the genus (multicellular base, erect filaments branched or unbranched, uniseriate to multiseriate-tubular, single multilobed purple-red to red-brown plastid with central pyrenoid, vegetative cells released directly as spores). Molecular data of two plastid genes (rbcL, psbA) support placement of the Australian isolate and isolates from India in Bangiopsis. The genetic variation between these isolates and isolates from Puerto Rico previously attributed to B. subsimplex indicates that these should be considered as a separate species. As the type locality is in the Atlantic Ocean, French Guiana, and not far from Puerto Rico, and the Puerto Rican isolate has been used often in phylogenetic analyses, we propose that the Indian and Pacific Ocean isolates be designated a new species, B. franklynottii, to acknowledge Ott's many years of research on inconspicuous freshwater and marine red algae. Our research also highlights the lack of careful descriptions in many of the records of this genus and the lack of morphological characters to distinguish species. Especially within the morphologically simple red algae, morphological distinctness does not necessarily reflect evolutionary divergences.

• Journal of Microbiology and Biotechnology
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• v.16 no.8
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• pp.1222-1228
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• 2006

Two kinds of Haematococcus pluvialis cells (green vegetative cells cultivated under optimal cell culture conditions and red cyst cells maintained under high light stress conditions to induce astaxanthin production) were used to investigate the protein expression profiles by two-dimensional electrophoresis, image analysis, and peptide mass fingerprinting. The cellular accumulation of astaxanthin was evident after exposure to high light intensity and reached the maximum cellular level after 78 h of high light stress. In a 2-D electrophoresis analysis, 22 proteins were upregulated over 2-fold in the red cyst cells when compared with the green vegetative cells and selected for further analysis by chemically assisted fragmentation (CAF)-MALDI-TOF sequencing to identify the protein functions. Among 22 different spots, several key enzymes specific to the carotenoid pathway, including isopentenyl pyrophosphate isomerase (IPP) and lycopene $\beta$-cyclase, appeared in H. pluvialis after exposure to high light intensity. Therefore, IPP and lycopene $\beta$-cyclase would appear to be involved with carotenoid accumulation in the cytoplasm, as these peptides were preferentially upregulated by high light intensity preceding an increase in carotenoid, and only these forms were detected in the red cyst cells.

• ALGAE
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• v.31 no.4
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• pp.289-301
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• 2016

Floating debris provides substrates for dispersal of organisms by ocean currents, including algae that thrive on plastics. The 2011 earthquake and tsunami in Tohuku, Japan resulted in large amounts of debris carried by the North Pacific Current to North America from 2012 to 2016. In 2015-2016, the plastics in the debris bore a complex biota including pink algal crusts. One sample (JAW4874) was isolated into culture and a three-gene phylogeny (psbA, rbcL, and SSU) indicated it was an unknown member of the red algal class Stylonematophyceae. It is a small pulvinate crust of radiating, branched, uniseriate filaments with cells containing a single centrally suspended nucleus and a single purple to pink, multi-lobed, parietal plastid lacking a pyrenoid. Cells can be released as spores that attach and germinate to form straight filaments by transverse apical cell divisions, and subsequent longitudinal and oblique intercalary divisions produce masses of lateral branches. This alga is named Tsunamia transpacifica gen. nov. et sp. nov. Sequencing of additional samples of red algal crusts on plastics revealed another undescribed Stylonematophycean species, suggesting that these algae may be frequent on drift oceanic plastics.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.2
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• pp.552-559
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• 2017

To assess the effect of LED lights on marine microalgae growth in the laboatory, Tetraselmis suecica, Chaetoceros simplex and Isochrysis galbana were cultured under $20{\pm}1^{\circ}C$, Walne's medium and aeration using 3.6 L glass vessels. The LED light sources were Blue, Red, Blue+Red, CoolWhite and WarmWhite. The experiments were conducted three times. The density of microalgae was shown as the counted number of cells per day, and the specific growth rate was calculated by using the density. The statistical analysis was performed by analysis of variance using the SPSS 20.0 program. T. suecica culture was the highest density under the Blue LED light source, so the light source was the most effective for the growth of this alga. C. simplex and I. galbana culture had the highest density under the Blue+Red LED light source, therefore this light source was the most effective for the growth of these algae. The result of analysis of variance showed significant between groups.

• Journal of Korean Society on Water Environment
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• v.34 no.3
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• pp.285-292
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• 2018

This study was performed in order to identify the red tide-causing organism and to understand the characteristics of the water quality during the winter of 2015 and 2016 in the Oncheon stream, a tidal river in Busan, where red tide often occurs in the wintertime. Two sites were selected on the stream and the surface water was sampled a total of 28 times during the experimental period. Twelve water quality characteristics, including water temperature, pH, DO, COD, total-N (T-N), total-P (T-P), and salinity were analyzed in order to test water quality. The cell numbers of cryptomonads were counted directly by microscopic observation. The nucleotide sequences of the partial 28S rRNA gene and psbA gene from metagenomic DNA, derived from each sampling site, were analyzed. According to the results, the alga most responsible for the bloom was identified as Teleaulax OC1 sp., which belongs to the cryptomonads. Three items of chl-a, pH, and DO were positively correlated with the cell numbers of the cryptomonads counted at the upper stream of the tidal area (St 1) while eight items of chl-a, TOC, BOD, total-N, COD, SS, pH, and DO were positively correlated with the cells located at the junction between the stream and Su-young river (St 2) in the order.

• ALGAE
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• v.29 no.4
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• pp.343-353
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• 2014

Despite the extensive literature on marine algae over the past few decades, a paucity of published research and studies exists on red algae. The purpose of this study was to evaluate the potential therapeutic properties of the ethanol extract of the red alga Callophyllis japonica against lipopolysaccharide (LPS)-stimulated macrophage inflammation. The C. japonica extract (CJE) significantly inhibited the nitric oxide (NO) production and the induced dose-dependent reduction of the protein and mRNA levels of inducible nitric oxide synthase and cyclooxygenase-2. Additionally, the CJE reduced the mRNA levels of inflammatory cytokines, including tumor necrosis factor-${\alpha}$, interleukin (IL)-$1{\beta}$, and IL-6. We investigated the mechanism by which the CJE inhibits NO by examining the level of mitogen-activated protein kinases (MAPKs) activation, which is an inflammation-induced signaling pathway in macrophages. The CJE significantly suppressed the LPS-induced phosphorylation of c-Jun N-terminal kinase, extracellular signal-regulated kinase and p38 MAPK. Taken together, the results of this study demonstrate that the CJE inhibits LPS-induced inflammation by blocking the MAPK pathway in macrophages.

• 한국해양학회지
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• v.10 no.2
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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.