• Journal of the korean society of oceanography
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• v.34 no.3
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• pp.167-171
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• 1999

Since toxic Alexandrium catenella and non-toxic A. fraterculus are morphologically similar, they are difficult to discriminate under the light microscope. However, a novel technology, such as fluorescein isothiocyanate (FITC)-conjugated lectin probes enables easy and rapid differentiation. Toxic A. catenella bound seven different lectins, whereas the non-toxic A. fratercuzus did not bind Arachis hypogaea (PNA) lectin. In addition, Pseudo-nitrschia species in this study were also difficult to identify to species level with light microscope techniques, but it was possible to classify them using fluorescent lectins. Pseudo-nitzschia multistriata, P. subfraudulenta and P. pungens bound Canavalia ensiformis (ConA), whereas P. subpaclfica did not, and P. pungens also bound Ricinus communis (RCA). These results imply that lectin could be used as a critical tool in the differentiation of P. multistriata, P. subfraudulenta and P. pungens. However, P. subpacifica was not differentiated by the lectins tested. Therefore, it isconcluded that lectin probes are useful for discriminating toxic A. catenella from non-toxic A. fraterculus, and for the identification of some Pseudo-nitzschia species. In addition, this method has a great potential to speed and detection between non-toxic and toxic harmful algal blooms (HABs) in Korean biotoxin monitoring systems.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.743-760
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• 2014

This study aimed to isolate and identify freshwater algae from the organic agricultural ecosystems and investigate its biological characteristics to study the possibility of utilizing a biomass freshwater algae in organic farming. In the survey area, average water temperature was $12.4{\sim}28.2^{\circ}C$ and the pH ranges were from 6.1 to 8.5. The solid culture method is more suitable than liquid culture method for isolation of freshwater algae with lower contamination level and higher isolation frequency. A total of 115 strains were isolated from six freshwater algae habitats in nine regions in Korea. BGMM (BG11 Modified Medium) amended with NaNO3 and $KNO_3$ as a nitrogen, and $Na_2CO_3$ as carbon source was designed to isolate and culture freshwater algae. Absorbance of freshwater algae culture has increased dramatically to four days and decreased after eight days after inoculation. CHK008 of the seven isolates showed the highest absorbance in seven days after culturing in BGMM. The optimal pH of BGMM for culturing freshwater algae was pH 6-7. As light intensity increased, growth of freshwater algae increased. Among the five kinds of carbon sources, glucose and galactose promoted good growth of freshwater algae in BGMM. The colony color of purified 16 green algae isolates showed a separation of green, dark and light green, and of them, eleven algae strains showed a strong fluorescent light under fluorescence microscopy. Cell size of the green algae showed a wide range of variation depending on the species. General morphology of the green algae strains was spherical. Chlamydomonas sp. was elliptical, and Chlorella sorokiniana was ellipsoidal and cylindrical. All strains of the green algae except for Chlamydomonas sp. did not have flagella. One isolate of Chlamydomonas sp. and five isolates of C. sorokiniana secreted mucus. Sixteen isolates of 16 green algae were identified as two family and six species, Chlorella vulgalis, C. sorokiniana, C. pyrenoidosa, C. kessleri, C. emersonii, and Chlamydomonas sp. based on their morphological characteristics.

• ALGAE
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• v.20 no.4
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• pp.305-314
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• 2005

5 Haptophyta 2 Chrysophyta and 1 Prasinophyta species of scale-bearing nanoflagellates were collected in coastal water of Korea and identified by examination of their scales with Field Emission Scanning Electron Microscope (JSM-6700F). These included Chrysochromulina ahrengoti, C. simplex, C. spinifera, Prymnesium parvum, P. patelliferum, Mamiella gilva, Paraphysomonas imperforata and Pa. vestita. The surface of cells covered with unmineralised scales (5 Haptophyte and 1 Prasinophyta species) or silica scales (2 Chrysophyta species). Scale-covered flagella are found in the 1 Prasinophyta species. One of the main structural characteristics of Haptophyte is the haptonema, a filiform organelle which occurs together with the two flagella. It may be long and coiling upon irritation as in Chrysochromulina, or short and noncoiling as in Prymnesium.

• ALGAE
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• v.20 no.1
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• pp.25-30
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• 2005

To clarify some confusions concerning identification of the Korean Peridinium species, genotypic analysis was performed with their SSU rDNA sequences. PCR was used to amplify the partial SSU rDNA of Peridinium isolates collected from three different Korean waters (Juam, Sang-sa and Togyo Reservoirs). The PCR products were allowed directly to sequence, which revealed each 942 bp of rDNA sequence. Analyses of the rDNA sequences showed that all the Korean isolates had the same genotype (100% sequence homology), and they were nearly identical to a Japanese strain of P. bipes f. occultatum (NIES 364; 99.8% sequence similarity). The sequence-based comparisons could clearly resolve P. bipes f. occultatum isolated from three different Korean waters.

• ALGAE
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• v.22 no.3
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• pp.147-152
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• 2007

We described two brownish freshwater Cryptomonas species, C. marssonii Skuja and C. pyrenoidifera Geitler as first records in Korea. The identification was based on light microscopy, scanning electron microscopy, and nuclear SSU rDNA sequences analysis. Cryptomonas marssonii is characterized by its sigmoid shape with a sharply pointed and dorsally curved antapex, dorso-ventrally flattened cell, two lateral plastids without pyrenoid, and its dimension of 18-25 μm in length and 8-13 μm in width. Cryptomonas pyrenoidifera is characterized by ovoid to elliptical shape with a partially twisted or rounded antapex, dorso-ventrally biconvex cell, lateral plastids with two pyrenoids, and the dimensions of 15-22 μm in length and 10-14 μm in width. Nuclear SSU rDNA sequences between C. marssonii WCK01 from Korea and CCAC0086 from Gernmay, and between C. pyrenoidifera WCK02 from Korea and CCMP152 from Australia were identical, respectively.

• ALGAE
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• v.21 no.4
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• pp.349-375
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• 2006

The application of modern ecological, ultrastructural and molecular methods, aided by the cultivation of numerous cyanobacterial morphotypes, has substantially changed our knowledge of these organisms. It has led to major advances in cyanobacterial taxonomy and criteria for their phylogenetic classification. Molecular data provide basic criteria for cyanobacterial taxonomy; however, a correct phylogenetic system cannot be constructed without combining genetic data with knowledge from the previous 150 years research of cyanobacterial diversity. Thus, studies of morphological variation in nature, and modern morphological, ultrastructural, ecophysiological and biochemical characters need to be combined in a “polyphasic” approach. Taxonomic concepts for generic and infrageneric ranks are re-evaluated in light of combined phenotypic and molecular criteria. Despite their usefulness in experimental studies, the limitations of using strains from culture collections for systematic and nomenclatural purposes is highlighted. The need for a continual revision of strain identification and proper nomenclatural practice associated with either the bacteriological or botanical codes is emphasized. Recent advances in taxonomy are highlighted in the context of prospects for understanding cyanobacterial diversity from natural habitats, and the evolutionary and adaptational processes that cyanobacteria undergo.

• ALGAE
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• v.23 no.3
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• pp.187-199
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• 2008

A study on the fine structure of the marine diatom Thalassiosira has been carried out during the periods from January 2007 to March 2008 in Korean coastal waters. As the third series of the Thalassiosira species, a fine structure, description, distribution and taxonomic remarks of the six Thalassiosira species were observed by means of light microscope and scanning electron microscope. The critical features of Thalassiosira species were a shape of external tubes of marginal strutted processes and labiate process. Six species showed each different shape of external tubes, marginal strutted processes and labiate process. The shape of external tube was divided into five types: T shape of Thalassiosira curviseriata, small-rounded shape of T. lundiana, double-layer form and flame shape of T. nordenskioeldii, tulip shape of T. punctigera and tooth-shape of T. tenera. This external character may be able to key character for positive identification of the Thalassiosira species. Of these Thalassiosira lundiana, T. minuscula and T. tenera were new records for Korean coastal waters.

• ALGAE
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• v.23 no.3
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• pp.201-207
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• 2008

Based on samplings during 2006-2007 on the intertidal zone of Playa Tampico, Eréndira and Punta Baja, Baja California, Ulva pertusa Kjellman (Ulvales, Chlorophyta) was recorded for the first time for the Pacific coast of Mexico. An alga native to Asia, U. pertusa has just recently been recorded in the southern coast of California (USA). The identification of U. pertusa was based on the observation of the morphology and reproductive characters of the collected specimens. Furthermore, the species identity was confirmed by molecular comparison between nuclearencoded ITS2 sequences of the Mexican samples and those of other Ulva species in GenBnak data. Habitat and distribution of U. pertusa along the Pacific coast of North America are also described. Considering our new report of its occurrence in Mexico, we conclude that U. pertusa is expanding its geographical distribution by trans-ocean introductions.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.4
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• pp.294-302
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• 2019

As a series of fundamental researches on the development of an automatic identification monitoring system for fishing gear. Firstly, the study on the installation method of automated identification buoy for the coastal improvement net fishing net with many loss problems on the west coast was carried out. Secondly, the study was conducted find out how to install an automatic identification buoy for coastal gill net which has the highest loss rate among the fisheries. GPS for fishing was used six times in the coastal waters around Seogwipo city in Jeju Island to determine the developmental status and underwater behavior to conduct a field survey. Next, a questionnaire was administered in parallel on the type of loss and the quantity and location of fishing gear to be developed and the water transmitter. In the field experiment, the data collection was possible from a minimum of 13 hours, ten minutes to a maximum of 20 hours and ten minutes using GPS, identifying the development status and underwater behavior of the coastal gillnet fishing gear. The result of the survey showed that the loss of coastal net fishing gear was in the following order: net (27.3%), full fishing gear (24.2%), buoys, and anchors (18.2%). The causes were active algae (50.0%), fish catches (33.3%) and natural disasters (12.5%). To solve this problem, the installation method is to attach one and two electronic buoys to top of each end of the fishing gear, and one underwater transmitter at both ends of the float line connected to the anchor. By identifying and managing abnormal conditions such as damage or loss of fishing gear due to external factors such as potent algae and cutting of fishing gear, loss of fishing gear can be reduced. If the lost fishing gear is found, it will be efficiently collected.

• Journal of Microbiology
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• v.45 no.6
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• pp.541-546
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• 2007

Red algae are distributed globally, and the group contains several commercially important species. Griffithsia okiensis is one of the most extensively studied red algal species. In this study, we conducted expressed sequence tag (ESTs) analysis and synonymous codon usage analysis using cultured G. okiensis samples. A total of 1,104 cDNA clones were sequenced using a cDNA library made from samples collected from Dolsan Island, on the southern coast of Korea. The clustering analysis of these sequences allowed for the identification of 1,048 unigene clusters consisting of 36 consensus and 1,012 singleton sequences. BLASTX searches generated 532 significant hits (E-value <$10^{-4}$) and via further Gene Ontology analysis, we constructed a functional classification of 434 unigenes. Our codon usage analysis showed that unigene clusters with more than three ESTs had higher GC contents (76.5%) at the third position of the codons than the singletons. Also, the majority of the optimal codons of G. okiensis and Chondrus crispus belonging to Bangiophycidae were G-ending, whereas those of Porphyra yezoensis belonging to Florideophycidae were G-ending. An orthologous gene search for the P. yezoensis EST database resulted in the identification of 39 unigenes commonly expressed in two rhodophytes, which have putative functions for structural proteins, protein degradation, signal transduction, stress response, and physiological processes. Although experiments have been conducted on a limited scale, this study provides a material basis for the development of microarrays useful for gene expression studies, as well as useful information for the comparative genomic analysis of red algae.