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Park J.S.,Sangmyung University | Jung S.W.,Korea Advanced Institute of Science and Technology | Lee S.D.,Nakdonggang National Institute of Biological Resources | Yun S.M.,Sangmyung University | Lee J.H.,Sangmyung University
Phycologia | Year: 2016

Thalassiosira species are an important component of phytoplankton populations, and most species are considered cosmopolitan. Many authors have investigated the diversity of Thalassiosira species in order to understand their ecological roles in local areas. Our regional taxonomic study revealed the presence of 44 Thalassiosira species at 124 sites in Korean coastal waters. Of these, 14 species are newly reported in Korean waters and are described in detail with external and internal valve illustrations. Some morphologically confused taxa, such as the Thalassiosira s.s. group, T. curviseriata/T. tealata, T. simonsenii/Planktoniella blanda and T. proschkinae/T. spinulata, are clearly distinguished using additional morphological criteria. In addition, the full biogeographical distribution of Thalassiosira is described and compared with the Korean species. Korean waters seem to be the 'Maginot Line' for the cold- and warm-water Thalassiosira species. Knowledge of Thalassiosira species diversity will increase with more intensive work in relatively little-studied regions, such as the Indo-Pacific and tropical Atlantic Oceans. © 2016 International Phycological Society. Source

Song M.-Y.,Inland Fisheries Research Institute | Lee W.-O.,Inland Fisheries Research Institute | Kim K.-H.,Inland Fisheries Research Institute | Park Y.-S.,Kyung Hee University | Bae M.-J.,Nakdonggang National Institute of Biological Resources
Annales de Limnologie | Year: 2016

Dams can cause fragmentation of the natural structure and function of fish communities up- and downstream of the dam. In this study, we examined the effects of the Goesan Dam on the longitudinal distribution of fish in the Dal stream, using two computational methods: a self-organizing map (SOM) and spatial autocorrelation. Fish were collected at 16 different study sites in two seasons (spring and autumn). SOM classified the study sites into four clusters (1-4), reflecting differences in the longitudinal distribution patterns of fish, and the effects of the dam on fish community composition. Samples in clusters 1 and 2 mostly originated from tributaries and the upstream section of the dam, whereas samples in cluster 4 originated from downstream study sites of the dam. Cluster 3 included study sites originating directly from up- and downstream of the dam. Species turnover and spatial autocorrelation results confirmed the fish community alteration near the dam. Species turnover was the highest between study sites directly up- and downstream of the dam. The Mantel correlogram was positive when applied to short distances between the study sites. However, it was negative for the farthest distance, including sites near the dam, indicating that the dam caused significant alterations to the fish community. Overall, our results suggest that the habitat alterations (e.g., fragmentation of longitudinal gradients and disruption of flow regimes) due to dam construction have caused fragmentation of fish communities. © 2016 EDP Sciences. Source

Jeong H.I.,Chung - Ang University | Jin H.M.,Chung - Ang University | Jin H.M.,Nakdonggang National Institute of Biological Resources | Jeon C.O.,Chung - Ang University
Journal of Biotechnology | Year: 2016

Sphingorhabdus sp. M41, capable of degrading aliphatic and aromatic hydrocarbons, was isolated from crude oil-contaminated costal sediment by an enrichment culture and its complete genome was sequenced. The genome of strain M41 has a chromosome with a size of 3,324,420 bp, including 44 tRNAs, 6 rRNAs, and 3118 protein-coding genes. In addition, many potential genes responsible for the biodegradation of aliphatic and aromatic hydrocarbons were identified from the genome. This is the first complete genome of the genus Sphingorhabdus, which will provide insights into the bioremediation of crude oil-contaminated costal sediment by strain M41. © 2016. Source

Kim D.-Y.,International Ginseng & Herb Research Institute | Yeom S.-J.,Synthetic Biology & Bioengineering Research Center | Park C.-S.,Catholic University of Daegu | Kim Y.-S.,Nakdonggang National Institute of Biological Resources
Biotechnology Letters | Year: 2016

Objectives: To optimize conversion of rutin to isoquercetin by commercial α-l-rhamnosidase using high hydrostatic pressure (HHP). Results: The de-rhamnosylation activity of α-l-rhamnosidase for isoquercetin production was maximal at pH 6.0 and 50 °C using HHP (150 MPa). The enzyme showed high specificity for rutin. The specific activity for rutin at HHP was 1.5-fold higher than that at atmospheric pressure. The enzyme completely hydrolysed 20 mM rutin in tartary buckwheat extract after 2 h at HHP, with a productivity of 10 mM h−1. The productivity and conversion were 2.2- and 1.5-fold higher at HHP than at atmospheric pressure, respectively. Conclusions: This is the first report concerning the enzymatic hydrolysis of isoquercetin in tartary buckwheat at HHP. © 2016 Springer Science+Business Media Dordrecht Source

Bae K.H.,National Institute of Biological Resources | Bae K.H.,Nakdonggang National Institute of Biological Resources | Kim S.-Y.,National Institute of Biological Resources
Journal of Plant Biotechnology | Year: 2015

Calanthe striata f. sieboldii Decne. ex Regel is a terrestrial orchid with beautiful flowers arranged in racemose inflorescences. This species is threatened due to over-collection and loss of suitable habitats. Asymbiotic germination is useful in the conservation efforts to re-establish plants in the wild, and for commercial propagation. In this study, we investigate the effects of sodium hypochlorite (NaOCl), three types of culture media (Phytomax Orchid Maintenance-POM, Seed Germination Maintenance-SGM, and Murashige and Skoog 1962-MS), and plant growth regulators on embryo swelling, protocorm formation, and embryo diameter of C. striata f. sieboldii. Treatment with 1% NaOCl for 30 min greatly enhanced embryo swelling (28.3%), embryo diameter (205.8 μm), and embryo protocorm formation (54.8%) compared to seeds without NaOCl treatment (embryo swelling 8.5%, embryo diameter 14.6 μm, and protocorm formation 13.4%) on POM medium. Protocorm formation on POM medium supplemented with 1.0 mg/L N6-benzyladenine (BA) (95.6%) was better than the control (54.5%). Additionally, the effects of activated charcoal (AC) and sucrose on seedling growth in in vitro culture were examined. The protocorm converted into healthy plants with well-developed shoot primordia on the POM medium with AC and sucrose. The most suitable conditions for seedling growth after 10 weeks of culture were the POM medium with AC or sucrose. These results show effective asymbiotic seed germination and in vitro seedling growth of C. striata f. sieboldii. © Korean Society for Plant Biotechnology. Source

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