• Microbiology and Biotechnology Letters
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• v.48 no.2
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• pp.205-214
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• 2020

Cyanobacteria are microorganisms which have important roles in the nitrogen cycle due to their ability to fix nitrogen in water and soil ecosystems. They also produce valuable materials that may be used in various industries. However, some species of cyanobacteria may limit the use of water resources by causing harmful algal blooms in water ecosystems. Many culture collection depositories provide cyanobacterial strains for research, but their systematic preservation is not well-developed in Korea. In this study, we developed a method for the cryopreservation of the cyanobacteria Trichormus variabilis (syn. Anabaena variabilis), using alginate microcapsules. Two approaches were used for the experiments and their outputs were compared. One of the methods involved the cryopreservation of cells using only a cryoprotectant and the other used the cryoprotectant within microcapsules. After cryopreservation for 35 days, cells preserved with both methods were successfully regenerated from the initial 1.0 × 10⁵ cells/ml to a final concentration of 6.7 × 10⁶ cells/ml and 1.1 × 10⁷ cells/ml. Irregular T. variabilis shapes were found after 14 days of regeneration. T. variabilis internal structures were observed by transmission electron microscopy (TEM), revealing that lipid droplets were reduced after cryopreservation. The expression of the mreB gene, known to be related to cell morphology, was downregulated (54.7%) after cryopreservation. Cryopreservation using cryoprotectant alone or with microcapsules is expected to be applicable to other filamentous cyanobacteria in the future.

• Korean Journal of Heritage: History & Science
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• v.53 no.2
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• pp.222-241
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• 2020

The Taereung Royal Tomb from the Joseon Dynasty is the tomb of Empress Munjeong, the second queen of King Jungjong, and it contains various types of stone artifacts. All of these stone artifacts were constructed using coarse- to medium-grained biotite granite. The major types of deterioration of the stone artifacts are identified as surface weathering and biological contaminants. Exfoliation (145 sculptures), granular decomposition (138 sculptures), and repair materials (156 sculptures), along with biological contaminant algae (154 sculptures), lichen (165 sculptures) and moss (97 sculptures), have a high occurrence frequency. In particular, it is deemed that immediate conservation treatment is required, as biological deterioration (algae) represents the most serious condition (grade 3 or higher in 94% of all stones), and it is thought that exfoliation and granulation decomposition are required for long-term conservation management. As a result of equo -tip hardness and ultrasonic measurement, more than 70% of stones were found to have very weak physical properties. Through hyperspectral analysis, organisms were shown to inhabit more than 80% of the surface of burial mound stone artifacts, and P (phosphorus), S (sulfur), Cl (chlorine), and Ca (calcium) were detected in this area. This is because Taereung Royal Tomb has been exposed to the outdoors for hundreds of years and has been weathered by physical, chemical, and biological factors. Therefore, among the stone artifacts in the Taereung Royal Tomb, those with high physical weathering grades are considered to require consolidation to reinforce them physically. Since organisms are highly likely to cause stone damage, they must be removed via dry and wet cleaning. In addition, in order to delay the reoccurrence of organisms following conservation treatment, it is necessary to regularly clean up the soil that has flowed into the burial mound, and to monitor conservation conditions over the long term.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.4
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• pp.243-252
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• 2006

Influence of the increasing carbon dioxide concentration in seawater on various marine organisms is assessed in this article with regard to the impacts of anthropogenic $CO_2$ introduced into surface or deep oceans. Recent proposals to sequester $CO_2$ in deep oceans arouse the concerns of adverse effects of increased $CO_2$ concentration on deep-sea organisms. Atmospheric introduction of $CO_2$ into the ocean can also acidify the surface water, thereby the population of some sensitive organisms including coral reefs, cocolithophorids and sea urchins will be reduced considerably in near future (e.g. in 2100 unless the increasing trend of $CO_2$ emission is actively regulated). We exposed bioluminescent bacteria and benthic amphipods to varying concentrations of $CO_2$ and also pH for a short period. The ${\sim}l.5$ unit decrease of pH adversely affected test organisms. However, amphipods were not influenced by decreasing pH when HCl was used for the seawater acidification. In this article, we reviewed the biological adverse effects of $CO_2$ on various marine organisms studied so for. Theses results will be useful to predict the potential risks of the increase of $CO_2$ concentrations in seawater due to the increase of atmospheric $CO_2$ emission and/or sequestration of $CO_2$ in deep oceans.

• Journal of Wetlands Research
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• v.4 no.1
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• pp.63-85
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• 2002

This study was carried out to provide basic data for water environmental control and conservation, and to elucidate monthly water environmental factor, phytoplankton flora and dominant species that each stations was maked a selection of a sites by represent 3 branch-river in the Taejon area from Nov. 1997 to Dec. 1998. Range of water temperature was $2.4^{\circ}C{\sim}30.9^{\circ}C$(means of $16.02^{\circ}C{\sim}18.92^{\circ}C$), pH was 7.1~10.4(means of 7.40~8.68). BOD was generally under $5mg/{\ell}$ except Gap-chon kyo in Nov. and COD was measured highly by interfer of men at the each sites. Especially, occasion of Gap-chon kyo, data was estimated about 3~13 times higher than another sites. DO was showed 1.03~10.43ppm, SS was showed $1.0{\sim}120.0mg/{\ell}$ TN was that, upper stream was 0.63ppm, middle was 0.35ppm and then lower was 0.44ppm, upper stream was higher than lower. TP was at upper stream 0.03ppm, middle 0.05ppm, lower 0.06ppm, lower stream was higher than another. The phytoplankton flora was identified as total 230 taxa composed of 7 classes, 18 oders 35 families, 75 genara, 184 species, 42 virieties, 4 forms. There are composed of that, Chlorophyceae 94 taxa(40.9%), Bacillariophyceae 66 taxa(28.8%), Euglenophyceae 39 taxa(17.0%), Cyanophyceae 24 taxa(10.4%), Chrysophyceae 4 taxa(1.7%), Rhodophyceae 2 taxa(0.8%) Xanthophyceae 1 taxa(0.4%), composition of Spesies of each sites was Gapchon-kyo 119, Wonchon-kyo 94, Gasuwon-kyo and Mannyon-kyo 87, Ochung-kyo 78, Hyunam-kyo and Suchim-kyo 77, Moonchang-kyo 70 taxa and Sansung-kyo 58 taxa. Number of species was showed tendency of increase lower stream. Taejon-chon and youdung-chon and at the sites of confluence were presented Synedra ulna and Diatom vugare like bacillariophyceae, Gap-chon was dominated variously Oscillatoria princeps and chlorophyceae, confluence of 3 branch-river was presented Euglenophyceae.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.9
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• pp.871-877
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• 2015

Deep-sea equipment such as underwater robots and unmanned submersible vehicles, include various machine components and sensors, and it is important that their reliabilities be tested before use in the fields. This is necessary because they are affected by complex extreme-environment conditions, such as high pressures, extreme temperatures, and tidal forces that are present in the deep sea. We require test equipment that can conduct empirical tests in conditions that mimic these complex oceanic environments. In this study, we propose specifications that should be met, and a design plan for the primary components, which should limit their use to a maximum water pressure of 2.0 MPa, water temperature of $5{\sim}60^{\circ}C$, and a maximum flow velocity of 2 m/s. in work-in type underwater combined environment test equipment and. We present test system development procedures to verify the reliability of products and systems used in deep-sea environments.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.494-499
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• 2010

In this study, Sargassum coreanum was enzymatically hydrolyzed to prepare water-soluble extracts by using five carbohydrates (Viscozyme, Celluclast, AMG, Termamyl and Ultraflo) and five proteases (Protamex, Kojizyme, Neutrase, Flavozyme and Alcalase) and their potential antioxidant activity were evaluated. The Celluclast and Neutrase extracts of Sargassum coreanum exhibited better DPPH radical scavenging activities (92.42% and 92.78%, respectively) and hydrogen peroxide ($H_2O_2$) scavenging activities (58.28% and 57.97%, respectively) compared to those of other enzymatic extracts. These results suggest that Sargassum coreanum would be a good raw materials for antioxidant and enzymatic hydrolysis would be a good strategy to prepare antioxidant extracts from seaweeds.

• Weed & Turfgrass Science
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• v.7 no.2
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• pp.87-97
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• 2018

Turfgrass provides various beneficial effects to our societies such as recreation, aesthetic components, and other public service. Diseases in turfgrass is the major issue, which cause quality problems in golf courses, playgrounds, parks and cultivation areas, and tremendous cost is required to prevent the diseases. Research activity and investigation for turfgrass disease remain to be further attributed when compared to other crops in Korea. In this study, we present previously reported turfgrass diseases researches, especially caused by fungal pathogens, and review the history of turfgrass research activity in Korea to contribute future turfgrass research direction. Research papers were searched and analyzed using Korea Educational and Research Information Service (www.riss.kr). More than eighty papers presented turfgrass diseases and among the papers, 50% were published in Korean Journal of Turfgrass. Half of the papers reported turfgrass diseases control. Research articles about large patch disease were the majority (36%), followed dollar spot (18%), Pythium blight (10%) and Typhular blight (8%). Number of the first disease reports in Korea were total fifteen. Total 542 fungicides have been registered in Korea to prevent turfgrass diseases and most of the fungicides were for brown patch, rust, yellow patch, dollar spot, snow mold, summer patch, anthracnose, Pythium blight, powdery mildew and algae. And we will also need to conduct ecological studies on turf diseases and to develop control methods with improved efficacy and environmentally-friend sound. Researches on epidemiology of turfgrass diseases which deals with the incidence, distribution, and interactions with other factors will be also greatly favored for precise control prescription, timing of control and use of less pesticides.

• The Korean Journal of Food And Nutrition
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• v.19 no.2
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• pp.169-175
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• 2006

A unicellular algae, Chlorella vulgaris(CV), was used as a biological response modifier. The effect of CV on forced swimming test and blood biochemical parameters related to fatigue was investigated. Blood urea nitrogen(BUN); creatine kinase(CK); lactic dehydrogenase(LDH); glucose(Glc); total protein(TP); and albumin were determined. CV was orally administered to mice in the range of 0.05 to 0.15 g/kg/day. A forced swimming test results on 3 and 7 day after administration of CV, showed that immobility time was decreased in the CV-administered group(0.15 g/kg). In addition, the contents of BUN in the blood serum were decreased in CV-fed group. The contents of CK and LDH were tended to decrease, but not statistically significant. The plasma Glc level was increased in CV-fed groups(0.05 and 0.1 g/kg) compared to control group. It had no effect on the elevation of TP and albumin level. The results indicate that CV could improve physical stamina.

• Journal of Life Science
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• v.20 no.11
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• pp.1640-1647
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• 2010

Seaweeds have been recognized as a health food, having anti-obesity, anti-constipation and anticoagulation activities, and the use of seaweeds in the food, medicine, and cosmetic industries have recently significantly increased. In this study, methanol extracts were prepared from 35 different seaweeds (17 phaeophyta, 11 rhodophyta and 7 chlorophyta), and thrombin time (TT), prothrombin time (PT) and activated partial thromboplastin time (aPTT) were determined in order to develop safe and novel anticoagulation agents from natural products. In TT experiments, Ecklonia cava, Ecklonia stolonifera, Eisenia bicyclis (Kjellman) Setchell, Ishige foliacea, I. okamurai, Sargassum confusum and S. yamade showed strong thrombin inhibition activity among the 35 different seaweeds. In PT experiments, the inhibitions of prothrombin were identified in the selected seaweeds from TT experiment, with the exception of S. yamade. In aPTT experiments, the seaweeds with blood coagulation inhibition factors were E. cava, E. stolonifera, E. bicyclis (Kjellman) Setchell, I. foliacea, I. okamurai, S. confusum and Hixikia fusiforme Okamura. Further anticoagulation assay with the selected 8 seaweeds suggested that S. confusum is most effective in antithrombosis, and E. stolonifera, E. bicyclis (Kjellman) Setchell, and I. foliacea have high potential as antithrombosis agents. Based on components-activity correlation analysis, flavonoids are considered as active anticoagulation components of seaweeds These results suggest that edible seaweeds, especially S. confusum, have potential as safe and novel anticoagulants, and S. yamade and H. fusiforme Okamura could be used as a thrombin-specific and coagulation factor-specific inhibitors.

• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.437-447
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• 2020

The purpose of this study is to research the countermeasures and expected effects through the use of drones in the field of disaster prevention as a drone-based smart quarantine performance method. The environmental, market, and technological approaches to the review of the current quarantine performance task and its countermeasures are as follows. First, in terms of the environment, the effectiveness of the quarantine performance business using drone-based control is to broaden the utilization of forest, bird flu, livestock, facility areas, mosquito larvae, pests, and to simplify and provide various effective prevention systems such as AI and cholera. Second, in terms of market, the standardization of livestock and livestock quarantine laws and regulations according to the use of disinfection and quarantine missions using domestic standardized drones through the introduction of new technologies in the quarantine method, shared growth of related industries and discovery of new markets, and animal disease prevention It brings about the effect of annual budget savings. Third, the technical aspects are (1) on-site application of disinfection and prevention using multi-drone, a new form of animal disease prevention, (2) innovation in the drone industry software field, and (3) diversification of the industry with an integrated drone control / control system applicable to various markets. (4) Big data drone moving path 3D spatial information analysis precise drone traffic information ensures high flight safety, (5) Multiple drones can simultaneously auto-operate and fly, enabling low-cost, high-efficiency system deployment, (6) High precision that this was considered due to the increase in drone users by sector due to the necessity of airplane technology. This study was prepared based on literature surveys and expert opinions, and the future research field needs to prove its effectiveness based on empirical data on drone-based services. The expected effect of this study is to contribute to the active use of drones for disaster prevention work and to establish policies related to them.