• Journal of Korean Society of Water and Wastewater
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• v.37 no.4
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• pp.177-186
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• 2023

Perfluorooctanoic acid(PFOA) was one of widely used per- and poly substances(PFAS) in the industrial field and its concentration in the surface and groundwater was found with relatively high concentration compared to other PFAS. Since various processes have been introduced to remove the PFOA, adsorption using GAC is well known as a useful and effective process in water and wastewater treatment. Surface modification for GAC was carried out using Cu and Fe to enhance the adsorption capacity and four different adsorbents, such as GAC-Cu, GAC-Fe, GAC-Cu(OH)₂, GAC-Fe(OH)₃ were prepared and compared with GAC. According to SEM-EDS, the increase of Cu or Fe was confirmed after surface modification and higher weight was observed for Cu and Fe hydroxide(GAC-Cu(OH)₂ and GAC-Fe(OH)₃, respectively). BET analysis showed that the surface modification reduced specific surface area and total pore volumes. The highest removal efficiency(71.4%) was obtained in GAC-Cu which is improved by 17.9% whereas the use of Fe showed lower removal efficiency compared to GAC. PFOA removal was decreased with increase of solution pH indicating electrostatic interaction governs at low pH and its effect was decreased when the point of zero charges(pzc) was negatively increased with an increase of pH. The enhanced removal of PFOA was clearly observed in solution pH 7, confirming the Cu in the surface of GAC plays a role on the PFOA adsorption. The maximum uptake was calculated as 257 and 345 ㎍/g for GAC and GAC-Cu using Langmuir isotherm. 40% and 80% of removal were accomplished within 1 h and 48 h. According to R², only the linear pseudo-second-order(pso) kinetic model showed 0.98 whereas the others obtained less than 0.870.

• KSBB Journal
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• v.22 no.5
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• pp.356-361
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• 2007

Cyanobacteria are a very old group of prokaryotic organisms that produce very diverse secondary metabolites, especially non-ribosomal peptide and polyketide structures. Although some cyanobacteria produce lethal toxins such as microcystins and anatoxins, some may be useful either for development into commercial drugs or as biochemical tools. Detection of unknown secondary metabolites was carried in the present study by a screening of 98 cyanobacterial strains from Cyanobiotech GmbH in order to establish a screening process, isolate pure substances and determine their bioactivities. A degenerated polymerase chain reaction technique as molecular approaches has been used for general screening of NRPS gene and PKS gene in cyanobacteria. A putative PKS gene was detected by DKF/DKR primer in 38 strains (38.8%) and PCR amplicons resulted from a presence of NRPS gene were showed by MTF2/MTR2 primer in 30 strains (30.6%), respectively. A screening of interesting strains was performed by comparing PCR screening results with HPLC analyses of extracts. HPLC analysis for a detection of natural products was performed in extracts from biomass. 5 strains were screened for further scale-up processing. 7 pure substances were isolated from the scale-up cultures and tested for bioactivities under consideration to purity, amount and molecular weight of substances. One substance isolated from CBT 635 showed cytotoxic activity. This substance may be regarded as Microcystin LR.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.70-77
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• 2020

Microalgae are independent organisms that perform photosynthesis and can alter the culture environment to increase accumulation of useful substances derived from microalgae. In this study, cell growth was measured by incubation for 39 days using MBBM, Neo medium, and seven light sources, which is the main factor affecting cell growth of microalgae S. obliquus. In the case of S. oliquus, which grew in MBBM and Neo medium, cell growth was highest under fluorescent light sources and Red2 LED (R660) light sources, and cell growth was lowest under Infra Red LED (R741) light sources. The average cell growth rate was 17.7% for MBBM and 15.4% for Neo. Comparing the effects of dry cell weight of Neo medium containing nutrients on the production of aquatic plants, MBBM and dry cell weight of Neo resulted in higher cell growth than Neo medium under all LED light sources except for Blue LED (B450). This proves that MBBM is more suitable for increasing the cell growth of microalgae than Neo medium and confirms that light source selection is important in the production of useful materials through mass cultivation of microalgae in the future.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.1
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• pp.23-28
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• 2009

There is several ways of recycling methods for waste FRP boats. The main one is mechanical recycling that is one of the simple and technically proven methods. It recently has been reported that FRP can be recycled by separating into laminated glass fiber layers instead of crushing into powder. Even though the mechanical recycling is a good way for the eligibility of laminated glass fiber reinforced material, the system should have another option which can collect resin of FRP. Because the resin is still very useful renewable energy source, that cannot be discarded, But FRP is made up of laminated glass fiber(roving cloth layer) which is fire retardant substances and very hard to break into each layer. Due to the high cost of fossil energy the waste plastics should be regenerated to the source of renewable energy. Laminated glass fiber which is recyclable in a very limited way, is currently a serious barrier to waste FRP boat regenerating. This study is to propose a new extracting method which is efficient and environment friendly FRP waste regenerating system. The recycled glass fiber which is obtained by the separation of the roving layer from FRP waste has been found to be useful for concrete(FRC) products or concrete(FRC) structures as fiber reinforced material. And it can be successively applied to renewable energy applications using the waste resins of FRP residue without laminated glass fiber.

• Journal of Life Science
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• v.25 no.7
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• pp.733-739
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• 2015

Microalgae are a renewable natural resource that requires only sunlight, carbon dioxide, phosphorus, and nitrogen for rapid growth. They produce a broad variety of basic chemical substances―such as vitamins, fatty acids and carotenoids―that have high added value potential for the pharmaceutical and food industries. The aim of this study was to develop axenic culture and to establish a cell growth assay for microalgae. A further experiment was carried out to determine the yield of astaxanthin derived from microalgae. The axenic culture was developed using a mixture of antibiotics [ampicillin (100 ${\mu}g/ml$), streptomycin (10 ${\mu}g/ml$), chloramphenicol (10 ${\mu}g/ml$), penicillin (10 ${\mu}g/ml$), neomycin (50 ${\mu}g/ml$), gentamycin (50 ${\mu}g/ml$), kanamycin (10 ${\mu}g/ml$), and nystatin (1.5 ${\mu}g/ml$)] and then used to extract a variety of useful components from the microalgae. The optimal concentration for the antibiotic mixture was 1-3 percent. A spectrophotometric cell growth assay was also established. Astaxanthin was extracted from Haematococus lacustris with a yield of $1.9{\times}10^{-3}{\mu}g/l$ per 1 ml of culture medium. In conclusion, the axenic culture method developed here allows extraction of high-quality astaxanthin and other useful components from microalgae.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.3
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• pp.396-400
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• 2009

Dodok (Codonopsis lanceolata Bench. et Hook) root contains abundant pharmaceutical substances and is widely used as a food and a medicinal herb. To identify the major components, fermented Codonopsis lanceolata was analyzed for its chemical compositions prior to their pharmaceutical substances, which were used as the fundamental data. The contents of carbohydrate, crude protein, crude lipid and ash are 79.3%, 13.0%, 2.40% and 5.3%, respectively. The calories of fermented Codonopsis lanceolata was 390.5 kcal. Total dietary fiber was 47.4% of total carbohydrates. The protein was composed of 18 different amino acids. The contents of essential and non-essential amino acids were 8,118.18 mg and 10,913.42 mg. The K was the largest mineral followed by P, Ca and Mg, which means fermented Codonopsis lanceolata is alkali material. The contents of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids were 37.76%, 3.84%, and 35.64%, respectively. Therefore, the amount of the total unsaturated fatty acid was higher than that of any other plant. The content of crude saponin in fermented Codonopsis lanceolata was 60.1 mg/g. It is expected that a follow up study on fermented Codonopsis lanceolata through development and evaluation of processed foods for their functional properties would provide useful information as a source of medicinal foods.

• Journal of Life Science
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• v.20 no.5
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• pp.782-788
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• 2010

The protective effects of a powder mixed with solid-cultured and liquid-cultured Lentinus edodes mycelia (2 : 1, w/w) (designate LED) with different doses of carbon tetrachloride ($CCl_4$) on induced hepatotoxicity in male Sprague-Dawley (SD) rats was investigated. The rats were divided into seven groups (6 rats/group) and the following substances were administered orally to each group: Vehicle (0.2 ml distilled water), Control (0.2 ml distilled water), LED (LED 100, 200, 300 and 400 mg/kg BW in 0.2 ml distilled water), and Silymarin (200 mg/Kg BW in 0.2 ml distilled water). After two weeks of daily administration, all groups except for the Vehiclegroup were subjected to abdominal injection with $CCl_4$ ($CCl_4$ : corn oil, 1 : 1 v/v; 0.5 ml/kg BW). One day later, blood and liver samples were collected to analyze biomarkers. All LED treatments elevated hepatic superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH peroxidase) activities, and reduced thiobarbituric reactive substances (TBARS), tumor necrosis factor-$\alpha$ (TNF-$\alpha$), interleukin-$1{\beta}$ (IL-$1{\beta}$) and interleukin-6 (IL-6), resulting in the reduction of glutamate-oxalate transaminase (GOT), glutamate-pyruvate transaminase (GPT) and lactic acid dehydrogenase (LDH) activities in plasma. These results indicate that LED effectively protected SD rat hepatotoxicity induced by $CCl_4$ through its antioxidative activity and reduction of some cytokines. The highest efficacy was found in LED 200 mg/kg BW, showing potential as a useful material for protection from hepatotoxicity in humans.

• Journal of Life Science
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• v.29 no.10
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• pp.1096-1103
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• 2019

Neuroinflammation is mediated by the activation of microglia and has been implicated in the pathogenesis of neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease. Therefore, the inhibition of neuroinflammation may be an effective solution to treat these brain disorders. Protaetia brevitarsis seulensis is an insect belonging to the order Coleoptera and inhabits Korea, China, Japan and Siberia. P. brevitarsis seulensis is an edible insect that can be consumed as a protein source for humans. It has been reported that P. brevitarsis seulensis contains useful bioactive substances for hepatoprotection and improving blood circulation, such as indole alkaloids. Microglia cells are the main source of proinflammatory cytokines and nitric oxide (NO) in the central nervous system, which Perform neuroimmune, inflammatory, and other neurobilogical functions. In this study, we investigated the anti-neuroinflammatory effects of P. brevitarsis seulensis ethanol extract (PBE) in activated microglia cells treated with lipopolysaccgarude (LPS, 100 ng/ml). As a result, PBE significantly inhibited NO production without cytotoxicity and decreased the expression levels of inducible NO synthase and cyclooxygenase-2. In addition, the production of inflammatory cytokine secreted by LPS was also reduced by PBE. These results suggest that PBE could be a good source of functional substances to prevent neuroinflammation and neurodegenerative diseases.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.128-136
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• 2014

Acyl homoserine lactone (AHL) lactonase has been proved to be the AHL-degrading enzyme with the highest substrate specificity for AHL molecules and has shown a considerable potential as low-cost and efficient quorum quenching (QQ) technique. However, few studies focused on its inhibitory effect on biofilm formation which is also a quorum sensing (QS)-regulated phenomenon. In this study, QQ activity of six isolates from biofouled reverse osmosis membranes was studied using Chromobacterium violaceum CV026 and Agrobacterium tumefaciens NTL4 as biosensors under various conditions. All of the isolates belonged to the genus Bacillus and showed QQ activity regardless of the acyl chain length or substitution of AHL molecule. The isolates were capable of significantly inhibiting biofilm formation (46.7-58.3%) by Pseudomonas aeruginosa PAO1 and produced heat-sensitive extracellular QQ substances. The LC-MS analysis of the QQ activity of a selected isolate, RO1S-5, revealed the degradation of N-(3-oxododecanoyl)-L-homoserine lactone (3-oxo-C12 AHL) and the production of corresponding acyl homoserine (3-oxo-C12-HS), which indicated the activity of AHL lactonase. The broad AHL substrate range and high substrate specificity suggested that the isolate would be useful for the control of biofilm-related pathogenesis and biofouling in industrial processes.

• Journal of Dairy Science and Biotechnology
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• v.33 no.3
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• pp.203-207
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• 2015

The majority of food drying processes are based on the use of thermal energy. However, such methods may deteriorate the quality of the final product. Freeze-drying is one of the most useful processes for drying thermosensitive substances. Food that contains beneficial bacteria, for example, is susceptible to heat treatment, but during freeze-drying beneficial bacteria are preserved in these food items. The primary goals of this study were to develop yogurt snacks and to compare the viability of lactic acid bacteria (LAB) in yogurt snacks under different freeze-drying temperatures. In addition, the survival of LAB during storage was investigated. Survival of LAB in freeze-dried yogurt snacks gradually decreased over 16 weeks of storage. LAB had a residual viability of 25.5% after 16 weeks of storage at room temperature. LAB survived better in freeze-dried plain yogurt snacks than in freeze-dried strawberry yogurt snacks during storage. Freeze-dried yogurt snacks contained 11.9% fat, 57.1% carbohydrate, and 18.7% protein. In conclusion, the viability of LAB in freeze-dried yogurt snacks depends on the temperature during freeze-drying: the higher the freeze-drying temperature, the lower the viability of LAB in yogurt snacks. The viability of LAB in yogurt snacks was also dependent on the moisture content and nutritional value.