• Journal of Life Science
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• v.14 no.2
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• pp.255-262
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• 2004

We applied nuclear DNA content stained with 4'-6'-diamidino-2-phenylindole (DAPI) and total protein concentration to predict the existence of Cochlodinium polykrikoides before huge blooms occurred, based on a short-term survey at sites in the South Sea. Fluctuations in environmental conditions and nutrients (nitrate, nitrite, and phosphate) were of a similar range, regardless of sampling sites or early and middle field observations. However, C. polykrikoides abundance was significantly different depending on the station, with a higher cell density of 34, 62, and 57 cells L$^{-1}$ at Stn C2, C5, and C6, respectively than what was found in early August, 2000. In mid August, 2000, the highest cell density of 547 cells L$^{-1}$ at Stn C3 was observed. The relationship between C. polykrikoides abundance, DAPI-stained DNA content, and total protein concentration was a positive correlation coefficient, in particular a higher positive correlation was exposed to even a smaller abundance of C. polykrikoides. These results suggest that DNA stained by DAPI and total protein concentration could play an important index in easily predicting the presence of C. polykrikoides before blooms.

• Journal of Environmental Science International
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• v.20 no.9
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• pp.1079-1085
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• 2011

The purpose of this study is to find the operational characteristics of nitrifier-dominated membrane bioreactor (MBR), which has been extensively studied for organic removal, especially in terms of nitrite ($NO_2$-N) build-up and membrane fouling. Membrane fouling is one of the important factor which determines the economics of MBR system. The characteristics of membrane fouling was monitored in terms of the fouling indices such as sludge volume index (SVI), the concentration of total organic carbon (TOC) and extracellular polymeric substances (EPS) in a membrane permeate or sludge extract, the absorbance of supernatant at 260 nm. Most of index values except for protein concentration in EPS had a close relation with the increase of suction pressure and SVI value. Nitrifying MBR was superior to the conventional organic-oxidizing MBR in terms of membrane fouling since the fouling index value of nitrifying MBR was lower than that of BOD-oxidizing MBR.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.3
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• pp.392-400
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• 2012

The purpose of this study was to analyze the physiological activity and antibiosis of mulberry powder by extract method. The total phenol content of mulberry powder extracted with methanol was 82.9 mg/g, while that of powder extracted with water was 46.9 mg/g. Extractions with methanol were therefore more effective than with water. The total flavonoid contents of mulberry powder extracted with methanol was 13.0 mg/g, while that of powder extracted with water was 9.4 mg/g. Also, the nitrite-scavenging ability of mulberry powder was lower than ascorbic acid and BHT. The SOD-like activity of mulberry powder extracts, natural antioxidant, and artificial antioxidant at 5 mg/mL arranged in order of decreasing concentration were ascorbic acid (98.3%) > BHT (88.1%) > water extract (9.8%) > methanol extract (3.0%). And, the OH radical scavenging activities of mulberry powder extracts and natural antioxidant at 5 mg/mL in order of decreasing concentration was ascorbic acid (97.0%) > methanol extract (46.2%) > water extract (35.8%). The antimicrobial effects of mulberry powder extracted with methanol could be detected on Bacillus cereus ($10,000{\mu}g/disc$) and Staphylococcus aureus ($10,000{\mu}g/disc$).

• Food Science and Biotechnology
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• v.17 no.3
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• pp.608-612
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• 2008

In Korea and China, cherry elaeagnus (Elaeagnus multiflora Thunb.) has been used traditionally to treat cough, diarrhea, itching, and foul sores. Therefore, in this study, the ethanol and water extracts of cherry elaeagnus leaves were examined for their antioxidant activities. The ethanol extract of the cherry elaeagnus leaves contained more phenolics than the water extract. All the cherry elaeagnus leaf extracts had higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability than ascorbic acid at concentrations of $250-1,000\;{\mu}g/mL$. The ethanol extract also showed higher superoxide dismutase (SOD)-like activity compared to the water extract. Furthermore, the SOD-like activity of the ethanol extract amounted to 89% of that of ascorbic acid at a concentration of $500\;{\mu}g/mL$. The nitrite scavenging ability and xanthine oxidase inhibitory (XOI) activity of the ethanol extract were higher than those of the water extract. In particular, the ethanol extract had higher XOI activity than ascorbic acid at a concentration of $1,000\;{\mu}g/mL$.

• KSBB Journal
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• v.28 no.3
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• pp.177-184
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• 2013

This research was to investigate the inhibitory effects of tyrosinase, elastase and collagenase using rapeseed meal extract for the functional cosmetics. Gamma-tocopherol and alpha-tocopherol contents were 304.9 and 212.2 mg/kg, respectively. In the case of delta-tocopherol and plastochromanol-8, they were 12.1 and 35.7 mg/kg, respectively. The total phenol content of methanol extract was the highest (49.6 mg/g) which was about 4.96 fold higher than that of water extract. The maximum nitrite scavenging activities of methanol and acetone extract at pH 1.2 were 85.2 and 80.1%, respectively, at 8.0 mg/mL. When the extract concentration of rapeseed meal increased upto 2.0 mg/mL, cell viabilities did not appear to have any significant cytotoxic effect, irrespective of extracts. Tyrosinase and elastase inhibition activities increased from 25.2 to 42.5% and 25.3 to 48.0%, respectively, as methanol extract concentration increased from 0.5 to 1.0 mg/mL. The collagenase inhibition activities of methanol and acetone extracts at 1.0 mg/mL were 67.2 and 68.0%, respectively. These results showed that the methanol and acetone extract of rapeseed meal can be used as a new source of functional cosmetic agent.

• Food Science of Animal Resources
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• v.43 no.4
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• pp.580-593
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• 2023

The purpose of this study was to analyze whether seawater has positive effects on appearance characteristics, such as CIE a^*, and to determine the gas composition concentration that is suitable for maintaining it. Pork hind meat was cured with four types of curing agent for 5 d at 4℃. The different curing agents comprised the control salt, control nitrite pickling salt (CN), treatment brine, and treatment bittern (BT). The cured hams were cooked at 65℃ for 4 h and packaged at O₂:N₂ gas ratios of 7:3, 8:2, and 9:1 for 3 wk. The physicochemical properties were assessed immediately after heating the sample, and the color properties were measured after a 3 wk storage period. Based on the correlation results of the physicochemical properties, BT had a higher curing and cooking yield than the other treatments, owing to its high salinity. Results of color properties for BT (7:3) and CN (8:2) showed similar color CIE L^*, CIE a^* chroma, and hue angle values. Therefore, BT can be said to be a sous-vide curing agent suitable for preserving the color of ham, and a high nitrogen concentration of 30% helps to maintain the appearance of seawater sous-vide ham.

• Korean Journal of Microbiology
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• v.20 no.3
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• pp.119-124
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• 1982

As a basic study to elucidate nutritional physiology and composition of synthetic medium of red rotting bacteria, Erwinia carotovora, of ginseng, the effects of hydrogen ion concentration, various kinds of carbon sources, nitrogen source, micrometallic salts and it's concentration on the gorwth of the bacteria were investigated and the results were as follows. Optimal pH in the basal medium for the growth of the bacteria was 6.5. After incubation the pH in culture media was neutralized. Among the various kinds of carbon sources, sucrose, glucose mannitol, but organic acids were not utilized effectively as nutrients. After incubation the pH turned acidic. Alanine as organic nitrogen sources nad ammonium sulfate as inorganic nitrogen promoted the growth, but L-valine and sodium nitrite were the least effective. Ferric chloride 1.0mg/dl and ferrous sulfate 100mg/dl were the most effective as micrometallic sources. Control and boric acid were the least effective. New synthetic medium based on the above results was follows ; Alanine 1.0g, $KH_2PO_4\;1.0g, \;sucrose\;30.0g, \;MgSo_4{\cdot}7H_2O\;0.5g, \;FeCl_3{\cdot}6H_2O\;1.0mg\;thiamine\;200{\gamma}g$, and distilled water 1000ml, pH6.5.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.90-95
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• 2009

This study investigates the oxidative degradation of N-nitrosodimethylamine (NDMA), a probable human carcinogen, by advanced oxidation process (i.e., UV process). The experiments were performed with various pH, initial concentration, UV intensity, and addition of $H_2O_2$ or $TiO_2$ on UV process. The results showed that the direct UV photolysis was the most effective treatment method. The lower pH, intial concentration and higher intensity of UV stimulated higher NDMA removal. However, addition of oxidant ($H_2O_2$, $TiO_2$) slows down photochemical treatment of NDMA since the oxidant can filter out the UV light and block it to reach the NDMA molecules. Dimethylamine (DMA) and nitrite were found to be a major byproduct from NDMA oxidation. To evaluate the chronic toxicity effects of UV-treated NDMA on the growth of microalgae, "Skeletonema costatum", was studied as long term experiments. Results demonstrated that after the 13 days exposure the chronic toxicity was decreased about 15% with application of UV process on NDMA degradation.

• Korean Journal of Microbiology
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• v.13 no.1
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• pp.37-44
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• 1975

As a basic study to elucidate nutritional physiology and composition of synthetic medium of red rotting bacteria, Erwinia carotovora, of ginseng, the effects of hydrogen ion concentration, various kinds of carbon sources, nitrogen source, micrometallic salts and it's concentration on the gorwth of the bacteria were investigated and the results were as follows. Optimal pH in the basal medium for the growth of the bacteria was 6.5. After incubation the pH in culture media was neutralized. Among the various kinds of carbon sources, sucrose, glucose mannitol, but organic acids were not utilized effectively as nutrients. After incubation the pH turned acidic. Alanine as organic nitrogen sources nad ammonium sulfate as inorganic nitrogen promoted the growth, but L-valine and sodium nitrite were the least effective. Ferric chloride 1.0mg/dl and ferrous sulfate 100mg/dl were the most effective as micrometallic sources. Control and boric acid were the least effective. New synthetic medium based on the above results was follows ; Alanine 1.0g, $KH_2PO_4$ 1.0g, sucrose 30.0g, $MgSo_4$ $7H_2$O 0.5g, $FeCl_36H_2$O 1.0mg thiamine 200.gamma.g, and distilled water 1000ml, pH6.5.

• Membrane and Water Treatment
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• v.10 no.4
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• pp.265-275
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• 2019

This study aimed to develop a compact partial nitritation step by forming granules with high Ammonia-Oxidizing Bacteria (AOB) fraction using the Air-lift Granulation Reactor (AGR) and to evaluate the feasibility of treating reject water with high ammonium content by combination with the Anammox process. The partial nitritation using AGR was achieved at high nitrogen loading rate ($2.25{\pm}0.05kg\;N\;m-3\;d^{-1}$). The important factors for successful partial nitritation at high nitrogen loading rate were relatively high pH (7.5~8), resulting in high free ammonia concentration ($1{\sim}10mg\;FA\;L^{-1}$) and highly enriched AOB granules accounting for 25% of the total bacteria population in the reactor. After the establishment of stable partial nitritation, an effluent $NO_2{^-}-N/NH_4{^+}-N$ ratio of $1.2{\pm}0.05$ was achieved, which was then fed into the Anammox reactor. A high nitrogen removal rate of $2.0k\; N\;m^{-3}\;d^{-1}$ was successfully achieved in the Anammox reactor. By controlling the nitrogen loading rate at the partial nitritation using AGR, the influent concentration ratio ($NO_2{^-}-N/NH_4{^+}-N=1.2{\pm}0.05$) required for the Anammox was controlled, thereby minimizing the inhibition effect of residual nitrite.