• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.772-779
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• 2005

Ammonia-oxidizing bacteria (AOB) were enriched by repeating fed-batch cultivations in an AOB-selective medium of activated sludges from a domestic wastewater treatment plant. Enriched culture showed strong capabilities of ammonia oxidation [0.810 mg $NH_4^+$-N/mg mixed liquor suspended solids (MLSS)$\cdot$day] as well as $NO_x^-$-N production (0.617 mg $NO_x^-$-N/ mg MLSS$\cdot$day). Degree of enrichment was examined through fluorescent in situ hybridization (FISH) analyses using an AOB-specific Cy3-labeled oligonucleotide probe (NSOl90) and terminal-restriction fragment length polymorphism (T-RFLP) analyses. FISH analyses confirmed that the fraction of AOB among 4',6-diamidino-2-phenylindole (DAPI)-stained cells increased from about less than $0.001\%$ to approximately $42\%$ after enrichment of AOB, and T-RFLP analyses showed that bacterial community became simpler as enrichment was continued. When the enriched culture of AOB was added (150 mg/l as dry suspended solid) to the normal activated sludge (3,000 mg/l as dry suspended solid), nitrification efficiencies were improved from 0.020 mg $NO_x^-$-N/mg MLSS$\cdot$day to 0.041 mg $NO_x^-$-N/mg MLSS$\cdot$day in a synthetic wastewater and also from 0.0007 mg $NO_x^-$-N/mg MLSS$\cdot$day to 0.0918 mg $NO_x^-$-N/mg MLSS$\cdot$day in a real domestic wastewater. Therefore, it is expected that this enrichment method could be used for improving efficiency of nitrification in wastewater treatment plants.

• 한국식생활문화학회지
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• 제30권1호
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• pp.77-85
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• 2015

This study investigated the physicochemical properties and antioxidative activity of soymilk added with buckwheat sprout (SBS), and sensory properties of SBS were analyzed with control soymilk (CS). Moisture content decreased while protein, ash, and lipid contents increased according to content of buckwheat sprout. Solids content and viscosity tended to increase with addition of buckwheat sprout from 0% (CS) to 2.5% (2.5SBS), 3.5% (3.5SBS), and 4.5% (4.5SBS). SBS was found the significant pH drop from 7.08 to 6.43, 6.34, and 6.21. Suspension stability of soymilk slightly decreased with addition of buckwheat sprout. Hunter's color value L of SBS decreased while a and b values increased in comparison with CS. Rutin content was measured 23.78 mg/100 g (2.5SBS), 39.68 mg/100 g (3.5SBS), and 44.80mg/100 g (4.5SBS). Vitamin C content in SBS was higher than CS. Daidzin content increased as buckwheat sprout was added. Total phenolic content increased from 100.95 mg/100 g (CS) up to 315.71 mg/100 g (4.5SBS). For free radical scavenging activity, SBS was significantly higher than CS. In conclusion, SBS can be used as a functional food with higher amounts of rutin, vitamin C, total phenolics, and daidzin. 2.5SBS and 3.5SBS also showed better overall quality characteristics.

• 한국식생활문화학회지
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• 제31권6호
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• pp.597-604
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• 2016

This study was performed to investigate the quality characteristics of lotus root tea (LT) prepared with Gardenia jasminoides powder (GLT) and Rubus coreanus Miquel powder (RLT). The proximate compositions, physicochemical properties, mineral contents, and sensory evaluations of samples were measured. GLT sample showed higher contents of crude protein, crude fat, crude ash, and moisture (p<0.001) as well as pH (p<0.001) compared to LT and RLT. In terms of color, lightness (L) and yellowness (b) of GLT were the highest among the samples, whereas redness (a) of GLT was the lowest. The results of mineral analysis showed that the mineral contents of K, Ca, and Fe of LT were the highest, whereas the content of Mg of GLT was the highest. The results of browning color intensity of all samples showed that LT had the lowest. GLT showed higher contents of water soluble solids than LT and RLT. In the sensory evaluation, the scores of color, flavor, aftertaste, feeling of throat, and overall preference of LT and GLT were significantly higher than those of RLT. From the findings, this study suggests that addition of Gardenia jasminoides powder was effective for preparation of lotus root tea in the aspects of consumer acceptability.

• 한국식생활문화학회지
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• 제36권1호
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• pp.84-91
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• 2021

The oriental plum (Prunus salicina) is one of the most popular fruits in Korea due to its sweet taste and pleasant aroma. The objective of this study was to analyze the quality characteristics and antioxidant activities of a puree made using plums stored at low-temperatures. The quality characteristics were determined by estimating total soluble solids (TSS, °Brix), titratable acidity (TA, % citric acid), TSS/TA ratio, pH, colors, sugar content, and sensory profiles. The antioxidant effects were estimated by total polyphenol and flavonoid content and radical scavenging activity. The results showed that the plum puree containing both the flesh and the peel had markedly higher red coloration (a⁎ value) than the puree without the peel, while yellow coloration (b⁎ value) and lightness (L⁎ value) were lower in the puree without the peel than with the peel. The sensory qualities including the plum taste and flavor, texture as well as overall acceptance showed no significant variation between the samples. Meanwhile, the total polyphenol/flavonoid content and radical scavenging activities were significantly improved by the presence of fruit peel and by frozen storage. These findings suggest that frozen plums could be a suitable ingredient for making a puree and concentrate for the food manufacturing industry.

• 한국식생활문화학회지
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• 제37권6호
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• pp.555-563
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• 2022

The purpose of this study was to confirm the quality characteristics of distilled soju with different rice pretreatment processes. The non-steamed fermentation method is a technology that uses starch to produce saccharification and alcohol without going through the steaming of raw materials. It has advantages such as reduction of manpower and cost, prevention of nutrient loss, and minimization of waste water. In this study, rice used were non-steamed and pulverized 'Baromi2', nonsteamed and steamed 'Samgwang', and puffed rice. As the fermenting agent, koji, modified nuruk, N9 yeast, and purified enzyme were used, and lactic acid was added to prevent contamination during fermentation. The amount of water was 300% in total, and after the first watering, 5 days after fermentation, the second watering was carried out. As a result of the study, it was confirmed that the non-steamed fermentation method using 'Baromi' was superior to the existing fermentation method in terms of temperature during fermentation, final alcohol content, soluble solids, and pH. By expanding the stability of the production technology of non-steamed fermentation technology, product quality improvement can be expected.

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.626-632
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• 2005

A new bacterium BL-2 excreting a novel cationic polyglucosamine biopolymer was isolated from the spoiled leaves of Chinese cabbage and identified as Enterobacter sp. BL-2. The isolated Enterobacter sp. BL-2 was cultivated in pH-stat fed-batch culture using acetic acid as the feeding stock at pH 8.0, resulting in 17.11 g/l of cells and 1.53 g/l of an extracellular biopolymer after 72 h. The excreted biopolymer was purified by a three-step procedure, involving ethanol precipitation and deproteinizations, to a nearly homogeneous state, and its molecular weight was found to be 106 kDa. It was composed of glucosamine, rhamnose, and galactose at a molar ratio of 86.4:1.6:1.0, respectively, indicating a rarely found novel high-glucosamine-containing biopolymer. The FT-IR and $^{13}C-NMR$ spectra of the novel cationic polyglucosamine biopolymer PGB-l revealed a close identity with chitosan from crab shell. It can effectively flocculate various suspended solids, including kaolin clay, $Ca(OH)_2,\;Al_{2}O_3$, active carbon, microbial cells, and acidic dyes.

• Fisheries and Aquatic Sciences
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• 제12권4호
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• pp.317-323
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• 2009

Waste products were biologically estimated from juvenile flounder (Paralichthys olivaceus) on three diet types-raw fish-based moist pellets, moist pellets, and extruded pellets. Total solid and soluble wastes were estimated by determining nutrient digestibility and accumulation in juvenile flounders through growth trials. Total solid wastes produced were 20%-23% of the organic matter supplied. Soluble excretions ranged from 45% to 49%. Soluble nitrogenous excretions ranged from 36.4% to 46.2%. These results indicate that about 30.2%-35.9% of supplied feed is retained in the fishes' bodies while the remainder of feed is excreted into culture systems or the surrounding environment.

• 한국농공학회논문집
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• 제52권6호
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• pp.19-26
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• 2010

Batch experiments were conducted to investigate growth and nutrient removal performance of microalgae Chlorella vulgaris by using piggery wastewater in different concentration of pollutants and the common growth models (logistic, Gompertz and Richards) were applied to compare microalgal growth parameters. Removal of nitrogen (N) and phosphorus (P) by Chlorella vulgaris showed correlation with biomass increase, implying nutrient uptake coupled with microalgae growth. The higher the levels of suspended solids (SS), COD and ammonia nitrogen were in the wastewater, the worse growth of Chlorella vulgaris was observed, showing the occurrence of growth inhibition in higher concentration of those pollutants. The growth parameters were estimated by non-linear regression of three growth curves for comparative analyses. Determination of growth parameters were more accurate with population as a variable than the logarithm of population in terms of R square. Richards model represented better fit comparing with logistic and Gompertz model. However, Richards model showed some complexity and sensitivity in calculation. In the cases tested, both logistic and Gompertz equation were proper to describe the growth of microalgae on piggery wastewater as well as easy to application.

• 한국축산식품학회지
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• 제38권6호
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• pp.1160-1167
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• 2018

The objective of this study was to evaluate the composition, pH, titratable activity, microbial properties, and antioxidant effect of yogurt using ginseng extract powder (GEP), Lactobacillus plantarum NK181, and Streptococcus thermophilus as the starter culture. Different concentration of GEP (0%, 0.5%, 1%, 1.5%, and 2% (w/v)) were used in the yogurt. During yogurt fermentation, pH was decreased; however, titratable acidity and viable cell counts were increased. The addition of GEP to yogurt led to a decrease in moisture content and an increase in the fat, ash, and total solids content. The antioxidant effect using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, ${\beta}$-carotene bleaching, and ferric reducing antioxidant power (FRAP) assay gradually increased with added GEP. Overall, yogurt fermented with 1% GEP was acceptable in terms of cell viability and antioxidant effect. These results might provide information regarding development of ginseng dairy products with enhanced antioxidant activities and probiotic properties.

• 한국식품과학회지
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• 제30권6호
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• pp.1470-1475
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• 1998

한국 전통약주의 암세포주에 대한 세포독성과 체내에서의 암세포 성장 및 전이에 대한 영향을 조사하기 위하여 무증자 발효 방법으로 발효시킨 전형적인 약주(전통약주II)와 이 약주에 한약재를 첨가하여 발효한 것(전통약주I), 비교 시료로 일본 청주에 대하여 연구하였다. 각 시료를 동결건조하고 증류수로 재용해하여 실험에 사용하였는데 암세포주에 대한 세포독성 실험 결과 B16BL6 mouse melanoma 세포에 대하여 전통약주는 2종류 모두 본래 농도의 16배 미만의 희석 배수에서 세포독성을 나타냈으며, 일본 청주는 8배 미만의 희석배수에서 나타냈다. HRT18 human colon adenocarcinoma 세포에 대한 독성은 비교적 B16BL6 세포의 경우 보다 모두 낮았다. 일상적인 음용 범위 내에서 모든 시료들의 세포에 대한 직접적인 독성은 미약하였으나, 낮은 희석배수에서도 대상 세포들의 형태가 변화하는 것을 관찰할 수 있었다. 각 시료들의 항암효과를 조사하기 위하여, B16BL6 세포를 이용하여 체내에서의 암세포 성장 및 전이를 분석하였다. 암세포를 마우스의 발바닥에 피하접종하고 시료를 섭취시켜 암세포의 성장과 전이를 조사한 결과 일본 청주에 비교하여 전통약주I과 전통약주II 섭취 군에서 높은 암세포 성장을 억제하는 경향을 나타냈으며, 특히 전통약주I은 암의 전이 억제에 뚜렷한 효과를 보였다. 본 연구의 결과에 의하면 이러한 항암효과는 전통약주의 어떤 성분이 직접적으로 암세포에 작용하기보다는 면역세포 등을 포함한 여러 다른 세포의 성장과 분화에 작용하여 간접적으로 항암효과를 나타내는 것으로 판단되었다.이내에는 소비하는 것이 바람직한 것으로 나타났다..3{\sim}11.9%$ 였으며 기온은 $4.3{\sim}6.5^{\circ}C$낮았다. 또한 지온은 5월에서 8월까지 $17.5{\sim}20.1^{\circ}C$로 경과되어 외기기온의 $25.1{\sim}30.8^{\circ}C$에 비하여 낮았으나 변화폭이 작았다.ol, cis-3-hexenol, trans-2-hexanol 등(等)이 높은 함양(含量)을 보였다. 유기물(有機物) 종류간(種類間)에는 침엽수(針葉樹)/이끼 퇴비(堆肥)에서 주요(主要) 향기성분(香氣成分)인 1-hexanol이 78.62, cis-3-hexenol이 36.65. trans-2-hexanol이 120.41 peak area%를 나타내었으며 이는 향기(香氣)가 높은 자생지(自生地) 토양(土壤)의 1-hexanol이 74.47, cis-3-hexenol이 44.21, trans-2-hexanol이 147.33 peak area%인 것과 유사(類似)하게 높았다.tarrow}6$보다 $4{\beta}{\rightarrow}8$의 결합방식이, 그리고 procyanidin 류에서는 gallate를 갖는 물질이 이를 함유하지 많은 물질보다 더욱 높은 ACE의 저해효과를 나타내었으며, 또한 hydroxyl 기가 많을수록 효소 저해효과도 증가하는 것으로 나타났다. 이와 같은 결과는 chocolate의 주원료인 cacao bean의 polyphenol 성분 또한 녹차 등에서 볼 수 있는 생리활성효과에 손색없는