• 한국유기농업학회지
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• 제24권3호
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• pp.497-510
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• 2016

본 연구는 Lactobacillus bulgaricus SP5 분비물의 항균물질 탐색과 특성을 조사하고 병원성 미생물에 대한 억제효과를 얻고자 실시하였다. L. bulgaricus로부터 얻어진 상징액에 대한 항균활성은 시험에 이용된 모든 병원성 미생물인 E. coli 11234, Salmonella. enteritidis 3313, S. enteritidis 12021, 그리고 S. typhimurium 40253에 대해서 항균활성을 가지는 것으로 나타났다. 상징액 중의 황균활성 성분을 확인하기 위하여 다양한 pH 조정과 열처리 후, 병원성 미생물에 대한 항균활성을 측정하였다. 상징액의 열처리 후, 병원성미생물에 대한 항균활성은 비열처리와 같은 항균활성을 나타내었으나, 상징액의 pH를 4.6에서 중성이상으로의 변화는 항균활성이 현저히 감소하였다. 따라서 상징액의 항균활성은 pH 변화에 대해서 불안정하였으나, 열에 대해서는 매우 안정한 것으로 밝혀졌다. 이상의 결과를 통해 상징액의 병원성균에 대한 항균작용은 박테리오신 같은 peptide 보다는 lactic, acetic, phosphoric, succinic, pyroglutamic, citric, malic, 그리고 formic acid 등 다양한 유기산의 작용에 의한 것으로 확인되었다.

• Journal of Microbiology and Biotechnology
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• 제26권10호
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• pp.1736-1745
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• 2016

The interactions of microbiota in the gut play an important role in promoting or maintaining the health of hosts. In this study, in order to investigate and compare the effects of dietary supplementation with Lactobacillus pentosus HC-2 (HC-2), Enterococcus faecium NRW-2, or the bacteria-free supernatant of a HC-2 culture on the bacterial composition of Litopenaeus vannamei, Illumina sequencing of the V1-V2 region of the 16S rRNA gene was used. The results showed that unique species exclusively existed in specific dietary groups, and the abundance of Actinobacteria was significantly increased in the intestinal bacterial community of shrimp fed with the bacteria-free supernatant of an HC-2 culture compared with the control. In addition, the histology of intestines of the shrimp from the four dietary groups was also described, but no obvious improvements in the intestinal histology were observed. The findings in this work will help to promote the understanding of the roles of intestinal bacteria in shrimps when fed with probiotics or probiotic supernatant.

• Applied Biological Chemistry
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• 제17권2호
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• pp.138-142
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• 1974

유산염배지(乳酸鹽培地)에서 배양(培養)한 Selenomonas ruminantium 균체(菌體)를 초음파처리후(超音波處理後) 추출(抽出)한 효소(酵素)와 cofactor로서 ATP, CoA, $Mg^{++}$, UTP를 사용(使用)하여 in vitro에서 당지질(糖脂質)을 생합성(生合成)하여 본 결과(結果)는 다음과 같다. 1. Selenomonas ruminantium의 효소(酵素)에 의(依)한 $^{14}C-glucosamine$과 tridecyl-Co A로 부터의 당지질(糖脂質)의 in vitro 생합성(生合成)은 ATP, $Mg^{++}$, UTP,에 의(依)하여 촉진(促進)되었다. 2. 효소추출액(酵素抽出液)을 원심분리(遠心分離)로 분획(分劃)하고 각분획(各分劃)의 glycolipid 합성능(合成能)을 본 결과(結果) 105,000의 supernatant에 6,000rpm supernatant의 약(約) 2배(倍)의 효소활성(酵素活性)을 나타내는 조효소(粗酵素)가 존재(存在)함을 알았다. 3. 효소반응(酵素反應)은 30분(分)일 때 대부분(大部分)이 진행(進行)되며 1시간(時間)에서 거의 완결(完結)됨을 알았다.

• 한국축산식품학회지
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• 제33권4호
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• pp.501-507
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• 2013

Lysozyme was trapped from $2{\times}$ diluted egg white using Amberlite FPC 3500 ion exchange resin (1 g/10mL of egg white). The lysozyme bound to the resin was recovered using 0.1 N glycine-NaOH buffers, pH 9.0, containing 0.5 M NaCl. After separating lysozyme, the pH of the egg white solution was adjusted to 4.75 and centrifuged to remove interfering proteins. The supernatant was collected, added with 2.5% citric acid and 5.0% ammonium sulfate combination to precipitate egg white proteins, except for ovalbumin. After centrifugation, both supernatant (S1) and precipitant were collected. The precipitant was dissolved with 4 volumes of distilled water, and then 2.0% ammonium sulfate and 1.5% citric acid combinations added, stirred overnight in a cold room, and centrifuged. The resulting supernatant (S2) was pooled with the first supernatant (S1), desalted using an ultrafiltration unit, heat-treated at $70^{\circ}C$ for 15 min, and then centrifuged. The supernatant was collected as an ovalbumin fraction and lyophilized. The separated proteins were confirmed using Western blotting. The yield of lysozyme and ovalbumin was > 88.9% and > 97.7%, respectively, and the purity of lysozyme and ovalbumin was > 97% and 87%, respectively. The results indicated that the protocol was simple, and separated lysozyme and ovalbumin effectively.

• Preventive Nutrition and Food Science
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• 제3권4호
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• pp.379-381
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• 1998

An angiotensin converting enzyme (ACE) inhibitor was isolated and partially purified from bovine blood plasma. Bovine blood plasma was obtained after removing blood cells by centrifugation, followed by the addition of anticoagulant to whole bovine blood. To precipitate plasma proteins, bovine blood plasma was treated with 4% trichloroacetic acid (TCA) as a final concentration .An ACE inhibitor was isolated from TCA supernatnat, using ultrafiltration, gel permeation chormatography, and reverse-phase high pressure liquid chromatogrpahy. The ACE inhibitor purified from TCA supernatant had IC50 values of 9.4$\mu$M.

• 연구논문집
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• 통권30호
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• pp.67-77
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• 2000

This study was performed to investigate the characteristics and performance of model Decanter for separating swine wastewater to solid and liquid which is slurry state with 12.6% TS. Swine wastewater of the slurry tank was pumped into model Decanter which capacity was $2m^3$/hr in 10% TS Slurry inside of bowl was separated to solid-liquid by centrifugal acceleration. Sampling was done in the section of slurry feed pipe, supernatant outflow pipe, cake discharge pipe. After solid-liquid separation TS, $COD_cr$ and slurry volume reduction effect represented 38%, 40%, 19.6% respectively. Relation factor of model Decanter operation slurry concentration, optimum retention time of slurry, overflow velocity of supernatant, supernatant concentration, sludge removal rate etc. Optimal operation conditions can be set and evaluated efficiency based on the experimental results in the case of Decanter adopted for solid-liquid separation in highly concentrated swine wastewater.

• Restorative Dentistry and Endodontics
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• 제22권2호
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• pp.761-768
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• 1997

Microorganisms and their by-products are considered to be the major causes of pulpal and periapical pathosis. The role of microorganisms in endodotic infection has been studied regarding the prevalence of particular organisms found in root canal and periapical lesions. The aim of this study was to investigate the effect of culture supernatants of several oral microorganims isolated from infected root canals on the viability of cultured cell lines using colorimetirc assay. S. simulans, S. sciuri, E. faecium, S. intermedius, S. mitis, S. sanguis and S. uberis were incubated in Todd-Hewitt broth for 16 hours. 20 and 100ul of filtered bacterial cell culture supernatants were added to MK and Hep-2 cells. Cell viability was measured using MIT colorimetric assay. 20ul and 100u1 of S. sanguis supernatant showed significant cytotoxicity compared to control on MK cells. 100ul of S. sanguis supernatant significantly depressed viability of HEp-2 cells. E. faecium and S. intermedius did not affect the viability of MK and HEp-2 cells.

• Journal of Microbiology and Biotechnology
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• 제30권12호
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• pp.1854-1861
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• 2020

Staphylococcus aureus is one of the most common microorganisms and causes foodborne diseases. In particular, biofilm-forming S. aureus is more resistant to antimicrobial agents and sanitizing treatments than planktonic cells. Therefore, this study aimed to investigate the anti-biofilm effects of cell-free supernatant (CFS) of Saccharomyces cerevisiae isolated from cucumber jangajji compared to grapefruit seed extract (GSE). CFS and GSE inhibited and degraded S. aureus biofilms. The adhesion ability, auto-aggregation, and exopolysaccharide production of CFS-treated S. aureus, compared to those of the control, were significantly decreased. Moreover, biofilm-related gene expression was altered upon CFS treatment. Scanning electron microscopy images confirmed that CFS exerted anti-biofilm effects against S. aureus. Therefore, these results suggest that S. cerevisiae CFS has anti-biofilm potential against S. aureus strains.

• 한국토양비료학회지
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• 제7권4호
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• pp.209-213
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• 1974

수도근(水稻根)의 Glutamic oxalacetic transaminase isozyme을 DEAE-cellulose column chromatography에 의(依)해서 분리(分離)하고 그에 대(對)한 몇가지 성질(性質)을 구명(究明)하였든 바 얻어진 결과(結果)를 요약(要約)하면 다음과 같다. 1. 수도근(水稻根)의 GOT 활성(活性)은 93%가 Supernatant 분획(分劃)에 존재(存在)하고 Mitochondria에는 5%정도(程度)의 활성(活性)을 보이고 비활성도(比活性度)도 같은 경향(傾向)으로 거의 대부분(大部分)이 Supernatant 분획(分劃)에 국재(局在)해 있다. 2. 수도근(水稻根)의 GOT isozyme은 Cationic GOT로 존재(存在)하나 모두 Sepernatant 분획(分劃)에 국재(局在)하는 것 같다. 3. GOT isozyme의 pH에 대(對)한 반응성(反應性)은 모두 7.4에서 최고(最高)의 활성도(活性度)를 나타내었다. 4. GOT isozmye의 열안정성(熱安定性)은 $70^{\circ}C$에서 Anionic GOT가 더 불안정(不安定)하다. 5. 수도근(水稻根)의 GOT isozyme의 L-aspartic acid에 대(對)한 Km치(値)는 Cationic GOT에서 14mM, Anionic GOT는 16mM을 나타내고 있다.

• Journal of the Korean Wood Science and Technology
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• 제44권3호
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• pp.398-405
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• 2016

본 연구에서는 셀룰로오스 CNF의 치수별 분획 가능성 및 그 효율성을 평가하기 위하여, 기계적 해섬처리로 얻어진 CNF 수현탁액을 중력침강시켜 치수별 CNF를 분획하고 형태학적 성질 및 치수분포를 조사하였다. 침강속도는 해섬처리 횟수가 증가할수록 늦었으며, 침강 높이 또한 작았다. 침전층의 분획수율은 해섬처리 횟수가 증가하면서 감소하였으며, 중간층 및 상등액층은 증가하였다. 상등액 CNF의 직경 분포폭이 가장 좁았으며, 중간층 및 침전층으로 분포폭이 넓어졌다. 또한, 해섬처리 횟수가 증가할수록 직경 및 분포폭이 감소하였다. 여수시간은 상등액층, 중간층, 침전층 순서로 길게 나타났다.