• Journal of Microbiology and Biotechnology
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• 제7권3호
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• pp.209-211
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• 1997

A quantitative method for assaying bioemulsifiers in culture broth was developed and applied to cultivation of Pseudomonas aeruginosa YPJ80. SED(Standard Emulsification Dilution), an indirect measure of bioemulsifier concentration, was proposed. Production of bioemulsifier and rhamnolipid reached their maximum simultaneously. However, the bioemulsifier/rhamnolipid ratio decreased with cultivation time. This indicates the presence of another bioemulsifier other than rhamnolipid. The bioemulsifier seems to be protein-like activator which showed emulsification activity in addition to rhamnolipid.

• 센서학회지
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• 제18권2호
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• pp.154-159
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• 2009

This paper describes two methods - stamp-to-stick bonding and microtransfer molding - to integrate microfluidic channel into an optoelectrofluidic device for in-channel microparticle manipulation. We have demonstrated the optoelectronic microparticle manipulation in the channel-integrated optoelectrofluidic device using a liquid crystal display. As injecting a liquid sample containing $15{\mu}m$-diameter polystyrene particles into the fabricated channel, trapping and transport of individual microparticles have been successfully demonstrated. This channel-integrated optoelectrofluidic device may be useful for several in-channel applications based on the optoelectrofluidics such as optoelectronic flow control, droplet-based protein assay and bead-based immunoassay.

• Nutrition Research and Practice
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• 제14권5호
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• pp.453-462
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• 2020

BACKGROUND/OBJECTIVES: Platycodon grandiflorum (PG), an oriental herbal medicine, has been known to improve liver function, and has both anti-inflammatory and antimicrobial properties. However, little is known about the immune-enhancing effects of PG and its mechanism. In this study, we aimed to investigate whether fermented PG extract (FPGE), which has increased platycodin D content, activates the immune response in a murine macrophage cell line, RAW 264.7. MATERIALS/METHODS: Cell viability was determined by Cell Counting Kit-8 assay and the nitric oxide (NO) levels were measured using Griess reagent. Cytokine messenger RNA levels of were monitored by quantitative reverse transcription polymerase chain reaction. To investigate the molecular mechanisms underlying immunomodulatory actions of FPGE in RAW 264.7 cells, we have conducted luciferase reporter gene assay and western blotting. RESULTS: We found that FPGE treatment induced macrophage cell proliferation in a dose-dependent manner. FPGE also modulated the expression of NO and pro-inflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-1β, and IL-6. The activation and phosphorylation levels of nuclear factor kappa B (NF-κB) were increased by FPGE treatment. Moreover, 5-aminoimidazole-4-carboxamide ribonucleotide, an activator of AMP-activated kinase (AMPK), significantly reduced both lipopolysaccharides- and FPGE-induced NF-κB reporter gene activity. CONCLUSIONS: Taken together, our findings suggest that FPGE may be a novel immune-enhancing agent acting via AMPK-NF-κB signaling pathway.

• KSBB Journal
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• 제24권3호
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• pp.253-258
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• 2009

본 연구에서는 ELISA와 면역-크로마토그래피 스트립기술을 결합하여 E. coli O157 : H7을 탐지할 수 있는 면역스트립 센서를 제작하기 위한 제작조건의 최적화 연구를 수행하였다. 포획항체 농도, 탐지항체 농도, 완충용액 첨가제 조성의 면역스트립 제작 또는 운전인자들의 최적화 조건을 결정하였다. 포획항체의 농도는 1 mg/mL를 최적 조건으로 선정하였고, 탐지항체의 최적 농도도 1 mg/mL로 결정하였다. 비특이적 결합을 방지하기 위한 시료 희석용 완충용액의 첨가제 조성으로는 0.5% Tween 20와 3% BSA 혼합 사용을 선정하였다.

• Journal of Microbiology and Biotechnology
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• 제23권11호
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• pp.1598-1609
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• 2013

Organochlorine pesticide residues continue to remain as a major environmental threat worldwide. Lindane is an organochlorine pesticide widely used as an acaricide in medicine and agriculture. In the present study, a new lindane-degrading yeast strain, Pseudozyma VITJzN01, was identified as a copious producer of glycolipid biosurfactant. The glycolipid structure and type were elucidated by FTIR, NMR spectroscopy, and GC-MS analysis. The surface activity and stability of the glycolipid was analyzed. The glycolipids, characterized as mannosylerythritol lipids (MELs), exhibited excellent surface active properties and the surface tension of water was reduced to 29 mN/m. The glycolipid was stable over a wide range of pH, temperature, and salinity, showing a very low CMC of 25 mg/l. Bio-microemulsion of olive oil-in-water (O/W) was prepared using the purified biosurfactant without addition of any synthetic cosurfactants, for lindane solubilization and enhanced degradation assay in liquid and soil slurry. The O/W bio-microemulsions enhanced the solubility of lindane up to 40-folds. Degradation of lindane (700 mg/l) by VITJzN01 in liquid medium amended with bio-microemulsions was found to be enhanced by 36% in 2 days, compared with degradation in 12 days in the absence of bio-microemulsions. Lindane-spiked soil slurry incubated with bio-microemulsions also showed 20-40% enhanced degradation compared with the treatment with glycolipids or yeast alone. This is the first report on lindane degradation by Pseudozyma sp., and application of bio-microemulsions for enhanced lindane degradation. MEL-stabilized bio-microemulsions can serve as a potential tool for enhanced remediation of diverse lindane-contaminated environments.

• 한국미생물·생명공학회지
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• 제24권1호
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• pp.119-125
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• 1996

In order to develop enzyme-linked immunosorbent assay (ELISA) for fumonisins, production of specific antibodies, establishment of ELISA conditions, and quantitation of the toxin from spiked corns by ELISA were performed. Fumonisin $B_1(FB_1)$ conjugated to cholera toxin (CT) with or without Freund's adjuvant was subcutaneously injected into 2 groups of rabbits. When the titer of the antisera produced by each rabbit was tested, higher titer was observed in case of the immunization with the adjuvant. By use of the antiserum showing the highest titer (1:16,000) and its purified antibodies, competitive indirect and direct ELISA's (ciELISA and cdELISA) were established, respectively. When the cross-reactivity of the antibody against fumonisin analogs was investigated by the ciELISA, it was very low against $B_3$ (2%) but high against fumonisin $B_2$ (179%). The sensitivity of the ELISAs was also very high, because the detection limit for $FB_1$ was 0.03 ppb in ciELISA and 0.3 ppb in cdELISA. When the ELISA's were applied to the spiked corns after extraction with 75% methanol, the assay recovery of $FB_1$ was too unstable to assay. However, when cleanup by strong anion exchange (SAX) cartridge was introduced to remove interfering materials, the mean ELISA recovery of $FB_1$ from corns spiked to 3~10 ppm was found to be 34.0% and stable (mean of CV, 8.2%).

• 생명과학회지
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• 제27권7호
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• pp.783-789
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• 2017

Malus melliana (Hand.-Mazz.) Rehder (M. melliana)는 장미과에 속하는 중국 자생 식물 중 하나로 현재까지 보고된 생리활성은 전무하다. 본 연구에서는 M. melliana 에탄올 추출물(MMEE)의 항산화 및 항염증 생리활성을 DPPH 라디칼 소거능, ROS 소거능, NO 생성 저해능 및 Western blot hybridization을 통한 연관 단백질 발현분석을 통해 평가하였다. MMEE의 항산화능을 DPPH 라디칼 소거능을 통해 분석한 결과 양성 대조군으로 사용한 대표적인 항산화제인 아스코르빈산과 유사한 정도의 높은 소거활성을 보여 MMEE가 매우 강한 항산화능을 보유함을 확인하였다. 또한 RAW 264.7 세포주에서 $H_2O_2$에 의해 유도된 ROS에 대한 MMEE의 소거능을 분석한 결과, 농도의존적인 강한 ROS 소거능을 보였다. 뿐만 아니라 대표적인 항산화 효소인 HO-1 및 그 전사 인자인 Nrf2의 단백질 발현에 미치는 영향을 분석한 결과 MMEE에 의해 HO-1 및 Nrf2의 발현이 증가됨을 보였다. 한편 MMEE가 LPS에 의해 유도된 NO 생성에 미치는 영향을 분석한 결과 농도의존적인 NO 생성 저해능을 보였으며 이는 NO 생성 단백질인 iNOS의 발현 저해에서 기인함을 확인하였다. 이러한 결과를 통해 MMEE의 높은 항산화능과 항염증 활성을 확인하였으며 향후 잠재적인 기능성 소재로서 유용하게 활용될 수 있을 것으로 판단된다. 추후 계속적인 연구를 통해 활성 물질의 규명이 필요할 것으로 판단된다.

• Weed & Turfgrass Science
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• 제4권4호
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• pp.308-314
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• 2015

본 연구는 식물세포막을 파괴시켜 제초활성을 나타내게 하는 화합물(막과산화형 제초제)을 미지의 많은 화합물로부터 신속하게 탐색하기 위한 새로운 검정법을 확립하기 위하여 실시되었으며, 확립한 전체적인 검정과정은 다음과 같다. 96-well microplate에 시험용액 $200{\mu}L$ 넣고 여기에 오이자엽으로부터 적출한 직경 4 mm의 절편 1개씩을 띄운다. 항온실의 광조건 하에서 회전진탕기로 조금씩 흔들어주면서 8시간 배양한 후 절편을 제거한 다음, 배양액에 HVA와 HRP를 첨가하여 반응시킨 후 마이크로평판용 형광검출기를 이용하여 형광도(Ex 320 nm, Em 425 nm)를 측정한다. 형광변화량이 높을수록 제초활성이 높은 것으로 판단한다. 본 방법은 96-well microplate에서 작업을 수행할 수 있고 형광검출 기술을 이용함으로써 검정과정과 작업을 간편하게 하여 검정효율을 기존보다 현저히 높인 것이 특징이다. 아울러 활성검정을 추출된 효소가 아닌 잎 절편수준에서 수행하기 때문에 보다 실용화에 근접한 정량적 데이터를 얻을 수 있는 장점을 가진다.

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.853-858
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• 2003

Helicobacter pylori specifically adhere to host cells through a number of putative receptors and ligands, mainly based on carbohydrate-protein interactions. Polysaccharide fractions isolated from the leaves of Artemisia capillaris showed different inhibitory activities against H. pylori adhesion by using hemagglutination assay. Among these fractions, an acidic polysaccharide fraction FlA showed highly effective inhibitory activity, and its minimum inhibition concentration was 0.63 mg/ml. The inhibition results by the hemagglutination assay were consistent with those obtained by the enzymelinked glycosorbent assay, which was developed by the conjugation of horseradish peroxidase with fetuin, a sialic acid-containing glycoprotein which was specific to H. pylori adhesion. FlA contained the highest carbohydrate content among polysaccharide fractions, and no protein was detectable when further purified by gel filtration FPLC. Sugar composition analysis using GC revealed the highest amount of galacturonic acid among sugars, which suggests that FlA contains essentially acidic polysaccharides. Our data suggest that acidic polysaccharides may play an important role in the inhibition of H. pylori adhesion to host cells.

• Ocean and Polar Research
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• 제33권2호
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• pp.99-111
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• 2011

To estimate the effects of limitation nutrients for phytoplankton growth and its influences on short-term variations of a winter phytoplankton community structure, we investigated the abiotic and biotic factors of surface and bottom waters at 20 stations of inner and offshore areas from 6 to 7 February in Gwangyang Bay, Korea. Also, several algal bio-assay studies were conducted to identify any additional nutrient effects on phytoplankton assemblage using surface water for the assay. The dominant species in the bay was diatom Skeletonema costatum, which occupied more than 70% of total species in most stations (St.1-16) of the inner bay. According to a cluster and multidimensional scaling (MDS) analysis based on phytoplankton community data from each station, the bay was divided into three groups. The first group included stations from the south-western parts of Myodo lsland, which can be characterized as a semien-closed eutrophic area with high phytoplankton abundance. The second group included most stations from the north-eastern part of Myodo lsland, influenced indirectly by surface water currents from offshore of the bay. The standing phytoplankton crops were lower than those of the first group. The other cluster was restricted to samples collected from offshore of the bay. In the bay, silicon (Si) and phosphorus (P) were not a major limiting factor for phytoplankton production. However, since the DIN: DIP and DSi: DIN ratios clearly demonstrated that there were potential stoichiometric N limitations, nitrogen (N) was considered as a limiting factor. Based on the algal bio-assay, in vivo fluorescence values in N (+) added experiments were higher compared to control and P added experiments. Our results suggested that nitrogen may act as one of the most important factors in controlling primary production during winter in Gwangyang Bay.