• 생명과학회지
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• 제22권9호
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• pp.1194-1200
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• 2012

유산균은 일반적으로 프로바이오틱스 균주로 알려져 있다. 가능성이 있는 프로바이오틱스 균주는 세포결합과 부착능 즉, 장상피세포 부착능 및 세포표면의 소수성이 기초적으로 구비되어야 한다. 본 연구에서는 김치로부터 몇몇의 토착 유산균을 분리하였으며, 세포표면 소수성에 근거한 가능성이 있는 프로바이오틱스로서 유산균 한종을 선발하였다. 프로바이오틱스균주로서 선별한 분리균주(BCNU 9070)의 16S 리보좀DNA 염기서열을 분석한 결과 Pediococcus pentosaceus에 속하는 균주임이 확인되었다. P. pentosaceus BCNU 9070 균주는 위액과 담즙산에 대하여 내성을 가졌으며 또한 Listeria monocytogenes 및 Shigella sonnei를 포함하는 6종의 식중독 병원균에 대하여 생육저해활성도 나타내었다. 게다가 P. pentosaceus BCNU 9070 균주는 담즙산 가수분해활성 및 콜레스테롤 동화능도 있음이 확인되었다. 이들 결과를 기초로, P. pentosaceus BCNU 9070은 기능성 식품에 적용가능한 천연 프로바이오틱스 특성을 가지고 있다고 판단된다.

• 미생물학회지
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• 제53권4호
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• pp.265-272
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• 2017

다른 탄화수소 분해 방법을 가진 여러 세균을 유류-오염 토양에서 분리하였다. Acinetobacter calcoaceticus SL1은 기름-분산 시험에서 계면활성제-생성능을 보였으며 경유와 n-hexane에 대해 각각 43.6과 54.5%의 유화활성을 나타내었다. 또한 높은 세포 표면 소수성을 가졌는데 이는 탄화수소에 쉽게 부착하여 그것을 분해할 수 있게 한다. 이 균주는 1,000 mg/L의 n-octadecane과 naphthalene을 3일 내에 100% 분해하였으며, 1,000 mg/L의 경유는 7일 동안 72.3%, 그리고 10,000 mg/L로 오염시킨 토양에서는 4주 간 78%를 제거하였다. 다른 분리균주 Bacillus amyloliquefaciens S10과 B. subtilis GO9는 생물계면활성제를 생산할 수 있으며 기름-분산 시험에서 각각 6.34와 2.5 cm직경의 투명대를 형성하였다. 배양 중 그들의 배양 상등액은 표면장력이 74.6 mN/m으로부터 각각 34.4와 33.3 mN/m으로 감소하였으며, 배양 상등액의 critical micelle concentration은 각각 2.0과 5.9%이었다. A. calcoaceticus SL1과 B. amyloliquefaciens S10의 컨소시엄은 10,000 mg/L의 경유를 3일만에 77.8% 분해하였는데 이는 A. calcoaceticus SL1 단독에 의한 것보다 높은 분해능이었다. 만일 이 세균들을 유류-오염 부지에 컨소시엄으로 같이 처리한다면 높은 석유탄화수소 제거율을 나타낼 수 있을 것이다.

• 대한소아치과학회지
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• 제29권4호
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• pp.618-624
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• 2002

시판되는 보리차 3종(티백형 2종 알곡형 1종)이 우식유발 세균인 Streptococcus mutans와Streptococcus sobrinus가 타액피복 수산화인회석에 부착되는 정도와 이들 세균의 체표소수성에 미치는 영향에 대해 평가하였다. 모든 실험군에서 보리차로 처리하였을 때 수산화인회석에의 부착능과 세균의 체표소수성은 감소하였고 이 값은 보리차의 종류와 처리방법에 따라 상이하였다. 이러한 결과는 보리차에 함유된 활성성분인 catechins와 melanoidins의 영향 때문인 것으로 추측되며 보리차로 전 처리한 수산화인회석에 세균이 부착하는 정도가 감소한 것은 활성물질이 흡착되어 치아표면의 수용체가 세균의 부착소와 작용하는 것을 방해함으로써 치아우식증 병인론의 초기 단계인 부착에 영향을 미칠 수 있다는 것을 의미한다. 본 연구결과 보리차가 우식유발 세균의 주요 독력인자 중 하나인 부착능을 억제하므로 보리차가 이러한 세균이 일으키는 치아우식증을 억제할 수도 있다는 가능성을 보여준다.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.759-769
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• 2002

Mutated forms of ras are found in many human tumors and the rate of incidence is significantly higher in colon and pancreatic cancers. The protein product from the ras oncogene is a small G-protein, $p21^{ras}{\;}(Ras)$ that is known to playa key role in the signal transduction cascade and cell differentiation and proliferation. Mutated Ras is unable to regulate itself and remains constantly activated, leading to uncontrolled cell growth. The function of Ras in signal transduction requires its location near the growth factor receptor at the cell membrane. However, Ras does not have a transmembrane domain. Ras requires farnesylation to increase its hydrophobicity and subsequent plasma membrane association for its transforming activity. This key post-translational modification is catalyzed by the enzyme Ras farnesyltransferase (FTase), which transfers a farnesyl group from farnesylpyrophosphate to the C-terminal cysteine of the Ras protein. The requirement has focused attention on FTase as a target for therapeutic intervention. Selective inhibition of FTase will prevent Ras protein from association with the plasma membrane, leading to a disruption of oncogenic Ras function.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.319-322
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• 2002

The bacterial transport in soil media was studied. Nonionic surfactants, enhanced the bacterial transports in soil media. The transport rate in soil column was increased by increasing the number of ethylene oxide in polyoxyethylene oxide surfactants. Ionic strength of solution affected the microbial transport characteristics in soil. The hydrophobicity of cell surface was proved that one of important characteristics on the bacterial transport in soil media.

• Journal of Dairy Science and Biotechnology
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• 제16권2호
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• pp.98-105
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• 1998

Various peptides derived from food are among the most potent physiologically active agents known, and include anticancer peptides, angiotensin converting enzyme(ACE) inhibitor exhibiting antihypertension action, opioid peptides, antithrombotic peptides, hypocholesterolemic peptides, immunomodulators, calcium absorption enhancers, and other peptides. Hydrophobic peptides extracted from a Cheddar-type cheese slurry were fractionated by gel chromatography and repeated HPLC. A peptide fraction from HPLC showed high cytotoxicity on the tumor cell lines such as a human colon carcinoma, and comprised of Tyr, Ser, Leu, Gly, and others. Hypocholesterolemic peptides were isolated from peptic hydrolyzates of casein and soy proteins. Macropeptides of 1,000${\sim}$5,000 dalton were effective on reducing the cholesterol level of mouse serum. Peptides showing high Krigbaum hydrophobicity and ANS surface hydrophobicity resulted in high hypocholesterolemic effect and fecal steroid concentrations. Caseinomacropeptides(CMP) were isolated from whey powder and treated with soluble and immobilized trypsin to obtain antithrombotic peptides. One fraction from the CMP hydrolyzed with immobilized trypsin for 24h exhibited high antithrombotic activity with 52.5% inhibition of platelet aggregation. These result suggested that peptides from various milk products could be utilized as a good bioactive agents for developing health functional foods.

• 한국유가공학회:학술대회논문집
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• 한국유가공기술과학회 1998년도 제46회 춘계 유가공 심포지움 - 우유 및 유제품의 기능성
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• pp.22-29
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• 1998

Various peptides derived from food are among the most potent physiologically active agents known, and include anticancer peptides, angiotensin converting enzyme(ACE) inhibitor exhibiting antihypertension action, opioid peptides, antithrombotic peptides, hypocholesterolemic peptides, immunomodulators, calcium absorption enhancers, and other peptides. Hydrophobic peptides extracted from a Cheddar-type cheese slurry were fractionated by gel chromatography and repeated HPLC. A peptide fraction from HPLC showed high cytotoxicity on the tumor cell lines such as a human colon carcinoma, and comprised of Tyr, Ser, Leu, Gly, and others. Hypocholesterolemic peptides were isolated from peptic hydrolyzates of casein and soy proteins. Macropeptides of 1,000${\sim}$5,000 dalton were effective on reducing the cholesterol level of mouse serum. Peptides showing high Krigbaum hydrophobicity and ANS surface hydrophobicity resulted in high hypocholesterolemic effect and fecal steroid concentrations. Caseinomacropeptides (CMP) were isolated from whey powder and treated with soluble and immobilized trypsin to obtain antithrombotic peptides. One fraction from the CMP hydrolyzed with immobilized trypsin for 24h exhibited high antithrombotic activity with 52.5% inhibition of platelet aggregation. These results suggested that peptides from various milk products could be utilized as a good bioactive agents for developing health functional foods.

• Journal of Microbiology
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• 제34권1호
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• pp.7-14
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• 1996

Teh baculovirus gp64 glycoprotein is a major component of the envelope of budded virus (BV) and has been shown that it plays an essential role in the infection process, especially virus-cell membrane fusion. We have cloned Autographa californica Nuclear Polyhedrosis Virus (AcNPV) gp64 protein were examined for membrane fusion activity by using a synchtium formation assay under various conditions. The optimal conditions required for inducing membrane fusion are 1) form pH 4.0 to 4.8 2) 15 min exposure of cells to acidic pH 3) at least 1 .mu.g of gp64 cloned plasmid DNA per 3 * 10$^{6}$ cells 4) and an exposure of cells to acidic pH at 72 h post-transfection. In order to investigate the role of hydrophobicity of the gp64 glycoprotein for the membrane fusion, the two leucine residues (amino acid position at 229 and 230) within hydrophobic region I were substituted to alanine by PCR-derived site-directed mutagenisis and the membrane fusion activity of the mutant was anlaysed. The gp64 glycoprotein carrying double alamine substitution mutation showed no significant difference in fusion activity. This result suggested that minor changes in hydrophobicity at the amino acid position 229 and 230 does not affect the acid-induced membrane fusion activity of the gp64 glycoprotein.

• Asian-Australasian Journal of Animal Sciences
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• 제21권10호
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• pp.1495-1500
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• 2008

In an attempt to develop a probiotic formulation for poultry feed, a number of lactic acid bacteria (LAB) were isolated from chicken intestinal specimens and a series of in vitro experiments were performed to evaluate their efficacy as a potential probiotic candidate. A total of 650 LAB strains were isolated and screened for their antagonistic potential against each other. Among all the isolates only three isolates (TMU121, 094 and 457) demonstrated a wide spectrum of inhibition and were thus selected for detailed investigations. All three selected isolates were able to inhibit the growth of E. coli and Salmonella species, although to variable extent. The nature of the inhibitory substance produced by the isolates TMU121 and 094 appeared to be associated with bacteriocin, as their activity was completely lost after treatment with proteolytic enzymes, while pH neutralization and catalase enzyme had no effect on the residual activity. In contrast, isolate TMU457 was able to resist the effect of proteolytic enzymes while pH neutralization completely destroyed its activity. Attempts were made to study the acid, bile tolerance and cell surface hydrophobicity of these isolates. TMU121 showed high bile salt tolerance (0.3%) and high cell surface hydrophobicity compared to the other two strains studied, while TMU094 appeared the most pH resistant strain. Based on these results, the three selected LAB isolates were considered as potential ingredients for a chicken probiotic feed formulation and were identified to species level based on their carbohydrate fermentation pattern by using API 50CH test kits. The three strains were identified as Lactobacillus fermentum TMU121, Lactobacillus rhamnosus TMU094, and Pediococcus pentosaceous TMU457.

• KSBB Journal
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• 제28권2호
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• pp.146-150
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• 2013

In this study, we investigated the effects of longterm exposure to ionic liquid (IL) on Shewanella oneidensis MR-1 (MR-1). MR1 was acclimated through repeated exposure to IL. The acclimated strain was named as S. oneidensis SH-1 (SH-1) and compared with MR-1 in various aspects including morphology, cell surface hydrophobicity (CSH), motility, and fatty acid. Compared to the MR-1, SH-1 showed elongated cell shape on scanning electron microscopy. Upon exposure to IL, hydrophobicity of SH-1 (28.2%) was higher that of MR-1 (3.3%). In contrast, motility of SH-1 (7 mm) was lower than that also of MR-1 (22 mm), and branched chain fatty acid of SH-1 was lower than that of MR-1, 27.6% and 41.1%, respectively.