• 한국식품영양과학회지
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• 제33권4호
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• pp.705-710
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• 2004

$\varepsilon$-Polylysine에 grapefruit seed extract와 glyceride를 각각 혼합한 항균보존제의 식품부패균에 대한 항균효과를 MIC test와 실제 쌀밥에 적용하였다. 두 혼합 항균제 모두 clear zone을 나타내었으나, $\varepsilon$-polylysine과 grapefruit seed extract 혼합물이 $\varepsilon$-polylysine과 monoglyceride 혼합물보다 약 100배정도 낮은 minimum inhibitory concentration을 보였다. Glyceride 첨가제의 실험에서 Bacilius cereus와 Pseudomonas aerugines의 경우 0.1 $\mu$L/mL에서 생육이 저해된 것에 반해 Escherishia coli의 경우 15 $\mu$L/mL에 저해되어 E. coli가 이 항균제에 대하여 강한 저항성을 보이는 것으로 나타났다. 취반 시 glyceride 흔합항균제를 여러 농도별 (0.3%, 0.5%, 1%)로 첨가시킨 쌀밥을 72시간동안 저장하였을 때 총균수는 항균제의 농도가 증가할수록 감소하는 경향을 보였다. 쌀밥에 E. coli를 접종하여 항균제 농도에 따른 생육억제효과를 측정한 결과 항균제 농도가 높을수록 강하게 생육을 억제하였다. 항균제가 쌀밥의 관능에 미치는 영향은 맛, 냄새, 입안에서의 조직감에서는 유의적인 차이를 보이지 않았으나, 전체적인 기호도에서 1% 첨가군이 유의적인 차이를 보여 0.5%의 첨가가 적합한 것으로 나타났다.

• Geomechanics and Engineering
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• 제12권5호
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• pp.753-770
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• 2017

The coagulation or flocculation of cohesive clay suspensions is one of the most widely used treatment technologies for contaminated water. Flocculated clay can transport pollutants and nutrients in ground water. Coagulants are used to accelerate these mechanisms. However, existing coagulants (e.g., polyacrylamide, polyaluminum chloride) are known to have harmful effects in the environment and on human health. As an alternative, eco-friendly coagulant, this study suggests ${\varepsilon}-polylysine$, a cationic biopolymer fermented by Streptomyces. A series of sedimentation experiments for various ${\varepsilon}-polylysine$ concentrations were performed, and the efficiency of sedimentation with ${\varepsilon}-polylysine$ was estimated by microscopic observation and light absorbance measurements. Two types of sedimentation were observed in the experiments: accumulation sedimentation (at 0.15%, 0.20%, 0.25% ${\varepsilon}-polylysine$) and flocculation sedimentation (at 0%, 0.1%, 0.5%, 1.0%, 2.0% ${\varepsilon}-polylysine$). These sedimentation types occur as a result of the concentration of counter ions. Additionally, the performance of ${\varepsilon}-polylysine$ was compared with that of a previously used environmentally friendly coagulant, chitosan. The obtained results indicate that flocculation sedimentation is appropriate for contamination removal and that ${\varepsilon}-polylysine$ functions more efficiently for clay removal than chitosan. From the experiments and analysis, this paper finds that polylysine is an alternative eco-friendly coagulant for removing chemical contaminants in groundwater.

• Geomechanics and Engineering
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• 제17권5호
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• pp.453-464
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• 2019

Soft marine soil has high fine-grained soil content and in-situ water content. Thus, it has low shear strength and bearing capacity and is susceptible to a large settlement, which leads to difficulties with coastal infrastructure construction. Therefore, strength improvement and settlement control are essential considerations for construction on soft marine soil deposits. Biopolymers show their potential for improving soil stability, which can reduce the environmental drawbacks of conventional soil treatment. This study used two biopolymers, an anionic xanthan gum biopolymer and a cationic ${\varepsilon}-polylysine$ biopolymer, as representatives to enhance the geotechnical engineering properties of soft marine soil. Effects of the biopolymers on marine soil were analyzed through a series of experiments considering the Atterberg limits, shear strength at a constant water content, compressive strength in a dry condition, laboratory consolidation, and sedimentation. Xanthan gum treatment affects the Atterberg limits, shear strength, and compressive strength by interparticle bonding and the formation of a viscous hydrogel. However, xanthan gum delays the consolidation procedure and increases the compressibility of soils. While ${\varepsilon}-polylysine$ treatment does not affect compressive strength, it shows potential for coagulating soil particles in a suspension state. ${\varepsilon}-Polylysine$ forms bridges between soil particles, showing an increase in settling velocity and final sediment density. The results of this study show various potential applications of biopolymers. Xanthan gum biopolymer was identified as a soil strengthening material, while ${\varepsilon}-polylysine$ biopolymer can be applied as a soil-coagulating material.

• Preventive Nutrition and Food Science
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• 제20권1호
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• pp.43-51
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• 2015

${\varepsilon}$-Polylysine (EPL) is used as a natural preservative in food. However, few studies have been conducted to assess the beneficial functions of dietary EPL. The purpose of this study was to elucidate the mechanism underlying the inhibition of neutral and acidic sterol absorption and hepatic enzyme activity-related fatty acid biosynthesis following EPL intake. EPL digest prepared using an in vitro digestion model had lower lipase activity and micellar lipid solubility and higher bile acid binding capacity than casein digest. Male Wistar rats were fed an AIN-93G diet containing 1% (wt/wt) EPL or L-lysine. After 4 weeks of feeding these diets, the marked decrease in serum and liver triacylglycerol contents by the EPL diet was partly attributed to increased fecal fatty acid excretion. The activities of hepatic acetyl-coenzyme A carboxylase and glucose-6-phosphate dehydrogenase, which are key enzymes of fatty acid biosynthesis, were enhanced in rats fed EPL diet. The increased fatty acid biosynthesis activity due to dietary EPL may be prevented by the enhancement of fecal fatty acid excretion. The hypocholesterolemic effect of EPL was mediated by increased fecal neutral and acidic sterol excretions due to the EPL digest suppressing micellar lipid solubility and high bile acid binding capacity. These results show that dietary EPL has beneficial effects that could help prevent lifestyle-related diseases such as hyperlipidemia and atherosclerosis.

• 한국산업융합학회 논문집
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• 제2권1호
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• pp.91-95
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• 1999

The Streptomyces albulus broth, when the polylysine in the broth, that has powerful growth inhibiting effect far many microbes, is its maximum, had filtered off the cells, to use the broth as preservative for keeping favorable taste of Korean Kimchi. Some microorganisms in their specific growth medium, known to deteriorate the useful nutrient of the Kimchi, has grown with different amounts of the inhibiting broth, to determine the minimum growth inhibition concentration. The ${\varepsilon}$-poly-L-lysine had been identified from the IR spectroscopic analysis of the purified poly lysine of the broth from ion exchange chromatographic separation. The content of the polylysine had been determined by methyl orange decoloration effect. Though the minimum inhibition concentration, evaluated by the naked eye based on the conventional method measuring the turbid feature after 18 hours of culture, has different values each other, the observed effects confirmed that the crude broth could be used as a natural preservative for the Kimchi in extending the fair taste.

• 한국산업융합학회 논문집
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• 제2권1호
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• pp.77-83
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• 1999

Grown in the secondary broth of production media, the strain Streptomyces albulus has increased more the production of its metabolite ${\varepsilon}$-poly-L-lysine, one of poly(amino acid)s used as disinfecting food additives, than the strain in the primary culture of growth nutrients. Having the strain removed, the large concentrate obtained by ultrafiltrating the secondary culture broth. The concentrated production broth exchanged into followed by detecting in UV flowcell at 220nm the peptide bond of the components eluting the adsorbed proteins and polylysine with NaCl salt of gradient concentration, and has separated into five components. Among them the component in the fourth peak fraction has proved to be the pure ${\varepsilon}$-poly-L-lysine after the portion being hydrolyzed the fraction with HCl into amino acid followed by being the composing amino acid analysis.

• 대한화장품학회지
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• 제47권2호
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• pp.155-161
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• 2021

본 연구는 항균 활성을 갖는 천연 소재를 검색하고 화장품의 보존제로써 적용을 위해 진행되었다. 디스크 확산법(disc diffusion method)을 통해 피부 병원성균 3 종(Staphylococcus aureus, Escherichia coli (E. coli), Pseudomonas aeruginosa)과 효모균(Candida albicans (C. albicans))에서의 천연 항균 소재 9 종을 검색하였다. Inhibition zone 크기를 측정한 결과, 오배자 추출물(Rhus Semialata gall (Gallnut) extract), 참나무 목초액 (Oak vinegar) 그리고 폴리리신(ε-polylysine)은 10 mm 이상으로 다른 추출물에 비해 우수한 항균활성을 나타내었다. 병원성균 3종과 효모균, 곰팡이균(Aspergillus brasiliensis (A. brasiliensis))에서 최소살균농도(minimum bactericidal concentration, MBC)를 측정한 결과, 오배자 추출물과 참나무 목초액은 5 종의 병원성균에서 10 ~ 20 mg/mL와 20 ~ 40 mg/mL, 폴리리신의 경우 진균류에서 0.5 ~ 2 mg/mL으로 살균 작용에 의한 항균효과를 각각 확인하였다. Checkerboard 방법에 따라 오배자 추출물과 참나무 목초액, 오배자 추출물과 폴리리신의 혼합 비율에 따른 시너지 효과(synergistic effect), 부가 효과(additive effect), 무관함(indifferent) 그리고 상쇄효과(antagonistic effect)를 평가하였다. 그 결과, 단독으로 사용할 때보다 오배자 추출물과 참나무 목초액 복합물은 E. coli, C. albicans, A. brasiliensis를, 오배자 추출물과 폴리리신 복합물은 C. albicans, A. brasiliensis를 4 배 낮은 농도에서 99.9% 억제하며 항균 시너지 효과를 확인하였다. 오배자 추출물과 참나무 목초액 복합물은 S. aureus와 P. aeruginosa를 2 배 낮은 농도에서 억제하며 부가 효과가 확인되었다. 이로써, 오배자 천연 복합물은 항균 시너지 효과를 발휘할 수 있음을 입증했을 뿐만 아니라 넓은 항균 스펙트럼을 갖춘 천연 방부 시스템으로써 화장품에서 응용할 수 있을 것으로 기대된다.

• 한국식품위생안전성학회지
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• 제24권3호
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• pp.262-266
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• 2009

기능성 음료의 저장성을 향상시키고자, 7종류의 천연항균물질($\varepsilon$-Polylysine, 유카추출물, TLS(Vitamin $B_1$ 유도체), BMB-FS(황금추출물), 키토올리고당, KDSP 001, KDSP 002) 곰팡이 성장저해활성을 비교 평가하였다. Aspergillus niger, Penicillium citrimum, Rhizopus oryzae, Fusarium moniliforme, Mucor rouxii, 5 종류의 곰팡이를 상대로 활성을 살펴보았으며, 성장저해활성이 가장 뛰어난 물질의 최소저해농도를 조사하였다. 모든 곰팡이에 대하여 성장 저해활성을 보인 물질은 vitamin $B_1$, 유도체인 TLS 이었으며, 100 ppm 이상의 농도에서는 균사체가 성장하지 못하였다. 황금추출 물 BMB-FS의 경우 F. moniliforme을 상대로 100 ppm이상의 모든 농도에서 성장저해활성을 보였으며 P. citrinum와 M. rouxii의 경우 1,000 ppm이상의 농도가 되어야 균체 성장을 저해하는 것으로 나타났다. 가장 뛰어난 활성을 보여준 TLS의 최소저해농도(MIC)는 A. niger를 제외한 4가지 곰팡이에 대하여 60ppm으로 나타났으며, A. niger에 대한 MIC는 100ppm으로 분석되었다. 이 같은 결과는 기능성 음료의 저장기간을 연장시키는데 중요한 정보를 제공하며, 천연보존료 연구에 도움이 될 것이라 생각된다.

• 한국식품위생안전성학회지
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• 제24권3호
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• pp.273-276
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• 2009

본 연구는 당 함량이 높고 ($12{\pm}0.1%$) pH가 낮아($3.0{\pm}0.1$) 세균보다는 효모에 의한 변패가 문제시 되고 있은 가능성 음료의 저장성을 향상시키고자 주요 천연항균제 8종의 항균력을 평가하였다. 이에 따라 대표적인 효모균주 Saccharomyces cerevisiae, Zygosaccharomyces bailii, Pichia membranaefciens, Candida albicans, Pichia anomala 5종을 대상으로 $\varepsilon$-Polylysine, 유카추출물, vitamin $B_1$ derivative, scutellaria baicalensis extract, 키토올리고당, allyl Isothiocyanate, 자당지방산에스테르, 올리고당 등 8가지 주요 항균력을 test 하여 최소저해농도 (Minimal Inhibitory Concerntration, MIC)로 나타내었다. S. cerevisiae와 Z. bailii는 올리고당 용액 10 ppm, 자당지방산에스테르 10 ppm, P. membranaefaciens와 C. albicans는 allyl isothiocyanate 10 ppm, P. anomala는 Allyl isothiocyanate 10 ppm, 올리고당 용액 10 ppm 사용 시 가징 높은 항균력을 나타냈다. 0.015% 이상의 안식향산나트륨 참가 가능성 음료에서는 다섯 효모균 모두 증식이 관찰되지 않았다. 종합적으로 S. cerevisiae, Z. bailii, P. anomala의 저항성이 P. membranaefaciens, C. albicans 보다 낮았으며, 균주별 차이는 보였으나 allyl isothiocyanate, 올리고당, 자당지방산에스테르가 큰 항균력을 보였다. 본 연구결과는 기능성 음료의 합성 보존료를 대체할 수 있는 천연항균제의 개발 및 이용에 기초 자료로 활용될 수 있을 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제28권3호
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• pp.405-410
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• 2015

The objective of this study was to evaluate the effects of sequential applications of ${\varepsilon}$-polylysine (EPL) or lauramide arginine ethyl ester (LAE) sprays followed by an acidic calcium sulfate (ACS) spray on inoculated chicken carcasses to reduce Salmonella (Salmonella enterica serovars including Salmonella typhimurium and Salmonella enteritidis) contamination during 6 days of storage ($4.4^{\circ}C$). Secondly, reductions of the resident microflora were studied on uninoculated chicken carcasses following the sequential application of the treatments, chilling and 10 days of storage at $4.4^{\circ}C$. The treatment of Salmonella inoculated carcasses with 300 mg/L EPL followed by 30% ACS (EPL300-ACS30) sprays reduced Salmonella counts initially by 1.5 log cfu/mL and then by 1.2 log cfu/mL (p<0.05) following 6 days of storage at $4.4^{\circ}C$. Likewise, 200 mg/L LAE followed by 30% ACS (LAE200-ACS30) treatment reduced initial Salmonella counts on poultry carcasses by 1.8, 1.4 and 1.8 log cfu/mL (p<0.05), respectively, after 0, 3, and 6 days storage. Immediately after the treatments, EPL300-ACS30 and LAE200-ACS30 both reduced Escherichia coli counts significantly by 2.6 and 2.9 log cfu/mL, respectively. EPL300-ACS30 and LAE200-ASC30 were effective in lowering psychrotroph counts by 1 log cfu/mL on day 10 when compared to the control and distilled water treatments. This study demonstrated that EPL300-ACS30 and LAE200-ACS30 were effective in reducing Salmonella on inoculated chicken carcasses both after treatment and during the storage at $4.4^{\circ}C$ for up to 6 days. In addition, reductions in psychrotroph counts indicated that these treatments might have the potential to increase the shelf-life of poultry carcasses.