• Journal of Microbiology and Biotechnology
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• 제14권2호
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• pp.317-323
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• 2004

This study was performed to investigate the antimicrobial effects of hetero-chitosans and their oligosaccharides against three Gram-negative bacteria and five Gram-positive bacteria. Nine classes of hetero-chitosan oligosaccharides consisted of partially deacetylated chitosans; 90％, 75％, and 50％ deacetylated chitosans. Based on molecular weight, they were prepared using an ultrafiltration membrane reactor system. Seventy-five percent deacetylated chitosan showed the highest antimicrobial acitivity as compared with the 90％ and 50％ deacetylated chitosan, and the activity was dependent on their molecular weights. It was apparent that the growth of Gram-negative bacteria is less inhibited in the presence of the heterochitosans and their oligosaccharides than Gram-positive bacteria. These results revealed that the antimicrobial effects of hetero-chitosans and their oligosaccharides depend on the degree of deacetylation, and their molecular weights.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.41-47
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• 2004

This study was performed to investigate the antimicrobial effects of hetero-chitosans and their oligosaccharides on the halophilic bacterium, Vibrio parahaemolyticus. Nine classes of hetero-chitosan oligosaccharides were prepared based on their molecular weights, using an ultrafiltration membrane reactor system with chitosanase and celluase, from partially different deacetylated chitosans, 90%, 75%, and 50% deacetylated chitosan, respectively. Thirty-two strains of V. parahaemolyticus were isolated from various marine organisms such as shellfish, shrimps, octopus, and seabirds. Seventy-five percent deacetylated chitosan showed the highest antimicrobial acitivity. The minimal inhibitory concentration (MIC) was 0.5 mg/ml on 14 strains of V. parahaemolyticus, and MIC of the rest strains (18 strains) was 1.0 mg/ml. In addition, MIC of most hetero-chitosan oligosaccharides was 8.0 mg/ml. The results revealed that the antimicrobial effects of hetero-chitosans and their oligosaccharides against V. parahaemolyticus depend on the degree of deacetylation, their molecular weights, and strains tested.

• 한국식품위생안전성학회지
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• 제10권4호
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• pp.271-277
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• 1995

Total 29 Monascus strains were isolated from Ang-Khak and 4 of them were selecte based on the relative intensity of soluble red pigment and growth rate. The optimum growth temperature of the selected isolates was 32.5$^{\circ}C$ on malt extract agar(MEZ) plate. The optimum growth pH was 5.0 on czapek yeast extract agar plate, while it was pH 6.2 or 6.5 on MEA plate. Isolate No. 116, especially, showed the strongest animicrobial activity aganist Bacillus subtilis and Staphylococcus aureus but much less aganist Escherichia coli and Enterobacter aerogenes. The maximun antimicrobial activity of isolate No. 116 against St. aureus was achieved at initial pH 5.3 on rice extract broth. The acitivity was increased with increasing amount of culture broth concentrate of isolate No. 116.

• Preventive Nutrition and Food Science
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• 제4권1호
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• pp.28-32
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• 1999

A novel antimicrbial peptide , named HFS-I, was isolated and characterized from the skin of the hagfish, Eptatretus bugeri. The decapeptide with a molecular mass of 1279.5 Da was purified to homogeneity using a gel-filtration column, ion-exchange and C18 reverse-phase high performance liquid chromatograpy . The complete amino acid sequence of HFS-I, which was determined by a combination of an automated amino acid sequencing and FAB-MS, was F-P-W-W-L-S-G-K-Y-P-NH2. Comparison of the amino acid sequence with those of other known antimicrobial peptides revealed that HFS-I was a novel antimicrobial peptide. HFS-I showed a weak antimicrobial activity in vitro aganinst a broad spectrum of microorganism without hemolytic acitivity.

• Preventive Nutrition and Food Science
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• 제4권2호
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• pp.97-102
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• 1999

Antimicrobial activity and chemical composition of volatile flavor extracts from Agastache rugosa were investigated. The volatile flavor extracts were obtained from leaves and stems of Agastache rugosa by simultaneous distillation extraction (SDE) method. Antimicrobial activity was investigated by disc diffusion and broth dilution methods against several microorganisms of Bacillus cereus, bacillus megaterium, Bacillus subtilis, Corynebacterium xerosis, Staphylo coccus aureus, Staphylococcus epidermidis, Agrobacterium rhizogenes , Agrobacterium tumefaciences, Enterobacter cloacae, Escherichia coli, Salmonella typhi, Vibrio parahaemolyticus, Candida utilis and Saccharomyces cerevisiae. Volatile flavor extractsfrom leaves have strong antimicrobial activity against C.utilis and S.cerevisiae. When 0.12% volatile flavor extracts from fresh leaves were included in the medium, lag phase of C. utilis was extended 6 hr and that of S.utilis and S.cerevisiae was extended 2hr. Further analyses were performed to elucidatethe effective component of the extracts. The major component of volatile flavor was estragole, a phenolic compound. Minor components were determined to be terpenes , alcohols, acids , esters, ketones and aldethydes.

• 한국식품조리과학회지
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• 제27권1호
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• pp.1-9
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• 2011

Anti oralmicrobial effects of Nulembo nucifera were determined against S.mutans, S.sobrinus S.sobrinus, F.nucleatum, and A.actinomycetemcomitans using paper disc method, minimum inhibitory concentrate (MICs). Extracts of lotus leaf showed the highest yield. MeOH extract is 21%, Chloroform fraction is 4.2%, ethylacetate fraction is 8.2%, water fraction is 19%. Different parts such as flower, leaf, seed and pod showed antimicrobial effects against S.mutans, with flower and seed extracts showing strong antimicrobial effect aganinst S.sobrinus KCCM11897. Leaf extract(1000pm concentration) showed over 50% inhibitory effect against S.mutans and S.sobrinus KCCM11897. Flower extract showed over 40% inhibitory effect against F.nucleatum and A.actinomycetemcomitans. MICs of flower extract against S.sobrinus KCCM11897,11898 and leaf extract against S.mutans, S.sobrinus KCCM11897 were $625\;{\mu}g/ml$, indicating Nulembo nucifera extract can exert antimicrobial activity even at low concentration. All extractes with heat at $120^{\circ}C$ had antimicrobial activity, which means that is a very stable substances. F.nucleatum and A.actinomycetemcomitans was stable against acid it had a trend that the more akali side was the lower acitivity.

• 한국자원식물학회지
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• 제11권1호
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• pp.40-46
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• 1998

For the comparison of the urushiol composition and biological acitivity between the fresh sap and fire distilled sap of lacquer tree(Rhus vernicifera), we analysed the urushiol composition by HPLC and EI-MS, and investigated the antioxidative , antimicrobial and anticancer acitivities according to solvent fractionations. There was no difference in the urushiol composition between fresh and fire distilled saps of lacquer tree. The hexane frqctionsof two saps showed a strong DPPH radical scaverging activity (RC50 : 7.0-7.5$\mu\textrm{g}$). They also showed a strong antifungal activity onthe spore germination of Cladosporium herbarum(MIC : 8$\mu\textrm{g}$/ml), whereas they have no or low activity against the bacteria(BAcillus subtilis , Escherichia coli). In addition , hexane and butanol fractions of two saps showed a strong inhibitory activity against cultured tumour cell lines (GI50 : 0.35, 12.29$\mu\textrm{g}$/ml) in vitro. These results confirm that the fresh sap and fire distilled sap might have the similar urushiol compositions and biological activities.

• 한국미생물·생명공학회지
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• 제29권3호
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• pp.127-133
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• 2001

냉각탑수 중의 Legionella 속 균을 저감시킬 수있는 방법개발의 일환으로 L. pneumophila에 강한 항균성물질을 생산하는P. seruginosa KLP-2 균주를 냉각탑수로부터 분리 동정하였다 P.aeruginosa KLP-2 균주를 냉각탑수로부터 분리 동정하였다. P. aeruginosa KLP-2 균주의 배양여액은 L. pneumophila의 Vibro cholerae non-Ol Bacillus cereus, Bacillus subtilis 및 Staphylococcus aureus에 대해서도 항균성을 나타내었다. P. seruginosa KLP-2 균주 배양여액의 항균활성을 증가시키기 위한 최적조건은 0.1%의 $K_2$$HPO_4$와 0.05%의 $MgSO_4$$7H_2$O로 조성되 무기염배지에 탄소원으로써 1%의 glycerol, 질소원으로써, 0.6%의 proteose peptone이 첨가된 pH 7.0의 배지 조건에서 가장 높은 항균 활성을 나타내었으며 $35^{\circ}C$에서 20시간 진탕배양(50 rpm)한 후 4일간 정치 배양하였을 때 최대의 항균활성을 나타내었다.

• 한국식품저장유통학회지
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• 제11권1호
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• pp.117-121
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• 2004

본 연구에서는 시판되고 있는 식초를 이용하여 6종의 식품 유해세근에 대한 항균력을 비교하였다. 그 결과, 감식초와 현미식초는 합성식초에 비해 S. aureu, M. luteus, S. enteritidius 및 E. coli에서 항균 활성이 높게 나타났으며, 현미식초가 감식초에 비해 식품유해세균에 대한 항균활성이 비교적 더 높게 나타났다. 현미식초의 농도에 따른 항균활성을 조사한 결과 5종의 그람양성 세균 및 음성 세균 모두 10$\mu$L/mL 이상의 농도에서 생육이 거의 억제되었으나, V. purahaermolyticus는 15$\mu$L/mL 농도에서 생육이 거의 정지되어, 현미식초는 식품 부패균과 대장균 생육억제에 우수한 것으로 나타났다. 식초처리에 의한 미생물의 형태 변화를 전자 현미경으로 관찰한 결과 S. aureu, E coli 모두 세포가 팽윤되고 일부 세포벽이 완전히 파괴된 형태를 관찰할 수 있어 식초처리로 인해 세균의 생육이 억제되는 것을 알 수 있었다.

• 생명과학회지
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• 제8권6호
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• pp.648-653
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• 1998

1. 포장 또는 비포장의 부패된 어육연제품에서 분리된 미생물의 대부분(약 98%)은 Bacillus속을 비롯한 세균류였다. 특히 비포장어묵제품에서는 곰팡이도 약 0.1%검출되었다. 이들 부패미생물에 대한 계피추출물의 최저증식억제농도는 세균과 곰팡이에 대하여 각각 160~640$\mu\textrm{g}$/$m\ell$과 40~80$\mu\textrm{g}$/$m\ell$으로 나타났다. 2. 흰살어묵의 원료 배합시 계피추출물을 0.5% 첨가하면 첨가하지 않은 것에 비하여 $25^{\circ}C$에서 보존기간이 2일 연장되었다. 또한, 계피추출물과 ethanol을 1 : 3으로 혼합한 액을 튀김어묵표면에 분무한 것은 ethanol만 분무한 대조구에 비하여 곰팡이 발육이 2일간 지연되었다. 3. 샌드위치와 찹쌀떡의 표면에 계피추출물과 ethanol을 1 : 1 비율로 혼합한 액을 분무하여 $25^{\circ}C$에서 저장하면 곰팡이 발육이 대조구에 비하여 보존기간이 각각 5일과 7일정도 연장되었다.