• BMB Reports
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• 제28권5호
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• pp.464-470
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• 1995

Quinolone antibiotics are DNA gyrase inhibitors, but their bactericidal action seems to involve more than the inhibition of DNA gyrase activity. Hence, the potentially crucial factors among possible mechanisms of quinolone action; cleavable complex formation, inhibition of DNA synthesis, and induction of SOS response were investigated. These parameters were measured in an Escherichia coli strain exposed to quinolones in the logarithmic growth phase, and correlated with the bactericidal activity of quinolones. Cleavable complex formation proved to be the factor most related to bactericidal action. Inhibition of DNA synthesis was substantially correlated with bactericidal activity, but induction of SOS response was least correlated with bactericidal activity. Therefore, it was concluded that quinolones exert bactericidal action primarily through cleavable complex formation, and subsequent unknown cellular processes together with inhibition of DNA synthesis contribute to the bactericidal activity of quinolones.

• Restorative Dentistry and Endodontics
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• 제7권1호
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• pp.125-130
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• 1981

The purpose of this study is to determine the effect of concentration and temperature on the bactericidal action of sodium hypochlorite by means of comparing the killing time of several kinds of microorganism on each different concentration and temperature of sodium hypochlorite. The results were as follows: 1. As the concentration of sodium hypochlorite was increased, the bactericidal action of sodium hypochlorite was increased in all specimens. 2. The bactericidal action of sodium hypochlorite at $37^{\circ}C$ was more potent than that of sodium hypochlorite at $21^{\circ}C$. 3. Among the 3 experimental microorganisms, Pseudomonas aeruginosa was the most resistant to sodium hypochlorite, then comes staphylococcus aureus, and the least resistant microorganism was Streptococcus mutans.

• 약학회지
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• 제11권3_4호
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• pp.17-21
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• 1967

At present, quarternary ammonium salts(cationic surfactant) and Tego compounds (amphoteric surfactant) are used as germicidal agent. In this paper, it was investigated whether their germicidal activities are influenced or not by some suspending agents which are added to them 0.005% benzalkonium chloride aq. solution and 0.05% dodecyl diaminoethyl glycine aq. solution sterilized respectively against Staphylococcus aureus and Escherichia coli within a minute. The solutions aded acacia, carboxymethyl cellulose, sodium alginate solutions to make to 0.005% to above surfactants solution decreased the germicidal activity, not being sterilized bacteria for more than 2 hours however, the solutions decreased the germicidal activity by addition of suspending agents such as acacia, carboxymethyl cellose, sodium alginate and bacteria were survival for more than 2 hrs, 0.05% of benzalkonium chloride and 0.1% dodecyl diaminoethyl glycine respectively would be sterilized within 10 minutes, when added to 5% suspending agents. This result show that bactericidal action of dodecyl diaminoethyl glycine is affected by suspending agents less than that of benzalkonium chloride.

• 한국축산식품학회지
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• 제38권6호
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• pp.1315-1321
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• 2018

Bacteriocin is ribosomally synthesized by bacteria and inhibits closely related species. In this study we aimed at isolating lactic acid bacteria producing bacteriocin presenting anti-staphylococcal activity. A Lactococcus lactis strain was isolated from kimchi for the purpose and identified by 16S rRNA gene sequencing. As preliminary tests, optimal culture conditions, stabilities against heat, solvents, and enzymes treatments, and type of action (bacteriostatic or bactericidal) of the bacteriocin were investigated. The optimal culture conditions for production of the bacteriocin were MRS broth medium and $25^{\circ}C$ and $30^{\circ}C$ culture temperatures. The bacteriocin was acidic and the activity was abolished by a protease treatment. Its stability was maintained at $100^{\circ}C$ for 15 min and under treatments of various organic solvents such as methanol, ethanol, acetone, acetonitrile, and chloroform. Finally, the bacteriocin showed bactericidal action against Staphylococcus aureus where 200 AU/mL of the bacteriocin decreased the viable cell count (CFU/mL) of S. aureus by 2.5 log scale, compared with a control (no bacteriocin added) after 4-h incubation.

• 한국식품위생안전성학회지
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• 제10권1호
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• pp.23-28
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• 1995

The effect of the ethanol extract from salviae miltiorrhizae radix (Salvia miltiorrhiza) on the microbial growht and the stability of the extracted antimicrobial material were investigated. The ethanol extract had strong growth inhibition activity (MIC, 3.13~50.0 $\mu\textrm{g}$/ml) against Gram-positive bacteria such as B. subtilis, L. monocytogenes and S. aureus. Among Gram-positive bacteria tested, B. subtilis was the most susceptible to the extracted substance. While the antimicrobial activity of the ethanol extract was weak (MIC, 400~800 $\mu\textrm{g}$/ml) to E. coli and yeasts (C. albicans, Sacch. diastaticus). The ethanol extract had bactericidal action at higher concentration than MIC against B. subtilis, while the extract had only bacteriostatic action against S. aureus. The extracted antimicrobial substance was stable in the pH range of 4.0 to 10.0, heat treatment at 121$^{\circ}C$ for 15 min, and freezing and thawing

• 약학회지
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• 제10권2_3호
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• pp.15-19
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• 1966

In order to find 2-(5-nitro)furylacrylic acid derivatives possessing antimicrobial activity, nine new 2-(5-nitro)furylacrylamino acids were synthesized which were obtained by the action of 2-(5-nitro)furylacryla chloride on amino acids, such as $_{L}$-phenylalanine, glycine, $_{L}$-isoleucine, $_{L}$-glutamic acid, $_{DL}$-methionine, $_{L}$-threonine, $_{L}$-valine, $_{L}$-tryptophan and $_{DL}$-alanine, according to Schotten-Baumann method. These compounds generally showed a good bactericidal and bacteriostatic activity against Bacillus subtilis but were less effective against staphylococcus aureus, Proteus vulgaris and Escherichia coli. Of the above nine compounds, 2-(5-nitro)furylacryl glycine exhibited a good bactericidal activity.

• 한국식품위생안전성학회지
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• 제13권4호
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• pp.365-369
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• 1998

가금류 가공등에서 사용이 허가된 Trisodium Phoshate(TSP)와 구강 청결제로 사용되면서 안전한 물질로 알려진 Cetylpyridinium chloride(CPC)를 이용하여 in vitro에서 E. coli O157:H7 및 Listerial monocytogenes에 대하여 살균작용을 조사하였다. E. coli O157:H7 및 Listerial monocytogenes에 대해서는 TSP는 $1{\times}10^{-2}\;M$ 농도에서} $37^{\circ}C$, 30분간 반응으로 각각 30~40%와 40~50%의 살균효과를 보였으며, CPC는 $5{\times}10^{-7}\;M$ 농도에서 $37^{\circ}C$, 30분간 반응으로 각각 90~95%와 95~99%의 살균효과를 보였다. 또한, TSP와 CPC는 온도와 pH에 따라 E.coli O157:H7 및 Listerial monocytogenes에 대한 살균작용이 영향을 받았는데, 온도가 높을수록 두 물질 모두 그 살균 효과 컸으며, TSP는 pH가 높을수록, CPC는 pH가 낮을수록 살균효과가 컸다. 이러한 결과로 보아 TSP와 CPC도 E. coli O157:H7 및 Listerial monocytogenes의 오염방지를 위하여 사용이 가능할 것으로 본다.

• Archives of Pharmacal Research
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• 제29권4호
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• pp.298-301
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• 2006

This study was investigated the bactericidal effects of calcium oxide (CaO) on three common foodborne pathogenic bacteria: Escherichia coli, Listeria monocytogenes, and Salmonella typhimurium. Each bacteria level was determined in a CaO solution (0.01, 0.03, 0.05, 0.10, 0.15, and $0.20\%$ [w/v]) exposed for either 15 sec, 30 sec, 1 min, 2 min, 3 min, 5 min, 10 min, or 30 min. All three bacteria were not greatly affected by CaO solutions at concentrations of 0.01 and $0.03\%$, however, the decline of E. coli $(99\%;\;2.78\;log_{10}CFU/mL)$, L. monocytogens $(45\%;\;1.44\;log_{10}CFU/mL)$, and S. typhimurium $(70\%;\;2.08\;log_{10}CFU/mL)$ was greatest when they were exposed to $0.05\%$ CaO solution for 10 min. Moreover, the bactericidal action of CaO was maintained for at least 24 h of storage. The results of this study provide evidence that CaO, as a substitute for synthetic chemical substances has potential for use in the disinfection and sanitization of foods and food processing equipment.

• 한국어병학회지
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• 제5권1호
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• pp.9-18
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• 1992

어류의 방어기구를 밝히기 위하여, 잉어, 틸라피아 및 넙치의 혈청 중에 존재하는 보체의 살균작용에 대하여 실험하였다. 실험어의 모든 정상혈청으로 E. coli는 살균되었고 가열하여 보체를 불활성화시킨 혈청에서는 살균되지 않았다. zymosan으로 처리한 실험어의 정상혈청에서는 살균작용이 나타나지 않았으므로 정상혈청 중의 살균작용에도 보체의 대체경로가 중요한 것으로 생각되었다. EGTA로 처리한 틸라피아와 넙치의 정상혈청에서는 살균작용이 지속되고 있었으나, 잉어의 살균작용은 소실되는 점으로 봐서 잉어의 대체경로에는 $Ca^{2+}$이 요구되는 것으로 나타났다. 실험어의 정상혈청이 병원성이 있는 E. tarda에 대해서는 살균작용을 나타내지 않았고 병원성이 없는 E. coli에 대해서는 살균작용을 나타냈다. E. coli와 E. tarda는 면역혈청 중에서 모두 살균되었고 그 살균속도는 정상혈청에 비하여 빠른 것으로 나타났다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2001년도 Proceedings of 2001 International Symposium
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• pp.149-153
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• 2001

To investigate the mode of bactericidal action for antimicrobial peptide, pediocin, synthetic and mutant pediocins were prepared by direct chemical synthesis. Native pediocin was purified from Pedio-coccus acidilactici M and its conformational structure and bactericidal functions were analyzed and compared to synthetic pediocin. Schematic mode of pediocin actions, how pediocin binds on the target cell membrane, penetrates and makes tunnel are proposed. For these purposes, primary and secondary structures of pediocin was analyzed and disulfide bond assignment was also done. The pediocin purified from P. acidilactici M had high effective bactericidal ability against gram positive bacteria, especially Listeria monocytogenes and was very stable at extreme pHs and even at high temperatures such as autoclaving temperature (121$^{\circ}C$). Pediocin was consisted of 44 amino acids with four cysteines. Novel synthetic peptides were achieved by solid phase peptide synthesis(SPPS) method. To explain the function of cysteine in C-terminal region, mutant pediocin, Ped[C24A＋C44A], was synthesized and their structural and biological functions were analyzed. Second mutant pediocin, Ped[KllE], was prepared to explain the function of lysine at 11 of N-terminal part of pediocin, especially loop of $\beta$-sheet, and to predict the initial binding site of pediocin. The native and synthetic pediocins was showed random coil conformation by spectropolarimetry in moderate conditions. This conformation was observed in extreme conditions such as high temperature and low and high pHs, also. Circular dichroism(CD) data also showed the existence of $\beta$-turn structure in N-terminal part both native and synthetic pediocins. A structural model for pediocin predicts that 18 amino acids in the N-terminal part of the peptide assume a three-strand $\beta$-sheet conformation. This random coil in C-terminal part of pediocin was converted to folding structure, helix structure, in nonpolar solvents such as alcohol and TFE. The disulfide bond between $^{9}$ Cys and $^{14}$ Cys was concrete and inevitable, however, evidences of disulfide bond between $^{24}$ Cys and $^{44}$ Cys was not. Data of Ped[C24A＋C44A], pediocin mutant showed that $^{44}$ Cys was required during killing the target cells but not inevitable, since Ped[C24A＋C44A] still have bactericidal activity but much less than native pediocin. Another pediocin mutant, Ped[KllE], had still bactericidal activity, was controversial to propose that positive charge like as $^{11}$ Lys in loop or hinge in bacteriocin bound or helped to binding to microorganism with electrostatic interaction between cell membrane especially teichoic acid and positive amino acid nonspecifically. The conformation of pediocin among native, synthetic and mutant pediocins did not show big difference. The conformations between oxidized and reduced pediocin were almost similar regardless of native or synthetic.