• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.720-723
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• 2001

The effect of long-term storage on garlic antibacterial activity was investigated. A concentration of 5% or more garlic was found to be necessary to completely inhibit Eschrichia coli growth in tryptic soy broth. This value is substantially higher than the minimum inhibitory concentration of 1% for E. coli reported previously. pH-modified garlic extract was stored at different temperatures to investigate the impact of storage conditions (i.e., temperature, pH, period of storage) on the stability of the antibacterial activity of the garlic extract used against E. coli B34. The antibacterial effectiveness of the garlic extract against E. coli remained stable when both the storage temperature and the pH of the extract were kept low. When the garlic extract was stored at $40^{\circ}C and above, most or all of the garlic antibacterial activity disappeared after a 24-h storage period, regardless of the storage pH. The antibacterial activity was weakened when the pH of the garlic extract was adjusted to 8, and at low temperatures.

• Food Science of Animal Resources
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• v.18 no.2
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• pp.157-163
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• 1998

This study was carried out to examine that pepsin-hydrolyzed bovine lactoferrin has applicabilities which are market milk and dairy products. The stability of pepsin-hydrolyzed bovine apo-lactoferrin and the change of its antibacterial character has been studied under various method for pasteurization (LTLT; 65$^{\circ}C$ / 30min., HTST ; 75$^{\circ}C$ / 15sec., UHT ; 135$^{\circ}C$ / 3sec.) and pH Values (pH 2.0, pH 4.0, pH 6.8). The ehated samples were assayed for minimal bacteriocidal concentrations (MBCs) and bacteriocidal effect against E. coli. The results obtained were summarized as follows: After fractionation of pepsin-hydrolyzed bovine lactofeerin by gel filtration. several peptide fractions were found that had strong antibacterial activity. SDS-PAGE showed that the one of these fractions with strong antibacterial activity, which had a molecular mass a range of 30∼33KDa. The MBCs for pepsin-hydrolyzed bovine lactoferrin fraction No. 2 against E. coli required to cause complete inhibition of growth varied within the range of 200∼400 $\mu\textrm{g}$/ml, depending on heat treatments and pH conditions. The peptide fraction No. 2 showed strong bacteriocidal activity against E. coli at LTLT and HTST treatments under acidic pH conditions. and was reduced activity at UHT treatment under pH 6.8 condition.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.11
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• pp.1774-1780
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• 2009

The dyeing properties of cotton fabric with Inonotus obliquus are studied by investigating the effect of dyeing conditions on dye uptakes such as, the concentration of Inonotus obliquus, dyeing temperature, time, and pH values. In addition, the effects of mordants on dye uptakes and antibacterial activities are also investigated. The results are summarized as follows: The dye uptakes of dyed fabrics were increased gradually with an increasing concentration of Inonotus obliquus. K/S values were the highest when the dyeing temperature and time were at $60^{\circ}C$ and 60 minutes, respectively. As for the changes of pH values of dyeing solution, K/S values recorded the highest at pH3-pH5. Antibacterial activities of Inonotus obliquus dyeing solution showed a significant effect in dyed cotton fabric with mordanting.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.353-359
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• 2004

This study was performed to examine the pseudomonas aeruginosa, antibacterial effect of a soft contact lens multi-purpose solution (MPS). Pseudomonas aeruginosa was incubated in the Muller Hinton Broth culture, and treated with 5 MPSs. TO investigate the antibacterial efficiency of MPSs, UV spectrometer was used for measuring optical density of pseudomonas aeruginosa. The antibacterial effect of 4 MPSs was significant except for one MPS. This result suggested that the antibacterial effect of MPSs is dependant on their components, pH. Therefore they had antibacterial effect of the pseudomonas aeruginosa.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.82-92
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• 2021

Purpose: It has been reported that the diversity and abundance of microbes in the vagina decrease due to the use of antimicrobial agents, and the high recurrence rate of female vaginitis due to this suggests that a new treatment is needed. Methods: In the experiment, we detected that 10% potassium sorbate solution, 1% eucalyptus oil solution, 1% tea tree oil solution, 400 µL/10 mL grapefruit seed extract solution, 100% lactic acid, 10% acetic acid solution, and 10% lactic acid solution were prepared and used. After adjusting the pH to 4, 5, and 6 with lactic acid and acetic acid in the mixed culture medium, each bacterium was inoculated into the medium and incubated for 72 h at 35℃. Incubate and 0 h each. 24 h. 48 h. The number of bacteria was measured after 72 h. Results: In the mixed culture test between lactic acid bacteria and pathogenic microorganisms, lactic acid bacteria showed good results at pH 5-5.5. Potassium sorbate, which has varying antibacterial activity based on the pH, killed pathogenic bacteria and allowed lactic acid bacteria to survive at pH 5.5. Conclusion: The formulation ratio obtained through this study could be used for the development of a feminine cleanser that can be used as a substitute for antibacterial agents. Further, the findings of this study may be able to solve the problem of antimicrobial resistance in the future.

• Korean journal of food and cookery science
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• v.16 no.4
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• pp.372-377
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• 2000

Six kinds of herbs(applemint, geranium, lemonbalm, rosemary, sage and thyme) were extracted with water and 95% methanol, and the electron donating ability, antibacterial activity and nitrite scavenging effect were examined. The electron donating ability of herbs ranged from 60.7 to 92.2% and the highest value was observed in geranium, followed by sage and lemonbalm. Antibacterial activity of methanol extracts was much stronger than that of water extracts and gram positive bacteria were more sensitive than gram negative bacteria. Rosemary and geranium exhibited excellent antimicrobial activities against a wide range of bacteria. Nitrite scavenging activity, which was measured at various pH conditions(1.2, 3.0, 3.6, 4.2), was the highest in all herbs at pH 1.2 and the lowest at pH 4.2, suggesting that it is pH dependent. Methanol fraction also provided higher nitrite scavenging effect than the water fraction.

• The Korea Journal of Herbology
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• v.29 no.4
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• pp.21-27
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• 2014

Objectives : This experimental study was performed in order to investigate the antibacterial effect of bio-fermented Galla Rhois extract. Methods : The Galla Rhois extract was fermented by Streptococcus thermophilus, Saccharomyces cerevisiae and Lactobacillus delbrueckii, and their products was tested for antibacterial activity against six pathogenic microorganisms namely, Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Vibrio parahaemolyticus, Escherichia coli and Salmonella typhimurium by paper disc diffusion method. Results : The Galla Rhois fermented extract by Lactobacillus delbrueckii and Saccharomyces cerevisiae showed more effective antibacterial activity than not fermented extract against Bacillus subtilis and Vibrio parahaemolyticus. Antibacterial activity of fermented extract using especially Lactobacillus delbrueckii and Saccharomyces cerevisiae was proved that it was good with even 2 percents concentration. Antibacterial activity of Galla Rhois extract within pH 3 to pH 7 had been safe regardless of pH but low over pH 9. The growth of Bacillus cereus, Staphylococcus aureus, and Vibrio parahaemolyticus had a tendency to decrease depend on the increasing concentration of the extract. EtOEt, EtOAc and n-BuOH fractions of the Galla Rhois extract had a high level of antibacterial activity against Bacillus cereus, Bacillus subtilis, Staphylococcus aureus and Vibrio parahaemolyticus, respectively. Surprisingly, EtOAc fractions of the Galla Rhois extract showed higher antibacterial activity against Vibrio parahaemolyticus alone. And antibacterial activity against six pathogenic microorganisms had a tendency to increase depend on the increasing concentration of the fractions of the Galla Rhois extract. Conclusions : Bio-fermented Galla Rhois extract, efficiently inhibited the growth of Bacillus cereus and Vibrio parahaemolyticus.

• Food Science of Animal Resources
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• v.38 no.1
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• pp.172-179
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• 2018

One of the critical limitations to use of bacteriocins produced by lactic acid bacteria as a substitute for chemical antibiotics is the narrow spectrum of their antibacterial activity. The aim of present study was isolation and molecular identification of bacteriocin-producing enterococci with broad antibacterial spectrum. Bacteriocin-producing bacteria were isolated from native dairies in Kerman. Bacteriocins were purified by ammonium sulfate method and the effects of them were investigated on different strains of bacteria. Also, the effects of pH and heat on produced bacteriocins were investigated. High level bacteriocin-producing isolates were identified based on molecular tests. A total of 15 strains of bacteriocin-producing Enterococcus were isolated initially. Enterococcus faecium C-2 and Y-1 strains produced bacteriocins with the highest antibacterial effect. The bacteriocins were stable in pH ranges from 2 to 12 and their antibacterial activity was maintained after autoclave treatment. The maximum bactericidal effect was observed against Listeria monocytogenes and Pseudomonas aeruginosa. In conclusion, use of these bacteriocins as a substitute for chemical antibiotics is recommended.

• KSBB Journal
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• v.17 no.1
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• pp.63-67
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• 2002

Silver-alginate and copper-alginate were prepared with Na-alginate extracted from marine brown algae(Sargassum fluitans). The antibacterial effect of Ag-alginate or Cu-alginate against Staphylococcus aureus and Escherichia coli was carried out by measuring optical density of liquid culture at 600 nm. The cell growth of Staphylococcus aureus and Escherichia coli was very active at pH 7, and was inhibited by adding Ag-alginate with more than 0.006 wt.% of silver content. The antibacterial effect of Ag-alginate against S. aureus and E. coli was better than that of Cu-alginate at the same metal concentration. The cell growth of S. aureus was less inhibitory than E. coli at the same concentration of Ag-alginate. The cell growth of S. aureus and E. coli was also influenced by the characteristics of counter ion of silver.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.1
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• pp.37-40
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• 2003

The antibacterial action of violet pigment, a mixture of violacein and deoxyviolacein, isolated from phychrotrophic bacterium RT102 strain was examined, and the operational conditions for the effective production of violet pigment were studied. The antibacterial activity of the violet pigment was confirmed for several bacteria such as Bacillus licheniformis, Bacillus subtilis, Bacillus megaterium, Staphylococcus aureus, and Pseudomonas aeruginosa, and the high concentration of violet pigment, above about 15mg/L, caused not only growth inhibition but also death of cells. The growth properties of RT102 strain were clarified under various incubation conditions such as pH, temperature, and dissolved oxygen concentration. The maximum violet pigment concentration, i.e. 3.7 g/L, and the maximum productivity of violet pigment, i.e. 0.12 g .L$\^$-1/H$\^$-1/, were obtained in a batch culture of pH 6, 20$^{\circ}C$, and 1 mg/L of dissolved oxygen concentration.