• Food Science of Animal Resources
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• v.36 no.4
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• pp.452-457
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• 2016

Lactoferrin is a glycoprotein with various biological effects, with antibacterial activity being one of the first effects reported. This glycoprotein suppresses bacterial growth through bacteriostatic or bactericidal action. It also stimulates the growth of certain kinds of bacteria such as lactic acid bacteria and bifidobacteria. In this study, Asn-Leu-Asn-Arg was selected and chemically synthesized based on the partial sequences of bovine lactoferrin tryptic fragments. Synthetic Asn-Leu-Asn-Arg suppressed the growth of Pseudomonas fluorescens, P. syringae and Escherichia coli. P. fluorescens is a major psychrotrophic bacteria found in raw and pasteurized milk, which decreases milk quality. P. syringae is a harmful infectious bacterium that damages plants. However, synthetic Asn-Leu-Asn-Arg did not inhibit the growth of Lactobacillus acidophilus. It is expected that this synthetic peptide would be the first peptide sequence from the bovine lactoferrin C-lobe that shows antibacterial activity.

• Journal of Microbiology and Biotechnology
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• v.9 no.5
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• pp.572-575
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• 1999

Miconazole was estimated to have a minimum inhibitory concentration of 0.78 ㎍/㎖ against the methicillin-resistant strains of Staphylococcus aureus (MRSA). The antibacterial activity of miconazole against MRSA was bacteriostatic in cation-adjusted Mueller-Hinton broth, but bacteriocidal in saline solution. The anti-MRSA activity of miconazole did not show a significant change under the susceptibility-testing conditions such as various inoculum sizes, pHs, or cations (Ca/sup ++/ or Mg/sup ++/) which was added to the medium. However, the anti-MRSA activity of miconazole was completely suppressed by lipophilic a-tocopherol (50 ㎍/㎖), but definitely not by water-soluble ascorbic acid.

• Korean Journal of Microbiology
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• v.12 no.2
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• pp.77-84
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• 1974

In order to study 5-nitro-2-furaldehyde derivatives having more effective antibacterial activity, four new $N^4$-(5-nitro-2-furfurylidene)-$N^1$-substituted sulfanilamides$N^1$-3,4-dimethyl-5-isoxazoyl-$N^4$-5-nitro-2-furfurylidene sulfanilamide, $N^1$-4,6-dimethyl-2-pyrimidyl-$N^4$-5-isoxazoyl-$N^4$-5-nitro-2-furfurylidene sulfanilamide, $N^1$-6-methoxy-3-pyridazinyl-$N^4$-5-nitro-2-furaldehyde with sulfa drugs such as sulfisoxazole, sulfamethazine, sulfamethoxypyridazine, and sulfadimethoxine. All compounds were tested for antibacterial activity in vitro on the following micro-organisms : Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Proteus vulgaris. Each compound exhibited a fair bacteriostatic activity against each microorganism. Above all, sulfisoxazole derivatives showed higher activity than the others. Each compound was most active against Staphylococcus aureus, whereas least active against proteus vulgaris.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.3
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• pp.183-188
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• 2002

Antibacterial glass ceramics composed of $5Li_2O{\cdot}36CaO{\cdot}20TiO_2{\cdot}27P_2O_5$ were Prepared. After ion exchange in the $AgNO_3$solution, crystallization phases were $AgTi_2(PO_4)_3$, $LiTi_2(PO_4)_3$ and $Ca_3(PO_4)_2$. In case of ion exchange, the crystallization phases started to be transformed from $LiTi_2(PO_4)_3$ to $AgTi_2(PO_4)_3$in 0.5 mole $AgNO_3$ solution and the transformation was almost completed in 1.0 mole. ion exchange rate of glass-ceramics powder, considering ion exchange time, was more fast than that of bulk. The bacteriostatic effect of the glass-ceramics on Staphyloroccus aureus and Salmonella typhi bacteria was more excellent than that of glass when the crystallization phase was transformed from LTP to AgTP.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.622-629
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• 2010

Biosynthetic studies on brasiliamides, potently convulsive and bacteriostatic compounds from an endophytic Penicillium brasilianum isolated from Melia azedarach (Meliaceae), confirms their phenylpropanoid origin, which is very uncommon in fungi. Feeding experiments with [$2-^{13}C$]-phenylalanine indicated the incorporation of two units of this amino acid on brasiliamide structures. The first step in the phenylpropanoid pathway to those compounds was evaluated through enzymatic bioassays and confirmed the phenylalanine ammonia-lyase (PAL) participation. The metabolism of phenylalanine in this fungus is discussed.

• Korean Journal of Veterinary Service
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• v.36 no.4
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• pp.297-301
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• 2013

The present study was to investigate anti-microbial effects of curcumin on major bacterial pathogens for farmed fish, such as Aeromonas hydrophila, A. salmonicida subsp. masoucida, A. salmonicida subsp. salmonicida, Edwardsiella tarda, Vibrio vulnificus, V. paraheamolyticus using disk diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests. In disc diffusion test, curcumin exhibited concentration-dependent antimicrobial activities to all bacteria pathogens used in the study. Antimicrobial effects of curcumin was found differently depending on bacterial species when determined by MIC or MBC tests. For examples, E. tarda and A. hydrophila was respectively the most sensitive bacterium for bacteriostatic and bacteriocidal effect of curcumin. Collectively, curcumin could be a potential natural drug for controlling pathogenic bacteria in the aquaculture industry.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.131-136
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• 2005

The selective extraction behavior of lactoferrin (Lf) from whey protein mixture was examined using reverse micelles formed by the cationic surfactant, cetyldimethylammonium bromide (CDAB). The major whey proteins, including ${\beta}$-lactoglobulin, ${\alpha}$-lactalbumin and bovine serum albumin, were solubilized from aqueous phase to organic phase while Lf was recovered in the aqueous phase. The solubilization behaviors of the proteins were manipulated by the process parameters such as the pH and salt concentration of the aqueous phase and the surfactant concentration in the organic phase. Efficient forward extraction was achieved with sodium borate buffer (50 mM, pH 9) containing 50 mM KCl and organic phase containing 100 mM CDAB. Based on SDS-PAGE and densitometry, about 96% of the initial Lf remained in the aqueous phase after forward extraction. The dialyzed Lf fully maintained its bacteriostatic activity against E. coli O157:H7.

• Journal of Microbiology
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• v.44 no.3
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• pp.255-262
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• 2006

Titanium and its alloys are technically superior and cost-effective materials, with a wide variety of aerospace, industrial, marine, and commercial applications. In this study, the effects of titanium ions on bacterial growth were evaluated. Six strains of bacteria known to be resistant to both metal ions and antibiotics were used in this study. Two strains, Escherichia coli ATCC 15489, and Pseudomonas aeruginosa ATCC 10145, proved to be resistant to titanium ions. Plasmid-cured p. aeruginosa resulted in the loss of one or move resistance markers, indicating plasmid-encoded resistance. The plasmid profile of p. aeruginosa revealed the presence of a 23-kb plasmid. The plasmid was isolated and transformed into $DH5{\alpha}$. Interestingly, the untransformed $DH5{\alpha}$ did not grow in 300 mg/l titanium ions, but the transformed $DH5{\alpha}$ grew quite well under such conditions. The survival rate of the transformed $DH5{\alpha}$ also increased more than 3-fold compared to that of untransformed $DH5{\alpha}$.

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.581-585
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• 1996

A new formal total synthesis of (+)-6-oxo-3, 4, 4a, 5-tetrahydro-3-hydroxy-2, 2-dimenthylnaphtho-1, 2-pyran (1) which has been known to have bactericidal, bacteriostatic, fungicidal, fungistatic activities against Staphylococcus aureus and other microorganism, is described. The key reaction involves enantioselective prenylation of .alpha.-tetralone via chiral lithioenamine.

• Journal of Life Science
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• v.28 no.1
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• pp.110-115
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• 2018

This study was conducted to investigate the potential of medicinal plants as oral health materials derived from natural products. Among the extracts from 200 medicinal plants grown in Nepal, Laos, Mongolia, Bangladesh, Vietnam, and China, stem extracts from Diospyros malabarica (1 mg/disc) showed the highest antibacterial activity against Porphyromonas gingivalis ATCC33277 and Streptococcus mutans ATCC25175. The D. malabarica stem extracts showed antibacterial activity similar to chlorhexidine, sodium lauryl sulfate, and triclosan, which were used as a positive control, as well as higher antibacterial activity against S. mutans ATCC25175 than P. gingivalis ATCC33277. The D. malabarica stem extracts showed bactericidal action (MBC, 0.4 mg/ml) against P. gingivalis ATCC33277 and bacteriostatic action against S. mutans ATCC25175. The biofilm production rate of S. mutans ATCC25175 and the expression of the comX gene associated to biofilm formation in the cultures treated with 0.2-1.0 mg/ml of D. malabarica stem extracts were suppressed in a concentration-dependent manner. Based on the above results, it can be concluded that D. malabarica stem extracts can be used as oral health material derived from natural materials, as demonstrated by the bacteriostatic action and inhibition of biofilm formation against S. mutans ATCC25175.