• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.131-137
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• 2021

This study aimed at isolating lactic acid bacteria with anti-MRSA (methicillin-resistant Staphylococcus aureus) bacteriocin activity from fermented shrimp. We selected three strains, named Weissella sp. S1, S2, and S3, using analysis based on 16S rRNA gene sequences. All strains showed appropriate growth in an MRS medium containing 5% (w/v) NaCl and showed antibacterial activities against Bacillus cereus, Escherichia coli, Staphylococcus aureus, and MRSA. The strains exhibited similar growth rates at 0-5% NaCl, with approximate reduction in growth rate observed at 9% NaCl. Weissella sp. S1, S2, and S3 exhibited maximum growth rates at pH 7, 9, and 8, respectively. The crude bacteriocin was prepared from Weissella sp. S3 and subjected to characterization. The remaining activities after 30 min of exposure at each temperature were 100%, beyond 75%, and 49% at 4℃ and 37℃, 50℃ and 70℃, and 100℃, respectively. The remaining activities after 24 h of exposure at each pH were 100%, 75%, and 49% at pH 3 and 5, 7 and 9, and 10, respectively. Use of 50% (v/v) ethanol or isopropanol treatment did not diminish the antibacterial activity of the bacteriocin, while the 50% (v/v) hexane treatment reduced the activity by 51%. The molecular weight of the bacteriocin was nearly 6 kDa that was quantified using tricine-SDS-PAGE. Our findings suggest that Weissella sp. S3 may be considered a probiotic and useful source of antimicrobial substances in the development of bio-preservatives for food or in MRSA treatment.

• Journal of Korean Academy of Oral Health
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• v.42 no.4
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• pp.210-215
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• 2018

Objectives: The main objectives of this study were to verify the antibacterial activity of two essential oils, lavender and peppermint, against dental caries and to review their synergistic effect when used in combination. Our results provide basic data for the evaluation of the use of these two substances towards the prevention and cure of dental caries. Methods: The sample solutions of lavender and peppermint oils were prepared in three different concentrations (30%, 50%, and 70% (v/v)) by diluting them with third-distilled water and Tween 20. Streptococcus mutans was selected as the bacterial species for testing. The disk diffusion method was used to measure the antibacterial activity of the sample solutions. For generating growth curves and measuring the number of clusters of the bacterial, the liquid medium-dilution method was used; the absorbance of the medium was measured at 600 nm after 3, 6, 12 and 24 hours. Results: When the antibacterial activity of the oils was tested via the disk diffusion method, the activity improved with increasing concentrations of all the sample solutions of peppermint, lavender, and the blend, but there was no significant difference between them with respect to the type of oil. In the growth curves of S. mutans, growth inhibition was observed after 12 hours. The inhibitory effect of 30% lavender oil on growth was 64.9% and 80.1% after 12 and 24 hours of treatment, respectively whereas that of peppermint oil was 71.3% and 80.1% after 12 and 24 hours of treatment, respectively. The inhibitory effect of the blended oil was 71.9% and 81.0% after 12 and 24 hours of treatment, respectively. Conclusions: Further research is still required in order to determine the efficacy of lavender and peppermint oils, as well as other essential oils, for wider use in preventing dental caries.

• Biomolecules & Therapeutics
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• v.24 no.4
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• pp.347-362
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• 2016

Marine sponges have been considered as a drug treasure house with respect to great potential regarding their secondary metabolites. Most of the studies have been conducted on sponge's derived compounds to examine its pharmacological properties. Such compounds proved to have antibacterial, antiviral, antifungal, antimalarial, antitumor, immunosuppressive, and cardiovascular activity. Although, the mode of action of many compounds by which they interfere with human pathogenesis have not been clear till now, in this review not only the capability of the medicinal substances have been examined in vitro and in vivo against serious pathogenic microbes but, the mode of actions of medicinal compounds were explained with diagrammatic illustrations. This knowledge is one of the basic components to be known especially for transforming medicinal molecules to medicines. Sponges produce a different kind of chemical substances with numerous carbon skeletons, which have been found to be the main component interfering with human pathogenesis at different sites. The fact that different diseases have the capability to fight at different sites inside the body can increase the chances to produce targeted medicines.

• Korean Journal Plant Pathology
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• v.11 no.2
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• pp.158-164
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• 1995

토마토의 엽권에서 분리한 Fusariym graminearum이 분비하는 물질은 벼 도열병균(Pyricularia oryzae)의 여러 종의 식물병원 진균에 대한 항균활성을 나타내었으며, 이러한 활성물질을 PDA에서 본 균을 배양 한 후 chloroform으로 추출하여 분리정제 하였다. HPLC에 의하여 5종류의 활성 물질을 분획하였으며, 그중 1번(F402) 화합물을 벼 도열병균(P. oryzae)을 포함한 22개 식물 병원 진균에 대하여 살균 활성범위를 조사한 결과, 이 화합물은 50$\mu\textrm{g}$/ml 농도에서 Pythium ultimum, Rhizoctonia solani, Sclerotinia sclerotiorum은 전혀 억제하지 못하였으며, Phytophthora spp., Cladosporium fulvum, Fusarium spp., Corynespora cassicola에는 어느 정도의 활성이 있었지만 낮게 나타났고, P. oryzae, Cochliobolus miyabeanus, Alternaria solani는 100% 억제하여 활성이 높게 나타났다. 또한 장내 세균에 대한 활성을 MIC로 비교할 때 Streptococcus pyogenes, Streptococcus faecium에 대하여는 각각 12.5, 25 $\mu\textrm{g}$/ml였고 Staphylococcus aureus는 25-50$\mu\textrm{g}$/ml으로 나타났으며, Pseudomonas aeruginosa, Salmonella typhimurium, Klebsiella aerogenes, Enterobacter cloacae에서는 100$\mu\textrm{g}$/ml 이상으로 활성이 나타나지 않았다. F402를 200$\mu\textrm{g}$/ml의 농도로 직접 살포한 식물체에서의 방제효과는 벼도열병, 벼 깨씨무늬병, 보리 흰 가루병에 대하여는 80%이상이었으나, 벼 잎집무늬마름병, 오이 잿빛곰팡이병, 토마토 역병, 밀 녹병에서는 낮았다.

• The Journal of the Korea Contents Association
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• v.18 no.3
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• pp.542-549
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• 2018

In this study BGn-incorporated non-fluoride release of pit and fissure sealant $Concise^{TM}$ was developed to improve the mechanical properties and promote antibacterial effect of fit and fissure sealant with the original material. The mechanical properties and antibacterial activity of BGn incorporating vary-ing amounts bioactive glass nano particles(BGn) (0,0.5,1.0 and 2.0 wt% in sealant) were characterized composition of the resulting were investigated. The solubility to aid absorption was calculated by weighing specimens with a diameter of 10 mm and a thickness of 2 mm according to ISO 4049 (2009). The antimicrobial effect was evaluated using three strains of S. mutans, S. aureus and E. coli. The absorbance of the test results was as high as the addition of BGn increased, and the lower the solubility as the solubility was added(p<0.05). Adhesion experiment results S. mutans in contrast to the control group $Concise^{TM}$, BGn-added experimental group showed a somewhat lower adherent surface but no statistically significant difference was observed (p<0.05). However S. aureus and E. coli statistical analysis indicated a significant difference for antibacterial agents between control and BGn containing(p<0.05). It seems that this BGn proved that even a antibacterial effect was demonstrated. Therefore, it was suggest that the additional effects of BGn and research on a wide range of substances.

• Korean Journal of Microbiology
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• v.41 no.2
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• pp.152-156
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• 2005

In the present study, lactic acid bacterium that has antibacterial activity against Helicobacter pylori was isolated from feces of newborn baby. The selection was based on the ability to inhibit the growth of H. pylori and to withstand harsh environmental conditions such as acidic pH and high bile concentration. By biochemical test and 16S rDNA sequencing, selected strain was turned out to be an Pediococcus acidilactici, therefore designated to P. acidilactici GMB7330. In order to investigate the inhibitory effects of P. acidilactici GMB7330 on the growth of H. pylori, we have tested in vitro studies such as cell viability and urease test. These results showed that antibacterial activity of P. acidilactici GMB7330 significantly decreased the viable cell count and urease activity of H. pylori. Antibacterial activity of P. acidilactici GMB7330 against H. pylori remained after pH adjustment to neutral, and the concentration of lactate produced from P. acidilactici GMB7330 was not enough to inhibit H. pylori. On the basis of the analysis by transmission electron microscope, it demonstrated that addition of P. acidilactici GMB7330 destroyed the cell structure of H. pylori. These results strongly suggested that P. acidilactici GMB7330 produce antibacterial substances to be able to inhibit the growth of H. pylori other than lactic acid.

• Microbiology and Biotechnology Letters
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• v.38 no.1
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• pp.105-111
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• 2010

Caesalpinia sappan L. has long been commonly used in oriental folk medicines to treat diseases. To investigate the antibacterial effects from C. sappan L. heart wood, the MeOH soluble extract was successively fractionated by using hexane, $CHC1_3$, EtOAc, BuOH, MeOH, and $H_2O$. Among of these extracts, the EtOAc fraction which partitioned to 3.94% of the highest yields was to be the most active against all human pathogenic bacteria in this experiment. In addition, the antibacterial activities of the EtOAc fraction were more effective against Gram (+) bacteria compared to those against Gram (-) bacteria, which showed difference of the antibacterial activities against Gram (-) bacteria. To confirm the identity of the active substances, the EtOAc fraction was further separated by silica gel adsorption column, high performance liquid chromatography, and 98.48% purity of brazilin (1.67 mg)/EtOAc (10 mg) fraction was obtained from 300 g of C. sappan L. heart wood. The isolated active substance was a single compound of yellow crystalline, and was identified as brazilin ($C_{16}H_{14}O_5$) by MS, and $^lH$-NMR and $^{13}C$-NMR. These results suggest that the brazilin in the EtOAc fraction from MeOH extract of C. sappan L. has a potential as a natural therapeutic agent against human pathogenic Gram (+) bacteria such as Staphylococcus aureus.

• Journal of dental hygiene science
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• v.8 no.4
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• pp.367-373
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• 2008

The natural products are used to be development of new antibacterial substances against human pathogenic bacteria. Adherence to the tooth surface by S. mutans is an important step in initiation of dental caries. This study was to examine antibacterial activity and anti-adhesive effect of Scutellaria baicalensis extract against S. mutans. Extracts of S. baicalensis were tested for antimicrobial activities by paper disc methods and radial diffusion assay methods, and bacterial adherence assay using 3 type of hydroxyapatite. The antibacterial level of ethyl acetate extract, IPK-3 on the growth of S. mutans was 125 mg/ml of minimum inhibitory concentration (MIC). The maximum growth of S. mutans in medium added with IPK-3 extract (50 mg/ml) was delayed to 30 hr, while the highest at 24 hr in control medium. The pH values of the control medium was 5.63 at 18 hr, but the media supplemented with IPK-3 extract was pH 6.50 at 12 hr. In adhesive inhibition assay, S. mutans was labelled with the fluorescent indicator DAPI and measured with fluorescence microscope. Adhesion of S. mutans on hydroxyapatite beads was inhibited by IPK-3 extracts. These results suggest that S. baicalensis extract can be used as an effective material for antibacterial activity and adhesive inhibition against S. mutans.

• Journal of Life Science
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• v.21 no.9
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• pp.1244-1250
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• 2011

The study was performed to evaluate the antibacterial and antiviral activities of ginseng fine root in order to search for antibacterial substances. Among 8 kinds of fermentation strains, Lactobacillus plantarum was selected based on viable cell count and antibacterial activities during incubation. Optimum conditions of ginseng fine root fermentation for L. plantarum were incubation at $35^{\circ}C$ for 48 hr in 5% ginseng fine root broth. That methanolic extract of fermented ginseng fine root broth was observed to be antibacterial and have antiviral activities. The results of paper disc method of non-fermented extract and fermented extract measured against E. coli was 11 mm and 20 mm, S. aureus was 15 mm and 22 mm, respectively. Shaking flask method was observed to inhibit the growth E. coli and S. aureus in fermented extract by 99.9%. However, antiviral activity of Feline calicivirus (FCV) was mostly activated. Fermented extract was used to investigate the compositional changes of ginsenosides on HPLC analysis. By fermentation, ginsenoside Rg1, Re and Rd were increased, with Rd showing a significant increase of 50 ${\mu}g/g$. These results suggest that ginseng fine root extract is a useful resource.

• Korean Journal of Environmental Agriculture
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• v.41 no.1
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• pp.50-54
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• 2022

BACKGROUND: Phyllospadix japonica Makino is a perennial plant belonging to the family Zosteraceae. This species is native to the eastern coast of the Korean Peninsula, and it is found attached to rocks on the seashore. As with all seagrass species, P. japonica is also known to play a major role in protecting the marine environment, and studies on its physiological activities suggestive of its antioxidant, antibacterial and anti-inflammatory potentials have been reported. In this study, purification and structural analysis were performed to identify the polyphenol substances derived from P. japonica. METHODS AND RESULTS: An polyphenol substance MP-1 was purified from the 70% aqueous methanol extract of P. japonica using Diaion® HP-20 column chromatography, ODS column chromatography, and medium-pressure liquid chromatography (MPLC). The purified MP-1 was identified as rosmarinic acid having a molecular weight of 360 and a molecular formula of C18H16O8 through electrospray ionization (ESI)-mass and nuclear magnetic resonance (NMR) spectroscopic analysis. CONCLUSION(S): This study highlights the processes used for the identification of the polyphenol substance derived from P. japonica. Rosmarinic acid, the polyphenol derived from P. japonica identified by this study, is a kind of bioactive substance mainly present in plants. These findings provide an important starting point and are valuable for future studies on bioactive substances in seagrass.