• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.11 no.2
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• pp.101-107
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• 2005

The term 'antimicrobial' packaging encompasses any packaging technique(s) used to control microbial growth in the food product. These include packaging materials and edible films and coatings that contain antimicrobial agents, and also techniques that modify the atmosphere within the package. In recent years, antimicrobial packaging has attracted much attention from the food industry because of the increase in consumer demand for minimally processed, preservative-free products. Reflecting this demand, the preservative agents must be applied to packaging in such a way that only low levels of preservatives come into contact with the food. The film or coating technique is considered to be more effective, although more complicated to apply. New antimicrobial packaging materials are being developed continually. Many of them exploit natural agents, to control common food-borne microorganisms. Current trends suggest that in due course, packaging will generally incorporate antimicrobial agents and the sealing systems will continue to improve. The focus of packaging in the past has been on the appearance, size and integrity of the package. A greater emphasis on safety features associated with the addition of antimicrobial agents is perhaps the next area for development in packaging technology.

• Food Science and Preservation
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• v.7 no.1
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• pp.1-7
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• 2000

To develop natural antimicrobial agents for keeping qualities of postharvested greenhouse produce the antimiocrobial actions of Polygonum cuspidatum Sieb. et Zucc. extract , which showed remarkable antimicrobial effects against microorganism causing the postharvest decay of greenhouse produce, were investigate. In the inhibitory experiment of enzymes related to energy production metabolism hexokinase activities decreased to 73% and 68% by treating with Polygonum cuspidatum Sieb. et.Zucc. extract and Eugenia caryophyllata Thumnberg extract in comparison with control, respectively. Direct visualization of microbial cells by using both transmission electron microscope and scanning electron microscope showed that microbial cell membrane was destroyed by treating with the dilute extract solution. this change of celluloar membrane permeability could be identified in the experiment that 0-nitrophenyl-${\beta}$-D-galactopyrano-side(ONPG), the artificial substrate of ${\beta}$-galactosidase, was hydrolyzed in the presence of the extract, indicating that the membrane was perturbed. The separation and identification of the most antimicrobialo substances isolated from Polygonum cuspidatum Sieb et. Zucc. extract and Eugenia caryophyllata Thunberg extract were carried out by using gas chromatography and mass spectrometry 9GC/MSD), which were identified as eugenol. As a result, the functionality of Polygonum cuspidatum Sieb. et Zucc. extract and Eugenia caryophyllata Thunberg extract as antimicrobial agents for keeping qualities of postharvested greenhouse produce may be recommended.

• Natural Product Sciences
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• v.17 no.1
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• pp.23-25
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• 2011

It has been shown that the butanol extract of Lonicera japonica has antimicrobial and other potentially useful biological activities. The purpose of this study was to determine the in vitro activity of Lonicera japonica compared to other antimicrobial agents against anaerobic bacteria. Specifically, the in vitro activity of the butanol extract was investigated against 104 clinical isolates of anaerobic bacteria using an agar dilution method and the results were compared to erythromycin, cefoxitin, imipenem, clindamycin, and metronidazole. It was found that Lonicera japonica and imipenem were the most active antimicrobial agents tested.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1112-1115
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• 2000

• Journal of Society of Preventive Korean Medicine
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• v.4 no.1
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• pp.144-151
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• 2000

This study was carried out to evaluate cytotoxic effects of Houttuynia cordata Thunberg extracts on murine leukemia tumor cell lines. Disruptions in cell organelles were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazol iumbromide (MMT) assay. The comparison of $IC_{50}$ values of Houttuynia cordata Thunberg extracts on $L1210,\;P388D_1$ and Vero cell lines showed that the methanol extract of Houttuynia cordata Thunberg indicated the most antitumor activity in the MTT assay. In order to develop a antimicrobial agent, dried Houttuynia cordata Thunberg was extracted with several solvents, and then antimicrobial activity was investigated. The minimal inhibitory concentration (MIC) of the extracted substance against microorganisms were also examined. Antimicrobial activity of amocla and ketoconazole as references was compared to those of other solvent extracts such as $H_2O$, n-hexane, chloroform, ethyl acetate ethanol and methanol. The antimicrobial activity of all extracts from the sample had growth inhibition activity against gram-negative bacteria, yam-positive bacteria and fungi $(MIC,\;>\;200\;{\mu} g/ml)$. These results suggest that the methanol soluble extract of Houttuynia cordata Thunberg may be a valuable choice for the studies on the treaeent of murine leukemia tumor cell lines and antimicrobial agents.

• KSBB Journal
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• v.27 no.1
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• pp.9-15
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• 2012

Antimicrobial peptides are widely used in various organisms as a defense system against infection. The peptides are lethal towards bacteria and fungi, however have minimal toxicity in mammalian and plant cells. In this aspect, it is considered that antimicrobial peptides are new alternative materials for defensing against microbial infection. Here, we describe overall characteristics of antimicrobial peptides based on the mechanism of action, classification of the peptides, report detection/screening methods and chemical/biological production. It is expected that understanding of innate immune system based on antimicrobial peptides tends to develop novel natural antimicrobial agents, which might be applied for defensing pathogenic microorganisms resistant to conventional antibiotics.

• Microbiology and Biotechnology Letters
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• v.37 no.1
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• pp.80-84
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• 2009

The in vitro antibacterial activities of anti-acne agents prepared from the extracts of natural sources were investigated against several bacteria including antibiotic-susceptible and -resistant Propionibacterium acnes. SD-1 and SD-2 were prepared with different formulations and they showed strong antibacterial activities. The anti-acne agents completely inhibited the growth of the tested strains at the concentration of 0.5%. There was no difference in antibacterial activity between antibiotic-susceptible and -resistant P. acnes. The inhibitory activities of two agents showed time-dependent manner. In S. aureus, time-kill curve demonstrated 2.8- and 3.4-$log_{10}$-unit killing after 8 h with SD-1 and SD-2, respectively. In P. acnes, time-killing curve demonstrated 5.1- and 6.1-$log_{10}$-unit killing after 24 h with SD-1 and SD-2, respectively. SD-2 showed stronger antimicrobial activity than SD-1. From these results, we expect that SD-1 and SD-2 have strong antibacterial activities and have advantages for treating acne.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1242-1248
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• 2017

Several medicinal plants are ethnomedically used in Korea as agents for treating infection, anti-inflammation, and pain relief. However, beyond typical inhibitory effects on cell growth, little is known about the potential anti-biofilm activity of these herbs, which may help to prevent cavities and maintain good oral health. This study aimed to investigate the antimicrobial and anti-biofilm activities of the methanol extracts of 37 Korean medicinal plants against dental pathogens Streptococcus mutans and Candida albicans, which synergize their virulence so as to induce the formation of plaque biofilms in the oral cavity. The antimicrobial activities were investigated by broth dilution and disk diffusion assay. The anti-biofilm and antioxidant activities were evaluated based on the inhibitory effect against glucosyltransferase (GTase) and the DPPH assay, respectively. Among 37 herbs, eight plant extracts presented growth and biofilm inhibitory activities against both etiologic bacteria. Among them, the methanol extracts (1.0 mg/ml) from Camellia japonica and Thuja orientalis significantly inhibited the growth of both bacteria by over 76% and over 83% in liquid media, respectively. Minimum inhibitory concentration (MIC) values of these methanol extracts were determined to be 0.5 mg/ml using a disk diffusion assay on solid agar media. Biofilm formation was inhibited by more than 92.4% and 98.0%, respectively, using the same concentration of each extract. The present results demonstrate that the medicinal plants C. japonica and T. orientalis are potentially useful as antimicrobial and anti-biofilm agents in preventing dental diseases.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.5
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• pp.437-441
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• 2003

This research investigated the effects of processing conditions and natural antimicrobial materials on quality of freeze-dried, seasoned and roasted Alaska pollack (Theragra chalcogramma). The optimum dipping time and moisture contents of freeze-dried Alaska pollack were 1 sec in $1\%$ salt solution, $48.6\%$ respectively. The freeze-dried, seasoned and roasted Alaska pollack product showed high sensory value. As sterilization time increased over 30 mins in water bath at $100^{\circ}C$ the browning degree of the freeze-dried, seasoned and roasted Alaska pollack product increased. Among various antibrowning agents, $3\%$ corn starch was better in preventing browning than sporix treatment. The freeze-dried, seasoned and roasted Alaska pollack product added with lactate Ca and catechin had the antimicrobial, and the VBN contents of the product showed low level.

• Journal of Microbiology and Biotechnology
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• v.28 no.8
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• pp.1299-1309
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• 2018

We previously reported on lactophoricin (LPcin), a cationic ${\alpha}-helical$ antimicrobial peptide derived from bovine milk, which has antimicrobial effects on Candida albicans as well as Gram-positive and Gram-negative bacteria. In this study, we designed the LPcin-YK3 peptide, a shorter analog of LPcin, and investigated its antimicrobial activity. This peptide, consisting of 15 amino acids with + 3 net charges, was an effective antimicrobial agent against the on the Gram-positive strain, Staphylococcus aureus (MIC: $0.62{\mu}g/ml$). In addition, the hemolytic activity assay revealed that the peptide was not toxic to mouse and human erythrocytes up to $40{\mu}g/ml$. We also used circular dichroism spectroscopy to confirm that peptide in the presence of lipid has ${\alpha}-helical$ structures and later provide an overview of the relationship between each structure and antimicrobial activity. This peptide is a member of a new class of antimicrobial agents that could potentially overcome the problem of bacterial resistance caused by overuse of conventional antibiotics. Therefore, it could be used as a therapeutic or natural additive, particularly in the cosmetics industry.