• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.10
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• pp.1466-1470
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• 2009

This study was focused on the development of anticariogenic edible films using pullulan containing grapefruit seed extract (GFSE), polylysine or propolis. According to the result of antimicrobial activity (disc diffusion method) of GFSE, polylysine and propolis against Streptococcus mutans, antimicrobial pullulan film was produced by adding grapefruit seed extract. The optimum combination of pullulan and sorbitol (plasticizer) was 10$\sim$15% (w/v) and 40$\sim$50% of pullulan (w/w), respectively. Minimum concentration of grapefruit seed extract for growth inhibition of Str. mutans was 50 ppm in medium. Formulation of antimicrobial pullulan films containing grape seed extract was established and these results evidently showed potential for commercial application.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.799-804
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• 2006

Antioxidative and antimicrobial activities were measured for the Pleurotus eryngii (P. eryngii) solvent extracts in order to discover new functional activities. In P. eryngii, the powder moisture was 9.0%, and the carbohydrate, crude protein, crude ash and crude fat contents were 63.06, 20.70, 5.20 and 2.0%, respectively. Among the detected minerals, potassium (K) had the highest levels and manganese (Mn) the lowest. The amount of polyphenol in EtEx (Ethanol Extract) was 387 mg% for the whole body, 158 mg% for the stipe, and 593 mg% for the pileus. Higher levels of polyphenol in the entire body were found in the BuEx (Butanol Extract) (594 mg%) and WaEx (Water extract) (404 mg%) of the P. eryngii powder. BuEx had the highest level in the pileus, and EtEx and BuEx were higher than the other extracts in the stipe. The electron donating ability (EDA) of EtEx of the P. eryngii powder was the highest, at 91.12%, for the whole body, while it was the lowest, at 62.90%, in the stipe. In addition, the EDA of WaEx was 90.39% for the whole body. These EDA values were similar to those for tocopherol (93.93%) and BHT (96.72%), supporting the potential of these extracts to act as antioxidants. A number of the extracts were certified to have antimicrobial activities for small number of microorganisms, especially for gram-negative microorganisms. In other words, BuEx and EAEx in the pileus and WaEx in the stipe were found to inhibit the growth of Pseudomonas aeruginosa (gram negative). Additionally, EtEx and WaEx in all parts were shown to act as antimicrobial agents for Escherichia coli of gram negative.

• Korean Journal of Microbiology
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• v.49 no.3
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• pp.245-252
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• 2013

Pseudomonas aeruginosa and Acinetobacter baumannii are significant opportunistic pathogens in hospitals and are resistant to most antibiotics. Multidrug-resistant P. aeruginosa (MDRPA) and A. baumannii (MDRAB) cause severe human nosocomial infections and are more difficult to treat than methicillin-resistant Staphylococcus aureus (MRSA). Bifidobacteria are among of the most beneficial probiotics and have been widely studied for their antimicrobial activities. The present study explored the antimicrobial activity of Bifidobacterium sp. isolated from healthy Koreans against MDRPA and MDRAB. The antimicrobial activity of the isolates against MDRPA and MDRAB, which are resistant to ciprofloxacin, tobramycin, gentamicin, meropenem, and ceftazidime, was determined by modified broth microdilution methods using absorbance. Among all tested bifidobacteria isolates (nine B. adolescentis, three B. longum, and two B. pseudocatenulatum), the culture supernatant of B. pseudocatenulatum SPM1309 showed a strong growth inhibitory effect against MDRPA and MDRAB. No change in the turbidity of the mixture was observed during incubation, and its inhibitory effect occurred through bacteriostastic action. Moreover, the antibacterial activity was observed in the fraction with molecular weights <10 kDa of bifidobacteria culture supernatant, and the active fraction was heat-stable because it maintained its activity when heated at $70^{\circ}C$ for 10 min. The results suggest that this Bifidobacterium strain could have potential applications for alternative therapy in MDRPA and MDRAB infections.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.163-170
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• 2012

In order to inhibit the growth of pathogens and degrade biogenic amines during the fermentation of soybean products, an isolate with antimicrobial activity against pathogens and biogenic amine-degrading property was obtained from 83 traditionally fermented soybean products. The morphological and biochemical tests and the phylogenetic relationship among 16S rRNA gene sequences indicated that the isolate named as the strain SCK B11 was most closely related to Bacillus licheniformis. The cell-free supernatant of two day cultures was active against several pathogens including Enterococcus faecalis, Listeria monocytosis, Micrococcus luteus, Pseudomonas aeruginosa, Bacillus cereus, and Staphylococcus aureus. PCR analysis was conducted to determine relatedness to antimicrobial lantibiotics and biosurfactants produced by Bacillus spp., but showed negative for the genes encoding surfactin, lichenysin, and lichenicidine. Electron microscopic observation indicated that the antimicrobial agent seemed to attack the membrane of the pathogens, leaving the ghost or shrunken cells. The strain was found to degrade histamine by 72% and tyramine by 66% in the cooked soybean containing 5.3% of biogenic amine over 10 days of fermentation time. The use of selected strain would be a potential control measure in manufacturing traditionally fermented soybean products that are difficult to control pathogens and biogenic amine levels.

• Journal of Life Science
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• v.20 no.10
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• pp.1505-1510
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• 2010

In this study, we investigated antimicrobial- and anticarcinogenic activities of Amphitrite albicostatu (AA) fractions. AA was extracted with methanol first and then further fractionated into four different types: hexane (AAMH)-, methanol (AAMM)-, buthanol (AAMB)- and aqueous (AAMA) partition layers. In the paper disk test, the antimicrobial activity of AA fractions increased in proportion to concentration. Among the various solvent fractions, only AAMB showed antimicrobial activity. We also determined the growth inhibition and quinone reductase (QR) induced effects of AA fractions on cancer cells. The growth inhibition effects of AA fractions on HepG2 and B16F10 cells were evaluated by MTT assay. AAMM showed the strongest growth inhibition effects on HepG2 and B16F10 cells. The quinine reductase (QR) induced effects of AAMM on HepG2 cells at 100 ug/ml concentration indicated it to be 2.04 times higher than the control values of 1.0. Although further studies are needed, the present work suggests that Amphitrite albicostatu (AA) could have a potential use as a food preservative and chemopreventive agent.

• Food Science and Preservation
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• v.9 no.2
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• pp.234-239
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• 2002

To study the potential of the chestnut(Castanea crenata S.) leaves, as raw materials for functional food and medicine, chemical components, antioxidative and antimicrobial activities were carried out. The proximate composition was composed of total sugar 11.95%, crude fat 11.50%, crude fiber 10.11%, crude protein 7.50% and ash 1.79% and the components of major minerals were Ca 215.7 mg%, 196.6 mg%. The content of vitamin C wag 12.5 mg% and free sugar was composed of glucose 3.33%, fructose 0.25% and sucrose 0.022%. The major fatty acids in leaves of chestnut were composed of linoleic acid and the amounts of those showed 37.88% area percent. The major amino acids of chestnut leaves were glutamic acid(295.4 mg%), proline(285.7 mg%), aspartic acid(245.5 mg%), arginine(240.8 mg%), phenylalanine(237.4 mg%) and leucine(230.6 mg%). The ratio of essential/total amino acid was 48.3%. Methanol extract and ethyl acetate fraction showed stronger activity of the hydrogen donating activities, each of 72.52 % and 84.12 %, respectively. In solvent extracts using methanol, ethanol, ethyl acetate, chloroform and hexane, methanol extract showed the most effective antimicrobial activities. Antimicrobial activities of ethyl acetate fraction of methanol extract was higher than those of other fractions.

• Journal of Life Science
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• v.26 no.6
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• pp.737-748
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• 2016

By this time, insect antimicrobial peptides (AMPs) have been characterized more than 150 peptides since purification of cecropin in the hemolymph of pupae from Hyalophora cecropia in 1980. Therefore, it is considered that insects are good sources of AMP selection. Insect AMPs are small (low molecular weight) and cationic, and amphipathic with variable length, sequence, and structure. They perform a pivotal role on humoral immunity in the insect innate immune system against invading pathogens such as bacteria, fungi, parasites, and viruses. Most of the insect AMPs are induced rapidly in the fat bodies and other specific tissues of insects after septic injury or immune challenge. Then the AMPs subsequently released into the hemolymph to act against microorganisms. These peptides have a broad antimicrobial spectrum against various microbes including anticancer activities. Insect AMPs could be divided into four families based on their structures and sequences. That is the α-helical peptides, cysteine-rich peptides, proline-rich peptides, and glycine-rich peptides/proteins. For instance, cecropins, insect defensins, proline-rich peptides, and attacins are common insect AMPs, but gloverins and moricins have been identified only in lepidopteran species. This review focuses on AMPs from insects and discusses current knowledge and recent progress with potential applications of insect AMPs.

• Korean Journal of Microbiology
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• v.44 no.4
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• pp.326-332
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• 2008

Various bacteria were isolated from Korean soil samples based on their capability inhibiting the growth of MRSA strains. Among them, strain YK5 with the highest activity was a Gram positive sporulative bacillus with motility. It did not produce indole and no acid was formed from mannitol by the bacterium. The 16S rRNA sequence of the strain showed $95{\sim}98%$ homology with those of Paenibacillus spp.. The bacterial isolate shared the highest homology with that of P. elgii (98%), but was named as Paenibacillus incheonensis YK5 due to differences in physiological properties. Butanol extract of the P. incheonensis YK5 culture grown in SST medium at $37^{\circ}C$ for 96 hr showed a broad antimicrobial activity against Gram-positive (MRSA and Streptococcus pneumoniae) and negative (Pseudomonas aeruginosa, Salmonella spp., Shigella spp., Escherichia coli, Klebsiella pneumoniae) pathogenic bacteria and fungi (Cryptococcus neoformans and Trichophyton). The antimicrobial activity in the crude extract was stable in a broad range of temperature and pH, $20{\sim}100^{\circ}C$ and $3.0{\sim}6.0$, respectively. Therefore, the antimicrobial activity of P. incheonesis YK5 had potential as a novel antibiotics for pathogens including MRSA.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.209-217
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• 2022

In this study, Enterococcus faecalis BMSE-HMP005 isolated from human breast milk demonstrated antimicrobial effects against multidrug-resistant (MDR) bacterial strains. The bacteriocin produced by E. faecalis BMSE-HMP005 was fractionated using reverse-phase high-performance liquid chromatography. This fraction showed antimicrobial effects against both gram-positive and gram-negative MDR bacteria. No hemolytic reactions were observed. E. faecalis BMSEHMP005 was resistant to vancomycin; however, kanamycin, ampicillin, and erythromycin showed minimum inhibitory concentrations that were lower than the acceptable range provided by the European Food Safety Authority. For artificial gastric juice and bile acid, the survival rates were 98.67% and 95.70%, respectively. These results show the potential utility of E. faecalis BMSE-HMP005 as a probiotic with remarkable antimicrobial effects against MDR bacteria.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.195-198
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• 2008

This study was carried out to investigate the potential use of Zanthoxylum schinifolium and Zanthoxylum piperitum A.P. DC. as a source of antimicrobial agents against food borne pathogens. Essential oils of Z. schinifolium and Z. piperitum A.P. DC. were collected by steam distillation and analyzed by GC-MS. The antimicrobial activity of the essential oils was examined using the agar diffusion and micro-dilution assays. The effectiveness of Z. schinifolium essential oil was greater against Bacillus cereus, Staphylococcus aureus, and Vibrio parahaemolyticus than other pathogens, and the minimal inhibitory concentration (MIC) values were 1.25, 2.5, and 1.25, 2.5, and $1.25\;{\mu}g/mL$, respectively. Z. piperitum A.P. DC. essential oil was the most effective against all pathogens tested except for Escherichia coli O157:H7, and the MIC values against B. cereus, Salmonella choleraesuis, and V. parahaemolyticus were 1.25, 2.5, and $1.25\;{\mu}g/mL$, respectively. Limonene, the major component of Z. piperitum A.P. DC. essential oils, had the highest inhibitory activity toward V. parahaemolyticus with a MIC value of $0.15\;{\mu}g/mL$. Meanwhile, citronellal and geranyl acetate, major components of both essential oils, displayed antibacterial activity against only B. cereus with MIC values of 1.25 and $5\;{\mu}g/mL$, respectively. Therefore, these essential oils could be useful as antimicrobial agents against foodborne pathogens.