• Journal of Microbiology and Biotechnology
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• v.10 no.3
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• pp.423-428
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• 2000

Bacteriocins are classified as proteins which are produced by heterogeneous groups of bacteria, having and antimicrobial effect of the closely related organisms. Recently, bacteriocins derived from lactic acid bacteria and other food-related organisms have been the subject of much research on potential food biopreservatives. The goal of this study was to screen and characterize the bacteriocinogenic lactic acid bacteria from Jeot-gal(commercial fermented fish foods). All bacteriocinogenic isolates were identified as lactic acid bacteria. Isolates NK24, NK34, and SA72 were tentatively identified as Lactobacillus brevis, according to the API 50 CHL kit database. All antimicrobial substances produced from four lactic acid bacteria isolates completely lost their antibacterial activity after being treated with some proteases, indicating to their proteinaceous nature. The bacteriocin produced from isolates NK24, NK34, and SA72 showed a broad spectrum of activity when compared to those produced from isolate SA131. All bacteriocins isolated during the course of this study showed a bactericidal mode of inhibition.

• Food Science of Animal Resources
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• v.34 no.1
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• pp.65-72
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• 2014

This study is executed to develop probiotics which produce S-adenosyl-L-methionine (SAM), a methyl group donor of the 5-methyltetrahydrofolate methylation reaction within the animal cell. SAM is an essential substance for the synthesis, activation, and metabolism of hormones, neurotransmitters, nucleic acids, phospholipids, and cell membranes of animals. The SAM is also known as a nutritional supplement to improve brain functions of the human. In this study, the SAM-producing strains are identified in 18 types of salted fish, and then, the strains with excellent SAM productions are being identified, with 1 strain in the Enterococcus genus and 9 strains in the Bacillus genus. Strains with a large amount of SAM production include the lactic acid bacteria such as En. faecium and En. durans, En. sanguinicola, as well as various strains in the Bacillus genus. The SAM-overproducing strains show antibacterial activities with certain harmful microbes in addition to the weak acid resistances and strong bile resistances, indicating characteristics of probiotics. It is possible that the jeotgal-originated beneficial strains with overproducing SAM can be commercially utilized in order to manufacture SAM enriched foods.

• Korean Journal of Pharmacognosy
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• v.40 no.4
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• pp.257-279
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• 2009

Plants of genus Dioscorea have long been served as important carbohydrate-stuffed foods in the tropical and subtropical regions, and utilized as traditional herb medicines to enhance digestive function, improve anorexia, and treat diarrhea in oriental countries. It is known that around 600 species of Dioscorea are distributed in the world including 107 species in Asia, but actually utilized Dioscorea species are restricted to small numbers. Phytochemical investigations for Dioscorea species have revealed a number of chemical components such as sapogenins, saponins, phenanthrenes, stilbenes, diterpenes and purine derivatives. According to recent pharmacological studies, Dioscorea species possess significant antioxidant, antibacterial and anti-inflammatory activities as well as anticancer, antidiabetic, cholesterol-lowering and hypolipidemic effects. Here, seven Dioscorea species (D. batatas, D. japonica, D. bulbifera, D. opposita, D. tokoro, D. nipponica and D. alata), mainly distributed and used in Korea, China, and Japan, are reviewed to provide their botanical, phytochemical and pharmacological properties were described.

• International Journal of Oral Biology
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• v.39 no.1
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• pp.35-40
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• 2014

Halitosis is caused by consumption of certain foods or drinks and production of volatile sulfur compounds (VSCs) by periodontopathogens. VSCs-related halitosis is not easily removed using mechanical or chemical therapies such as dental floss, plaque control and mouth rinse. Lactobacillus are known to be probiotics and stimulate immune systems of human. Furthermore, L. casei ATCC 334 and L. rhamnosus GG have an effect on protection of dental caries in vitro studies. The aim of this study was to investigate effect of Lactobacillus on halitosis by Fusobacterium nucleatum- and Porphyromonas gingivalis-producing VSCs and to analyze inhibitory mechanism. The periodontopathogens were cultivated in the presence or the absence Lactobacillus, and the level of VSCs was measured by gas chromatograph. For analysis of inhibitory mechanisms, the susceptibility assay of the spent culture medium of Lactobacillus against F. nucleatum and P. gingivalis was investigated. Also, the spent culture medium of Lactobacillus and periodontopathogens were mixed, and the emission of VSCs from the spent culture medium was measured by gas chromatograph. L. casei and L. rhamnosus significantly reduced production of VSCs. L. casei and L. rhamnosus exhibited strong antibacterial activity against F. nucleatum and P. gingivalis. The spent culture medium of L. casei inhibited to emit gaseous hydrogen sulfide, methyl mercaptan and dimethyl sulfide from the spent culture medium of periodontopathogens. However, the spent medium of L. rhamnosus repressed only dimethyl sulfide. L. casei ATCC 334 may improve halitosis by growth inhibition of periodontopathogens and reduction of VSCs emission.

• Journal of Dairy Science and Biotechnology
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• v.30 no.1
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• pp.37-44
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• 2012

Milk-derived bioactive peptides have been found to exhibit various physiological activities such as angiotensin-converting enzyme (ACE) inhibitory, antibacterial, and antioxidative effects. Bioactive peptides can be used in the formulation of functional foods, nutraceuticals, and natural drugs because of their beneficial effects. However, the degree of variability in the composition, functionality, and sensory properties of such peptides has greatly limited their use in the food industry. In this review, we discuss the main peptides obtained from milk proteins and summarize findings from previous studies on the production and biological activities of these peptides. In addition, we compare the methods used to separate and identify the structure of the bioactive peptides and highlight current investigations into engineering and implementation of technologies that would allow more efficient isolation of bioactive peptides for functional food production. To improve human health, further molecular biology studies will also be required to elucidate the complex network of interactions between food microorganisms and the digestive system.

• Korean Journal of Microbiology
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• v.53 no.1
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• pp.55-57
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• 2017

Bacillus subtilis BS16045 was isolated from Gochujang, a Korean red chili paste, in order to get a starter strain that can be used for preservation of the fermented foods. We report the whole genome sequence of B. subtilis BS16045, which contains 4,165,121 bp with a G+C content of 43.6%. We also confirmed the set of antibiotic genes producing surfactin, kanosamine, bacillaene, plipastatin, subtilosin A, and bacilysin, which are related to antifungal and antibacterial activities. These results indicate that B. subtilis BS16045 could be a potential starter strain for solving contamination by food-borne pathogens in the soybean products factory.

• Journal of Microbiology and Biotechnology
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• v.29 no.7
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• pp.1033-1042
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• 2019

Bacillus velezensis BS2 was isolated from meongge (common sea squirt) jeotgal, a Korean fermented seafood, and produces a bacteriocin, BacBS2, which strongly inhibits Listeria monocytogenes and Bacillus cereus. BacBS2 was partially purified by Q-Sepharose column chromatography after ammonium sulfate precipitation of the culture supernatant, then further purified by Sephadex G-50 column chromatography. Partially purified BacBS2 was estimated to be 6.5 kDa in size by Tricine-SDS PAGE and activity detection by gel-overlay. Enzyme treatment and FT-IR spectrum of partially purified BacBS2 confirmed its proteinaceous nature. BacBS2 was fully stable at pH 4-9, and half of activity was retained at pH 1-3. Full activity was retained after exposure to $80^{\circ}C$ for 15 min, but half of the activity was retained upon exposure to $90^{\circ}C$ for 15 min or $100^{\circ}C$for 10 min. BacBS2 inhibited L. monocytogenes by bactericidal mode of action. B. velezensis BS2 and its BacBS2 seem useful as biopreservatives for fermented foods such as jeotgal.

• Journal of Microbiology and Biotechnology
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• v.33 no.12
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• pp.1625-1634
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• 2023

Leuconostoc lactis strain DMLL10 was isolated from kimchi, a fermented vegetable, as a starter candidate through safety and technological assessments. Strain DMLL10 was susceptible to ampicillin, chloramphenicol, clindamycin, erythromycin, gentamicin, kanamycin, streptomycin, and tetracycline. It did not show any hemolytic activity. Regarding its phenotypic results related to its safety properties, genomic analysis revealed that strain DMLL10 did not encode for any toxin genes such as hemolysin found in the same genus. It did not acquire antibiotic resistance genes either. Strain DMLL10 showed protease activity on agar containing NaCl up to 3%. The genome of DMLL10 encoded for protease genes and possessed genes associated with hetero- and homo-lactic fermentative pathways for lactate production. Finally, strain DMLL10 showed antibacterial activity against seven common foodborne pathogens, although bacteriocin genes were not identified from its genome. These results indicates that strain DMLL10 is a novel starter candidate with safety, enzyme activity, and bacteriocin activity. The complete genomic sequence of DMLL10 will contribute to our understanding of the genetic basis of probiotic properties and allow for assessment of the effectiveness of this strain as a starter or probiotic for use in the food industry.

• Journal of Food Hygiene and Safety
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• v.22 no.1
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• pp.37-44
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• 2007

The approval of use of certain food-grade phosphates as food additives in a wide variety of meat products greatly stimulated research on the applications of phosphates in foods. Although phosphates have never been classified as antimicrobial agents, a number of investigators have reported that phosphates have antimicrobial activities. Phytic acid is a natural plant inositol hexaphosphate constituting 1-5% of most cereals, nuts, legumes, oil seeds, pollen, and spores. In this study, we investigated antibacterial activities of sodium phytate(SPT), sodium pyrophosphate (SPP), sodium tripolyphosphate (STPP) on Escherichia coli O157:H7 on tryptic soy broth and in beef, pork and chicken. In tryptic soy broth, SPT, SPP and STPP at the concentrations of 0.05, 0.1, and 0.5% effectively inhibited the growth of Escherichia coli O157:H7 in a concentration-dependent manner. The bactericidal activity of SPT was the stronger than that of SPP or STPP at the same concentrations. In addition, the antibacterial effects of SPT, SPP and STPP at the concentrations of 0.05, 0.1, 0.3, and 0.5% on Escherichia coli O157:H7 were also investigated in raw or cooked meats including beef, pork and chicken. SPT, SPP and STPP significantly inhibited the bacterial growth in a dose-dependant manner (p<0.05). The bactericidal effect of SPT was stronger than that of SPP or STPP. The addition of SPT, SPP and STPP in meats increased meat pHs. SPP and STPP also increased the levels of soluble orthophosphate in meats but STP did not. These results indicate that SPT is very effective for inhibition of bacterial growth and that can be used as a muscle food additive for increasing functions of meats.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.172-178
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• 2018

The sterilization rates were investigated to develop effective pretreatment methods of garlic and ginger using antimicrobial agents and blanching. Antibacterial components in chopped garlic and ginger, such as allicin, ginger, and shogaol, exhibited an antibacterial effect that reduced bacteria by a factor of $10^1(CFU/g)$. The total number of bacteria in garlic and ginger was decreased by $10^1(CFU/g)$ after individually soaking in 1% (w/w) citric acid, calcium oxide and 200 ppm sodium hypochlorite solution for 1 h, respectively. When chopped garlic and ginger were immersed in 1% (w/w) calcium oxide solution for 1 h, the bactericidal effect was increased by $10^4-fold$. Total cells with thermoduric bacteria exhibited a $10^3-10^4-fold$ reduction after heating for 30-40 s at $90-95^{\circ}C$. The combination of soaking in 200 ppm sodium hypochlorite solution and blanching at $95^{\circ}C$, 40 s showed $10^1-fold$ decrease in total number of cells compared to blanching in whole ginger.