• Journal of Life Science
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• v.18 no.3
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• pp.395-402
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• 2008

Level of microbial contamination was examined in four fish farms of Jeju east coast for sanitary indication of bacterial contamination such as heterotrophic bacteria, Escherichia coli O157:H7, Salmonella spp., Vibrio parahaemolyticus, Staphylococcus aureus, Bacillus cereus and total coliforms. The samples were collected and investigated from June to October in 2007. Bacterial species of S. aureus, B. cereus and Salmonella spp. were frequently detected from the seawater of above fish farms. Salmonella spp., S. aureus, B. cereus were detected in the range of $0{\sim}4.3{\times}l0^3,\;0{\sim}2.7{\times}l0^4,\;0{\sim}7.6{\times}l0^3$ CFU/ml, respectively, from the fish feed used in all four selected farms. Additionally, Salmonella spp., S. aureus, B. cereus were detected in oliver flounder (Paralichthys olivaceus) of these farms, however total coliforms and E. coli O157:H7 were not detected during our experimental period. For the production of microbiologically safe and healthy oliver flounder, proper quality control of feed, sanitation programs, and continuous monitoring of microorganism are essential practices, which required to include in the farm management system.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.324-330
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• 2014

A marine bacterial strain producing agar-degrading enzymes was isolated from a mud flat in Jeboo-do (Korea) using a selective artificial sea water (ASW) agar plate containing agar as the sole carbon source. The isolate, designated as SH-1, was gram-negative, aerobic, and motile with single polar flagellum. 16S rRNA gene sequence similarity analysis showed the isolate SH-1 had the highest homology (96.5%) to marine bacterium Neiella marina J221. Cells could grow at $28-37^{\circ}C$ but not at $42^{\circ}C$, and the agarase activity of the cell culture supernatant was higher when grown at $28^{\circ}C$ than when grown at $37^{\circ}C$. Cells could grow when concentrations of 1-5% (w/v) NaCl were added to the growth media with the best growth observed at 3% NaCl, and the agardegrading enzyme activity of the cell culture supernatant was best when grown at 3% NaCl-containing growth media under the conditions we examined. The crude enzyme prepared from 48-h culture broth of strain SH-1 exhibited an optimum pH and temperature for agar-degrading activity at 7.0 and $40^{\circ}C$, respectively. Zymogram analysis of the crude supernatant and cell extract showed that strain SH-1 produced at least 3 agar-degrading enzymes with molecular weights of 15, 35, and 52 KD. Thinlayer chromatography (TLC) analysis also suggested that HS-1 produces ${\beta}$-agarase to degrade agarose to neoagarooligosaccharides.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.319-326
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• 2014

Two bacterial strains, named as LE17 and LE22, were isolated from traditionally fermented soybean products in order to select lactic acid bacteria for the reduction of biogenic amines and harmful bacteria. Both strains were identified as Pediococcus pentosaceus by 16S rRNA sequence analysis and additional biochemical tests. The strain LE17 reduced the amines by 13.7% for histamine and by 25.9% for tyramine, when it grew in minimal synthetic media containing 0.1% (w/v) histamine and 0.1% tyramine at $30^{\circ}C$ for 48 h, while the strain LE22 reduced the amines by 23.7% for histamine and by 15.7% for tyramine. Both strains also had broad inhibition spectra against pathogens. Considering their properties, they could be used as starters for industrial soybean fermentation.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.273-285
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• 2017

The purpose of this study was to investigate the inhibitory effect of antibacterial substances produced by probiotic lactic acid bacteria (LAB) against biogenic amines-producing bacteria and the influence of culture conditions on the antibacterial activity of bacteriocin and organic acid. The bacteriocin solutions of Lactobacillus plantarum FIL20 (64 AU/ml) and Lactobacillus paracasei FIL31 (128 AU/ml) showed strong antibacterial activity against Serratia marcescens CIH09 and Aeromonas hydrophilia RIH28, respectively. And the lactic acid contents in the cell-free culture supernatants (CFCS) obtained from FIL20 and FIL31 strains were $107.3{\pm}2.7mM$ and $129.5{\pm}4.6mM$, respectively. Therefore, the bacteriocin solution (200 AU/ml) and the CFCS ($200{\mu}l/ml$) produced by L. plantarum FIL20 and L. paracasei FIL31 significantly (P < 0.05) decreased the bacterial numbers and histamine and tyramine production ability of S. marcescens CIH09 and A. hydrophilia RIH28. The amounts of histamine and tyramine produced by the CIH09 strain under conditions of low initial pH (5.0) and incubation temperature ($15^{\circ}C$) was significantly reduced by treatment with bacteriocin solution and CFCS obtained from L. plantarum FIL20. In addition, the bacterial counts and biogenic amines contents of CIH09 strain were significantly decreased (P < 0.05) when sodium chloride (5%) or potassium nitrite (200 mg/g) were mixed with the antibacterial substances of L. plantarum FIL20. Consequently, the bacteriocin and organic acid solution of L. plantarum FIL20 and L. paracasei FIL31 can be used as a biological preservation to effectively control the production of biogenic amines by the application of hurdle technology.

• Animal Bioscience
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• v.34 no.5
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• pp.867-879
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• 2021

Objective: Fibronectin 3 (FN3) and immunoglobulin like modules (Ig) are usually collocated beside modular cellulase catalytic domains. However, very few researches have investigated the role of these modules. In a previous study, we have sequenced and analyzed bacterial metagenomic DNA in Vietnamese goats' rumen and found that cellulase-producing bacteria and cellulase families were dominant. In this study, the properties of modular cellulases and the role of a FN3 in unique endoglucanase belonging to glycosyl hydorlase (GH) family 5 were determined. Methods: Based on Pfam analysis, the cellulases sequences containing FN3, Ig modules were extracted from 297 complete open reading frames (ORFs). The alkaline, thermostability, tertiary structure of deduced enzymes were predicted by AcalPred, TBI software, Phyre2 and Swiss models. Then, whole and truncated forms of a selected gene were expressed in Escherichia coli and purified by His-tag affinity column for assessment of FN3 ability to enhance enzyme activity, solubility and conformation. Results: From 297 complete ORFs coding for cellulases, 148 sequences containing FN3, Ig were identified. Mostly FN3 appeared in 90.9% beta-glucosidases belonging to glycosyl hydrolase family 3 (GH3) and situated downstream of catalytic domains. The Ig was found upstream of 100% endoglucanase GH9. Rarely FN3 was seen to be situated downstream of X domain and upstream of catalytic domain endoglucanase GH5. Whole enzyme (called XFN3GH5 based on modular structure) and truncate forms FN3, XFN3, FN3GH5, GH5 were cloned in pET22b (+) and pET22SUMO to be expressed in single and fusion forms with a small ubiquitin-related modifier partner (S). The FN3, SFN3 increased GH5 solubility in FN3GH5, SFN3GH5. The SFN3 partly served for GH5 conformation in SFN3GH5, increased modules interaction and enzyme-soluble substrate affinity to enhance SXFN3GH5, SFN3GH5 activities in mixtures. Both SFN3 and SXFN3 did not anchor enzyme on filter paper but exfoliate and separate cellulose chains on filter paper for enzyme hydrolysis. Conclusion: Based on these findings, the presence of FN3 module in certain cellulases was confirmed and it assisted for enzyme conformation and activity in both soluble and insoluble substrate.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.717-724
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• 2023

we are investigated the anti-inflammatory effects of Safflower and Mother wort Ethanol Complex Extracts(SEC) on lipopolysaccharide (LPS)-activated RAW 264.7 cells. The results demonstrated that pretreatment of SEC(500㎍/mL) significantly reduced NO production by suppressing iNOS protein expression in LPS-stimulated cells. Anti-inflammatory effects by Safflower and Mother wort Ethanol Complex Extracts were observed in the following. Safflower and Mother wort Ethanol Complex Extracts inhibited the translocation of NF-κB from the cytosol to the nucleus via the suppression of IκB-α phosphorylation and also inhibited LPS-stimulated NF-κB transcriptional activity. These findings suggest that Safflower and Mother wort Ethanol Complex Extracts exert anti-inflammatory actions and help to elucidate the mechanisms underlying the potential therapeutic values of Safflower and Mother wort Ethanol Complex Extracts. Therefore, Safflower and Mother wort Ethanol Complex Extracts could be regarded as a potential source of natural anti-inflammatory agents.

• Journal of Mushroom
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• v.22 no.1
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• pp.22-26
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• 2024

Tricholoma matsutake is a traditional favorite food in East Asia, cultivated in fairy rings called "shiro," which are found near Pinus densiflora. For effective artificial cultivation of Tri. matsutake, microorganisms from symbiotic fairy rings are co-cultivated. In this study, one bacterial isolate (Y22_B35) and two fungal isolates (Y22_F64 and Y22_F68) displayed growth-promoting effects on Tri. matsutake mycelium (158.47, 125.00, and 122.26% enhanced growth, respectively). For identification, 16S rRNA or ITS regions from the microorganisms¡¯ genomes were sequenced. Other sequences, including BenA, CaM, and RPB2 were sequenced in the fungal isolates. The bacterial isolate Y22_B35 was identified as Bacillus cereus. Y22_F64 and Y22_F68 were identified as Umbelopsis nana and Aspergillus parvulus, respectively. To identify the effects of the dominant microorganisms on Tri. Matsutake cultivation, metagenomic analyses were performed. Discovery of these Tri. matsutake mycelium growth-promoting microorganisms and metagenomics analyses are expected to contribute to our understanding of Tri. matsutake fruiting body growth and construction of biomimicry.

• Journal of Life Science
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• v.26 no.4
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• pp.496-502
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• 2016

This review describes the diversity of Korean fermented foods and their significance as potential sources of probiotic bacteria. Fermented foods consumed in Korea are categorized according to their base material. Fermented foods such as kimchi, meju, doenjang, kangjang, jeotgal, and makgeolli are reported to have significant medicinal properties. These fermented products, which are consumed regularly by local people, are rich sources of beneficial microbes represented by several genera, including Weissella spp., Lactobacillus spp., Leuconostoc spp., Mucor, Penicillium, Scopulariopsis, Aspergillus, Rhodotorula, Candida, Saccharomyces, and Bacillus, as well as lactic acid bacteria. Fermented foods are now taken beyond the boundaries of their use as mere side dishes and are used significantly as a functional as well as medicinal foods. Fermented foods are a rich source of potential natural substances with antioxidant, anticancer, anticholesteric, antiobesitic, and antiaging properties, so that traditional fermented foods used as food supplements can impart health benefits. Publication of scientific studies on the dietary benefits of various fermented foods and growing consciousness about the potential health benefits of traditional fermented food are reflected in the scores of reports currently available in this field. Food microbiologists now have abundant opportunities to explore Korean traditional fermented foods for the isolation of new bacterial strains and to evaluate the potential applications of these strains through microbiological research.

• Journal of Dairy Science and Biotechnology
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• v.33 no.3
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• pp.215-221
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• 2015

This study aimed to establish the optimum culture conditions for Mozzarella cheese by using Streptococcus macedonicus LC743, a strain selected for its immunomodulatory activity. For process optimization, 1.0% and 2.0% strain was inoculated and incubated at $32^{\circ}C$ and $35^{\circ}C$, respectively. The general components, bacterial count, total solids, yields, and immunomodulatory activity of the Mozzarella cheese were investigated. When the strain was inoculated at 2.0% and incubated at $32^{\circ}C$, the product quality and immunomodulatory activity was optimal and required minimal processing time. Therefore, 2.0% of S. macedonicus LC743 starter culture was added to milk at $32^{\circ}C$, after pasteurization at $63^{\circ}C$ for 30 min, and agitated for 4~5 min after addition of $230{\mu}L/kg$ of rennet. Curd was made by setting the milk 25~35 min after addition of 0.01~0.02% calcium chloride. The curd was cut at 0.1~0.12% acidity (81 min later) and after heating the cheese to up to $43^{\circ}C$. Whey was removed at an acidity of 0.17~0.18% by agitation for 53 min. Next, cheddaring for 210 min up to an acidity of 0.6~0.65%, stretching at $72{\sim}75^{\circ}C$, and molding at $65{\sim}70^{\circ}C$ were performed, and the product was allowed to cool down to $5^{\circ}C$. Salting was done with a solution of $18{\sim}20^{\circ}B{\acute{e}}$ at $12^{\circ}C$ for 20 min and drying occurred at 80~90% relative humidity at $10^{\circ}C$ for 2~3 days.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.165-169
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• 2014

Salmonella spp. and Brucella spp. are associated with considerable diseases of both humans and animals. In addition, these microorganisms cause the economic loss in animal farming and food industry. In this study, the disinfection efficacy of a commercial disinfectant, composed to povidone-iodine was evaluated against S. typhimurium and B. ovis. A bactericidal efficacy test by broth dilution method was used to determine the lowest effective dilution of the disinfectant following exposure to test bacteria for 30 min at $4^{\circ}C$. The disinfectant and test bacteria were diluted with hard water (HW) or organic matter suspension (OM) according to treatment condition. On HW condition, the bactericidal activity of the disinfectant against S. typhimurium and B. ovis was 400 and 150 fold dilutions, respectively. On OM condition, the bactericidal activity of the disinfectant was 5 and 20 fold dilutions against S. typhimurium and B. ovis, respectively. As the disinfectant composed to povidine-iodine possesses bactericidal efficacy against animal pathogenic bacteria such as S. typhimurium and B. ovis, the disinfectant solution can be used to control the spread of bacterial diseases.