• Korean Journal of Microbiology
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• v.39 no.1
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• pp.56-61
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• 2003

The purpose of the present study was to screen the effective of lactic acid bacteria (LAB), as probiotics which are able to protect bacterial fish diseases and investigate their characteristics. Twenty strains of lactic acid bacteria were isolated from fish intestine. fermented fish foods and kimchis. These bacteria were screened for antagonistic activity against fish pathogenic bacteria. Seven tested LAB strains were able to inhibit the fish pathogenic bacteria, including Vibrio anguillarum, Edwardsiella tarda and Streptococcus sp. Of the probiotic candidates, BK19 strain which from fermented pollack viscera indicated the largest inhibition activity. This particular probiotic bacteria was identified and named as Lactobacillus sakei BK19. In the scanning electron microscope observation, L. sakei BK19 supernatant treated V.anguillarum cell wall had been destroyed incubate after 3 hr.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.229-235
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• 2016

Korea has a long history of brewing traditional rice wine using a authentic starter culture called nuruk, which contains natural microbial flora. Because rice wine is consumed fresh without filtration, its viable cells contribute to the biological activities of the wine. In numerous studies, microbial strains isolated from rice wine have been screened for their functionalities, which were mainly probiotic properties and antimicrobial activities. Indeed, some lactic acid bacteria (LAB) were confirmed to have strong probiotic activities as well as other health-promoting effects. Moreover, some of the isolated probiotic strains produced functional compounds, such as exopolysaccharides and γ-aminobutyric acid. For antimicrobial activities, some LAB and yeast strains were identified to produce bacteriocins and killer toxins, respectively, with significantly broad spectrum of antimicrobial activity. These functional strains originating from traditional rice wine and their metabolites can be used directly for the production of value-added food products.

• Microbiology and Biotechnology Letters
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• v.31 no.2
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• pp.129-134
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• 2003

The purpose of the present study was to screen the effective of lactic acid bacteria (LAB) as probiotics, which are able to protect aquacultural fish pathogenic bacteria, and investigate their characterization. Twenty strains of lactic acid bacteria were isolated from fish intestine, fermented fish foods and kimchis. These bacteria were screened for antagonistic activity against fish pathogenic bacteria. Seven tested LAB strains were able to inhibit the fish pathogenic bacteria, including Vibrio anguillarum, Edwardsiella tarda, and Streptococcus sp.. Of the probiotic candidates, BK19 strain isolated from fermented pollack viscera indicated the largest inhibition activity. Moreover, this strain showed a resistance over low pH and antibiotic agents. Therefore this probiotic candidate BK19 was finally selected and identified as a probiotic strain. This particular probiotic bacteria was identified as Lactobacillus sakei BK19 by biochemical characteristics and 165 rRNA PCR amplification.

• Food Science of Animal Resources
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• v.35 no.1
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• pp.91-100
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• 2015

The present study was conducted to screen candidate probiotic strains for anti-inflammatory activity. Initially, a nitric oxide (NO) assay was used to test selected candidate probiotic strains for anti-inflammatory activity in cultures of the murine macrophage cell line, RAW 264.7. Then, the in vitro probiotic properties of the strains, including bile tolerance, acid resistance, and growth in skim milk media, were investigated. We also performed an in vitro hydrophobicity test and an intestinal adhesion assay using Caenorhabditis elegans as a surrogate in vivo model. From our screening, we obtained 4 probiotic candidate lactic acid bacteria (LAB) strains based on their anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cell cultures and the results of the in vitro and in vivo probiotic property assessments. Molecular characterization using 16S rDNA sequencing analysis identified the 4 LAB strains as Lactobacillus plantarum. The selected L. plantarum strains (CAU1054, CAU1055, CAU1064, and CAU1106) were found to possess desirable in vitro and in vivo probiotic properties, and these strains are good candidates for further investigations in animal models and human clinical studies to elucidate the mechanisms underlying their anti-inflammatory activities.

• Korean journal of food and cookery science
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• v.26 no.2
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• pp.214-219
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• 2010

In this study, phytoestrogen for the industrial production of soybean probiotics by lactic acid bacteria (LAB) was studied in a soybean extract. Soybean was fermented with LAB, Lactobacillus plantarum KCTC 3108 and Bifidobacterum longum ATCC 15707. The change in the content of various isoflavones (aglycone and glucoside) and the $\beta$-glucosidase activity in soybean during fermentation were investigated and shown to be dependent on the starter organism. Soybean extract powder fermented with L. plantarum showed the highest $\beta$-glucosidase activity and the greatest increase in the aglycone content. After 48h of fermentation, the contents of daidzin, genistin and glycitin in L. plantarum decreased from a mean initial levels of $83.03{\pm}2.17$, $168.13{\pm}8.17$ and $20.02{\pm}1.07$, respectively, to mean levels of $5.34{\pm}3.24$, $3.79{\pm}0.57$ and $1.87{\pm}1.09\;mg$/100 g. Whereas, after 48h fermentation, the contents of daidzein, genistein and glycitein increased from a mean initial levels of $8.09{\pm}0.78$, $11.20{\pm}0.84$ and $4.71{\pm}0.46$, respectively, to mean levels of $85.76{\pm}0.84$, $175.87{\pm}2.21$ and $22.41{\pm}0.91\;mg$/100 g. Taken together, these results suggested an increase of aglycones and decrease of glucoside in isoflavones occurred during fermentation, which coincided with an increase of $\beta$-glucosidase activity in the fermented soybean extract powder.

• Food Science of Animal Resources
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• v.34 no.3
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• pp.346-354
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• 2014

Fermented foods with probiotics having functional properties may provide beneficial effects on health. These effects are varied, depending on the type of lactic acid bacteria (LAB). Different probiotic LAB might have different functional properties. Thus, this study was performed to evaluate the quality of fermented sausages manufactured with functional starter cultures (Lactobacillus plantarum 115 and 167, and Pediococcus damnosus L12) and different fat levels, and to determine the optimum condition for the manufacture of these products. Medium-fat (~15%) fermented sausages reduced the drying time and cholesterol contents, as compared to regular-fat counterparts. In proximate analysis, the contents of moisture and protein of regular-fat products were lower than medium-fat with reduced fat content. The regular-fat products also had a lighter color and less redness, due to reduced fat content. Approximately 35 volatile compounds were identified in functional fermented sausages, and hexanal, trans-caryophyllene, and tetradecanal were the major volatile compounds. Selected mixed starter culture showed the potential possibility of replacing the commercial starter culture (LK30 plus) in flavor profiles. However, medium-fat fermented sausage containing selected mixed starter culture tended to be less acceptable than their high-fat counterparts, due to excess dry ring developed in the surface. These results indicate that the use of combinations of L. plantarum 115 and 167, and P. damnosus L12 as a starter culture, will prove useful for manufacturing the fermented sausage.

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1266-1273
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• 2008

Lactic acid bacteria (LAB) with antimicrobial activity and high exopolysaccharide (EPS) production ability isolated from sourdough were studied for their fermentation characteristics as potential new starter cultures. The values of pH, titratable acidity, and viable cell counts were $4.06{\pm}0.009-4.50{\pm}0.015,\;0.787{\pm}0.020%-1.172{\pm}0.018%,\;and\;8.78{\pm}0.08-8.98{\pm}0.06$ log CFU/ml, respectively. In order to select probiotics with a high survival rate in the gut, isolates were tested to assess resistance against the artificial gastric acid and bile juice. Viable LAB counts were significantly (p<0.05) affected by the acidity. At pH 2.0, the total declines in the initial bacterial counts were 4.52$\pm$0.07 log for S. thermophilus St-Body-1, >7.98$\pm$0.03 log for E. flavescens DU-10, >7.95$\pm$0.05 log for E. faecium DU-12, and 3.15$\pm$0.06 log for L. amylovorus DU-21. Among the strains, L. amylovorus DU-21 was the only strain that had bile tolerance under simulated gastrointestinal conditions. In order to improve EPS production by L. amylovorus DU-21, the influence of carbon source was studied. When glucose was used as a carbon source, EPS production dramatically increased to 17.19$\pm$0.28 g/l (p<0.05). The maximum cell growth (10.012$\pm$>0.012 log CFU/ml) and EPS production (18.71$\pm$0.19 g/l) were achieved when 15 g/l of glucose was employed as the carbon source.

• Food Science of Animal Resources
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• v.33 no.1
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• pp.75-82
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• 2013

This study aimed to isolate lactic acid bacteria (LAB) from Kimchi and to identify suitable probiotic strain for application in fermented dairy product as a commercial starter culture. A total of 106 (LAB) strains were isolated from Kimchi collected from different regions in Korea and their phenotypic characteristics were assayed. Four isolates from MRS agar plates were selected and designated as DKL109, DKL119, DKL121 and DKL128. They were identified first by API 50 CHL kit and then 16S rRNA gene sequencing. DKL121 and DKL128 were identified as Lactobacillus paracasei and Lactobacillus casei, respectively. Other two isolates (DKL109 and DKL119) were identified as Lactobacillus plantarum. To estimate their applicability in dairy products, the characteristics including acid and bile tolerance, cold shock induced cryotolerance and enzymatic activities were determined. There was wide variation in ability of strains to acid tolerance, but no significant differences in bile tolerance, cold shock induced cryotolerance within selected strains. DKL119 and DKL121 showed the highest resistance to acid and bile and the highest ${\beta}$-galactosidase activity, respectively. When these two strains were used for yogurt preparation as a single starter culture, their viable cell counts reached to $1.0{\times}10^9CFU/mL$. Lactobacillus plantarum DKL119 showed faster acid development than commercial starter culture. Also storage trials at $10^{\circ}C$ showed that the viability of these strains was retained over 15 d. With these results, it was indicated that probiotics isolated from Kimchi can be used in yogurt manufacturing as a starter culture.

• Journal of Environmental Science International
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• v.31 no.8
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• pp.715-725
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• 2022

Lactic Acid Bacteria (LAB) are among the representative probiotics that have been used for a long time in fermented food. Although there are many studies on detecting the radical scavenging activity of LAB, few studies have been conducted on the environmental factors that improve scavenging activity. This study investigated the environmental factors affecting the DPPH radical scavenging and various antioxidant activities of Kimchi-derived Lactobacillus plantarum K-21 with antihypertensive and radical scavenging activities. The optimal conditions for scavenging DPPH radicals were glucose 2%, bactopeptone 0.5%, Tween 80 0.05%, L-cysteine 0.05%, and an initial pH 6.5 at 35℃. Under optimal conditions, the DPPH radical scavenging activity was 94.8±2.2%, which was 1.5 times higher than that of the basic medium. In addition, L. plantarum K-21 had other antioxidant activities; ABTS radical scavenging (93.6±1.5%), hydroxyl radical scavenging (8.5±0.9%), metal chelating (65.9±0.5%), NO scavenging (53.1±19%), SOD-like (25.1±1.5%), and reducing power (11.7±1.4%) activities were detected. Therefore, L. plantarum K-21 may act not only as a starter for lactic acid-fermented foods with improved functionality but also as a drug for various diseases caused by oxidative stress.

• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.519-526
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• 2023

Panax ginseng is one of the most important herbal medicinal plants consumed as health functional food and can be fermented to achieve better efficacy. Lacticaseibacillus, one of the representative genera among lactic acid bacteria (LAB), has also been used as a probiotic material for health functional foods due to its beneficial effects on the human body. To achieve a synergistic effect by using these excellent dietary supplement ingredients together, a novel LAB strain was isolated from the root of 6-year-old ginseng. Through similarity analysis of 16S rRNAs and whole-genome sequences, the strain was confirmed as belonging to the genus Lacticaseibacillus and was named L. casei KGC1201. KGC1201 not only met all safety standards as food, but also showed excellent probiotic properties such as acid resistance, bile salt resistance, and intestinal adhesion. In particular, KGC1201 exhibited superior acid resistance through morphological observation identifying that the cell surface damage of KGC1201 was less than that of the L. casei type strain KCTC3109. Gene expression studies were conducted to elucidate the molecular mechanisms of KGC1201's acid resistance, and the expression of the glycosyltransferase gene was found to be significantly elevated under acidic conditions. Exopolysaccharides (EPSs) biosynthesized by glycosyltransferase were also increased in KGC1201 compared to KCTC3109, which may contribute to better protection of KGC1201 cells from strong acidity. Therefore, KGC1201, with its increased acid resistance through molecular mechanisms and excellent probiotic properties, can be used in health functional foods to provide greater benefit to overall human health and well-being.