• Food Science of Animal Resources
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• v.31 no.4
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• pp.609-616
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• 2011

In this study, a LCH1227 bacterial strain that possesses anti-listerial activity was isolated from fermented food and identified as Lactobacillus salivarius LCH1227 based on its morphological and biochemical properties, as well as its 16S rRNA gene sequences. Anti-listerial substance also inhibited the growth of various Gram-positive bacteria, such as vancomycinresistant Enterococcus faecalis, Streptococcus agalactiae, Bacillus cereus, Lactobacillus fermentum. The highest level of production of antimicrobial substances from L. salivarius LCH1227 occurred during the early stationary phase. The antilisterial activity was found to be stable over a broad range of pH values (2.0-12.0) and after heat treatment. However, it was inactivated by proteolytic enzymes, indicating its proteinaceous nature. The apparent molecular mass of the partially purified anti-listerial substance, as measured by Tricine-SDS-PAGE, was approximately 5 kDa.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.291-295
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• 2010

A novel bacteriocin produced by Streptococcus parauberis Z49 strain was characterized and efficiently extracted from fermented cultures by use of aqueous two-phase systems. The nisin-like bacteriocin, which was active even after a heat treatment at $121^{\circ}C$ for 15 min and in the broad pH range from 2 to 12, showed inhibition of bacterial growth of Micrococcus luteus, Lactobacillus spp., Lactobacillus fermentum, Enterococcus faecium, Listereia monocytogenes, and Pseudomonas fluorescens. Optimal conditions of PEG 600/$Na_2SO_4$ aqueous two-phase systems for the simple and rapid extraction of a novel bacteriocin were determined to be PEG 600 15%, $Na_2SO_4$ 30%, and NaCl 8%, where the bacteriocin was concentrated in PEG layer.

• Korean Journal of Food Science and Technology
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• v.39 no.1
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• pp.66-70
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• 2007

Lactobacillus fermentum YL-3 was encapsulated to increase acid tolerance and its total viability. After micro-encapsulation of L. fermentum YL-3 cells with sodium alginate and soybean oil, the morphology of the microcapsule was observed using confocal laser scanning microscopy (CLSM) after staining with pyronin Y and fluorescein isothiocyanate. The sizes of the microcapsules were 120-126 ${\mu}m$, 444-486 ${\mu}m$ and 401-463 ${\mu}m$ when manufactured at pH 2, 3 and 4, respectively. The microcapsule could hold live cells of L. fermentum YL-3 up to $1.2{\times}10^{7}$, $8.1{\times}10^{7}$ and $1.1{\times}10^{8}$ CFU/mL at pH 2, 3 and 4, respectively. The acid tolerance and preservative ability of L. fermentum YL-3 in microcapsule and macrocapsule at $4^{\circ}C$ and $25^{\circ}C$ were tested. L. fermentum YL-3 cells were evenly located in the alginate capsule matrix structure and the firmness of microcapsule was highest at pH 2. Micro-encapsulation showed the most effective acid tolerance at pH 2.0 and preservation of viability at $4^{\circ}C$. However, at $25^{\circ}C$, the macrocapsules showed more effective cell protection than the microcapsules. The application range for microcapsules could be wider than for macrocapsules in the food industry.

• Food Engineering Progress
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• v.15 no.1
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• pp.22-27
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• 2011

Changes in total nitrogen (T.N.) and total phosphate (T.P.) content in environmental waste water upon the reaction of biological purifying reagents were measured and the reaction rate was evaluated. The purification capacity of two biological purifying reagents composed of vegetable Lactobacillus fermentum (V.L.F.), Saccharomyces cerevisiae(S.C), and Bacillus subtilis(B.S.) were evaluated and compared with that of commercial water purification system operating by local government. After 18days of reaction, the mixture of V.L.F. and S.C. showed dramatic decrease of T.N.(36.21% of the initial value). The mixture of V.L.F., S.C., and B.S. showed faster reaction rate to decrease T.P. compared with that of the mixture of V.L.F. and S.C. The reaction constant of mixture of V.L.F. and S.C. was estimated to be 0.178 $day^{-1}$ by the curve fitting of the data of changes in T.N. during the reaction.

• Preventive Nutrition and Food Science
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• v.15 no.2
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• pp.159-166
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• 2010

The aim of this study was to develop species-specific primer sets for kimchi Lactobacillus. Known gene sequences of Lactobacillus 16S rRNA were collected from the NCBI Gene bank, and 69 primer sets were designed using the homologous gene sequence. Six species of kimchi Lactobacilli were used as reference strains: Lactobacillus brevis KCTC3102, Lactobacillus farciminis KCTC3681, Lactobacillus fermentum KCTC3112, Lactobacillus hilgardii KCTC3500, Lactobacillus plantarum KCTC3099, and Lactobacillus sanfranciscensis KCTC3205. PCR amplification and gel electrophoresis were performed to identify the accuracy and specificity of the developed primer set. The results show that the primer set of 5'-aagcctgcgaaggcaag-3' & 5'-aggccaccggctttg-3', 5'-acatactatgcaaatctaagagattagacg-3' & 5'-actgagaatggctttaagagattagcttac-3' resulted in a specific PCR band on L. hilgardii, and primer set of 5'-ctaataccgcataacaactactttcacat-3' & 5'-aacttaataaaccgcctacattctctttac-3' on L. farciminis. The results indicate that the developed primer sets can provide a useful tool for the identification and differentiation of L. hilgardii and L. farciminis from other Lactobacillus species of kimchi.

• KSBB Journal
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• v.24 no.2
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• pp.182-188
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• 2009

Lactobacillus spp., primary members of probiotics, have significant benefits for health and well-being of human. In this study Lactobacillus strains representing six species (L. paracasei KLB58, L. fermentum MS79 and KLB282, L. plantarum KLB213, L. gasseri KLB238, and L. reuteri KLB270) isolated from Korean adults were electrotransformed with plasmid pNCKH104. To determine optimal electrotransformation conditions, various conditions including cell wall weakening agent, electroporation buffer, electric field strength and time constant were tested for each strain. Overall, high transformation efficiency of approximately 2.5 ${\times}$ $10^3$ ${\sim}$ 5.5 ${\times}$ $10^4$ CFU/${\mu}g$ DNA was obtained where conditions of 0.5 M sucrose electroporation buffer, 1.8 kV pulse voltage and 5 ms time constant were applied. The common conditions developed in this study will make transformation of various Lactobacillus spp. easier than previous procedures.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2002.11a
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• pp.199-199
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• 2002

• Food Science of Animal Resources
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• v.27 no.4
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• pp.538-542
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• 2007

This study was carried out to investigate the toxicity of exopolysaccharides (EPS) from kefir toward MA104 cells and evaluate the inhibitory effects of kefir EPS on rotavirus infection. The results obtained are summarized as follows: Lactic acid bacteria (Lactobacillus fermentum, L. acidophilus, L. brevis) and yeasts (Candida kefyr, Cryptococcus albidus, Pichia ohmeri) were isolated and identified from kefir grain and culture. At 1% EPS, the inhibitory effects of EPS on the infection of MA-104 cells using the MTT assay were $72.52{\pm}6.48%$ for human rotavirus (KU), $36.06{\pm}7.63%$ for bovine rotavirus (NCDV), and $81.66{\pm}1.11%$ for porcine rotavirus (OSU). At 1/128% EPS, the effects were $24.98{\pm}4.58%$ for human rotavirus (KU), $4.71{\pm}6.16%$ for bovine rotavirus (NCDV), and $4.05{\pm}14.90%$ forporcine rotavirus (OSU). EPS isolated from kefir have inhibitory effects on rotaviruses of various serotypes and rotaviruses from different animals.

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.257-264
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• 2019

Rice bran is considered a natural source of antioxidants. In this study, rice bran was fermented with lactic acid bacteria to increase its antioxidant activity. Four strains isolated from fermented food, Lactobacillus plantarum MJM60383, Lactococcus lactis subsp. lactis MJM60392, Lactobacillus fermentum MJM60393, and Lactobacillus paracasei MJM60396, were confirmed as safe through stability tests such as safety assessment for biogenic amine production, hemolytic activity, and mucin degradation, and showed high reducing capacity. The antioxidant activity of rice bran fermentation altered by these strains was evaluated using several methods including measurement of $Fe^{2+}$ chelating activity and scavenging activity by 1,1-diphenyl-2-picryl-hydrazil (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and nitric oxide assays. In this study, the total phenolic content and ${\gamma}$-oryzanol were evaluated by high-performance liquid chromatography. Compared to non-fermented rice bran and a commercial product, rice bran fermented with Lactococcus lactis subsp. lactis MJM60392 showed the highest phenolic content (844.13 mg GAE/g). Moreover, the content of ferulic acids, ${\rho}$-coumaric acid, and ${\gamma}$-oryzanol in rice bran increased after fermentation with L. lactis subsp. lactis MJM60392 and L. fermentum MJM60393 compared to other samples. Indeed, the DPPH radical scavenging activity and NO scavenging activity were also found to be high in these fermented rice brans. These results indicated that fermentation with lactic acid bacteria increases the active compound levels and the potent antioxidant activities of rice bran.

• Food Science of Animal Resources
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• v.23 no.3
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• pp.262-268
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• 2003

Kefir is a traditional fermented milk in Caucasusian area and is made mainly of milk fermented with lactic acid bacteria and yeasts. Six typical kefir grains were selected from ten kefir grains collected from different locals in Korea. Kefir grains were gelatinous in texture and had various shapes of villi, grapes, leaves, hulled millets, and towels. To investigate predominant microflora of kefir grains, SPC, MRS, M17, Rogosa, and APT agar media were used for viable cell count MRS, SPC, and Rogosa media were most acceptable for bacterial cell counts of the selected kefir grains. From one or two of the SPC agar plates which contained around 25∼50 colonies, all grown colonies were isolated and identified. Most predominant bacteria was identified as Lactobacillus fermentum by API 50 CHL kit. The proportions of Lb. fermentum and Lb. brevis among the total identified bacteria were around 41~88% and M4%, respectively. To select the best preservation method for kefir grains, refrigeration, freezing, and freeze drying were compared. Freeze drying was found most suitable for the preservation of kefir grains, based upon their acid-producing activities and production of off-flavors.