• Journal of Microbiology and Biotechnology
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• v.1 no.2
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• pp.96-101
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• 1991

Phenotypic changes after plasmid curing experiment suggested that the bacteriocin production phenotype ($Bac^{+}$) might be linked to a chromosomal DNA and the mucin production phenotype ($Muc^{+}$) might be linked to a 62.5 kilobase (kb) plasmid (pMUC62) in Lactobacillus plantarum 27 isolated from meat starter culture. The non-mucoid ($Muc^{-}$) variants were missing pMUC62 but they produced bacteriocin as the wild strain ($Bac^{+}$). There was no difference in antibiotic resistance and sugar fermentation patterns between the wild strain ($Bac^{+}$ $Muc^{+}$) and the nonmucoid ($Bac^{+}$ $Muc^{-}$) variants. Antimicrobial spectrum of bacteriocin produced by both wild strain and $Muc^{-}$ variant of Lb. plantarum 27 included strains of Pediococcus acidilactici (A, M, H), Pediococcus sp. isolated from meat, Lactobacillus sp. isolated from meat, Lb. plantarum NCDO 955 and Staphylococcus aureus 485. Neither of the tested Gram negative bacteria were inhibited by bacteriocin. Antimicrobial activity of crude bacteriocin was retained after autoclaving, DNase or catalase treatment and exposure from pHs 4 to 9 but was lost after treating with several proteolytic enzymes and exposure at pH 10.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.1
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• pp.9-14
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• 2018

Bacterial species, Bacillus amyloliquefaciens and Lactobacillus species (L. sp.5-1), are known to inhibit the growth of pathogenic bacteria and fungi. Metarhizium anisopliae is a pathogenic fungal species which causes fatal damage to P. brevitarsis populations. Therefore, we investigated the inhibitory effect of B. amyloliquefaciens and L. sp. 5-1 on M. anisopliae induced fatality rates in P. brevitarsis. Samples of M. anisopliae-infected sawdust were treated with strain B. amyloliquefaciens KACC10116, strain L. sp. 5-1 KACC19351, and a combination of the two. P. brevitarsis were fed treated sawdust samples, and their subsequent fatality rate was monitored. The fatality rate fell below 1.5% after 10 days and decreased by approximately 40% after 15 days. On average, the fatality rate decreased by 20%, compared to the control. The difference in the decrease in fatality rate between B. amyloliquefaciens treatment and L. sp. 5-1 treatment was not significant. Results indicate that both strains exhibit high anti-fungal activity, which may be useful in environmental purification efforts. These strains may be used for effective prevention of fungal infection in P. brevitarsis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.560-566
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• 1998

The bacteriocin produced by Lactobacillus sp. GM7311 showed strong inhibitory activity against the growth of three Gram positive bacteria, Listeria monocytogenes, Bacillus subtilis, and Staphylococcus aureus. When the bacteriocin was added to the culture at different phases, viable cells of all of the tested strains were decreased, although the most inhibited phase was different. Thereby, when the bacteriocin $(100\;Bu/m{\ell})$ was added to exponential and stationary phase of L. monocytogenes, the rapid reduction of viable cell counts occured. And, in the case of B. subtilis, the highest inhibitory effect occured at lag phase and mid-exponential phase by the addition of the bacteriocin under same condition as mentioned above. Also, we can observe the accelerated reduction of survivors counts for the all of the phase except stationary phase in the S. auresus. Transmission electron microscopic observation of L. monocrogenes and B. subtilis treated with bacteriocin revealed apparent Iysis of the cell wall and excretion of the cell contents, indicating bacteriolysis. Also, the amino acids and fatty acids compositions were different from controls. However, the Iysis of cell wall didn't occur in S. aureus, though the cytoplasmic materials were reduced. This result indicates that the bacteriocin inhibits the synthesis of nuclear materials such as DNA, RNA and proteins.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.446-452
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• 2011

Total 480 lactic acid-producing bacteria were isolated from five kinds of kimchi, and their antibacterial activity was tested against Salmonella enterica serovar Typhimurium, Bacillus subtilis, and Pseudomonas aeruginosa using an agar diffusion assay. Among them, 340 isolates showed a halo on MRS agar against one or more indicator strains, which were identified using multiplex PCR, an API 50CHL kit, and a 16S rDNA sequence analysis. As a result, 169 Lactobacillus plantarum, 20 Lactobacillus fermentum, two Lactobacillus paracasei ssp. paracasei, two Lactobacillus sp., and 15 Pediococcus sp. were identified. This may be the first report on the isolation of antibacterial Lactobacillus fermentum from kimchi.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2010.10a
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• pp.15-15
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• 2010

Ginseng contained many different kinds of saponin which was the most valuable for people, but its yield cannot satisfy the demand using traditional extract methods. Enzyme transformation is a conformable and highly performed method which was fit for today. A ${\beta}$-glucosidase producing bacterium ($DCY51^T$) was isolated from Korean fermented-vegetable food kimchi. The 16S rRNA gene sequence analysis revealed that the strain $DCY51^T$ belongs to the genus Lactobacillus. The highest sequence similarity was found with Lactobacillus paracollinoides LMG $22473^T$ and Lactobacillus collinoides LMG $9194^T$ with levels of 16S rDNA similarity of 97.4% and 97.3%, respectively. Based on the above results the strain $DCY51^T$ placed in the genus Lactobacillus and proposed a new species, Lactobacillus kimchicus sp. nov. $DCY51^T$ (= KCTC $12976^T$ = JCM $15530^T$). It was culture solution reacted with Red Ginseng extract and $Rb_1$, respectively. The medium of bacteria was the liquid of MRS, the temperatures of growing and reacting between bacteria liquid and saponin were samely $37^{\circ}C$, there spective reacting time were 12 hours and 48 hours. Thus we got different saponins, and TLC and HPLC analysis showed that: enzyme respectively reacted with $Rb_1$ and Red Ginseng extract got the transformed saponin, respectively. The polarity position in TLC was a little higher than Rd; and the polarity position was the same as that of Compound K's, the saponin obtained from HPLC and other experimental results was not Compound K. The constitution of its saponin was hoped to be further confirmed.

• Journal of the Korean Society of Food Culture
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• v.27 no.6
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• pp.743-750
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• 2012

A tissue cultured wild ginseng (TCWG) suspension was inoculated with lactic acid bacteria and fermented to improve the functionality of TCWG. The utilization of TCWG was increased directly using the freeze-dried powder. The optimal ratio of TCWG powder and water for fermentation was 1:19 (5%), which was selected by measuring the fluidity and viable cell count according to concentration. The effects on ADH activation and immune cell activation by each ferments with 10 kinds of Lactobacillus sp. strains were examined. The ferments with the Lactobacillus casei KFRI 692 strain showed 5.4 times higher ADH activity and 1.3 times higher ALDH activity than the non-fermented TCWG powder (control). The level of NO production and cytotoxicity was also measured by Raw 264.7 cells. The ferment with the Lac. casei KFRI 692 strain showed the highest level of NO production and lower cytotoxicity than the others. Therefore, the Lac. casei KFRI 692 strain was selected as a strain for fermentation of a TCWG suspension to maximize its functionality. To identify the optimal fermentation time of the selected Lac. casei KFRI 692 strain on the 5% TCWG suspension, the viable cell count of lactic acid bacterial and the changes in pH were observed for 72 hours. 24-hrs was found to be the optimal fermentation time. In this way, fermented TCWG with lactic acid bacteria showed higher ADH activation efficacy and immune cell activation than non-fermented TCWG.

• Food Science of Animal Resources
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• v.32 no.1
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• pp.31-39
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• 2012

The purpose of this study was to isolate bacteriocin-producing bacteria with antagonistic activities against pathogens from the intestines of pigs for probiotic use. Lactobacillus sp. AP 116 possessing antimicrobial property was selected from a total of 500 isolates. The AP 116 strain showed a relatively broad spectrum of inhibitory activity against Listeria monocytogenes, Clostridium perfringens, Pediococcus dextrinicus, and Enterococcus strains using the spot-on-lawn method. Bacteriocin activity remained unchanged after 15 min of heat treatment at $121^{\circ}C$ and exposure to organic solvents; however, it diminished after treatment with proteolytic enzymes. Maximum production of bacteriocin occurred at $34^{\circ}C$ when a pH of 6.0 was maintained throughout the culture during fermentation. According to a tricine SDS-PAGE analysis, the molecular weight of the bacteriocin was approximately 5 kDa. The isolate tolerated bile salts and low pH, and also induced nitric oxide (NO) in mouse peritoneal macrophages. Bacteriocin and bacteriocin-producing bacteria, such as Lactobacillus sp. AP 116, could be potential candidates for use as probiotics as an alternative to antibiotics in the pig industry.

• Journal of Microbiology
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• v.45 no.6
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• pp.515-520
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• 2007

Vaginal lactic acid-producing bacteria of 80 pre-menopausal women were studied by isolation on Blood and DeMan-Rogosa-Sharpe agar, PCR with group-specific primers for Lactobacillus-denaturing gradient gel electrophoresis (DGGE), and PCR with specific primers for V3 region in 16S rRNA-temporal temperature gel electrophoresis (TTGE). Conventional isolation method on media detected only one lactobacillus (Lactobacillus brevis) while TTGE detected only Lactobacillus sp. DGGE detected seven Lactobacillus species; L. coleohominis, L. crispatus, L. iners, L. reuteri, L. rhamnosus, L. vaginalis, and Leuconostoc lactis. L. acidophilus and L. gasseri, which are prevalent in Western women, were not detected in Korean women. Furthermore, L. rhamnosus, Leuc. lactis, L. coleohominis, and Weissella cibaria, which were not previously reported in the vaginal microbiota of Korean women, were detected. The five most prevalent LABs in vaginal microbiota in Korean women were L. iners, Enterococcus faecalis, L. crispatus, Leuc. lactis, and W. cibaria.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.666-670
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• 2003

Strains producing the protease, which is essential for growth of lactic acid bacteria and fermented kimchi, were screened and identified. Among five types of selected pulmuone kimchis (Jeonlado kimchi, ripened kimchi, yeolmu kimchi, kakdugi, and baechu kimchi), nine strains of bacteria were screened and identified by whole cell protein pattern and API test. The nine strains consisted of one of Lactobacillus sp., one of Leuconostoc sp., six of Bacillus sp., and one of Brevibacillus sp. The protease activities of these strains were compared with known strains (Bac. subtilis KCCM 12248 and Bac. licheniformis KCCM 11851) producing protease. Among tested strains, K-2 (Brevibacillus sp.) showed the highest value (0.11 unit/mg) in protease activity.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.755-755
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• 2003