• Proceedings of the Microbiological Society of Korea Conference
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• 2003.05a
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• pp.34-37
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• 2003

• Proceedings of the Microbiological Society of Korea Conference
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• 2007.05a
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• pp.131-131
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• 2007

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2002.10a
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• pp.98-98
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• 2002

• Food Science and Preservation
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• v.14 no.2
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• pp.188-193
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• 2007

The purpose of this study was to isolate lactic acid bacteria, useful in the fermentation industry from Hahyangju Nuruk. Five strains were isolated, and identified as Lactobacillus based on growth inhibition by 10% (v/v) alcohol at pH 4.0. Isolated strains were identified to species, and named Lactobacillus plantarum L-3, L. sakei L-10, and L. curvatus strains L-8, L-11, and L-12. Morphological characteristics, physiological data, carbohydrate fermentation patterns, and 16S rRNA sequence data, were all used to characterize the bacterial isolates. L. plantarum L-3 showed the highest lactic acid productivity of all isolates, but grew only poony in the presence of 10% (v/v) alcohol at pH 4.0. The other strains exhibited lower lactic acid productivity than did L. plantarum L-3 and did not grow in the presence of 10% (v/v) alcohol at pH 4.0. The optimal temperature and pH for lactic acid production were $30^{\circ}C$ and pH 6.0 7.0, respectively. The lactic acid productivity of L. plantarum L-3, L. sakei L-10 and the three L. curvatus strains L-8, L-11, and L-12 were (% v/v of culture supematant) 1.55, 1.0, 1.06, 1.0, and 0.99, respectively, at $30^{\circ}C$ and pH 6.0. While L. plantarum L-3 suffered growth inhibition in the presence of 10% (v/v) alcohol, growth of the other strains was inhibited at 8% (v/v) alcohol.

• Journal of Microbiology and Biotechnology
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• v.28 no.7
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• pp.1112-1121
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• 2018

Jeotgal is a Korean traditional fermented seafood with a high concentration of salt. In this study, we isolated lactic acid bacteria (LAB) from galchi (Trichiurus lepturus, hairtail) and myeolchi (Engraulis japonicas, anchovy) jeotgal on MRS agar and MRS agar containing 5% NaCl (MRS agar+5% NaCl), and identified them by using 16S rRNA gene sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as culture-dependent methods. We also performed polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) as a culture-independent method to identify bacterial communities. Five samples of galchi-jeotgal and seven samples of myeolchi-jeotgal were collected from different regions in Korea. A total of 327 and 395 colonies were isolated from the galchi- and myeolchi-jeotgal samples, respectively. 16S rRNA gene sequencing and MALDI-TOF MS revealed that the genus Pediococcus was predominant on MRS agar, and Tetragenococcus halophilus on MRS agar+5% NaCl. PCR-DGGE revealed that T. halophilus, Tetragenococcus muriaticus, and Lactobacillus sakei were predominant in both types of jeotgal. T. halophilus was detected in all samples. Even though the same species were identified by both culture-dependent and -independent methods, many species identified by the culture-dependent methods were not in the bacterial list identified by the culture-independent methods. The distribution of bacteria in galchi-jeotgal was more diverse than in myeolchi-jeotgal. The diverse LAB in galchi- and myeolchi-jeotgals can be further studied as candidates for starter cultures to produce fermented foods.

• Journal of Microbiology and Biotechnology
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• v.30 no.5
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• pp.726-732
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• 2020

Indonesian kefir grains are potential sources of lactic acid bacteria (LAB) that may act as probiotics with specific functional properties. In this study we explored the potential of the probiotic and cholesterol-lowering effect of LAB isolated from Indonesian kefir grains obtained from Bogor, Bandung, Jakarta, and Yogyakarta. The results revealed that 10 isolates showed considerable survivability at low pH and bile salt with total cell reduction of ~3 log colony-forming units per milliliter after exposure to pH 2.5 and 0.5% (w/v) bile salt for 1 and 3 h, respectively. All strains exhibited strong antimicrobial activities against pathogenic bacteria and were sensitive to a wide spectrum of antibiotics but exhibited weak bile salt hydrolase activity. Identification based on 16S RNA suggested that nine isolates were Lactobacillus kefiri and one was Lactobacillus rhamnosus. The ability of the isolates to reduce cholesterol from the media varied, ranging from 22.08% to 68.75% with the highest reduction shown by L. kefiri JK17. The ability to remove cholesterol from the media decreased greatly in resting and dead cells, ranging from 14.58% to 22.08% in resting cells and from 7.89% to 18.17% in dead cells. It can be concluded that Indonesian kefir grains contain LAB potentially acting as probiotics capable of reducing cholesterol. The cholesterol-lowering effect especially occurs when the cells are metabolically active.

• Microbiology and Biotechnology Letters
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• v.20 no.1
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• pp.102-109
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• 1992

The microfloral changes of lactic acid bacteria during Kimchi fermentation at 5, 20 and $30^{\circ}C$ were compared by using various selective media, and the lactic acid bacterial strains were isolated and identified. The patterns of microfloral changes in each lactic acid bacterial group, leuconostoc, lactobacilli, streptococci and pediococci, were similar at different fermentation temperature, and the changes were accelerated by increased temperature. Among them, leuconostoc and lactobacilli showed high population, and at low temperature the number of leuconostoc were higher than at high temperature. Leuconostoc and streptococci were increased in number from the beginning, but they rapidly decreased after the optimum ripening period. Pediococci increased their number after streptococci, but they were rapidly decreased later. Lactobacilli were highly distributed throughout the whole fermentation period. However, they were slightly declined as the acidity increased. Those strains of leuconostoc, streptococci, pediococci and lactobacilli were identified as Luuconostoc mesenteroida subsp. musenteroides, Streptococcus fuecalzs, S, faeciurn, Pediococcus pentosaceus, Lactobacillus plarttarum, L. sake and L. brevis. Among lactobacilli, Id. sake and L. brmk, and L. plantarum were isolated mainly at the beginning and around the overripening period of fermentation, respectively.

• Microbiology and Biotechnology Letters
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• v.44 no.2
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• pp.201-207
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• 2016

The aim of this study was to investigate the potential of lactic acid bacteria (LAB) strains as probiotics. Two strains were isolated from healthy chicken cecum and their acid and bile tolerance, residual organic acids, antibacterial activity against pathogenic bacteria, and immunomodulation activity were measured. Identification of the isolated strains was performed using the API 50CHL system and phylogenetic analysis using 16S rDNA sequencing. The isolates were determined to be Lactobacillus sakei strains. The acid tolerance of strains L2 and L8 was high enough that 75% of the inoculum survived in pH 2 for 2 h. The bile tolerance of both strains was observed at a 1% Oxgall concentration in MRS broth. The production of organic acids (lactic acid and acetic acid) and pH changes during growth were monitored and the maximum concentrations were obtained after 48 h of incubation. Culture supernatants of the two LAB strains showed strong antibacterial activity against pathogenic bacteria. The heat-killed LAB cells also induced high levels of immune cell proliferation compared with the control, and stimulated IL-6 and TNF-α production in mouse macrophages. Therefore, L. sakei strains L2 and L8 can be considered suitable probiotic bacteria.

• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.13-17
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• 1994

We estabilished the procedure for isolation of Streptococcus salivarius subsp. thermophilus from raw milk. First, urease-producing lactic acid bacteria in raw milk were screened on the HY agar medium containing urea. Thereafter the urease-producing colonies were tested the ability to ferment maltose and to grow at43$\circ $C. We obtained about 400 maltose-negative colonies that grew at 43$\circ $C. No significant difference in carbohydrate fermentation test for isolated and type strains(S. salivarius subsp. thermophilus ATCC 19258 and ST-4) was found. And all of the isolated strains were able to ferment galactose. Furthermore, it was investigated that the cellular fatty acid profiles of isolated strains were similar to that of type strains. These results indicated that the isolated strains from raw milk were S. salivarius subsp. thermophilus. But when the isolated and type strains were incubated in 12% reconstituted skim milk at 43$\circ $C, the isolates produced lactic acid more slowly than the type strains.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.68-76
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• 2006

Despites many attempts to explore the microbial diversity in kimchi fermentation, the predominant flora remains controversial to date. In the present study, major lactic acid bacteria (LAB) were investigated in Chinese cabbage kimchi in the early phase of fermention. For the samples over pH 4.0, viable cell counts of Leuconostoc and Pediococcus were $10^6\;cfu/ml$ and below $10^2\;cfu/ml$, respectively, and 20 isolates out of 172 were subjected to a biochemical identification (API 50 CH kit) as well as molecular-typing methods including ITSPCR with a RsaI digestion and 16s rRNA gene sequence analysis for species confirmation. Seven isolates were nicely assigned to Lb. brevis, 6 to Leuconostoc spp. (2 mesenteroides, 2 citreum, I carnosum, I gasicomitatum), 4 to Weissella (3 kimchii/cibaria, 1 hanii) and 2 to other Lactobacillus spp. (1 farciminis, 1 plantarum). On the other hand, the biochemical identification data revealed 9 strains of Lb. brevis, 6 strains of Leuconostocs,2 strains of Lb. plantarum and 1 strain each of Lb. coprophilus and Lactococcus lactis. However, a single isolates, YSM 16, was not matched to the ITS-PCR database constructed in the present study. Two Lb. brevis strains by API 50 CH kit were reassigned to W kimchii/cibaria, Lb. coprophilus or W hanii, respectively, judging from the results by the above molecular typing approaches. As a whole, the identification data obtained by the biochemical test were different from those of ITS-PCR molecular method by about $63\%$ at genus-level and $42\%$ at species-level. The data by the ITS-PCR method conclusively suggest that predominant LAB species is probably heterolactic Lb. brevis, followed by W kimchii/cibaria, Leuc. mesenteroides, and Leuc. citreum, in contrast to the previous reports [3] that Leuc. mesenteroides is the only a predominant species in the early phase kimchi fermentation.