• 고신대학교 의과대학 학술지
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• 제33권3호
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• pp.422-430
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• 2018

Leuconostoc species are Gram-positive coccobacilli and are used in dairy products and are intrinsically resistant to vancomycin. Leuconostoc infections are rare in humans, usually occurring in immune-compromised patients. We describe 6 patients with Leuconostoc bacteremia at Dong-A university hospital between 1990 and 2015. One isolate (L. lactis) was identified to species level using 16S rRNA gene sequencing analysis. All patients had underlying diseases and 5 patients underwent procedures that interrupted the normal integumentary defense. Four patients died within 30 days after being identified as carrying Leuconostoc species.

• 한국미생물·생명공학회지
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• 제39권2호
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• pp.175-181
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• 2011

Kimchi is a group of traditional fermented vegetable foods in Korea and known to be the product of a natural mixed-fermentation process carried out principally by lactic acid bacteria (LAB). According to microbial results based on conventional identification, Leuconostoc mesenteroides and Lactobacillus plantarum were considered to be responsible for the good taste and over-ripening of kimchi, respectively. However, with the application of phylogenetic identification, based on 16S ribosomal RNA gene similarities, a variety of Leuconostoc and Lactobacillus species not detected in the previous studies have been isolated, together with a species in the genus Weissella. Additionally, Lactobacillus sakei has been accepted as the most populous LAB in over-ripened kimchi. In this study, Leuconostoc and Weissella species inhibiting the growth of Lb. sakei were isolated from kimchi for future applications to do with kimchi fermentation. From 25 kimchi samples, 378 strains in the genera Leuconostoc and Weissella were isolated and 68 strains identified as Lc. mesenteroides, Lc. citreum, Lc. lactis, W. cibaria, W. confusa, and W. paramesenteroides exhibited growth inhibition against Lb. sakei. Most of the strains also had antagonistic activities against Lb. brevis, Lb. curvatus, Lb. paraplantarum, Lb. pentosus, and Lb. plantarum. Their antagonistic activities against Lb. sakei were more remarkable at lower temperatures of incubation.

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.166-171
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• 2002

The genus Leuconostoc is generally recognized as a favorable microorganism associated with a good taste of Kimchi and Lactobacillus plantarum is responsible for the overripening and acidification of Kimchi. A rapid and reliable PCR-based method to monitor the change of these lactic acid bacterial populations during Kimchi fermentation was attempted. A Leuconostoc-specific primer set was chosen from the conserved sequences of 16S rRNA genes among Leuconostoc species. The Lb. plantarum-specific primer set was the internal segments of a Lb. plantarum-specific probe which was isolated after randomly amplified polymorphic DNA (RAPD) analysis and tested for identification. The specificity of this protocol was examined in DNA samples isolated from a single strain. In agarose gel, as little as 10 pg of template DNA could be used to visualize the PCR products, and quantitative determination was possible at the levels of 10 pg to 100 ng template DNA. For the semi-quantitative determination of microbial changes during Kimchi fermentation, total DNAs from the 2 h-cultured microflora of Kimchi were extracted for 16 days and equal amounts of DNA templates were used for PCR. The intensities of DNA bands obtained from PCR using Leuconostoc-specific and Lb. plantarum-specific primer sets marked a dramatic contrast at the 1 ng and 100 ng template DNA levels during Kimchi fermentation, respectively. As the fermentation proceeded, the intensity of the band for Leuconostoc species increased sharply until the 5th day and the levels was maintained until the 11 th day. The sharp increase for Lb. plantarum occurred after 11 days with the decrease of Leuconostoc species. The results of this study indicate that Leuconostoc species were the major microorganisms at the beginning of Kimchi fermentation and reach their highest population during the optimum ripening period of Kimchi.

• Journal of Microbiology and Biotechnology
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• 제23권6호
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• pp.837-842
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• 2013

A cryptic plasmid, pMBLR00, from Leuconostoc mesenteroides subsp. mesenteroides KCTC 3733 was isolated, characterized, and used for the construction of a cloning vector to engineer Leuconostoc species. pMBLR00 is a rolling circle replication plasmid, containing 3,370 base pairs. Sequence analysis revealed that pMBLR00 has 3 open reading frames: Cop (copy number control protein), Rep (replication protein), and Mob (mobilization protein). pMBLR00 replicates by rolling circle replication, which was confirmed by the presence of a conserved double-stranded origin and single-stranded DNA intermediates. An Escherichia coli-Leuconostoc shuttle vector, pMBLR02, was constructed and was able to replicate in Leuconostoc citreum 95. pMBLR02 could be a useful genetic tool for metabolic engineering and the genetic study of Leuconostoc species.

• 미생물학회지
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• 제27권4호
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• pp.404-414
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• 1989

김치발효 중 Gram 양성세균 또는 유산균의 분리와 동정을 시도하였다. 종의 다양성은 분리배지와 온도에 영양을 받았고, 다양성은 온도가 낮아질수록 감소하는 경향이었다. MRS는 세균의 분리에 KM(김치재료로 만든 자연배지)은 종의 수를 파악 하는데 각각 적합하였다. 분리균의 동정은 Bergey's manual of Systematic Bacterio]ogy (1986)를 기초로 하여 작성한 이 분농생표(dichotomous Identification scheme)에 의하여 선행하였다. 각 온도(5, 15, $25^{\circ}C$)에서 동정된 Gram 양성세균은 Leuconostoc 5종, Streptococcus 4종, Pediococcus 3종, Bacillus 2종 그리고 Ltobacillms 18종이였다. 각 온도에서 출현 빈도가 높은 종은 $25^{\circ}C$에서 LactobaIlus ptantanmz, Streptococcµs faffinolactis, Leuconostoc maιnteroid, subsp mlsentιroides 이었고, $15^{\circ}C$에서 L. mesenteroides Lactobacillus fructosus, L. maen teroid,l.I subsp. mesent,roid, 이였고, $5^{\circ}C$ 에서 Leuconostoc sp.(65.2 빈도)에 의하여 이루어졌다. 그리고 각 온도에 따른 김치발효 중 지금까지 알려진 Pediococcus cerevisiae 와 Streptococcus faecalis는 분리되지 않았다.

• Journal of Applied Biological Chemistry
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• 제62권4호
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• pp.441-446
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• 2019

The assortment of endophytic lactic acid bacteria (LAB) in kimchi derives from its raw vegetables, which include Chinese cabbage, radish, welsh onion, onion, garlic, red pepper, and ginger. These vegetables were examined during mulkimchi fermentation using gene-specific multiplex polymerase chain reaction and 16S ribosomal RNA sequence analysis. Sixteen species from five LAB genera (Leuconostoc, Lactobacillus, Lactococcus, Pediococcus, and Weissella) appeared in the raw kimchi materials. Interestingly, nine LAB species were identified in mulkimchi on fermentation day 0 as follows: Leuconostoc carnosum, Leuconostoc citreum, Leuconostoc gelidum, Leuconostoc inhae, Leuconostoc mesenteroides, Lactobacillus plantarum, Lactobacillus sakei, Lactococcus lactis, and Weissella confusa. Seven additional LAB species were present in mulkimchi at fermentation day 9 as follows: Leuconostoc gasicomitatum, Leuconostoc kimchii, Lactobacillus brevis, Lactobacillus curvatus, Lactobacillus pentosus, Pediococcus pentosaceus, and Weissella koreensis. These species corresponded completely with the LAB in kimchi vegetables. Wei. confusa was the predominant LAB during early fermentation (pH 6.20 to 4.98 and acidity 0.20 to 0.64%), while Lac. sakei, Lac. plantarum, and Wei. koreensis became dominant later in fermentation (pH 4.98 to 3.88 and acidity 0.64 to 1.26%). These results collectively demonstrate that the LAB involved in mulkimchi fermentation originates from the raw vegetables examined.

• 한국식품저장유통학회지
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• 제16권6호
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• pp.804-809
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• 2009

최근, 저온 장시간 발효된 묵은지에 대한 소비가 증가하고 있다. 본 논문에서는, 저온($5^{\circ}C$)에서 46주 동안 발효된 묵은지의 pH, 산도, 유기산, 생균수, 아미노산, polygalacturonase (PG) 활성 등을 분석하였다. 10주 발효한 김치에서는 pH 4.1, 산도 0.99%를 나타낸 반면, 46주 발효한 김치에서는 pH 3.9, 산도 1.29%를 보였다. 한편, 10주에서 46주로 발효 기간이 증가하면서, 젖산, 젖산/초산비, Lactobacillus species/Leuconostoc species비 등은 증가한 반면, 호기성 세균, 효모, Lactobacillus species, Leuconostoc species, 유리아미노산, PG 효소 활성은 감소하였다.

• Food Science and Biotechnology
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• 제14권3호
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• pp.416-419
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• 2005

Unknown bacterium isolated from garlic was characterized using phenotypic methods, phylogenetic analysis, DNA-DNA hybridization, and cultural methods. The strain was identified as typical leuconostoc; Gram-positive, non-sporeforming, heterofermentative, catalase-negative and spherical. Although its 16S rRNA gene sequence showed high homology to Leuconostoc argentinum DSM $8581^T$(99.8%), DNA-DNA hybridization experiments indicated it represents novel genomic species in the genus Leuconostoc. The garlic-specific leuconostoc was more resistant to antimicrobial activity of garlic compared to other common laboratory lactic acid bacteria, and was even stimulated by low concentrations (1-2%) of garlic extract supplemented in trypticase soy broth. Growth stimulation was concentration-dependent when tested with residual aqueous layer after solvent extraction of fresh whole garlic extract.

• Journal of Microbiology and Biotechnology
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• 제23권10호
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• pp.1428-1433
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• 2013

Jeotgal fermentation is dependent upon a diverse microbial community, although a detailed understanding of its microbial composition is limited to a relatively small number of jeotgal. Pyrosequencing-based bacterial community analysis was performed in fermented squid, ojingeo jeotgal. Leuconostoc was identified as the predominant bacterial genus, with Bacillus and Staphylococcus also accounting for a large proportion of the bacterial community. Phylogenetic analysis with 16S rRNA genes of Leuconostoc type species indicated that L. citreum- and L. holzapfelii-like strains could be the major Leuconostoc strains in jeotgal. High concentrations of NaCl were thought to be an important factor determining the makeup of the bacterial community in the fermented squid; however, a genomic survey with osmotic stress-related genes suggests the existence of more complex factors selecting the dominant bacterial species in fermented squid.

• Journal of Microbiology
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• 제38권3호
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• pp.132-136
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• 2000

We recently identified Leuconostoc gelidum, a typical psychrophile, as a microbial component from kimchi that has been laboratory-prepared and fermented at 20$^{\circ}C$ . However, it has been shown that the growth of leuconostocs in food products is highly influenced by fermenting temperature. To determine the distribution of L. gelidum species in kimchi fermented at a lower temperature , 8$^{\circ}C$, we characterized a total of 64 dextran-forming strains isolated from kimchi using a polyphsic method including 16S rDNA sequencing and DNA-DNA gybridization. We found that 80% of the isolated were L. gelidum, which has been found mainly at chill-stored meat products. We also found that L. gelidum could be a dominant Leuconostoc species in so-called KimJang Kimchi, which is traditionally prepared at lat fall to be preserved during winter in Korea. These results suggest that L. gelidum can be a predominant species in kimchi especially when fermented at low temperature.