• Quantitative Bio-Science
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• 제37권2호
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• pp.125-132
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• 2018

In this study, noble strains of lactic acid bacteria were isolated and identified by genetic analysis of 16s rRNA. Also, pH-dependent growth curve, cholesterol assimilation ability and sugar production efficiency were measured. Lactic acid bacteria were identified to inhabit in the milks from various animals. Results of sequence analysis showed that there were differences in 16S rRNA sequence among strains and part of gene deletion was also recognized. Growth rates were varied, too, depending on the pH of the medium. Lactobacillus rhamnosus LOCK908 isolated from cow milk showed the highest growth rate and high cholesterol assimilation ability. Results of sugar fermentation tests were relatively consistent with the sequencing results. So, we propose newly isolated Lactobacillus rhamnosus LOCK908 as useful candidate for a starter of fermented beverage and probiotics. Results of this study will contribute to the isolation and identification of noble Lactic acid bacteria and to the public health.

• 한국식품저장유통학회지
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• 제12권3호
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• pp.292-298
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• 2005

발효식품 담금 용기로 사용되고 있는 유리, polypropylene(PP), polyethylene terephthalate(PET), 스테인레스 용기, 옹기에 고추장을 담아 $30^{\circ}C$에서 4개월 동안 발효하는 동안 물리적, 화학적, 미생물적인 품질변화를 측정하여 담금 용기의 효과를 비교 평가하였다. 높은 기공성을 가진 옹기는 다른 용기에 비해 전체 발효기간에서 높은 호기성 세균수, 젖산균수, 효모수를 보여서 가장 왕성한 발효진행을 보였으며, 이와함께 높은 protease 활성을 유지시키고, 아미노태 질소와 유리 아미노산을 생산하였다. 아울러 옹기에 담금 한 고추장에서는 높은 총산함량과 낮은 pH를 얻게 하였으며, 환원당도 많이 생성시켰다. 이러한 변화는 발효 $2{\sim}3$개월에 완성되어졌다. 하지만 높은 기공성에도 불구하고 옹기에서 발효된 고추장은 타용기구에 비해서 수분손실과 염도상승은 현저하지 않았는데, 이는 시간의 경과에 따라 옹기벽면에서의 기공이 고추장 성분에 의하여 일부 닫혀짐에 의한 것으로 해석된다. 이러한 성분변화의 결과로 인하여 옹기에서 발효된 고추장은 관능적인 품질에서 타 용기처리구에 비해 유의적으로 우수하였다.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1517-1526
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• 2016

Lactic acid bacteria (LAB) isolated from fermented foods have potential as a treatment for immune-related disorders and the use of LAB has been increasing worldwide. In this study, the differential cytokine regulatory effect was examined with three isolates of lactobacilli strains; namely, Lactobacillus plantarum K55-5 isolated from dairy product, and L. sakei K101 and L. plantarum K8 previously isolated from kimchi (a Korean traditional fermented vegetable). Production of cytokines such as IL-10, IL-12, IFN-γ, and TNF-α was significantly increased in L. sakei K101- and L. plantarum K55-5-treated splenocytes as compared with controls. The oral administration of L. sakei K101 and L. plantarum K55-5 increased cytokine production in the immunosuppressed mouse splenocytes and blood. NK cell cytotoxic activity was also increased in L. sakei K101- and L. plantarum K55-5-fed mice. On the other hand, L. plantarum K8 did not affect cytokine induction in all the experiments performed in this study. The cytokine-inducing effect of L. plantarum K55-5 was significantly increased by lysates of heat-killed bacteria as compared with live, heat-killed, or supernatant of cell lysates. TNF-α production by lipoteichoic acids (LTAs) isolated from the three isolates of lactobacilli was compared, and it was found that K55-5 LTA had a highest cytokine-inducing ability, which was mediated by TLR2-mediated NF-κB and ERK activation. Taken together, our study suggests that L. plantarum K55-5 and L. sakei K101 can be used for the treatment of immunosuppressed disorders.

• Journal of Microbiology and Biotechnology
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• 제28권4호
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• pp.534-541
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• 2018

Kimchi (a traditional Korean fermented vegetable) was prepared with a starter, Lactobacillus zymae GU240 producing ${\gamma}$-aminobutyric acid (GABA), and one precursor of GABA (glutamic acid, glutamic acid monosodium salt (MSG), or kelp extract). L. zymae GU240, an isolate from kimchi, can grow at 7% NaCl and low temperature. Five different kimchi samples were fermented for 20 weeks at $-1^{\circ}C$. Kimchi with starter alone could not produce GABA. The GABA content was highest in kimchi with co-inoculation of the starter and MSG (1% (w/w)). Kimchi co-inoculated with the starter and kelp extract powder (3% (w/w)) had the second highest GABA content. Addition of glutamic acid powder (1% (w/w)) caused a reduction in the pH level of kimchi and growth inhibition of lactic acid bacteria and yeasts. Kimchi samples with MSG or kelp extract showed improvement of sensory evaluation scores. The results demonstrate the possibility to produce kimchi with improved functionality and taste by using L. zymae GU240 as a starter along with a suitable precursor such as MSG or kelp extract.

• Journal of Microbiology and Biotechnology
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• 제27권8호
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• pp.1419-1427
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• 2017

As probiotics play an important role in maintaining a healthy gut flora environment through antitoxin activity and inhibition of pathogen colonization, they have been of interest to the medical research community for quite some time now. Probiotic bacteria such as Lactobacillus plantarum, which can be found in fermented food, are of particular interest given their easy accessibility. We performed whole-genome sequencing and genomic analysis on a GB-LP1 strain of L. plantarum isolated from Korean traditional fermented food; this strain is well known for its functions in immune response, suppression of pathogen growth, and antitoxin effects. The complete genome sequence of GB-LP1 is a single chromosome of 3,040,388 bp with 2,899 predicted open reading frames. Genomic analysis of GB-LP1 revealed two CRISPR regions and genes showing accelerated evolution, which may have antibiotic and antitoxin functions. The aim of the present study was to predict strain specific-genomic characteristics and assess the potential of this new strain as lactic acid bacteria at the genomic level using in silico analysis. These results provide insight into the L. plantarum species as well as confirm the possibility of its utility as a candidate probiotic.

• 한국식품과학회지
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• 제31권4호
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• pp.1071-1076
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• 1999

본 연구에서는 김치발효에 관여하는 우세 발효균들의 집락을 분리하고, 발암원인 MNNG에 대하여 이들 분리주들이 갖는 DNA 손상 억제효과를 조사하였다. 이를 위해서 세포의 DNA 손상 및 복구를 측정하는데 이용되는 매우 신속하고 감도가 높은 Single Cell Gel Electrophoresis(SCGE 법, 또는 comet assay)를 사용하였다. 배추김치에서 분리한 3개의 분리주중에서 B-3를 제외한 B-1과 B-2는 양성 대조구와 비교하였을 때 우수한 항유전 독성효과를 나타내었으며(p<0.01), 율무김치의 3 개의 분리주(Y-1, Y-2, Y-3)와 1개의 분리주(Y-4)도 각각 항유전 독성효과를 나타내었다(p<0.05, p<0.01). 총각김치의 5 개 분리주중에서 3개의 분리주와 깍두기의 9개의 분리주중에서 2 개의 분리주들도 각각 항유전 독성효과를 나타내었다(p<0.05, p<0.01).

• 한국수산과학회지
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• 제48권2호
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• pp.151-157
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• 2015

This study was conducted to evaluate the effect of lactic acid bacterial fermentation on the antioxidant and anti-inflammatory activity of an edible brown alga, Eisenia bicyclis. Lactic acid bacteria were inoculated into and cultivated in E. bicyclis water extract. The antioxidant activity of the extract was assayed before and following fermentation. Antioxidant activity was determined by assaying the levels of radical scavenging activity against 2,2'-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical and alkyl radical. The lactic acid bacterial fermentation of E. bicyclis extract resulted in enhanced antioxidant activity. The greatest enhancement of antioxidant activity was seen in the DPPH radical scavenging assay, in which E. bicyclis extract was fermented by Pediococcus pentosaceus MBP-34 strain for 12 h. This fermented extract also exhibited higher inhibitory activity (96.66%) on nitric oxide production compared with other lactic acid bacterial fermented extracts or raw extract (189.60%). In conclusion, fermentation by bacterial strain is an attractive strategy for developing value-added food ingredients.

• 한국식품저장유통학회지
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• 제8권1호
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• pp.92-101
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• 2001

전통 발효 식품인 가자미 식 해로부터 cholesterol oxidase 생산성이 있는 균주를 분리하고 이들 분리된 균주들로 부터 여러 단계의 균주 선별시험을 통하여 cholesterol oxidate 생산성이 우수한 미생물을 선별하여 그 특성을 조사하였다. Cholesterol oxidase의 생산성이 가장 우수한 SFF34의 배양학적, 생리학적 특성 및 세포벽 지방산 조성을 조사하여 Bergey's Mannual of Systematic Bacteriology의 분류기준에 따라 동정한 결과 Bacillus sp. 또는 그 유연균으로 동정되어 분리균을 Bacillus sp. SFF34로 명명하였다. Cholesterol oxidase의 생산 조건을 검토한 결과 최적 배지 조성은 2.0% glucose, 0.5% yeast extract, 0.03% MgSO$_4$.7$H_2O$, 0.02% $K_2$HPO$_4$, 0.2% NH$_4$NO$_3$, 0.2% Cholesterol로 판명되었으며, 배양 조건은 3$0^{\circ}C$, 초기 pH 7.0, 진탕속도는 150rpm에서 24시간 배양시효소 생성이 가장 우수하였다 (2.42 U/ml).

• Journal of Dairy Science and Biotechnology
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• 제30권2호
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• pp.119-129
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• 2012

Lactic acid bacteria (LAB) have been used as starter cultures in the manufacturing processes of fermented dairy products such as cheese and yogurt. LAB have a proteolytic system to use the nitrogen source from milk for their growth. The proteolytic system involved in casein utilization provides cells with essential amino acids during growth in milk and is also of industrial importance, because of its contribution to the development of the organoleptic properties such as flavor of fermented milk products. In the most extensively studied LAB, Lactococcus lactis, the main features of the proteolytic system comprise 3 groups. The first is proteinase, which initially cleaves the milk protein to peptides. The second group consists of transport systems for the internalization of oligopeptides, which are involved in the cellular uptake of small peptides and amino acids. The third group, peptidases in the cell, cleaves peptides into smaller peptides and amino acids. This review is to provide the information about the proteolytic system of LAB.

• 한국수산과학회지
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• 제44권2호
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• pp.111-117
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• 2011

We previously reported that fermentation by Lactobacillus brevis LB-20 isolated from Kimchi resulted in improvement of the sensory quality of Hizikia fusiforme water extract. This study was conducted to evaluate the possible application of lactic acid bacteria fermentation to improve the functional qualities of H. fusiforme extract. L. brevis LB-20 was inoculated and cultivated in H. fusiforme extract. The antioxidant and anti-inflammatory activities of extract were then assayed both before and following fermentation for two days. Antioxidant activity was determined by assaying levels of radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, superoxide, and alkyl radical. Lactic acid bacterial fermentation of H. fusiforme extract resulted in enhancement of antioxidant activity. The greatest enhancement of antioxidant activity was seen in the hydroxyl radical scavenging assay that incorporated 0.5 mg/mL of raw and fermented H. fusiforme extract. Fermented extract exhibited greater (21.95%) inhibition of nitric oxide synthesis than did raw extract (14.66%) at a concentration of 1 mg/mL. The fermented extract exerted its potent anti-inflammatory activity via attenuation of expression of inflammation-related cytokine proteins (TNF-${\alpha}$ and iNOS).