• Preventive Nutrition and Food Science
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• 제2권2호
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• pp.101-108
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• 1997

A lactic acid bacterium LAB3113, isolated from traditionally fermented Kimchi was found to produce bacteriocin whose activity was very specific toward lactobacilli and not effective against any other bacteria. Lactobacilli affected by the inhibitory substance included Lactobacillus delbrueckii-lactis, L. johnsonii, L. gsseri, and L. curvatus. Based upon biochemical and physiological characteristics, LAB3113 was classified as Lactococcus lactis, and its bacteriocin was named as lactococcin K3113. Lactococcus lactis. LAB3113 produced bacteriocin at th early stage of growth and the concentration of the bacteriocin did not decrease even after alt stationalry phase. Optimal temperature of bacteriocin production was $25^{\circ}C$ at the initial pH 7.0. Partially purified lactococcin K3113 was completely inactivated by protease, but not affected by lipase, lysozyme and RNase. The bacteriocin was very heat-stable even after autoclaving for 20 min. It was also stable in pH changes, an was not affected by th presence of solvents. lacotococcin K3113 appeared to act in bactericidal mode against L. delbrueckii-lactis ATCC4797. Molecular weight of lactococcin K3113 was calibrated as 10,500 dal by SDS-PAGE an activity staining. Lactococcus lactis LAB3113 had four residential plasmids of 3.7kb, 11.2kb, 15.5kb, and 48kh in molecular sizes. Plasmid profile analysis of mutant strain revealed that 15.5 kb plasmid was re-sponsible for the production of lactococcin K3113 and its immunity to the bacteriocin.

• 한국작물학회지
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• 제63권2호
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• pp.106-111
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• 2018

현재 국내에는 C사에서 생산하는 한 종의 사일리지 제조 유산균이 있다. 본 연구는 이를 대체할 균주를 선발하기 위해서 사일리지의 특성과 사료가치를 분석하였다. C사의 유산균(CMRT, 비교균주)보다 우수한 균주를 선발하기 위해 김치에서 발견한 유산균 4종(Lactobacillus. leuconostoc mesenteroides M17, L. sakei C11, M5, SP2)을 이용하였다. 성장속도를 측정할 수 있는 흡광도는 L. sakei C11이 가장 높았고, 향은 M17이 제조 20일부터 비교균주와 유사하였다. M17의 pH는 비교 균주보다 낮았다. 단백질 함량은 M17의 사일리지에서 비교균주의 사일리지보다 유의성 있는 증가를 보였다. 유기산 중 초산과 낙산은 검출되지 않았고 젖산은 4개의 선발균주가 비교균주보다 높았다. 4개의 선발 균주 ADF와 NDF의 함량은 비교균주와 비교시 각각11~24% 및 13~20% 낮아 유의성(p < 0.05)있는 차이를 보였다. 비교균주 TDN은 평균 63.44%로 4개의 선발균주의 TDN 값(66.05~69.65)보다 낮은 유의성(p < 0.05)있는 감소를 보였다. 한편 상대사료가치(RFV)는 비교균주 사일리지에서 107.35로 2등급(RFV 124~103)에 해당하는 품질이었으나 4개의 선발 균주 사일리지는 특(RFV 151 이상)~1등급(RFV 125~150)에 해당하여 선발 균주의 사일리지가 품질이 우수한 것으로 조사되었다. 이상의 결과를 종합하여 볼 때, 선발 균주 중 M17에 의해 제조된 사일리지는 비교균주(CMRT) 사일리지 보다 pH, ADF 및 NDF가 낮고, 단백질, 젖산 및 상대사료가치가 높아 고품질의 사일리지 생산이 가능할 것으로 판단되었다.

• Journal of Microbiology and Biotechnology
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• 제27권10호
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• pp.1736-1743
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• 2017

Sourdough is made by fermentation of dough by lactic acid bacteria (LAB) and yeast to improve bread properties like volume, flavor, and texture. A Korean traditional sourdough was made by fermenting rice flour with rice wine (makgeolli) and used to make sponge-like bread (jeung-pyun). The aim of this study was to investigate the microbial diversity of makgeolli products and their influence on the organoleptic quality of jeung-pyun. Three commercial makgeolli were tested for jeung-pyun production, with each product exhibiting varied dough swelling rates and organoleptic qualities, and among them, J-product was ranked highest in texture and taste. Microbial analysis of the three makgeolli also showed a big difference in their population and diversity. J-product had the highest LAB and yeast counts, and the predominant species were Lactobacillus casei, Lactobacillus brevis, Leuconostoc pseudomenteroides, and Saccharomyces cerevisiae. Using J-product, sourdough was fermented at $25^{\circ}C$, $30^{\circ}C$, and $35^{\circ}C$, and the microbial growth in and textural properties of jeung-pyun were examined by instrumental and sensory tests. At high temperature ($35^{\circ}C$), the rates of dough swelling and acidification were fast due to rapid microbial growth mainly caused by LAB, resulting in a short leavening time and soft and sour jeung-pyun. Sensory tests showed consumer preference for the soft and mild-sour jeung-pyun. This study shows that LAB in makgeolli play key roles in production of jeung-pyun, influencing the textural and sensory properties. For the production of high-quality jeung-pyun, development of LAB starters with high gas productivity and low acidity and establishment of an optimal fermentation procedure for rice dough are necessary.

• International journal of advanced smart convergence
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• 제11권4호
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• pp.227-239
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• 2022

Purpose: In our study, in order to find lactic acid bacteria (LAB) with multi-drug resistance to antibiotics, we isolated 140 strains from 15 types of kimchi commercially available in Korea and 20 types of Kimchi made at home from January to December in 2016, and investigated their H₂O₂ generating ability and multi-drug resistance to antibiotics. Methods: In order to observe the H₂O₂ generation ability of LAB, we performed the experiment with methods such as Rabe, Hillier, and Kang. To test the antibacterial susceptibility of LAB, we used the disc agar diffusion method using MRS agar (Difco, USA) according to the CLSI and WHO test methods. There are 18 types of antibiotic discs used. Results: Out of the total numbers of 140 strains, 6 strains of Ent. Faecium, 25 strains of L. plantarum, 1 strain of L. rhamnosus, 3 strains of L. sakei, 1 strain of L. acidophilus, 1 strains St. thermophilus, and 7 of unidentified strains generated H₂O₂. The antibiotic susceptibility of Ent. Faecium indicated SXT, OX, NA, and E; and the antibiotic susceptibility of L. plantarum indicated NA; and the antibiotic susceptibility of St. thermophilus indicated NA, CC, RA, CTT, CM, and P ; and the antibiotic susceptibility of L. rhamnosus indicated SXT, VA, NA and CTT; and the antibiotic susceptibility of 6 strains of L. sakei indicated SXT, OX, NOR, NA, CTT and CIP, all indicating antibiotic resistance. In the case of multi-drug resistance to antibiotics for 53 strains of L. antarum, 8-drug resistance was the most common with 25 strains, followed by 7-drug-resistant strains with 18 strains, 9-drug-resistant strains with 4 strains, 6-drug-resistant strains with 3 strains, 5-drug-resistant strains with 2 strains, and 17-drug-resistant strains with 1 strain. In the case of multi-drug resistance to antibiotics for Ent. Faecium 27 strains, 9-drug resistance was most commonly identified as 9 strains, 8-drug resistance was identified as 6 strains, 7- and 11 drug resistances were identified as 4 strains each, and 4- and 6-drug resistances were identified as 1 strain each. Conclusion: Ent. Faecium, L. plantarum, L. rhamnosus, L. sakei, and St. thermophilus, shown to have anantibacterial activity in previous studies on LAB and shown to have and H₂O₂ generating ability, antibiotic resistance and multi-drug resistance in this study, are expected to be able to play an excellent role for long-term inpatients to use as an alternative to antibiotics and to cope with emerging antibiotic resistance.

• 한국초지조사료학회지
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• 제44권1호
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• pp.50-57
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• 2024

Silage inoculants, crucial in modern silage production, comprise beneficial microorganisms, primarily lactic acid bacteria (LAB), strategically applied to forage material during ensiling. This study aimed to compare the effectiveness of various inoculants produced by different companies. Five treatments were evaluated, including a control group: T1 (Lactobacillus plantarum), T2 (Lactobacillus plantarum + Pediococcus pentosaceus), T3 (Lactobacillus plantarum + Pediococcus pentosaceus + Lactobacillus buchneri), T4 (Lactobacillus plantarum + Lactobacillus acidophilus + Lactobacillus bulgaricus), and T5 (Lactobacillus plantarum + Pediococcus pentosaceus + Enterococcus faecium). Italian ryegrass was harvested at the heading stage and treated with these silage inoculants. Samples were collected over a 60-day ensiling period. Co-inoculation with L. plantarum and P. pentosaceus (T2) resulted in significantly higher CP compared to the control group co-inoculation exhibited with resulted in Lactobacillus plantarum and Pediococcus pentosaceus in the T2 treatment exhibited higher CP content of 106.35 g/kg dry matter (DM). The T3 treatment, which included heterofermentative bacterial strains such as Lactobacillus buchneri, exhibited an increase in acetic acid concentration (11.15 g/kg DM). In the T4 treatment group, which utilized a mixed culture of Lactobacillus acidophilus and Lactobacillus bulgaricus, the NH₃-N/TN content was observed to be the lowest (20.52 g/kg DM). The T5 containing Enterococcus faecium had the highest RFV (123) after 60 days. Expanding upon these findings, the study underscores not only the beneficial effects of particular inoculant treatments on silage quality but also underscores the potential of customized inoculation strategies in maximizing nutrient retention and overall silage preservation.

• 한국식품영양과학회지
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• 제42권6호
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• pp.991-995
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• 2013

본 연구는 곡류 및 두류를 이용하여 식용 가능한 젖산균 모배양용 식용배지를 개발하고자 실시하였다. 식용 배지의 제조를 위하여 곡류는 발아현미, 찰현미, 발아찰현미를 사용하였고, 두류는 대두콩(대두콩, 껍질을 제거한 대두콩, 발아 대두콩, 껍질을 제거한 발아 대두콩)과 검은 대두콩(검은 대두콩, 껍질을 제거한 검은 대두콩, 발아 검은 대두콩, 껍질을 제거한 발아 검은 대두콩)으로 나누어서 젖산균 증식배지를 제조하였다. 실험에 사용된 젖산균은 Lactobacillus(Lb.) farciminis, Lb. homohiochii, Lb. pentosus, Lb. plantarum, Leuconostoc(Leu.) paramesenteroides, Leu. citreum 및 Leu. lactis 총 7종이다. 곡류를 이용한 식용배지에서 배양한 경우, 7개 종균의 평균 균수는 7.6~8.0 log CFU/mL의 균수를 나타내었다. 대두콩으로 제조한 식용배지는 껍질을 제거한 발아 대두콩 배지에서 대부분의 균이 높은 증식량을 나타내었다. 특히 Lb. plantarum은 10.08 log CFU/mL로 가장 높은 균수를 보였다. 검은 대두콩의 경우는 껍질을 제거한 발아 검은 콩배지에서 증식량이 많았다. Lb. homohiochii는 껍질제거 발아 검은 콩배지에서 9.90 log CFU/mL로 가장 많은 증식량을 보였다. 모든 결과에서 곡류와 두류를 이용한 식용배지를 이용하여 배양할 때 젖산균 증균량이 우수함을 알 수 있었고, 특히 가장 증식량이 우수한 '껍질을 제거한 발아 검은 대두콩' 식용 배지를 향후 젖산균 모배양에 이용하는 것을 권장한다.

• Journal of Dairy Science and Biotechnology
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• 제33권1호
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• pp.83-91
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• 2015

Yogurt is a product of the acidic fermentation of milk, which affects the survival of lactic acid bacteria (LAB). The aim of this present study was to examine the survival and acid stress response of Lactobacillus rhamnosus GG to low pH environment. The survival of LAB in commercial yogurt was measured during long-term storage. The enumeration of viable cells of LAB was determined at 15-day intervals over 52-weeks at $5^{\circ}C$. L. acidophilus, L. casei, and Bifidobacterium spp. showed low viability. However, L. rhamnosus GG exhibited excellent survival throughout the refrigerated storage period. At the end of 52-weeks, L. rhamnosus GG survived 7.0 log10 CFU/mL. $F_0F_1$ ATPase activity in L. rhamnosus GG at pH 4.5 was also evaluated. The ATPase activities of the membranes were higher when exposed at pH 4.5 for 24 h. The survival of L. rhamnosus GG was attributable to the induction in $F_0F_1$ ATPase activity. In addition, the mRNA expression levels of acid stress-inducible genes at low pH were investigated by qRT-PCR. clpC and clpE genes were up-regulated after 1 h, and atpA and dnaK genes were up-regulated after 24 h of incubation at pH 4.5. These genes could enhance the survival of L. rhamnosus GG in the acidic condition. Thus, the modulation of the enzymes or genes to assist the viability of LAB in the low pH environment is thought to be important.

• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.217-223
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• 2010

To evaluate the antiallergic effect of fermented Ixeris sonchifolia (IS, family Compositae), we prepared IS kimchi, isolated lactic acid bacteria (LAB) from it, fermented IS with these LAB, and investigated their antiallergic effects. IS kimchi inhibited the passive cutaneous anaphylaxis (PCA) reaction induced by an IgE-antigen complex as well as the scratching behavior induced by compound 48/80 or histamine more potently than IS. When IS was fermented with LAB isolated from IS kimchi, its antiallergic effects was also increased. Of LAB used for fermentation, Lactobacillus brevis more potently increased the antiallergic effects. Its main constituents, chlorogenic acid and luteolin, potently inhibited the PCA reaction induced by the IgE-antigen complex as well as the pruritis induced by compound 48/80 or histamine. These constituents inhibited the expression of pro inflammatory and allergic cytokines, TNF-$\alpha$. and IL-4, and transcription factor NF-${\kappa}B$ activation induced by the IgE-antigen complex in RBL-2H3 cells, as well as the degranulation of RBL-2H3 cells induced by the IgE-antigen complex. Luteolin more potently inhibited these allergic reactions than chlorogenic acid. These findings suggest that the antiallergic effect of IS can be increased by LAB fermentation, and the fermented IS might improve allergic reactions such as pruritus, anaphylaxis, and inflammation.

• Asian-Australasian Journal of Animal Sciences
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• 제33권8호
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• pp.1292-1300
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• 2020

Objective: To explore feed resources capable of replacing regular poor-quality fodder, this study was conducted to evaluate the effects of additives on the fermentation quality, in vitro digestibility and aerobic stability of mulberry leaves silage. Methods: The mulberry leaves were ensiled either untreated (control) or treated with 1×10⁶ cfu/g fresh matter Lactobacillus plantarum (L), 1% glucose (G), 3% molasses (M), a combination of 1% glucose and Lactobacillus plantarum (L+G), and a combination of 3% molasses and Lactobacillus plantarum (L+M). The fermentation quality and chemical composition were analyzed after 7, 14, 30, and 60 d, respectively. The 60-d silages were subjected to an aerobic stability test and fermented with buffered rumen fluid to measure the digestibility. Results: Inoculating lactic acid bacteria (LAB) resulted in more rapid increase in lactic acid concentrations and decline in pH of mulberry leaves silage as compared control. Higher acetic acid and lower ethanol and ammonia nitrogen concentrations (p<0.05) were observed in the LAB-inoculated silages as opposed to control during ensiling. The LAB-inoculated silages contained lower water-soluble carbohydrates compared with control during the first 14 d of ensiling, and lower neutral detergent fibre (p<0.05) concentrations as compared with non-LAB inoculated silages. Adding molasses alone increased (p<0.05) the digestibility of dry matter (DM). The aerobic stability of mulberry leaves silage was increased by LAB inoculation, whereas decreased by adding glucose or molasses. Conclusion: The LAB inoculation improved fermentation quality and aerobic stability of mulberry leaves silage, while adding glucose or molasses failed to affect the fermentation and impaired the aerobic stability. Inoculating LAB alone is recommended for mulberry leaves especially when ensiled at a relatively high DM.

• Asian-Australasian Journal of Animal Sciences
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• 제23권7호
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• pp.960-964
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• 2010

Water-cooked salted ducks were tray-packaged and stored under refrigeration ($4{\pm}1^{\circ}C$) in order to evaluate the quality changes during storage. pH, total volatile basic nitrogen (TVB-N), sensory and microbiological analysis were determined at 0, 2, 4, 6, 8, 9 and 10 days of storage. pH value and TVB-N (mg N/100 g) varied from $6.47{\pm}0.16$ to $6.69{\pm}0.10$ and from $5.90{\pm}0.93$ to $13.42{\pm}2.46$, respectively. Sensory results indicated that ducks were unacceptable at the 10th day of storage. The predominant spoilage bacteria at the end of the shelf-life were Brochothrix thermosphacta, lactic acid bacteria (LAB) and minor components were Enterobacteriaceae, members of Micrococci, yeasts and moulds. Pseudomonads were also detected. Both total bacteria and the various spoilage ones, overall, increased from the initial sampling to the final day.