• 한국식품영양학회지
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• 제14권6호
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• pp.512-520
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• 2001

한국의 대표적인 전통식품 중 하나인 김치의 발효시 문제가 되고 있는 저장성과 미생물의 과도 성장으로 인한 부패를 지연시키기 위한 방법을 모색하고자 과숙김치의 pH와 산도, 유기산, 효소활성 등의 이화학적 특성과 미생물학적 특성을 살펴 본 결과는 다음과 같다. 1. 김치의 발효초기단계에 pH는 급격히 감소하다가 산도가 0.5% 부근일 때부터 완만한 감소를 보였고 반면에 산도는 초기에는 완만히 증가하다가 pH가 4부근일 때부터 발효미생물의 영향으로 급격한 증가를 보였다. 2. 김치의 숙성과정시 생성되는 유기산은 oxalic acid, lactic acid, acetic acid, malic acid, succinic acid 등 이며, GC-MSD로 확인 작업을 하였다. 유기산들 중 lactic acid가 발효기간 중 가장 큰 변화를 보였으며, malic acid는 저장기간이 경과함에 따라 감소하였다. 3. 과숙김치에서 산도가 0.75%인 kimchi A의 acidic protease activity, lipase activity가 가장 높았고, Amylase activity는 산도 0.95%인 kimchi C가 가장 높았다. 4. 5가지 과숙김치 각각(A, B, C, D, E순으로)의 총균에서는 8.1$\times$$10^{5}$ , 4.7$\times$$10^4$, 1.2$\times$$10^3$, 3.2$\times$$10^4$, 4.9$\times$$10^{5}$ (CFU/ml)를 나타내었다. 유산균수는 1.0$\times$$10^{5}$ , 1.3$\times$10s, 1.2$\times$$10^3$, 2.3$\times$ $10^3$, 2.1$\times$$10^4$(CFU/ml)이 었다. 또한, 초산균수는 1.8$\times$$10^{5}$ , 9.3$\times$$10^4$, 7.0$\times$$10^1$, 4.5$\times$$10^4$, 5.3$\times$$10^3$(CFU/ml)으로 계수되었다.

• 미생물학회지
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• 제50권1호
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• pp.73-83
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• 2014

단백질이 풍부한 식품을 고온 하에서 조리하는 과정 중에 주로 발생되는 돌연변이원 heterocyclic amines (HCAs)에 대한 유산균의 결합력 및 제거능을 조사하였다. 당 발효능 및 16S rRNA 염기서열 분석을 통해 동정된 19종의 유산균 중 Lactobacillus acidophilus D11, Enterococcus faecium D12, Pediococcus acidilactici D19, L. acidophilus D38, Lactobacillus sakei D44, Enterococcus faecalis D66 및 Lactobacillus plantarum D70의 세포이나 배양 상등액은 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1)과 3-amino-1-methyl-5Hpyrido[4,3-b] indole (Trp-P-2)에 의한 Salmonella typhimurium TA98 및 TA100의 돌연변이 유발을 억제할 수 있었다. HCAs에 대한 유산균 세포의 결합력은 cell wall, exopolysaccharide 및 peptidoglycan 보다 높게 나타났다. 한편, 이들의 결합력은 단백질 분해효소, 가열, sodium metaperiodate 및 산 처리에 의해 유의하게 감소되었으므로 세포벽에 존재하는 당이나 단백질 성분이 이들 HCAs을 결합시키는데 중요한 역할을 하는 것으로 확인되었다. 또한 E. faecium D12, L. acidophilus D38 및 E. faecalis D66의 결합력은 SDS나 금속이온에 의해 감소되었으므로 이들세포와 돌연변이원 사이에는 이온 결합이나 소수성 결합이 작용하는 것으로 추정되었다. 한편, HCAs 결합력이 높은 L. acidophilus D38과 L. plantarum D70은 장관 상피세포에 대한 부착력이 낮으므로 돌연변이원을 세포에 결합시켜 체외로 배출함으로써 독성물질을 제거하는데 효과적인 것으로 확인되었다.

• Applied Biological Chemistry
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• 제30권1호
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• pp.17-23
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• 1987

본 연구는 농축대두단백으로 만든 두유에 L-methionine을 여러가지 농도로 첨가하여 6종의 유산균 (Lactobacillus 4종, Leuconostoc 1종, Streptococcus 1종)의 생육과 산생성에 미치는 영향을 조사하고 아울러 DL-methionine, D-methionine 또는 L-cysteine이 L. acidophilus에 미치는 영향을 조사한 것으로서 그 결과를 요약하면 다음과 같다. 두유에 첨가된 L-methionine은 6종의 유산균 가운데 4종 (L. bulgaricus, L. casei, Leuconostoc mesenteroides, S. lactis)의 생육과 산생성에 거의 영향을 미치지 않았으나 L. acidophilus 2종의 산생성을 억제시켰으며, 같은 L. acidophilus 중에서도 KFCC 12731은 AKU 1122보다 더 큰 영향을 받는 것으로 나타났다. 두유에 첨가된 DL-methionine은 L-methionine과 동일하게 L. acidophilus(KFCC 12731)의 산생성을 현저하게 억제시켰으나, D-methionine은 높은 농도에서도 생육과 산생성에 전혀 영향을 미치지 않았다. 한편 L-cysteine에 의하여 L. acidophilus (KFCC 12731)의 산생성이 다소 억제되었으나 그 정도는 L-methionine이 비하여 매우 완만한 것이었다.

• 생약학회지
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• 제38권3호통권150호
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• pp.245-253
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• 2007

Artemisia princeps PAMPANINI has been used in traditional medicine of the treatment of inflammatory, liver dysfunction and order disorder in the far east countries including Korea. The present study was carried out to investigate the hepatoprotective effects of ethanol extract of Artemisia princeps (AP) and its fermented agents (AP-F) by lactic acid bacteria derived from human intestinal bacteria on liver injured rat induced by $CCl_4$ and d-galactosamine. Hepatoprotective activity was monitored by estimating serum ALT, AST, ALP, LDH, superoxide dismutase (SOD), glutathione redeuctase (GR) and glutathione peroxidase (Gpx) activities in the liver injured by hepatotoxin. Pretreating rats with AP or AP-F at the same dosage regimen significantly suppressed the acute elevation of serum transaminase, ALP, LDH and GR activities, and significantly increased the lowering of blood SOD and GR activites induced by hepatoxin. Based on these findings, it is presumed that AP and APF may have the hepatoprotective effect on $CCl_4$ and d-galactosamine-induced hepatotoxicity rat.

• Journal of Microbiology and Biotechnology
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• 제25권9호
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• pp.1510-1518
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• 2015

In this work, we wanted to develop a probiotic from famous longevity villages in Korea. We visited eight longevity villages in Korea to collect fecal samples from healthy adults who were aged above 80 years and had regular bowel movements, and isolated lactic-acid-producing bacteria from the samples. Isolated colonies that appeared on MRS agar containing bromophenol blue were identified by means of 16S rRNA sequencing, and 102 of the isolates were identified as lactic-acid-producing bacteria (18 species). Lactobacillus fermentum was the most frequently found species. Eight isolates were selected on the basis of their ability to inhibit the growth of six intestinal pathogens (Escherichia coli O157:H7, Salmonella enterica subsp. enterica Typhimurium, Salmonella enterica subsp. enterica Enteritidis, Enterococcus faecalis, Staphylococcus aureus, and Listeria monocytogenes) and their susceptibility to 15 antimicrobial agents. Among these eight isolates, four Lactobacillus fermentum isolates were found not to produce any harmful enzymes or metabolites. Among them, Lactobacillus fermentum isolate no. 24 showed the strongest binding to intestinal epithelial cells, the highest immune-enhancing activity, anti-inflammation activity, and anti-oxidation activity as well as the highest survival rates in the presence of artificial gastric juice and bile solution. This isolate, designated Lactobacillus fermentum PL9988, has all the characteristics for a good probiotic.

• 한국축산식품학회지
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• 제33권3호
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• pp.335-340
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• 2013

This study screened for radio-resistant strains lactic acid bacteria (LAB) by evaluating their capability to survive exposure to ionizing radiation. Ten strains of LAB - Lactobacillus bulgaricus, Lactobacillus paracasei, Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus delbruekii, Lactococcus lactis, Streptococcus thermophilus, Bifidobacterium breve, and Pediocuccos pentosaceus - were selected and subcultuted twice. The LAB was then further cultured for 3 d at $37^{\circ}C$ to reach 7-10 Log colony-forming units (CFU)/mL prior to irradiation and immediately exposed to gamma rays or electron beams with absorbed doses of 0, 1, 2, 3, 4, 5, 6, 8, and 10 kGy. Gamma irradiation gradually decreased the number of the tested viable LAB, and the effect was irradiation dose dependent. A similar effect was found in electron beam-irradiated LAB. Radiation sensitivity of LAB was calculated as $D_{10}$ values, which ranged from 0.26 kGy to 0.9 kGy and 0.5 kGy to 1.44 kGy with exposure to gamma and electron beam irradiation, respectively, in all tested LAB. L. acidophilus was the most resistant to gamma and electron beam irradiation, with $D_{10}$ values of 0.9 kGy and 1.44 kGy, respectively. These results suggest that L. acidophilus might be suitable for the preparation of probiotics as direct-fed microbes for astronauts in extreme space environments.

• Journal of Microbiology
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• 제44권4호
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• pp.439-446
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• 2006

In this study, the growth kinetics of Lactobacillus rhamnosus and lactic acid production in continuous culture were assessed at a range of dilution rates $(0.05 h^{-1}\;to\;0.40h^{-1})$ using a 2L stirred tank fermenter with a working volume of 600ml. Unstructured models, predicated on the Monod and Luedeking-Piret equations, were employed to simulate the growth of the bacterium, glucose consumption, and lactic acid production at different dilution rates in continuous cultures. The maximum specific growth rate of L. rhamnosus, ${\mu}_{max}$, was estimated at $0.40h^{-1}$I, and the Monod cell growth saturation constant, Ks, at approximately 0.25g/L. Maximum cell viability $(1.3{\times}10^{10}CFU/ml)$ was achieved in the dilution rate range of $D=0.28h^{-1}\;to\;0.35h^{-1}$. Both maximum viable cell yield and productivity were achieved at $D=0.35h^{-1}$. The continuous cultivation of L. rhamnosus at $D=0.35h^{-1}$ resulted in substantial improvements in cell productivity, of 267% (viable cell count) that achieved via batch cultivation.

• 한국축산식품학회지
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• 제30권3호
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• pp.443-448
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• 2010

유제품, 김치 및 신생아 분변 등에서 유산균을 분리하여 우유 casein을 분해시켜 배양상등액에 존재하는 serine의 함량을 측정함으로써 간접적으로 CPP 생산을 평가하였다. CPP 생산 능력은 OPA방법으로 측정했을 때 E. faecalis A-2 균주가 1.244 mg/mL로 가장 많은 peptide를 생산 하였다. 본 실험에 사용된 유산균의 경우, 세포내 효소와 세포외 효소로 각각 나누어 proteolytic 활성을 평가한 결과 세포내 효소에 의한 proteolytic 활성은 E. faecalis A-6 균주가 가장 높은 것으로 나타났으며, 세포외 효소에 의한 proteolytic 활성은 L. plantarum A-14 균주에서 가장 높게 나타났다. 가용성 칼슘함량은 Leuconostoc mesenteroides A-1(11 mg/dL), E. durans A-16(10.481 mg/dL), 그리고 L. planatarum A-3(10.356 mg/dL) 균주의 경우에는 대조구보다 높은 유리 칼슘함량을 나타내었다. 따라서 이러한 유산균을 이용한다면 소장 내에서 칼슘 흡수를 극대화시킬수 있는 장점이 있어 이들 유산균을 이용한 고칼슘 제품 개발이 가능할 것이다.

• 한국축산식품학회지
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• 제35권4호
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• pp.541-550
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• 2015

The purpose of this study was to investigate the effect of lactic acid bacteria (LAB) cell wall extract on the proliferation and cytokine production of immune cells to select suitable probiotics for space food. Ten strains of LAB (Lactobacillus bulgaricus, L. paracasei, L. casei, L. acidophilus, L. plantarum, L. delbruekii, Lactococcus lactis, Streptococcus thermophilus, Bifidobacterium breve, and Pedicoccus pentosaceus) were sub-cultured and further cultured for 3 d to reach 7-10 Log colony-forming units (CFU)/mL prior to cell wall extractions. All LAB cell wall extracts failed to inhibit the proliferation of BALB/c mouse splenocytes or mesenteric lymphocytes. Most LAB cell wall extracts except those of L. plantarum and L. delbrueckii induced the proliferation of both immune cells at tested concentrations. In addition, the production of T_H1 cytokine (IFN-γ) rather than that of T_H2 cytokine (IL-4) was enhanced by LAB cell wall extracts. Of ten LAB extracts, four (from L. acidophilus, L. bulgaricus, L. casei, and S. thermophiles) promoted both cell proliferating and T_H1 cytokine production. These results suggested that these LAB could be used as probiotics to maintain immunity and homeostasis for astronauts in extreme space environment and for general people in normal life.

• 한국미생물·생명공학회지
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• 제25권2호
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• pp.229-234
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• 1997

Shizandra chinensis(SC) and Pinus regida(PR) showed antimicrobial activity against 3 strains(B-5, D-1, A-1) of lactic acid bacteria(LAB) isolated from kimchi among eight kinds of plant extracts such as Shizandra chinensis, Phellodendron amurense, ornus officinalis, Pinus regida, Allium tuberosum, Machilus thunbergii, Cyperus rotundus and Schizonepeta tenuifloia. The growth of LAB was inhibited apparently in modified MRS broth containing 1% Schizandra chinensis at $35^{\circ}C$. Pinus regida showed weaker inhibitory effect on the growth of isolated LAB than Shizandra chinensis. pH of SC added kimchi did not change greatly compare with control during 25 days of fermentation. Degree of titratable acidity change and ratio of reducing sugar utilization in control were more higher than in SC added kimchi during fermentation. Growth of total bacteria and lactic acid bacteria was inhibited about 1 to 2 $log_10$ cycle by addition of SC extracts during kimchi fermentation for 10 days at $10^{\circ}C$. Fermentation of kimchi was delaved about 5 to 7 days by addition of 1 or 2% of SC. extract, but sensory quality (falvor, taste and overall acceptability) of SC added kimchi was lower than that of control (p>0.05).