• 한국미생물·생명공학회지
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• 제24권4호
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• pp.393-398
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• 1996

In order to develop a lactic acid bacterial powder which can be used as a probiotic for human and animal, a lactic acid bacteria which has high resistance against low pH and ox-gall, and shows a good growth inhibition against E. coli, was isolated from an animal intestine and characterized. The isolated strain was identified as Enterococcus faecium. It had more than 90% of survival at low pH for 2 hours and almost 100% of survival in the presence of 0.3% ox-gall. When co-cultured with E. coli in MRS broth, all of the E. coli cells were killed within 24 hours. The final powdered product of the isolated strain was manufactured after a freeze drying process using an industrial media, and then checked its stability. Its storage stability was 80% for 11 months at 18$\circ$C.

• Journal of Microbiology and Biotechnology
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• 제23권1호
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• pp.40-46
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• 2013

A variety of nuruk were collected from various provinces in Korea, and their microflora profiles were analyzed at the species level. A total of 42 nuruk samples were collected and when the viable cell numbers in these nuruk were enumerated, the average cell numbers of bacteria, fungi, yeast, and lactic acid bacteria from all nuruk were 7.21, 7.91, 3.49, and 4.88 log CFU/10 g, respectively. There were no significant differences in viable cell numbers of bacteria or fungi according to regions collected. Bacillus amyloliquefaciens and B. subtilis were the predominant bacterial strains in most samples. A significant portion, 13 out of 42 nuruk, contained foodborne pathogens such as B. cereus or Cronobacter sakazakii. There were various species of lactic acid bacteria such as Enterococcus faecium and Pediococcus pentosaceus in nuruk. It was unexpectedly found that only 13 among the 42 nuruk samples contained Aspergillus oryzae, the representative saccharifying fungi in makgeolli, whereas a fungi Lichtheimia corymbifera was widely distributed in nuruk. It was also found that Pichia jadinii was the predominant yeast strain in most nuruk, but the representative alcohol fermentation strain, Saccharomyces cerevisiae, was isolated from only 18 out of the 42 nuruk. These results suggested that a variety of species of fungi and yeast were distributed in nuruk and involved in the fermentation of makgeolli. In this study, a total of 64 bacterial species, 39 fugal species, and 15 yeast species were identified from nuruk. Among these strains, 37 bacterial species, 20 fungal species, and 8 yeast species were distributed less than 0.1%.

• 한국미생물·생명공학회지
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• 제47권2호
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• pp.183-194
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• 2019

The consumption of fresh vegetables has been related to recurrent outbreaks of foodborne diseases (FBD) worldwide. Therefore, the development of effective alternative technologies is necessary to improve the safety of these products. This study aimed to isolate and identify epiphytic lactic acid bacteria (LAB) from fresh fruits and leafy vegetables and characterize their antagonistic capacity due to their ability to produce bacteriocins or antibacterial compounds. For this, 92 LAB isolates from fruits and leafy vegetables were screened for antagonistic activity. Two strains with the highest and broadest antagonistic activities were selected for further characterization; one from cantaloupe melon (strain CM175) and one from cilantro leaves (strain C15). The cell-free supernatants (CFS) of CM175 and C15 were found to exhibit antagonistic activity against FBD-causing pathogens. The CM175 and C15 strains were identified as Pediococcus pentosaceus and Lactobacillus graminis, respectively. Notably, the P. pentosaceus CM175 CFS stopped the growth of Salmonella Typhimurium, Salmonella Saintpaul, Staphylococcus aureus, and Listeria monocytogenes, and delayed Escherichia coli O157:H7 growth. Moreover, L. graminis C15 CFS delayed the growth of all indicator pathogens, but did not completely stop it. Organic acids and bacteriocin-like molecules were determined to be possibly exerting the observed antagonistic activity of the identified LAB strains. Thus, application of the antagonistic compounds produced by Pediococcus pentosaceus and Lactobacillus graminis could be a novel and ecological strategy in developing antimicrobial biopreservatives for the food industry and mitigating FBD by reducing the biological contamination in fruit and vegetable orchards, mainly via their potential in controlling both gram-negative and gram-positive pathogenic bacteria.

• 미생물학회지
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• 제52권4호
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• pp.471-481
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• 2016

본 연구에서는 묵은지로부터 분리된 박테리오신을 생산하는 이상발효 유산균 및 내산성 효모가 사워도우의 저장 기간 연장과 품질 개선에 미치는 영향을 조사하였다. 유전자 염기서열 분석 결과 빵 부패세균인 Bacillus 속에 대한 항균활성을 나타낸 이상발효 유산균은 Leuconostoc mesenteroides LAS112, Lactobacillus brevis LAS129 및 L. mesenteroides subsp. dextranicum LAB137으로 동정되었고, 산성 pH 하에서 증식 가능한 효모는 Pichia membranifaciens YS05, Pichia fermentans YS19 및 Pichia anomala YS26으로 확인되었다. 사워도우 발효에 사용된 L. brevis LAS129는 L. mesenteroides LAS112 및 L. mesenteroides subsp. dextranicum LAS 137 보다 더많은 양의 초산과 박테리오신 활성을 나타내었으나, LAS112는 가장 많은 양의 유산을 생산하였다. Bacillus subtilis ATCC 35421에 대한 최대의 박테리오신 활성(640 AU/g)은 L. brevis LAS129와 P. membranifaciens YS05 혹은 P. anomala YS26으로 혼합 발효시킨 사워도우 내에서 관찰되었다. $30^{\circ}C$에서 24시간 발효 후 사워도우 내 LAS129의 균수($10^9CFU/g$)는 YS05 혹은 YS26의 효모 균수($10^7CFU/g$)보다 높게 검출되었다. 한편, 이들 균주들을 이용하여 발효시킨 사워도우 내에 존재하는 빵 부패균의 균수는 대조구 보다 유의하게(P < 0.05) 낮은 수준으로 나타났다.

• KSBB Journal
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• 제24권3호
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• pp.273-278
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• 2009

본 연구는 김치에서 분리한 Lactobacillus plantarum YK-9의 다양한 특성을 조사하기 위하여 실시되었다. 형태학적 관찰 및 생리화학적 특성에 대하여 조사하였다. 16S rRNA 염기서열 분석을 통해 균주를 동정하였고, 그 결과 Lactobacillus plantarum로 확인되었고, L. plantarum YK-9으로 명명하였으며, 이 균주는 GenBank에 [FJ669130]로 등재하였다. 배양 시간에 따른 L. plantarum YK-9의 생장과 pH의 변화를 조사하였으며, 대사산물로서 유기산 (lactic acid와 acetic acid)의 생성은 HPLC를 통하여 확인하였다. 유기산의 생성은 L. plantarum YK-9의 생장에 따라 증가 하는 것을 확인하였다. 초기 pH 7.0은 배양 기간동안 3.6으로 감소하였고, 배양 72시간이 지난 후 생성된 lactic acid와 acetic acid의 농도는 각각 588.7 mM과 255.5 mM이었다. 식중독 원인균인 S. aureus, B. cereus, L. monocytogenes, E. coli, E. faecalis, S. enteritidis에 대하여 20배로 농축된 YK-9 배양 상등액에 처리하여 항균력을 조사하였으며, 실험에 사용된 6가지 식중독 원인세균 모두에 대한 항균효과가 있는 것이 관찰되었고, 이는 유기산 생성에 기인하는 것으로 나타났다.

• Journal of Dairy Science and Biotechnology
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• 제22권2호
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• pp.99-106
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• 2004

포자형성 유산균주에 대하여 종양세포에 대한 증식 억제 활성과 항산화 활성 및 세포내 glutathione 함유율을 측정하였다. 종양세포에 대한 억제활성은 균주에 따라 큰 차이를 나타내었고 Bacillus coagulans KTCC 3675는 높은 수준의 특이한 수준의 억제 활성을 나타내었고 human lymphoma cell NCLH-1299에 대한 억제 활성은 미약한 수준인 것으로 확인되었다. TBA 방법에 의한 linoleic acid에 대한 항산화 활성은 5~25% 정도의 항산화 활성을 보였고 특별히 높은 수준의 항산화 활성을 보인균주는 Bacillus coagulans KTCC 625, Bacillus coagulans KTCC 1015 및 Lactobacillus sporogens CU 815인 것으로 확인되었다. 포자형성 유산균체 추출액의 linoleic acid과산화 억제 활성과 세포내 glutathione함유율과의 상관계수는 0.78로서 고도의 유의성이 인정되는 상관계수를 나타내었다.

• 한국식품영양과학회지
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• 제27권6호
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• pp.1065-1070
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• 1998

Lactic acid bacteria KL 1, KD 6, KL 4 strains isolated from kimchi, or obtained Lactobacillus acidophilus, Lactobacillus plantarum, Leuconostoc mesenteroides with and without yeast(Saccharomyces cerevisiae) were inoculated in fruit vegetable juice for mixed culture fermentation 3 days at 3$0^{\circ}C$, and then their chemical changes were studied during fermentation. The amount of organic acid produced by the mixed culture fermentation of KL 1 and yeast was 0.82%(3 days) or 0.58%(1 day) and with the final pH of 3.3(3 days) or 4.2(1 day). These mixed culture systems of isolated strains or other bacterial strains had almost similar results of growth rate and acid production. The contents of vitamin C and carotene were retained and stabilized as 70~80% level of their initial values after 24 hrs fermentation. And also ethanol was produced as of the range in 9.6mg%(W/V) by the mixed culture fermentation of KL 1 and yeast, however, the content of ethanol in single culture fermentation by KL 1 strain was much lower than that of mixed culture. The major components of organic acids in fermented juice by mixed culture were considered as malic(26.0%), lactic(49.9%), succinic and citric acid, whereas these of unfermented juice were malic(53.2%), citric and other acids. On other hand, reducing sugar was decreased from 18.3mg/ml in fresh juice to about 12mg/ml in juice by mixed culture fermentation. Concentrations of fructose, glucose and sucrose were also greatly reduced in fermented juice.

• 한국초지조사료학회지
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• 제40권3호
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• pp.182-189
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• 2020

This study was conducted to evaluate the effect of lactic acid bacteria (LAB) inoculation to domestically-cultivated Italian ryegrass (IRG) on silage fermentation and in vitro ruminal fermentation. There were six treatments based on the LAB inoculants: 1) no addition of LAB (negative control: NC), additions of 2) commercially-available LAB (positive control: PC), 3) Lactobacillus plantarum (LPL), 4) L. paracasei (LPA), 5) L. acidophilus (LA), and 6) L. pentosus (LPT). All treatments were inoculated at a concentration of 10⁶ CFU/g and ensiled for 3, 7, 21, and 42 days in triplicate and analyzed for nutritive values when ensiling was terminated. Day 42 silage from all treatments were also examined for in vitro ruminal fermentation. After 42 days, LAB-inoculated silages had higher (P<0.05) lactic acid concentration compared to the NC. In terms of nutritive values, the silages treated with LPA, LA, and LPT showed higher (P<0.05) crude protein and lower (P<0.05) neutral detergent fiber and acid detergent fiber content compared to the rest of the treatment. In vitro ruminal dry matter degradability was not affected by LAB addition. However, LAB-treated IRG had shown higher (P<0.05) ammonia-N compared with that of the NC. LPA had shown the highest (P<0.05) volatile fatty acid concentration among the LAB examined. In conclusion, the addition of a single strain of LAB appeared to produce a quality IRG silage compared with the NC and the PC. Among the strains examined, LPA seemed to be superior to the others.

• Preventive Nutrition and Food Science
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• 제9권2호
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• pp.113-120
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• 2004

Selected microbiological and biochemical characteristics of the steeping process for the production of yukwa, a traditional Korean oil-puffed snack made of waxy rice, were investigated during steeping of waxy rice in water for 15 days. The lengthy steeping process was largely predominated by lactic acid bacteria (LAB), particularly, Lactobacillus and Leuconostoc. The predominat type of bacterium isolated was the Y26 strain tentatively identified as Lactobacillus plantarum. The titratable acidity of the steeping medium increased from 0.01 to 1.13%, in parallel with the decrease in pH ranging from 6.3 to 4.2 as the steeping period increased from 0 to 15 days. A high amount of lactic acid and to a much lesser extent, butyric acid, acetic acid, propionic acid, and succinic acid were detected during the steeping process. The amount of reducing sugars in the steeping medium increased from 0.61 to 10.43 mg/mL, whereas sucrose decreased from 0.46 mg% to an undetectable level. Starch degradation products including glucose, maltose and oligosaccharides ranging G3-G7 were not initially noticed, but their content increased during the steeping process until completion. However, no oligosaccharides larger than G8 were detected in the steeping medium. The activities of $\alpha$-amylase, $\beta$-amylase and protease in the steeping medium of waxy rice tended to rise increase with time during the steeping process. From these results, the lengthy steeping process in yukwa production can be characterized as the spontaneous fermentation, dominated by lactic acid bacteria, which is a necessary process for inducing biochemical modification of waxy rice.

• 한국식품과학회지
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• 제10권3호
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• pp.337-343
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• 1978

우유(牛乳)의 이용도(利用度)를 다양화하기 위하여 새로운 발효유(醱酵乳)를 개발(開發)할 목적(目的)으로 몇가지 기초실험(基礎實驗)을 실시(實施)하고 알코올함량 및 산도(酸度)를 달리하여 8종(種)의 알코올발효유(醱酵乳)를 제조(製造)하고 관태검사(官態檢査)를 실시(實施)하였던 바 그 결과를 요약하면 다음과 같다. 1. 유산균(乳酸菌)은 4종(種)을 분리(分離)했고 그중 Y-2균주(菌株)가 산생성도(酸生成度)가 우수했고 모든 균주(菌株)는 우유배지보다 합성배지에서 산 생성도가 높았다. 2. 우유배지(牛乳培地)에 Y-2균주(菌株)를 접종(接種)하고 $30^{\circ}C$ 24시간(時間) 배양(培養)하면 pH는 6.2에서 5.2로 하강되며 배양중(培養中) Amino-N의 함량은 증감하였다. 3. K. fragilis 균주(菌株)를 우유배지에 접종(接種)하고 $30^{\circ}C$ 7일간(日間) 배양(培養)하면 pH는 6.2에서 5.2로 하강되며 Amino-N의 함량은 $0.12{\sim}0.27mg/ml$의 분포(分布)를 나타냈다. K. fragilis균주는 E-2, E-4 균주에 비해 알코올생성도(生成度)가 높았으며 각 균주(菌株)의 알코올생성도(生成度)는 우유배지(牛乳培地)와 합성배지(合成培地)에서 별 차이가 없었다. 4. 효모(酵母)를 접종배양(接種培養) 후 유산균(乳酸菌)을 접종(接種)하면 유산균(乳酸菌)의 증식(增殖) 및 산생성도(酸生成度)는 억제된다. 5. 효모와 유산균(乳酸菌)을 동시에 접종배양(接種培養)하면 일단 유산균의 산생성(酸生成)이 완료된후 알코올 생성(生成)이 급격히 증가되었다. 6. 관능검사를 실시한 결과 알코올 1% 산(酸) 0.8%의 제품(製品)이 가장 기호도가 좋았다. 7. 일반분석(一般分析) 결과 최종제품(最終製品)의 성분(成分)은 회분, 단백질, 수분함량에서 우유쿠머스와 비슷하였다.