• 한국축산식품학회지
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• 제36권4호
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• pp.499-507
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• 2016

In this study, traditional culture method and 16S rRNA gene analysis were applied to reveal the composition and diversity of lactic acid bacteria (LAB) of fermented cow milk, huruud and urum from Baotou and Bayannur of midwestern Inner Mongolia. Also, the quantitative results of dominant LAB species in three different types of dairy products from Baotou and Bayannur were gained by quantitative polymerase chain reaction (q-PCR) technology. Two hundred and two LAB strains isolated from sixty-six samples were identified and classified into four genera, namely Enterococcus, Lactococcus, Lactobacillus, Leuconostoc, and twenty-one species and subspecies. From these isolates, Lactococcus lactis subsp. lactis (32.18%), Lactobacillus plantarum (12.38%) and Leuconosto mesenteroides (11.39%) were considered as the dominated LAB species under the condition of cultivating in MRS and M17 medium. And the q-PCR results revealed that the number of dominant species varied from samples to samples and from region to region. This study clearly shows the composition and diversity of LAB existing in fermented cow milk, huruud and urum, which could be considered as valuable resources for LAB isolation and further probiotic selection.

• 한국축산식품학회지
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• 제40권3호
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• pp.362-376
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• 2020

Rabbit meat bekasam is a traditional fermentation product from Indonesia. This study aimed to determine the chemical and microbiological characteristics of rabbit meat bekasam during the fermentation process in order to isolate, characterize (in vitro and in vivo), and identify lactic acid bacteria (LAB) as the probiotic candidate. The chemical contents of bekasam on 7-day fermentation were investigated in explorative and experimental methods in a completely randomized design. A proximate analysis reported a decrease in the moisture content, fat and carbohydrate content, and an increase in protein content. Also, lactic acid content was increased from 0.48% to 1.12%, and pH was decreased from 5.3 to 4.3. Other properties indicated different values, such as bacteria (2.75×10⁶ to 4.45×10⁷ CFU/g), total LAB (3.82×10⁶ to 4.67×10⁸ CFU/g), total yeast (9.89×10⁶ to 3.82×10⁸ CFU/g) and total mould (4.34×10¹ to 4.86×10³ CFU/g). The experiment produced nine LAB isolates, including two probiotics subjected to further 16S rRNA gene analysis, which indicated that Lactobacillus buchneri was the potential probiotic isolate. After being tested on BALB/c mice, L. buchneri could improve the immune system by inhibiting the growth of Coliform and Salmonella.

• Journal of Microbiology and Biotechnology
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• 제28권10호
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• pp.1581-1588
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• 2018

The growth of lactic acid bacteria (LAB) generates a high number of metabolites related to aromas and flavors in fermented dairy foods. These microbial proteases are involved in protein hydrolysis that produces necessary peptides for their growth and releases different molecules of interest, like bioactive peptides, during their activity. Each genus in particular has its own proteolytic system to hydrolyze the necessary proteins to meet its requirements. This review aims to highlight the differences between the proteolytic systems of Streptococcus thermophilus and other lactic acid bacteria (Lactococcus and Lactobacillus) since they are microorganisms that are frequently used in combination with other LAB in the elaboration of fermented dairy products. Based on genetic studies and in vitro and in vivo tests, the proteolytic system of Streptococcus thermophilus has been divided into three parts: 1) a serine proteinase linked to the cellular wall that is activated in the absence of glutamine and methionine; 2) the transport of peptides and oligopeptides, which are integrated in both the Dpp system and the Ami system, respectively; according to this, it is worth mentioning that the Ami system is able to transport peptides with up to 23 amino acids while the Opp system of Lactococcus or Lactobacillus transports chains with less than 13 amino acids; and finally, 3) peptide hydrolysis by intracellular peptidases, including a group of three exclusive of S. thermophilus capable of releasing either aromatic amino acids or peptides with aromatic amino acids.

• Journal of Applied Biological Chemistry
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• 제60권4호
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• pp.391-402
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• 2017

Lactic acid bacteria (LAB) are widely used as starter culture in food fermentation due to their harmless entity and health beneficial properties along with the ability to change texture, aroma, flavor and acidity of food products. In this study, five different LAB (FB003, FB058, FB077, FB081, and FB111) isolated from different Korean traditional fermented foods, assigned to Lactobacillus plantarum, Pediococcus pentosaceus, Weissella viridescens, Lactobacillus sakei, and Leuconostoc mesenteroides, respectively, on the basis of their physiological properties and 16S rRNA sequence analysis, to use as fermentation starter and check their ability to fasten the ripening time as well as the overall optimization in the fermentation condition. To check their suitability as starters, their safety, acid and bile tolerance, NaCl and temperature resistance, susceptibility to common antibiotics, and antimicrobial activities were determined. Squid jeotgal samples were prepared by adding $10^8CFU/g$ of each strain in different samples, which were then kept for fermentation at $4^{\circ}C$ and checked for their antioxidant activities at 0, 7, 15, and 21-day intervals. The samples fermented with FB003 and FB077 displayed the highest antioxidant activity. This study revealed two effective starter cultures (FB003, FB077) for squid jeotgal fermentation, which presented increased functionalities. The results of this study will lead to the development of novel industrial-scale production avenues for jeotgal preparation, and offer new insights into the prevention and control of chronic diseases.

• 한국식품과학회지
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• 제27권1호
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• pp.101-104
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• 1995

유제품 30여종과 야채발효 제품 2종에서 Lactobacillus casei ssp.(5 strains), Lactobacillus acidophilus(2 strains), Lactobacillus delbrueckii ssp. bulgaricus(6 strains), Lactobacillus plantarum(3 strains), Streptococcus salivarius ssp. thermophilus(11 strains), and Streptococcus faecalis(2 strains)를 각각 분리하여 이들의 내산성과 담즙산 내성을 평가하였다. 초기생균수를 고려하여 공분산분석으로 내산성을 비교한 결과, L. casei에 속하는 균주들의 내산성이 가장 우수하였으며, L. bulgaricus와 균주들은 가장 낮은 내산성을 보였다(p<0.05). 담즙산 내성은 L. casei, L. plantarum, L. acidophilus, S. feacalis 균주들의 경우 비슷한 경향을 보였으나, L. bulgaridus와 S. thermophilus 그룹에 속하는 균주들의 담즙산 내성은 거의 없는 것으로 나타났다.

• 한국축산식품학회지
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• 제36권6호
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• pp.787-790
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• 2016

Kefir is a unique fermented dairy product produced by a mixture of lactic acid bacteria, acetic acid bacteria, and yeast. Here, we compared the antimicrobial spectra of four types of kefirs (A, L, M, and S) fermented for 24, 36, 48, or 72 h against eight food-borne pathogens. Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Enterococcus faecalis, Escherichia coli, Salmonella Enteritidis, Pseudomonas aeruginosa, and Cronobacter sakazakii were used as test strains, and antibacterial activity was investigated by the spot on lawn method. The spectra, potencies, and onsets of activity varied according to the type of kefir and the fermentation time. The broadest and strongest antimicrobial spectrum was obtained after at least 36-48 h of fermentation for all kefirs, although the traditional fermentation method of kefir is for 18-24 h at $25^{\circ}C$. For kefir A, B. cereus, E. coli, S. Enteritidis, P. aeruginosa, and C. sakazakii were inhibited, while B. cereus, S. aureus, E. coli, S. Enteritidis, P. aeruginosa, and C. sakazakii were inhibited to different extents by kefirs L, M, and S. Remarkably, S. aureus, S. Enteritidis, and C. sakazakii were only inhibited by kefirs L, M, and S, and L. monocytogenes by kefir M after fermentation for specific times, suggesting that the antimicrobial activity is attributable not only to a low pH but also to antimicrobial substances secreted during the fermentation.

• Archives of Pharmacal Research
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• 제27권1호
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• pp.61-67
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• 2004

When ginseng water extract was incubated at $60^{\circ}C$ in acidic conditions, its protopanaxadiol ginsenosides were transformed to ginsenoside $Rg_3$ and ${\Delta}^{20}$-ginsenoside $Rg_3$. However, protopanaxadiol glycoside ginsenosides $Rb_1, Rb_2$ and Rc isolated from ginseng were mostly not transformed to ginsenoside $Rg_3$ by the incubation in neutral condition. The transformation of these ginsenosides to ginsenoside $Rg_3$ and ${\Delta}^{20}$-ginsenoside $Rg_3$ was increased by increasing incubation temperature and time in acidic condition: the optimal incubation time and temperature for this transformation was 5 h and $60^{\circ}C$ resepectively. The transformed ginsenoside $Rg_3$ and ${\Delta}^{20}$-ginsenoside $Rg_3$ were metabolized to ginsenoside $Rh_2$ and $\Delta^{20}$--ginsenoside $Rh_2$, respectively, by human fecal microflora. Among the bacteria isolated from human fecal microflora, Bacteroides sp., and Bifidobacterium sp. and Fusobacterium sp. potently transformed ginsenoside $Rg_3$ to ginsenoside $Rh_2$. Acid-treated ginseng (AG) extract, fermented AG extract, ginsenoside $Rh_2$ and protopanaxadiol showed potent cytotoxicity against tumor cell lines. AG extract, fermented AG extract and protopanaxadiol potently inhibited the growth of Helicobacter pylori.

• 한국미생물·생명공학회지
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• 제47권3호
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• pp.359-363
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• 2019

국내 5개 지역에서 수집한 12개 메주로부터 Bacillus, Enterococcus, Staphylococcus 속 bacteria를 선택배지를 이용하여 분리하고, 16S ribosomal RNA 유전자 및 gmk(guanylate kinase) 유전자 염기서열분석을 통해 동정하여, 이들 속의 우점종을 검토하였다. Bacillus 속과 Enterococcus 속은 모든 시료로부터 검출되었고, Bacillus 속은 11개 시료에서 총균수 대비 15% 이상 검출되어 메주 발효에서 가장 우점하는 bacteria로 확인되었다. Staphylococcus 속은 6개 시료에서만 검출되었다. Bacillus 속으로 동정된 151개 분리주는 B. velezensis, B. sonorensis 순으로 우점하였고, B. subtilis, B. licheniformis가 그 뒤를 이었다. Enterococcus 속으로 동정된 165개 분리주 중, 163균주가 E. faecium으로 확인되었다. Staphylococcus 속으로 동정된 82개 분리주에는 6종의 coagulase-negative Staphylococcus 존재가 확인되었고, S. xylosus가 우점종으로 확인되었다.

• Journal of Microbiology and Biotechnology
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• 제33권8호
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• pp.1066-1075
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• 2023

Kimchi is a traditional Korean fermented vegetable that is stored and fermented at low temperatures. However, kimchi lactic acid bacteria (LAB) are typically isolated under mesophilic conditions, which may be inappropriate for isolating the diverse LAB. Therefore, this study investigated the suitable conditions for isolating various LAB from kimchi. Here, LAB were isolated from four kimchi samples using MRS, PES, and LBS media and varying isolation temperatures (30, 20, 10, and 5℃). Then, MRS was selected as the suitable medium for LAB isolation. A comparison of culture-dependent and culture-independent approaches indicated that 5℃ was not a suitable isolation temperature. Thus, the number and diversity of LAB were determined at 30, 20, and 10℃ using 12 additional kimchi samples to elucidate the effect of isolation temperature. With the exception of two samples, most samples did not substantially differ in LAB number. However, Leuconostoc gelidum, Leuconostoc gasicomitatum, Leuconostoc inhae, Dellaglioa algida, Companilactobacillus kimchiensis, Leuconostoc miyukkimchii, Leuconostoc holzapfelii, and Leuconostoc carnosum were isolated only at 10 and 20℃. The growth curves of these isolates, except Leu. holzapfelii and Leu. carnosum, showed poor growth at 30℃. This confirmed their psychrotrophic characteristics. In Weissella koreensis, which was isolated at all isolation temperatures, there was a difference in the fatty acid composition of membranes between strains that could grow well at 30℃ and those that could not. These findings can contribute to the isolation of more diverse psychrotrophic strains that were not well isolated under mesophilic temperatures.

• 한국조리학회지
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• 제21권6호
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• pp.218-228
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• 2015

본 연구는 오미자청을 쌀가루에 첨가해 sourdough를 제조하여 이화학적 특성을 살펴봄으로써 제빵 이용 가능성에 대한 기초 자료를 얻기 위해 시도되었다. 오미자청, 비발효 쌀가루, 쌀가루 sourdough의 pH와 총산도, 효모와 유산균수, 팽창률, 호화 특성을 살펴보았다. 쌀가루 sourdough의 pH는 발효 시간이 경과할수록 유의적(p<0.05)으로 감소하는 경향을 보인 반면, 총산도는 유의적으로 증가하였다(p<0.05). 효모, 유산균수는 발효시간이 경과함에 따라 유의적으로 증가하는 경향을 보였다(p<0.05). 오미자청 쌀가루 sourdough의 최고 팽창률은 80%, 쌀가루로만 발효시킨 쌀가루 sourdough의 최고 팽창률은 52%인 것으로 나타났다(p<0.05). RVA에 의한 오미자청 쌀가루 sourdough의 호화 특성은 발효시간이 경과할수록 최종점도와 setback 값이 감소한 것으로 보아, 오미자청 쌀가루 sourdough를 이용 시 노화 지연 효과가 있을 것으로 사료된다. 따라서 본 연구의 결과로 보아 오미자청을 쌀가루 sourdough 발효 시 첨가해 줄 경우, 풍부한 효모와 유산균으로 인해 보다 위생적으로 안전하게 sourdough 제조가 가능할 뿐 아니라, 팽창률이 높아 제빵 시 이용할 경우 쌀가루의 단점은 개선시킬 수 있을 것으로 기대된다.