• 한국미생물·생명공학회지
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• 제49권4호
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• pp.552-558
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• 2021

세계 각국의 민족은 자신의 국토의 삶과 기후 풍토, 지역 특산 산물과 식습관 및 식생활 등에 따라 색다른 전통식품이 만들어 진다. 한국은 오랫동안 농경을 중심으로 먹거리를 해오며 쌀과 함께 곁들일 채소류를 중심으로 조미료가 발달되었고, 염절임 기법을 통해 발효식품을 만들었다. 이러한 발효식품에서 주로 찾아볼 수 있는 종은 Lactobacillus sp.과 Pediococcus sp. 및 Bacillus sp. 등과 같은 유산균을 분리할 수 있었고 다양한 방법으로 동정 되어왔다. 본 연구에서는 시장에서 시판되고 있는 한국전통발효식품을 통해 유산균을 분리 및 동정하였고, 유해세균에 대한 항균능력이 우수한 균주를 선별하였다. 그리고 우수 후보 균주의 인공위액 및 담즙액에 대한 내성과 용혈능 등을 검토하여 최종 균주를 선별하였다. 최종 선별된 유산균은 3종의 prebiotics와 혼합한 synbiotics로서의 항균활성 능력을 평가하였다. 1차 항균 활성에서 C13은 인체 및 어류질병세균에서 가장 넓은 항균 스펙트럼을 보였고, β-haemolysis를 생산하지 않고 인공위액과 담즙액의 내성을 지닌 M1, K1 및 C13을 synbiotics의 2차 항균 활성을 수행하였다. Prebiotics 3종(FOS, GOS, Inulin)과 선별된 균주가 혼합된 synbiotics에서는 이전 보다 항균 활성이 증진 또는 저해됨을 알 수 있었다. 16 rDNA 염기서열 결과, K1과 M1은 Bacillus tequiensis 99.72%, Bacillus subtilis 99.65%, Bacillus inaquosorum 99.72%, Bacillus cabrialesii 99.72%, Bacillus stercoris 99.58%, Bacillus spizizenii 99.58%, Bacillus halotolerans 99.58%, Bacillus mojavensis 99.51%로 분석되었다. 그리고 C13은 Bacillus velezensis 99.71%, Bacillus nematocida 99.36%, Bacillus amyloliquefaciens 99.44%, Bacillus atrophaeus 99.22%, Bacillus nakamurai 99.44%로 분석되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제21권7호
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• pp.1027-1032
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• 2008

A study was conducted to evaluate the effects of dietary yeast derived ${\beta}$-glucan and single-strain probiotics on the growth performance and antibody response in broiler chicks. Six hundred and thirty 1-d-old male broiler chicks were divided into seven groups, placed into three pens per group (30 birds per pen) and fed one of seven non-medicated corn-SBM based experimental diets containing 0.025, 0.05 or 0.1% Saccharomyces cerevisiae ${\beta}$-glucan and 0.05, 0.1 or 0.2% Bacillus amyloliquefaciens (BA-pro, $1.3{\times}10^9/g$) or devoid of them for 5 wk. The body weight gains in groups fed diets containing 0.025 or 0.1% ${\beta}$-glucan, 0.1% or 0.2% BA-pro were significantly higher (p<0.05) than the control over 1-35 d. Feed conversion rates of groups fed ${\beta}$-glucan and BA-pro tended to be improved compared to the control group. There were no significant differences in the relative weights of liver, abdominal fat and breast muscle. No significant differences were observed in the activities of serum enzymes and concentrations of various cholesterol fractions. The antibody titers against Newcastle disease or infectious bronchitis virus in the chicks fed diets containing ${\beta}$-glucan and BA-pro were significantly higher (p<0.05) than in the control. The concentrations of cecal lactic acid bacteria in all groups fed BA-pro were significantly increased (p<0.05) compared to the control. These results indicated that dietary yeast derived ${\beta}$-glucan and BA-pro exerted growth-promoting and immune-enhancing effects in broiler chickens. In addition, BA-pro added to the diets modulated the profiles of cecal microflora, reflecting a potential to be beneficial microorganisms in chickens.

• 한국축산식품학회지
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• 제29권5호
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• pp.640-646
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• 2009

발효유제품, 김치, 및 신생아 분변 등에서 유산균을 분리하여 isoflavone 전환 능력을 평가하였다. 유산균 중 높은 수준의 $\beta$-glucosidase 활성을 보인 균주는 Enterococcus sp. 77, L. paracasei, Lactobacillus sp. 712, L. brevis ATCC 8287, Lactococcus sp. KU107, L. acidophilus KCNU, L. plantarum L155 등으로 나타났다. 이들 유산균에 대하여 유당 발효성을 평가하여 가장 우수한 유산균을 선발하여 API, 16S rDNA를 분석한 결과 Lactobacillus plantarum으로 동정되었으며 이 활성 유산균을 Lactobacillus plantarum YS712로 명명하였다. Lactobacillus plantarum YS712는 pH 2.5에서도 약 50% 이상의 강한 생존율을 보였으며 DPPH 라디칼 소거능도 95.8%로, 선발된 유산균 중 가장 높은 라디칼 소거능을 나타내었다. 이로써 Lactobacillus plantarum YS712는 발효식품 및 유제품에 다양하게 이용할 가치가 있다고 판단된다.

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.157-161
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• 2002

A lactic acid bacteria with ${\beta}$-gal activity was isolated from Kimchi, a traditional fermented vegetable food in Korea. The isolate was identified as a Lactococcus lactis strain and named L. lactis A2. The gene encoding ${\beta}$-gal of L. lactis A2 was cloned as a 5.8 kb PstI fragment. DNA sequencing identified the complete lacA (galactoside acetyltransferase)-lacZ (${\beta}$-galactosidase) genes together with the 3' part of upstream galT (galactose-1-phosphate uridyltransferase), and the 5'region of downstream galE (UDP-galactose-4-epimerase) genes. L. lactis A2 had the same gal/lac operon structure as in L. lactis subsp. lactis 7962. Other genes of the Leloir pathway are most likely to be located in the 5'upstream of the 5.8 kb fragment on the A2 chromosome. Sequences downstream of galE were different from those of L. lactis subsp. lactis 7962.

• Journal of Microbiology and Biotechnology
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• 제27권12호
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• pp.2094-2103
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• 2017

Aging is associated with distinct changes in immune cells and a decline in immune function, leading to increased susceptibility to infection and reduced responses to vaccination. Certain strains of lactic acid bacteria exert beneficial effects on the immune system. Previously, we reported that Weissella cibaria JW15 isolated from kimchi possesses immune stimulatory activity in vitro. In the present study, we further investigated whether oral administration of JW15 improves immune function in aged mice. Eighteen-month-old female mice were administered JW15 daily at low (JW15-L; $1{\times}10^8CFU/mouse$) or high dosage (JW15-H; $1{\times}10^9CFU/mouse$), or with Lactobacillus rhamnosus GG (LGG) using oral gavage. Two-month-old female mice were included as healthy young mice. After 4 weeks, the mice were euthanized and immune profiles were analyzed using whole blood and spleen. In complete blood count analysis, the numbers of white and red blood cells were significantly increased in the JW15-L group compared with those in the old mouse (OM) control group. In addition, administration of either JW15 of LGG resulted in higher numbers of splenocytes in comparison with the OM group. Furthermore, proliferative potentials were higher in all probiotic groups than OM. Cytokines such as IFN-${\gamma}$ and IL-6 were secreted at higher levels in splenocytes isolated from JW15-fed mice than in OM control mice. Similarly, mRNA expression of various cytokines was altered in the JW15 groups. Collectively, these results suggest that JW15 supplementation induces immunomodulatory effects in aged mice and indicate JW15 as a potential probiotic strain to improve immune function in aged animals.

• 한국축산식품학회지
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• 제35권4호
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• pp.551-556
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• 2015

The aim of this study was to evaluate the functional properties of lactic acid bacteria from various sources and to identify strains for use as probiotics. Ten Lactobacillus strains were selected and their properties such as bile tolerance, acid resistance, cholesterol assimilation activity, and adherence to HT-29 cells were assessed to determine their potential as probiotics. Lactobacillus sp. JNU 8829, L. casei MB3, L. sakei MA9, L. sakei CH8, and L. acidophilus M23 were found to show full tolerance to the 0.3% bile acid. All strains without L. acidophilus M23 were the most acid-tolerant strains. After incubating the strains at pH 2.5 for 2 h, their viability decreased by 3 Log cells. Some strains survived at pH 2.5 in the presence of pepsin and 0.3% bile acid. Lactobacillus sp. JNU 8829, L. acidophilus KU41, L. acidophilus M23, L. fermentum NS2, L. plantarum M13, and L. plantarum NS3 were found to reduce cholesterol levels by ＞50% in vitro. In the adhesion assay, Lactobacillus sp. JNU 8829, L. casei MB3, L. sakei MA9, and L. sakei CH8 showed higher adhesion activities after 2 h of co-incubation with the intestinal cells. The results of this comprehensive analysis shows that this new probiotic strain named, Lactobacillus sp. JNU 8829 could be a promising candidate for dairy products.

• Applied Biological Chemistry
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• 제10권
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• pp.33-38
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• 1968

(1) 숙성(熟成)된 김치로부터 강(强)한 산생성능(酸生成能)과 내열성(耐熱性)을 갖인 유산균(乳酸菌)을 분리(分離)하고 Lactobacillus plantarum으로 동정(同定)하였다. (2) 내열성(耐熱性) 유산균(乳酸菌) L.plantarum k-3 균주(菌株)에 대(對)한 열저항성(熱抵抗性)을 관찰(觀察)하였고 $60^{\circ}C$에서의 가열치사곡선(加熱致死曲線)으로부터 D=3의 값을 얻었다. (3) 김치통조림 제조시 내용물(內容物)의 양(量) 살균온도(殺菌溫度) 및 김치의 숙성도(熟成度)가 열전도(熱傳導)에 미치는 영향을 조사하였으며 (4) 김치통조림의 완전(完全) 살균시간(殺菌時間)을 산정(算定)하였으며 그시간은 살균온도(殺菌溫度) $85^{\circ}C$에서 25.2분(分)이 있다. (5) 식품(食品) 방부제(防腐劑)로 Sudium sorbate와 p-hydroxybutyl benzoate를 사용(使用)하여 김치통조림을 제조하였다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.296-303
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• 2005

A strain named as HJ35 was isolated from the skin of sixty-five men and fourteen women for acne therapy, in order to find an effective antimicrobial agent against Propionibacterium acnes. Isolate HJ35 was identified as Enterococcus faecium based on 16 rDNA sequence and produced enterocin HJ35 having antimicrobial activities against most lactic acid bacteria, En­terococcus spp., Staphylococcus aureus, S. epidermidis, Clostridium perfringens, some bacilli, Mi­crococcus flavus, Listeria monocytogenes, L. ivanovii, Escherichia coli, Pseudomonas fluorescens and Propionibacterium acnes, in the modified well diffusion method. Especially, enterocin HJ35 showed a bactericidal activity against Propionibacterium acnes P1. The antimicrobial activity of enterocin HJ35 was disappeared completely with the use of protease XIV. But enterocin HJ35 activity is very stable at high temperature (up to $100^{\circ}C$ for 30 min), in wide range of pH (3.0${\~}$9.0), and by treatment with organic solvents. The apparent molecular mass of enterocin HJ35 was estimated to be approximately 4${\~}$4.5 kDa on detection of its bactericidal activity after SDS-PAGE. In batch fermentation of E. faecium HJ35, enterocin HJ35 was produced at the mid­log growth phase, and its maximum production was obtained up to 2,300 AU/mL at the late stationary phase. By employing fed-batch fermentation, the enhanced production of enterocin HJ35 was achieved up to 12,800 AU/mL by feeding with 10 g/L glucose or 6 g/L lactate.

• 한국축산식품학회지
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• 제33권5호
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• pp.565-571
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• 2013

An enzyme ${\beta}$-galactosidase or ${\beta}$-galactohydrolase [EC3.2.1.23], commonly called lactase, mediates galacto-oligosaccharide (GOS) synthesis under conditions of high substrate concentrations. Also, lactase hydrolyzes ${\beta}$($1{\rightarrow}4$) lactose into glucose and galactose, the latter is successively transferred to free lactose to make various oligosaccharides via transgalactosylation. GOS is non-digestible to human digestive enzymes and has been used as a functional prebiotics. Among the 24 lactic acid bacteria (LAB) strains used, Lactobacillus paracasei YSM0308 was selected based on its exhibition of the highest ${\beta}$-galactoside hydrolysis activity, and the crude lactase was prepared for examination of reaction conditions to affect the GOS synthesis. Lactase activity was measured with a spectrophotometer using ONPG (o-nitropheyl ${\beta}$-D-galactopyranoside) method. Lactase activity was not detected in the culture supernatant and was mostly present in the cell pellet after centrifugation. Activity of the crude lactase preparation ranges from102 to 1,053 units/mL, with the highest activity determined for L. paracasei YSM0308. Optimal conditions for GOS synthesis are as follows: concentration of whey powder, pH, temperature, and time were 30%, pH 6.5-7.0, $30^{\circ}C$, and 4 h, respectively. The final GOS concentration was 19.41% (w/v) by the crude YSM0308 lactase, which was obtained from strain YSM0308 grown in the 10% (w/v) reconstituted whey-based medium.

• Journal of Microbiology and Biotechnology
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• 제19권8호
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• pp.810-817
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• 2009

The effect of cryoprotectants (maltodextrin+glycerol) and cryoprotectants+antioxidant [ascorbic acid and/or butylated hydroxytoluene (BHT)] mixtures on the survival, electrolyte leakage, and lipid degradation of freeze-dried Weissella paramesenteroides LC11 during storage was investigated and compared with that of the control (cells without additives) over a 90-day storage period at 4 or $20^{\circ}C$ in glass tubes with water activity ($a_w$) of 0.23. The survival, electrolyte leakage, and lipid degradation were evaluated through colony counts, electrical conductivity, and thiobarbituric acid reactive substances (TBARS) content, respectively. The fatty acids composition was determined by gas chromatography, in both the total lipid extract and the polar lipid fraction, and compared with that of the control after the 90-day storage period. As the storage proceeded, increases in leakage value and TBARS content, as well as a decrease in viability, were observed. After 90 days of storage, the major fatty acids found in both the total lipid extract and the polar lipid fraction were palmitic (16:0), palmitoleic (16:1), stearic (18:0), oleic (18:1), linoleic (18:2), and linolenic (18:3) acids. The survival, leakage value, TBARS content and 18:2/16:0 or 18:3/16:0 ratio were the greatest for the protected strain held at $4^{\circ}C$. Cells with the cryoprotectants+BHT mixture showed the highest percentage of survival and 18:2/16:0 or 18:3/16:0 ratio in both lipid extracts, as well as the lowest leakage value and TBARS content after the 90-day storage period. Drying cells with the cryoprotectants+BHT mixture considerably slowed down polar lipid degradation and loss of membrane integrity, resulting in improved viability during storage.