• 생명과학회지
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• 제26권6호
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• pp.689-697
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• 2016

Kefir는 약한 신맛과 백색의 끈적한 특징을 가지는 산성-알코올성 발효유제품이다. Kefir는 오랫동안 probiotic 미생물로 면역조절 효과를 포함한 건강에 도움이 되는 발효유로 알려져 왔다. 본 연구는 Kefir grain를 이용한 유청발효액의 발효특성과 pro-inflammatory cytokine의 발현과 분비에 미치는 영향을 in vitro 실험을 통하여 조사하기 위해 수행했다. Kefir grain를 이용한 유청발효액의 유산균수와 효모수는 발효 16시간에 최고 수준인 1.83×10⁸ CFU/ml, 6.5×10⁵ CFU/ml로 나타났다. 또한 유당과 유청단백질은 부분적으로 가수분해되었다. Human mast cell (HMC)-1을 이용하여 in vitro에서 조사한 항염증 효과는 8, 16, 24시간 동안 발효한 유청발효액에서 pro-inflammatory cytokine인 interleukin (IL)-4가 발현되었으나 48시간 유청발효액에서는 발현되지 않았다. 또한 IL-8도 8, 16, 24시간 동안 발효한 유청발효액에서 발현되었으나 48시간 유청발효액에서는 발현되지 않았다. 이러한 cytokine들의 분비는 IL-4는 8, 16, 24시간 동안 발효한 유청발효액에서는 20-25 ng 정도였으나 48시간 유청발효액에서는 5 ng 정도로 낮았다. IL-8은 8, 16, 24시간 발효한 유청발효액에서는 15-20 ng 분비되었으나 48시간 유청발효액에서는 8 ng 정도로 낮았다. 이와 같이 Kefir grains을 이용한 유청발효액은 항염증 기능이 있어 기능성 식품소재와 의약품 소재로 응용할 수 있을 것으로 판단된다.

• Journal of Dairy Science and Biotechnology
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• 제34권1호
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• pp.9-20
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• 2016

Various microflora, including lactic acid bacteria, are important and necessary components of various cheeses and have significant roles in cheese manufacturing and ripening. In general, the starter culture and secondary microflora could affect the physicochemical properties of various cheeses and could contribute to modifications during manufacturing and ripening. Therefore, during cheese manufacturing and ripening, microbial diversity may depend on continuous interactions among microflora and various environmental conditions. The microbial diversity of cheese is very complex and difficult to control using the classical microbiological techniques. However, recent culture-independent methods have been rapidly developed for microflora in cheese, which could be directly detected using DNA (and/or RNA) in combination with culture-dependent methods. Therefore, this review summarizes state-of-the-art molecular methods to analyze microbial communities in order to understand the properties that affect quality and ripening as well as the complex microbial diversity of various raw-milk, long-ripened cheeses.

• 한국축산식품학회지
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• 제35권1호
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• pp.91-100
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• 2015

The present study was conducted to screen candidate probiotic strains for anti-inflammatory activity. Initially, a nitric oxide (NO) assay was used to test selected candidate probiotic strains for anti-inflammatory activity in cultures of the murine macrophage cell line, RAW 264.7. Then, the in vitro probiotic properties of the strains, including bile tolerance, acid resistance, and growth in skim milk media, were investigated. We also performed an in vitro hydrophobicity test and an intestinal adhesion assay using Caenorhabditis elegans as a surrogate in vivo model. From our screening, we obtained 4 probiotic candidate lactic acid bacteria (LAB) strains based on their anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cell cultures and the results of the in vitro and in vivo probiotic property assessments. Molecular characterization using 16S rDNA sequencing analysis identified the 4 LAB strains as Lactobacillus plantarum. The selected L. plantarum strains (CAU1054, CAU1055, CAU1064, and CAU1106) were found to possess desirable in vitro and in vivo probiotic properties, and these strains are good candidates for further investigations in animal models and human clinical studies to elucidate the mechanisms underlying their anti-inflammatory activities.

• Journal of Dairy Science and Biotechnology
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• 제31권2호
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• pp.153-159
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• 2013

유아 분변, 우분, 염소 분변, 개 분변, 돼지 분변, vaginal tract 채취물, 채소류, 부패한 과일류, 김치, 젓갈, 발효 소세지, 원유, 치즈, 발효유, 청국장, 메주, 막걸리 등 다양한 시료로부터 3,000주의 미생물을 분리하였다. 분리미생물은 L. monocytogenes, E. coli O157:H7, S. enterica serovar Enteritidis에 대해 항균활성을 측정하여 박테리오신 생산 미생물 26주를 최종 선발하였다. 16S rDNA gene sequencing 분석을 통하여 동정한 결과, Enterococcus faecalis(7주), E. faecium(8주), E. hirae(5주), Lactobacillus acidophilus(1주), L. amylovorus(1주), L. curvatus(2주), L. plantarum(1주), Pediococcus acidilactici(1주)와 같이 8종의 미생물이 박테리오신을 생산하는 것으로 확인되었다. 미생물이 생산한 박테리오신은 대부분이 단백질 또는 펩타이드성 물질이어서 인간 또는 동물의 소화효소에 의해 분해되므로 식품에서 안전한 천연보존제로 사용할 수 있을 것으로 기대된다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권3호
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• pp.402-413
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• 2001

Food safety is a term broadly applied to food quality that may adversely affect human health. These include zoonotic diseases and acute and chronic effects of ingesting natural and human-made xenobiotics. There are two major areas of concern over the presence of residues of antibiotics in animal-derived foodstuffs with regard to human health. The first is allergic reactions. Some antibiotics, such as penicillins can evoke allergic reactions even though small amounts of them are ingested or exposed by parenteral routes. The second is development of antibiotic resistance in gut bacteria of human. Recently multi-resistant pneumococcal, glycopeptide-resistant enterococci and gram negative bacteria with extended-spectrum $\beta$-lactamases have spread all over the world, and are now a serious therapeutic problem in human. Although it is evident that drugs are required in the efficient production of meat, milk and eggs, their indiscriminate use should never be substituted for hygienic management of farm. Drug should be used only when they are required. In addition to veterinary drugs, environmental contaminants that were contaminated in feed, water and air can make residues in animal products. Mycotoxins, heavy metals, pesticides, herbicides and other chemicals derived from industries can be harmful both to animal and human health. Most of organic contaminants, such as dioxin, PCBs and DDT, and metals are persistent in environment and biological organisms and can be accumulated in fat and hard tissues. Some of them are suspected to have endocrine disrupting, carcinogenic, teratogenic, immunodepressive and nervous effects. The governmental agencies concerned make efforts to prevent residue problems; approval of drugs including withdrawal times of each preparation of drugs, establishment of tolerances, guidelines regarding drug use and sanitation enforcement of livestock products. National residue program is conducted to audit the status of the chemical residues in foods. Recently HACCP has been introduced to promote food safety from farm to table by reducing hazardous biological, chemical and physical factors. Animal Production Food Safety Program, Quality Assurance Programs, Food Animal Residue Avoidance Databank are para- or non-governmental activities ensuring food safety. This topic will cover classification and usage or sources of chemical residues, their adverse effects, and chemical residue status of some countries. Issues are expanded to residue detection methodologies, toxicological and pharmacokinetic backgrounds of MRL and withdrawal time establishments, and the importance of non-governmental activities with regard to reducing chemical residues in food.

• 한국축산식품학회지
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• 제32권5호
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• pp.635-643
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• 2012

As an appraisal for the application of a new starter culture, more than 200 lactic acid bacteria strains were isolated from raw milk and healthy human feces. The strains showing excellent growth and acid production ability in 10% skim milk media were selected and identified as Lactobacillus casei based on the results of their API carbohydrate fermentation patterns, as well as 16S rDNA sequence analysis. To assess the effect of L. casei strains on irritable bowel disease (IBD), the inhibitory effect of the selected strains against the nitric oxide (NO) production of lipopolysaccharide (LPS)-stimulated RAW 264.7 cells was measured. Among the tested L. casei strains, L. casei MCL was observed to have the greatest NO inhibitory activity. Additionally, L. casei MCL was found to inhibit mRNA expression of pro-inflammatory cytokines (interleukin-$1{\beta}$, IL-6, TNF-${\alpha}$), as well as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) involved in pathophysiologic processes such as inflammation. The mRNA expression of anti-inflammatory cytokines, including IL-10 and transforming growth factor-$1{\beta}$ (TGF-${\beta}$) of L. casei MCL, was confirmed using quantitative real-time PCR. In conclusion, L. casei MCL showed decreases in the expression of pro-inflammatory cytokines and up-regulated expression of the anti-inflammatory cytokine.

• 한국미생물·생명공학회지
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• 제29권3호
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• pp.162-168
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• 2001

분변과 요구르트에서 10주의 젖산균을 분리하여 이중 6주는 Bifidobactria로 4주는 Lactobacilli로 동정하였다. 이들은 이용하여 8% 증숙밤용액을 발효시켰을 때 발효액의 산도는 요구르트보다는 낮았으나 두유를 비롯한 식물성 요구르트보다는 2배이상 높았다. 산도를 증가시키기 위해 Yeast extract 와 tryptone peptone를 첨가할 때 0.2%와 0.4%의농도에서 가장 높았다. 포도당을 0.5-0.8% 범위의 첨가하였을 때 lactobacilli에 의한 발효액에서는 산생성이 촉진되었으나. bifidobacteria 에서는 그렇지 않았다. 시험된 과일과 채소즙 중에서는 당근즙의 첨가가 가장 큰 촉진 효과를 나타내었다. 25% 밤용액에서는 고지추출액에 의한 가수분해는 젖산생성을 크게 촉진하였으나 가수분해하지 않은 8% 밤용액에서는 젖산생성량과 비교하였을 때 산생성 순증가량은 그다지 크지 않았다.

• Journal of Dairy Science and Biotechnology
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• 제28권2호
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• pp.25-30
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• 2010

For centuries, probiotics have been known to promote health and prevent diseases. In recent times, modulation of diseases related to the immune function by probiotics has been recognized as very important to the health of the host's gut. Inflammatory bowel diseases (IBDs) are the most frequently studied diseases in which probiotic administration has been tested as a potential therapy. Various in vitro and in vivo studies have been performed. The studies discussed in this review suggest several mechanisms: probiotics could modulate the gut microflora by competing with disease-causing pathogenic bacteria and could directly regulate the mucosal immune system, which activates the innate and adaptive immune systems. In addition, human clinical trials have shown alleviation of disease symptoms of ulcerative colitis (UC), Crohn's disease, etc. This study aimed to understand the molecular mechanisms underlying immune modulation by probiotics and review studies on the functional aspect of IBD alleviation by probiotics. With more scientific studies confirming the effect of probiotics, this therapy holds promise for use in alternative medicine and/or pharmaceutical preparations, given the long history of safe consumption of probiotics.

• Journal of Microbiology and Biotechnology
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• 제28권8호
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• pp.1299-1309
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• 2018

We previously reported on lactophoricin (LPcin), a cationic ${\alpha}-helical$ antimicrobial peptide derived from bovine milk, which has antimicrobial effects on Candida albicans as well as Gram-positive and Gram-negative bacteria. In this study, we designed the LPcin-YK3 peptide, a shorter analog of LPcin, and investigated its antimicrobial activity. This peptide, consisting of 15 amino acids with + 3 net charges, was an effective antimicrobial agent against the on the Gram-positive strain, Staphylococcus aureus (MIC: $0.62{\mu}g/ml$). In addition, the hemolytic activity assay revealed that the peptide was not toxic to mouse and human erythrocytes up to $40{\mu}g/ml$. We also used circular dichroism spectroscopy to confirm that peptide in the presence of lipid has ${\alpha}-helical$ structures and later provide an overview of the relationship between each structure and antimicrobial activity. This peptide is a member of a new class of antimicrobial agents that could potentially overcome the problem of bacterial resistance caused by overuse of conventional antibiotics. Therefore, it could be used as a therapeutic or natural additive, particularly in the cosmetics industry.

• 한국식품과학회지
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• 제46권3호
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• pp.328-333
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• 2014

본 연구에서는 총 65균주의 Bifidobacterium과 Lactobacillus로부터 엽산 생성능력이 있는 11균주의 Lactobacillus를 1차 선정하였다. 그 중 microbiological assay를 통해 엽산 생성능력이 가장 우수한 것으로 선발된 L. plantarum Fol 708을 이용하여, 우유배지에서 L. brevis GABA 100과의 공동배양 및 배양 pH을 일정하게 유지한 후, 각각의 pH조건에서 균체 내부 및 배양 상등액의 엽산 생성과 균체량을 측정하였다. 공동 배양은 1% glutamic acid가 첨가된 우유배지에 균주를 각각 1% (v/v) 접종하여 발효시켰으며, L. plantarum Fol 708과 L. brevis GABA 100의 접종비율이 1:1에서 가장 높은 엽산 생성(약 $8{\mu}g/100mL$)을 보여주었다. 배양 pH을 일정하게 유지한 후 균체량과 엽산 생성을 측정한 경우, 균체량은 pH 4.5에서 가장 높게 측정되었고, 총 엽산 생성은 pH 5.5에서 가장 높게 측정되었다. 본 연구에서 선발한 L. plantarum Fol 708을 이용하면 엽산 함량이 높은 다양한 발효 식품의 개발에 도움이 될 것이다.