• Journal of Dairy Science and Biotechnology
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• 제32권2호
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• pp.131-139
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• 2014

본 연구는 숙성기간 단축 및 최종 제품의 소비자 편의를 높이기 위한 방법으로 1년 이상 숙성된 고다치즈에서 단백분해능이 우수한 유산균주를 screening하여 단백분해능 및 내산성이 높은 L. rhamnosus_p1을 분리 동정하였으며, 이 균주를 이용한 고다치즈를 제조하여 숙성기간에 따른 품질변화를 측정하였다. 1년 숙성된 고다치즈 3개 제품에서 분리해낸 유산균주는 총 5종이며, 16S rDNA의 염기서열을 표준 균주와 비교하여 작성한 계통수 결과, L. rhamnosus 2종, L. casei, L. curvatus 및 S. saprophyticus로 판명되었고, 이 중 단백분해능과 내산성이 높은 L. rhamnosus_p1을 우선적으로 선정하여 절단형 고다치즈 제조 후 질소포장하여 숙성기간 중 이화학적 변화 및 아미노산 변화를 측정하였다. 숙성기간에 따른 수분, 단백질, 지방 및 회분의 변화는 대조구의 경우, 숙성기간이 증가할수록 수분함량이 감소하여 이에 따른 지방, 단백질 및 회분의 함량이 증가하였고, L. rhamnosus_p1을 처리한 실험구는 숙성기간에 따른 일반성분 함량의 변화 없는 것으로 나타났다. 대조구 및 L. rhamnosus_p1을 첨가한 실험구의 유리아미노산의 함량은 숙성 초기 각각 16.63 및 16.01 mg/100 g에서 숙성기간이 증가함에 따라 숙성 3개월째 각각 40.80 및 54.70 mg/100 g 증가하였고, 숙성 5개월째에 71.55 및 77.12 mg/100 g으로 증가하였다. 주요 유리아미노산으로는 glutamic acid, leucine 및 phenylalanine으로 대조구는 각각 14.32, 10.26 및 6.25 mg/100 g으로, L. casei_p2를 첨가한 실험구는 각각 16.33, 12.31 및 5.80 mg/100 g 나타났다. 관능검사 결과, 맛, 향기, 조직감 및 전체적인 기호도에 있어서 대조구보다는 L. rhamnosus_p1을 첨가한 실험구가 우수한 것으로 보이며, 향후 복합균주에 대한 연구가 추가적으로 진행된다면 Gouda cheese 제조를 위한 스타터로서의 이용 가능성이 높을 것으로 판단된다.

• 대한본초학회지
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• 제27권1호
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• pp.35-39
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• 2012

Objectives : The purpose of this study was to investigate the changes in the contents of constituents in Samultang and its fermentations with 10 species of lactic acid bacteria. Methods : Ten strains of lactic acid bacteria, Lactobacillus casei, L. acidophilus, L. casei, L. plantarum, L. amylophilus, L. curvatus, L. delbruekil subsp. lactis, L. casei, B. breve, and B. thermophilum, were used for the fermentation of Samultang. The increased and decreased constituents were identified using HPLC/DAD and various liquid chromatographic techniques, and the structure was elucidated using NMR and MS. These compounds were quantitatively analyzed using an HPLC/DAD system. Results : A remarkably increased component was identified to be nodakenetin and a decreased component was determined to be nodakenin. The fermentation of the ten lactic acid bacteria demonstrated that the decomposable rate of these two compounds in fermented Samultang were different. Samultang fermented by L. plantarum showed the most remarkable changes. Conclusion : Nodakenetin was identified as bioconversion component after fermentation and L. plantarum was discovered the best bacteria to increase the component.

• Preventive Nutrition and Food Science
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• 제2권2호
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• pp.101-108
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• 1997

A lactic acid bacterium LAB3113, isolated from traditionally fermented Kimchi was found to produce bacteriocin whose activity was very specific toward lactobacilli and not effective against any other bacteria. Lactobacilli affected by the inhibitory substance included Lactobacillus delbrueckii-lactis, L. johnsonii, L. gsseri, and L. curvatus. Based upon biochemical and physiological characteristics, LAB3113 was classified as Lactococcus lactis, and its bacteriocin was named as lactococcin K3113. Lactococcus lactis. LAB3113 produced bacteriocin at th early stage of growth and the concentration of the bacteriocin did not decrease even after alt stationalry phase. Optimal temperature of bacteriocin production was $25^{\circ}C$ at the initial pH 7.0. Partially purified lactococcin K3113 was completely inactivated by protease, but not affected by lipase, lysozyme and RNase. The bacteriocin was very heat-stable even after autoclaving for 20 min. It was also stable in pH changes, an was not affected by th presence of solvents. lacotococcin K3113 appeared to act in bactericidal mode against L. delbrueckii-lactis ATCC4797. Molecular weight of lactococcin K3113 was calibrated as 10,500 dal by SDS-PAGE an activity staining. Lactococcus lactis LAB3113 had four residential plasmids of 3.7kb, 11.2kb, 15.5kb, and 48kh in molecular sizes. Plasmid profile analysis of mutant strain revealed that 15.5 kb plasmid was re-sponsible for the production of lactococcin K3113 and its immunity to the bacteriocin.

• 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.

• 한국한의학연구원논문집
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• 제17권3호
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• pp.115-121
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• 2011

Objective : The purpose of this study was to investigate the changes in the contents of constituents in Socheongryong-tang (CY) and its fermentations (FCY) with 10 species of lactic acid bacteria. Methods : Ten strains of lactic acid bacteria, Lactobacillus casei 127, L. acidophilus 128, L. casei 129, L. plantarum 144, L. amylophilus 161, L. curvatus 166, L. delbruekil subsp. lactis 442, L. casei 693, B. breve 744, and B. thermophilum 748, were used for the fermentation of Socheongryong-tang. The increased and decreased constituents were identified using HPLC/DAD and various liquid chromatographic techniques, and the structure was elucidated using NMR and MS. These compounds were quantitatively analyzed using an HPLC/DAD system. Results : The increased constituents were identified to be liquiritigenin (1) and cinnamyl alcohol (2), and the decreased constituent was determined to be liquiritin (3). Liquiritigenin (1) and cinnamyl alcohol (2) were increased in all of the FCYs, while liquiritin (3) was decreased. The fermentation of the ten lactic acid bacteria demonstrated that the decomposable rate of these three compounds in FCYs were different. Socheongryong-tang fermented by L. plantarum 144 and L. amylophilus 161 showed the most remarkable changes. Conclusions : CY could be increased antibacterial, neuroprotective, or antiinflammatory effect by fermentation with lactic acid bacteria, especially with L. plantarum and L. amylophilus, considering their known biological activities. In addition, it is expected that this study will help to establish quality control parameters for FCY.

• 한국축산식품학회지
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• 제18권3호
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• pp.255-260
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• 1998

The aroma concentrates from mold fermented sausages were isolated by steam distillation and simultaneous steam-distillation-extraction(SDE). methods. Quantitative estimation of the aroma concentrates in mold fermented sausages was carried out by using GC-MC. Mold fermented sausages were manufactured into two types. The first was manufactured with starter culture containing Lactobacillus plantarum and Staphylococcus carnosus(LP). The second was manufactured with starter culture containing L. curvatus and S. carnosus(LC). The aroma concentrates containing hexanoic acid and 2-butyl-2-octenal were identified in mold fermented sausages immediately after manufacture. After 28 days, the volatile flavor components from LP and LC were determined to be 14 (trimethylsilylester of hexadecanoic acid and 2-methyl-3-octanol, etc.) and 16 substances(hexadecanoic acid and 1-hexadecanol, etc.), respectively. The distribution of aroma concentrates in LP and LC was different, but their panel test placed them in similarity.

• Journal of Microbiology and Biotechnology
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• 제31권2호
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• pp.298-303
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• 2021

Comparative genomic analysis was performed on eight species of lactic acid bacteria (LAB)-Lactococcus (L.) lactis, Lactobacillus (Lb.) plantarum, Lb. casei, Lb. brevis, Leuconostoc (Leu.) mesenteroides, Lb. fermentum, Lb. buchneri, and Lb. curvatus-to assess their glutamic acid production pathways. Glutamic acid is important for umami taste in foods. The only genes for glutamic acid production identified in the eight LAB were for conversion from glutamine in L. lactis and Leu. mesenteroides, and from glucose via citrate in L. lactis. Thus, L. lactis was considered to be potentially the best of the species for glutamic acid production. By biochemical analyses, L. lactis HY7803 was selected for glutamic acid production from among 17 L. lactis strains. Strain HY7803 produced 83.16 pmol/μl glutamic acid from glucose, and exogenous supplementation of citrate increased this to 108.42 pmol/μl. Including glutamic acid, strain HY7803 produced more of 10 free amino acids than L. lactis reference strains IL1403 and ATCC 7962 in the presence of exogenous citrate. The differences in the amino acid profiles of the strains were illuminated by principal component analysis. Our results indicate that L. lactis HY7803 may be a good starter strain for glutamic acid production.

• 한국축산식품학회지
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• 제23권3호
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• pp.269-277
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• 2003

한국인 모유중 미생물을 분리 및 동정하여 미생물의 분포를 파악함으로써 영 유아의 건강에 대한 안정성을 확보하고자 하였다. 건강한 한국인 149명의 산모로부터 비유기간을 고려하여 유즙기에 의한 수집과 손에 의한 수집방법에 따라 모유를 나누어 미생물의 동정을 실시하였다. 유즙기로 수집한 경우 일반세균수는 평균 2.33${\times}$$10^4$ cfu/mL이구 손으로 착유시는 평균 7.83${\times}$$10^3$ c려/mL로서 유즙기를 이용하여 착유한 경우 평균 9.80${\times}$$10^2$∼3.06${\times}$$10^4$ cfu/mL 많이 존재하였으며, 대장균군 또한 유즙기를 이용하여 착유할 경우 평균9.36${\times}$$10^3$∼8.57${\times}$$10^4$ cfu/mL 많이 존재하는 것으로 나타났다. 반면에 유산균수는 평균 8.63${\times}$$10^2$∼7.64${\times}$$10^4$ cfu/mL로서 기계착유와 손착유 방법에 따른 차이점이 없었다. 일반세균의 동정은 산모로부터 수집된 모유를 Standard plate count agar를 이용하여 콜로니의 형태학적 특성에 따라 5가지 형태로 나누어 100개군으로 분리하였으며, Microbial Identification System(MIDI)을 이용하여 일반세균군을 동정한 결과, 휴 13개 균종으로 분포하고 있었으며, 그 중 Staphylococcus속이 7가지의 아종으로 전체 일반세균의 81% (1.07${\times}$$10^4$ cfu/mL)로서 가장 많이 존재하고 있는 것으로 나타났다. 그 밖에 Mcrococcus속, Bacillus속, Providencia속, Pseudomonas속, Yersinia속 및 Acinetobacter속이 각각 1종씩 검출되었다. 유산균의 동정은 BCP agar를 이용하여 콜로니의 형태학적 특성에 따라 6가지 형태로 나누어 36개군의 유산균군을 분리하였다. 그리고 Bergey's Manual 및 API 50CH system을 이용하여 생리적 및 생화학적 동정을 실시한 결과, 총 7개 균종으로 분포하고 있었으며, Lactobacillus brevis 균주간 전체 유산균중 50.9% (4.72${\times}$$10^4$ cfu/mL)로서 가장 많이 존재하고 있는 것으로 나타났다. 그 밖에 Lactobacillus curvatus, Lactobacillus delbrueckii subsp. lactis, Lactobacillus acidophiiu 등 85.1%(7.89x$10^4$ cfu/mL)가 간균으로 분포하고 있었으며 구균으로는 Leuconostoc lactis와 Streptococcus salivarius subsp. thermophilus가 총 14.9% (1.39${\times}$$10^4$ cfu/mL)분포하고 있는 것으로 동정되었다.

• Journal of Microbiology and Biotechnology
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• 제24권4호
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• pp.497-506
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• 2014

In this study, crude glycerol was used as a carbon source in the cultivation of wild yeasts, aiming at the production of microbial lipids and citric acid. Forty yeasts of different sources were tested concerning their growth in crude and commercial glycerol. Four yeasts (Lindnera saturnus UFLA CES-Y677, Yarrowia lipolytica UFLA CM-Y9.4, Rhodotorula glutinis NCYC 2439, and Cryptococcus curvatus NCYC 476) were then selected owing to their ability to grow in pure ($OD_{600}$ 2.133, 1.633, 2.055, and 2.049, respectively) and crude ($OD_{600}$ 2.354, 1.753, 2.316, and 2.281, respectively) glycerol (10%, 20%, and 30%). Y. lipolytica UFLA CM-Y9.4 was selected for its ability to maintain cell viability in concentrations of 30% of crude glycerol, and high glycerol intake (18.907 g/l). This yeast was submitted to lipid production in 30 g/l of crude glycerol, and therefore obtained 63.4% of microbial lipids. In the fatty acid profile, there was a predominance of stearic (C18:0) and palmitic (C16:0) acids in the concentrations of 87.64% and 74.67%, respectively. We also performed optimization of the parameters for the production of citric acid, which yielded a production of 0.19 g/l of citric acid in optimum conditions (38.4 g/l of crude glycerol, agitation of 184 rpm, and temperature of $30^{\circ}C$). Yarrowia lipolytica UFLA CM-Y9.4 presented good lipid production when in the concentration of 30 g/l of glycerol. These data may be used for production in large quantities for the application of industrial biodiesel.

• Asian-Australasian Journal of Animal Sciences
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• 제33권8호
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• pp.1233-1241
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• 2020

Objective: The present investigation was aimed to explore the potential of lactobacilli for conjugated linoleic acid (CLA) production, isolated from rumen fluid samples of lactating goats. Methods: A total of 64 isolates of lactobacilli were obtained using deMan-Rogosa-Sharpe (MRS) agar from rumen fluid of goats and further subjected to morphological and biochemical characterizations. Isolates found as gram-positive, catalase negative rods were presumptively identified as Lactobacillus species and further confirmed by genus specific polymerase chain reaction (PCR). The phylogenetic tree was constructed from the nucleotide sequences using MEGA6. Results: Out of the 64 isolates, 23 isolates were observed positive for CLA production by linoleate isomerase gene-based amplification and quantitatively by UV-spectrophotometric assay for the conversion of linoleic acid to CLA as well as gas chromatography-based assay. In all Lactobacillus species cis9, trans11 isomer was observed as the most predominant CLA isomer. These positive isolates were identified by 16S rRNA gene-based PCR sequencing and identified to be different species of L. ingluviei (2), L.salivarius (2), L. curvatus (15), and L. sakei (4). Conclusion: The findings of the present study concluded that lactic acid bacteria isolated from ruminal fluid samples of goat have the potential to produce bioactive CLA and may be applied as a direct fed microbial to enhance the nutraceutical value of animal food products.