• 한국식생활문화학회지
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• 제30권4호
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• pp.475-480
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• 2015

Jeju citrus, which contains an abundance of calcium and vitamin, was used to develop fermented citrus peel extract. A total of seven probiotic strains were applied to tangerine dermis to select the best growing bacteria in citrus peel extracts. B. longum, B. bifidum, and L. mesenteroides were found to grow best in citrus peel extract culture containing glucose, yeast extracts, peptone, and potassium phosphate. Citrus peel extract culture consisting of 1% yeast extract, 5% peptone, and 0.1% phosphate was the best environment for growth of probiotics. The pH, acidity, and viable cell numbers of these fermented extracts were measured. The initial pH level of fermented extracts with nutrients was 5.25 and dropped rapidly to 3.39 after 72 hours of fermentation. The acidity of fermented extracts increased to 4.08 % after 72 hours of fermentation, and the viable cell number in fermented extracts after refrigeration for 2 weeks was $1.3{\times}10^{10}CFU/mL$. The antimicrobial activity of citrus peel fermented extracts against Campylobacter jejuni was determined, and concentrations more than 25,000 ppm showed antimicrobial activity.

• 급식외식위생학회지
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• 제4권1호
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• pp.21-28
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• 2023

Saccharomyces cerevisiae and Zygosaccharomyces rouxii are known to produce alcohol in gochujang. To reduce alcohol production, garlic and chives were applied to gochujang solution to find their inhibitory effect on S. cerevisiae and Z. rouxii. The 70% ethanol extract of garlic and chives showed significant inhibition activity against S. cerevisiae and Z. rouxii, showing growth inhibition zone of 14.00±0.00~25.33±0.58 mm by disc diffusion method. In addition, the addition of 70% ethanol extract of garlic and chives in 10% gochujang solution spiked with S. cerevisiae and Z. rouxii reduced the numbers of total aerobic bacteria (below 7 Log CFU/g) and yeast (below 4 Log CFU/g), alcohol content (below 0.30%), respectively. In conclusion, the addition of garlic ethanol (70%) extract or chives ethanol (70%) extract to gochujang inhibited the growth of S. cerevisiae and Z. rouxii, resulting in reduced alcohol content in gochujang. For further study, it is necessary to conduct food application experiments by using real gochujang paste.

• 한국식품영양과학회지
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• 제39권3호
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• pp.461-466
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• 2010

총 110 가닥의 테플론 튜브와 9개의 자외선(UV)램프(총 1395 W)로 구성된 허니컴 방식의 UV살균기를 제작하고 원심분리를 통해 생탁주의 고형분을 제거시킨 청징탁주(CT)를 순환시켜 살균하였다. 미생물살균과 관능적 품질 등을 고려한 전반적인 품질평가 결과, 최적의 살균조건은 2 L/min의 유속에서 1.5분간 살균하는 것이 최적의 조건으로 확인되었다. 이러한 살균조건에서 약 일반세균수와 진균수를 5~6 log cycle 감소시킬 수 있었다. 자외선으로 살균된 청징탁주는 $30^{\circ}C$에서 8일 동안 저장하며 pH, 아미노태질소 함량, 산도, 환원당 함량, 일반세균수 및 진균수 등의 품질 평가를 수행하였다. 자외선으로 살균된 청징탁주의 진균수는 저장 4일 후에 이르러서야 $10^8\;CFU/mL$에 도달하였고 일반세균수는 6일 후에 이르러서야 $10^8\;CFU/mL$에 도달하여 생육이 억제되었음을 확인할 수 있었다. 또한 환원당 함량을 제외하고는 자외선으로 살균된 청징탁주의 pH, 아미노태질소 함량, 산도는 저장 중에 변화를 나타내지 아니하였다. 또한 저장 기간 동안 청징탁주와 자외선으로 살균된 청징탁주 간에는 L, a 및 b 값 간에 차이를 보이지 않아 색도의 변화에는 자외선 살균이 영향을 미치지 않은 것으로 확인되었다.

• 한국조리학회지
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• 제21권1호
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• pp.267-280
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• 2015

조국, 분국, 맥국 누룩으로 각각 탁주, 약주, 증류주를 제조하여 이들의 품질특성 평가를 위하여 발효 시 pH, 당도, 효모 생균수, 알코올 농도 등을 분석하였고, GC를 이용하여 향기성분, LC를 이용하여 유기산을 분석하였으며 관능검사를 실시하였다. 발효가 진행되는 동안 pH는 낮아졌으나, 당도는 높아졌고 누룩의 종류에 따라 값에 차이가 있었다. 알코올 농도는 발효 12일째까지 증가 하였으나, 이후에는 유의적 차이가 없었다(p<0.05). 효모 생균수는 발효 5일째까지 급격하게 증가하였으나, 이후에는 감소하기 시작하여 발효 13일째에 주류 간에 차이가 없었다. 향기성분 중 acetone과 n-amyl alcohol은 모든 주류에서 검출되지 않았으나, fusel oil은 맥국에서 494.65 mg/L, 분국에서 525.4 mg/L가 검출되었다. 유기산 중에는 lactic acid가 가장 많이 검출되었다. 관능검사에서 탁주는 조국과 분국에서, 약주는 맥국에서 높은 점수를 얻었다. 증류주는 조국, 분국, 맥국 모두에서 유사한 점수를 얻었다.

• The Plant Pathology Journal
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• 제31권2호
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• pp.108-114
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• 2015

Curvularia lunata is an important maize foliar fungal pathogen that distributes widely in maize growing area in China, and several key pathogenic factors have been isolated. An yeast two-hybrid (Y2H) library is a very useful platform to further unravel novel pathogenic factors in C. lunata. To construct a high-quality full length-expression cDNA library from the C. lunata for application to pathogenesis-related protein-protein interaction screening, total RNA was extracted. The SMART (Switching Mechanism At 5' end of the RNA Transcript) technique was used for cDNA synthesis. Double-stranded cDNA was ligated into the pGADT7-Rec vector with Herring Testes Carrier DNA using homologous recombination method. The ligation mixture was transformed into competent yeast AH109 cells to construct the primary cDNA library. Eventually, a high qualitative library was successfully established according to an evaluation on quality. The transformation efficiency was about $6.39{\times}10^5$ transformants/$3{\mu}g$ pGADT7-Rec. The titer of the primary cDNA library was $2.5{\times}10^8cfu/mL$. The numbers for the cDNA library was $2.46{\times}10^5$. Randomly picked clones show that the recombination rate was 88.24%. Gel electrophoresis results indicated that the fragments ranged from 0.4 kb to 3.0 kb. Melanin synthesis protein Brn1 (1,3,8-hydroxynaphthalene reductase) was used as a "bait" to test the sufficiency of the Y2H library. As a result, a cDNA clone encoding VelB protein that was known to be involved in the regulation of diverse cellular processes, including control of secondary metabolism containing melanin and toxin production in many filamentous fungi was identified. Further study on the exact role of the VelB gene is underway.

• Mycobiology
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• 제49권5호
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• pp.469-475
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• 2021

Three strains, YP416^T, YP421^T, and Y422, were isolated from soil samples in Pocheon City, Gyeonggi province, South Korea. The strains belong to two novel yeast species in the genus Mrakia. Molecular phylogenetic analysis showed that the strain YP416^T was closely related to Mrakia niccombsii. Still, it differed by 9 nucleotide substitutions with no gap (1.51%) in the D1/D2 domain of the LSU rRNA gene and 14 nucleotide substitutions with 7 gaps (2.36%) in the ITS region. The strain YP421^T differed from the type strain of the most closely related species, Mrakia aquatica, by 5 nucleotide substitutions with no gap (0.81%) in the D1/D2 domain of the LSU rRNA gene and 9 nucleotide substitutions with one gap (1.43%) in the ITS region. The names Mrakia terrae sp. nov. and Mrakia soli sp. nov. are proposed, with type strains YP416^T (KCTC 27886^T) and YP421^T (KCTC 27890^T), respectively. MycoBank numbers of the strains YP416^T and YP421^T are MB 836844 and MB 836847, respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제30권2호
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• pp.211-220
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• 2017

Objective: The aim of the present study was to investigate the effect of yeast with bacteriocin and Lactobacillus cultures (mixture of Lactobacillus agilis BCRC 10436 and Lactobacillus reuteri BCRC 17476) supplements, alone or in combination, on broiler chicken performance. Methods: A total of 300, 1-d-old healthy broiler chickens were randomly divided into five treatment groups: i) basal diet (control), ii) basal diet+0.25% yeast (Saccharomyces cerevisiae) (YC), iii) basal diet+0.25% yeast with bacteriocin (BA), iv) basal diet+Lactobacillus cultures (LAB), and v) basal diet +0.25% yeast with bacteriocin+Lactobacillus cultures (BA+LAB). Growth performance, cecal microbiota, cecal fermentation products, and blood biochemistry parameters were determined when chickens were 21 and 35 d old. Results: The supplementation of YC, BA, and BA+LAB resulted in a significantly better feed conversion rate (FCR) than that of the control group during 1 to 21 d (p<0.05). The LAB supplementation had a significant effect on the presence of Lactobacillus in the ceca at 35 d. None of the supplements had an effect on relative numbers of L. agilis and L. reuter at 21 d, but the BA supplementation resulted in the decrease of both Lactobacillus strains at 35 d. The BA+LAB supplementation resulted in higher short chain fatty acid (SCFA) in the ceca, but LAB supplementation significantly decreased the SCFA at 35 d (p<0.05). All treatments tended to decrease ammonia concentration in the ceca at 21 d, especially in the LAB treatment group. The BA supplementation alone decreased the triacylglycerol (TG) concentration significantly at 21 d (p<0.05), but the synergistic effect of BA and LAB supplementation was required to reduce the TG concentration at 35 d. The YC supplementation tended to increase the plasma cholesterol at 21 d and 35 d. However, the BA supplementation significantly decreased the cholesterol and low density lipoprotein cholesterol level at 35 d. In conclusion, the BA+LAB supplementation was beneficial to body weight gain and FCR of broiler chickens. Conclusion: The effect of BA and LAB supplementation may be a result of the growth of lactic acid bacteria enhancement and physiological characterization of bacteriocin, and it suggests that the BA and LAB supplementation level or Lactobacillus strain selection should be integrated in future supplementation designs.

• 한국식품영양학회지
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• 제12권3호
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• pp.226-232
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• 1999

To evaluate the characteristics of modified nuruk made by inoculation and cultivation of Rhizopus jap-onicus T2, Aspergillus oryzae L2 and hansenula sp. BC26 three different Takju mashes were made with modified Nuruk commercial Nuruk and rice koji and the changes in microorganisms and major compon-ents of mashes were investigated uring brewing. The numbers of yeast kept higher in the mash of mod-ified Nuruk or rice koji. The numbers of lactic acid bacteria were high in mash of commercial Nuruk but those were not in mash of modified Nuruk or rice koji. all mashes showed stable pH in a day and the pH kept higher in mash of modified Nuruk than in that of commer-cial Nuruk or rice koji. Increase in the content of total acid was moderate in mash of modified Nuruk or rice koji but it was too much in that of commercial Nuruk. increase in the content of amino acid was much highr in mash of modified Nuruk or commercial Nuruk than in that of rice koji. Increase in the content of alcohol was more rapid in mash of modified nuruk or rice koji than in that of commercial Nur-uk. The content of reducing sugar kept highter in mash of commercial Nuruk or modified Nuruk than in that of rice koji. A small amount of modified Nuruk accomplished favorable fermentation showing nor-mal patterns in microbiological and physicochemical changes during brewing.

• 한국식품과학회지
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• 제43권1호
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• pp.45-50
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• 2011

혼합 probiotics 균과 제빵용 효모의 비를 각각 2.0:0.1, 1.5:0.1, 1.0:0.1(g/g)로 다르게 하였을 때, 다음과 같은 결과를 도출하였다. Sourdough starter의 probiotics 균의 생균수는, 발효 초기와 비교 시, 25시간 발효한 후의 생균수가 Exp 2에서는 약 130배 가까이 증가하여 다른 두 군에 비해 가장 많이 증가하였다. Sourdough starter의 pH는 전반적으로 4.1-4.4의 범위에 있어 세 군 모두 sourdough starter로 사용하기에 적당한 수치였으며, TTA는 측정결과 Exp 2군이 가장 많이 증가하였다. Sourdough starter의 발효율은 Exp 2에서 165 mL로 세 군 중에서 가장 높게 나타났다. CrumbScan의 영상분석의 결과는 Exp 2의 부피가 2,332 mL로 세군 중에서 가장 큰 것으로 나타났고, 기공의 조밀도는 유의적인 차이를 보이지 않았으며, 기공의 찌그러짐의 정도는 Exp 1에 비해 Exp 2와 Exp 3에서 1.44로 높았다. Sourdough starter와 sourdough bread의 향 성분 분석결과는, 반죽과 빵의 향 조성은 매우 다르게 나타났으나, 각각의 starter를 이용하여 sourdough bread를 제조한 후, 향성분의 변화를 살펴보면 sourdough starter에서의 주요향성분과 동일하였다. 식빵의 속질 색에 대한 관능평가에서는 전반적으로 보통의 정도로 나타났고 유의적인 차이가 없었다. Exp 2에서 기공의 상태가 가장 균일하였고, 촉감에서도 가장 부드러웠다. 그리고 향, 맛 및 전체적인 품질 평가에서도 Exp 2의 선호도가 유의적으로 높게 나타났다. 결과적으로, sourdough starter Exp 2 조성으로 제조한 sourdough bread가 모든 항목에서 가장 높게 평가되었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권6호
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• pp.400-406
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• 2000

Since the 1950s, the numbers of species and chemicals produced have significantly increased. Despite the fact that industrial chemicals have given us numerous benefits, there is no doubt that they have damaged the environment. The chemicals being dispersed on the earth should be carefully controlled to prevent adverse effects. Bioassay is one of the methods to assess chemical safety. In bioassay systems, chemical safety is estimated by monitoring biological responses to environmental pollutants and newly synthesized chemicals. This report introduces multiple-point bioassay systems that are based on chemical sensitivities of microorganisms, responses of one kind of organism, and micro-array technology. Multiple-end-point bioassays enable the prediction of chemicals in the environment and the understanding of toxicities of newly synthesized chemicals.