• Journal of Microbiology and Biotechnology
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• 제18권7호
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• pp.1266-1273
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• 2008

Lactic acid bacteria (LAB) with antimicrobial activity and high exopolysaccharide (EPS) production ability isolated from sourdough were studied for their fermentation characteristics as potential new starter cultures. The values of pH, titratable acidity, and viable cell counts were $4.06{\pm}0.009-4.50{\pm}0.015,\;0.787{\pm}0.020%-1.172{\pm}0.018%,\;and\;8.78{\pm}0.08-8.98{\pm}0.06$ log CFU/ml, respectively. In order to select probiotics with a high survival rate in the gut, isolates were tested to assess resistance against the artificial gastric acid and bile juice. Viable LAB counts were significantly (p<0.05) affected by the acidity. At pH 2.0, the total declines in the initial bacterial counts were 4.52$\pm$0.07 log for S. thermophilus St-Body-1, >7.98$\pm$0.03 log for E. flavescens DU-10, >7.95$\pm$0.05 log for E. faecium DU-12, and 3.15$\pm$0.06 log for L. amylovorus DU-21. Among the strains, L. amylovorus DU-21 was the only strain that had bile tolerance under simulated gastrointestinal conditions. In order to improve EPS production by L. amylovorus DU-21, the influence of carbon source was studied. When glucose was used as a carbon source, EPS production dramatically increased to 17.19$\pm$0.28 g/l (p<0.05). The maximum cell growth (10.012$\pm$>0.012 log CFU/ml) and EPS production (18.71$\pm$0.19 g/l) were achieved when 15 g/l of glucose was employed as the carbon source.

• 생명과학회지
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• 제28권1호
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• pp.68-77
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• 2018

바이오제닉 아민 비생성 유산균의 선별을 위해 순창군에서 재배된 베리류 및 엑기스, 식초 등으로부터 42종의 유산균을 분리하였다. 분리주를 대상으로 세포외 효소 활성, 항균 활성, 항산화 활성과 같은 다양한 생리활성 분석을 실시하여 5종의 분리주를 1차 선별하였다. 분리주를 대상으로 바이오제닉 아민 생성 여부를 분석하여 최종적으로 SBB07을 선별하였고, 16S rRNA 염기서열 분석을 통해 Lactobacillus brevis SBB07로 명명하였다. SBB07의 프로바이오틱스 활용 가능성을 확인하기 위해 효소 생산 여부, 내산성, 내담즙성, 내열성, 항생제 내성을 조사하였고, pH 2.0에서의 내산성 및 0.5% oxgall을 함유한 내담즙성에서 각각 86% 이상과 54% 이상의 높은 생존율을 나타내었다. 또한 $60^{\circ}C$에서도 113% 이상의 생존율을 나타내어 내열성도 우수하며 다양한 항생제 내성을 갖는 것을 확인하였다. 프리바이오틱스 이용가능성을 확인한 결과에서는 GOS의 이용 능력이 가장 우수하였으며, FOS와 inulin의 이용 능력도 높게 나타났다. 따라서 SBB07은 세포외 효소 및 항균 활성이 우수하고, 내담즙, 내산성, 내열성 및 항생제 내성을 지니며 프리바이오틱스 기질 이용 능력도 우수한 프로바이오틱스 소재로 활용가능성이 높은 유산균으로 기대된다.

• 한국환경보건학회지
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• 제48권3호
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• pp.167-175
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• 2022

Background: Disinfection is essential to provide drinking water from a water source. The disinfection process mainly consists of the use of chlorine and ozone, but when chlorine is used as a disinfectant, the problem of disinfection by-products arises. In order to resolve the issue of disinfection by-products, electro-chlorination technology that produces chlorine-based disinfectants from salt water through electrochemical principles should be applied. Objectives: This study surveys the possibility of optimally producing active chlorine from synthetic NaCl solutions using an electro-chlorination system through RSM. Methods: Response surface methodology (RSM) has been used for modeling and optimizing a variety of water and wastewater treatment processes. This study surveys the possibility of optimally producing active chlorine from synthetic saline solutions using electrolysis through RSM. Various operating parameters, such as distance of electrodes, sodium chloride concentration, electrical potential, and electrolysis time were evaluated. Results: Various operating parameters, such as distance of electrodes, sodium chloride concentration, electrical potential, and electrolysis time were evaluated. A central composite design (CCD) was applied to determine the optimal experimental factors for chlorine production. Conclusions: The concentration of the synthetic NaCl solution and the distance between electrodes had the greatest influence on the generation of hypochlorite disinfectant. The closer the distance between the electrodes and the higher the concentration of the synthetic NaCl solution, the more hypochlorous acid disinfectant was produced.

• 생명과학회지
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• 제17권7호통권87호
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• pp.970-975
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• 2007

국내해안의 젓갈과 김치류로부터 86종의 GABA 생산균주를 분리하였다. 분리된 균주들을 Thin layer chromatography를 이용하여 GABA 생성능이 우수한 AML15, AML45-1, AML72의 3종의 균주를 선발하였다. 선별된 3종의 균주의 아미노산 분석 결과 GABA 생성능이 가장 우수한 AML15 균주를 본 실험에 사용하였다. AML15의 분류학적 위치를 규명하기 위하여 16S ribosomal DNA 영역의 부분염기서열 분석을 실시하였다. 165 rDNA 분석결과 Lactobacillus brevis ATCC 367과 99%의 유사도를 나타내어 L. brevis AML15로 명명하였다. MRS 배지에 최종 전환 농도로 설정된 5%(w/v) monosodium glutamic acid를 첨가하고 배지의 초기 pH를 4.0, 5.0과 6.0으로 조정하여 배양한 결과 배지의 초기 pH가 5.0일 때 GABA 생성능이 가장 높게 조사되었다. GABA 생산배지에 GAD 효소활성에 조효소로 작용하는 PLP를 0. 10. 50과 100 ${\mu}M$의 농도로 첨가하여 아미노산 분석결과 PLP를 10${\mu}M$ 첨가하였을 때 10,424 $nM/{\mu}$l의 GABA가생산되었다. PLP를 첨가하지 않았을 때보다 PLP 첨가 후 GABA 생성이 증가됨을 확인할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제29권7호
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• pp.1083-1095
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• 2019

Butyrate is known to play a significant role in energy metabolism and regulating genomic activities that influence rumen nutrition utilization and function. Thus, this study investigated the effects of an isolated butyrate-producing bacteria, Clostridium saccharobutylicum, in rumen butyrate production, fermentation parameters and microbial population in Holstein-Friesian cow. An isolated butyrate-producing bacterium from the ruminal fluid of a Holstein-Friesian cow was identified and characterized as Clostridium saccharobutylicum RNAL841125 using 16S rRNA gene sequencing and phylogenetic analyses. The bacterium was evaluated on its effects as supplement on in vitro rumen fermentation and microbial population. Supplementation with $10^6CFU/ml$ Clostridium saccharobutylicum increased (p < 0.05) microbial crude protein, butyrate and total volatile fatty acids concentration but had no significant effect on $NH_3-N$ at 24 h incubation. Butyrate and total VFA concentrations were higher (p < 0.05) in supplementation with $10^6CFU/ml$ Clostridium saccharobutylicum compared with control, with no differences observed for total gas production, $NH_3-N$ and propionate concentration. However, as the inclusion rate (CFU/ml) of C. saccharobutylicum was increased, reduction of rumen fermentation values was observed. Furthermore, butyrate-producing bacteria and Fibrobacter succinogenes population in the rumen increased in response with supplementation of C. saccharobutylicum, while no differences in the population in total bacteria, protozoa and fungi were observed among treatments. Overall, our study suggests that supplementation with $10^6CFU/ml$ C. saccharobutylicum has the potential to improve ruminal fermentation through increased concentrations of butyrate and total volatile fatty acid, and enhanced population of butyrate-producing bacteria and cellulolytic bacteria F. succinogenes.

• 한국식품과학회지
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• 제51권6호
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• pp.592-595
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• 2019

Paprika (Capsicum annuum L.) contains various phytochemicals, including carotenoids, ascorbic acid, tocopherol, flavonoids, and phenolic compounds, as well as natural food colorants. Very little information is available regarding wine produced from different colored paprikas. The objectives of this study were to prepare wines from red, orange, and yellow paprika and evaluate their physicochemical characteristics. The alcohol concentration, pH, titratable acidity, and reducing sugar content were not significantly affected by the type of paprika. Hunter's color values varied with the color of paprika. The total mineral content and 2,2-diphenyl-1-picrylhydrazyl radical scavenging potential of red paprika wine were significantly higher; however, the total polyphenol content of yellow paprika wine was significantly higher than that of the other wine samples. This study suggested that paprika could be used to prepare wine and red paprika might be appropriate for producing good-quality wine.

• Asian-Australasian Journal of Animal Sciences
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• 제18권10호
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• pp.1505-1512
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• 2005

Bile salt deconjugation is the most biologically significant reaction among the bacterial alterations of bile acids in the gastrointestinal tract of human and animal. The responsible enzyme, bile salt hydrolase (BSH), catalyzes the hydrolysis of glycineand/or taurine-conjugated bile salts into amino acid residues and deconjugated bile acids. Herein we review current knowledge on the distribution of BSH activity among various microorganisms with respect to their biochemical and molecular characteristics. The proposed physiological impact of BSH activity on the host animal as well as on the BSH-producing bacterial cells is discussed. BSH activity of the probiotic strains is examined on the basis of BSH hypothesis, which was proposed to explain cholesterol-lowering effects of probiotics. Finally, the potential applications of BSH research are briefly discussed.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.386-390
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• 2003

To evaluate the potential capacity of mine wastes in the production of heavy metal containing acid water, samples from depths of 0, 30 and 60cm were collected and analyzed. The waste from surface showed the lowest pH which indicates the oxidation of wastes and the capacity of contamination of the area around the waste file. And the lower pH values of leachate of the wastes through the leaching tests with pH controlled water(3, 4, 5) may indicate that minerals producing the acidity still exist. Reduction of sulfur contents in wastes after the leaching test well fit to the increased contents of iron oxide.

• 한국분말재료학회지
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• 제24권5호
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• pp.351-356
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• 2017

Tin dioxide nanoparticles are prepared using a newly developed synthesis method of plasma-assisted electrolysis. A high voltage is applied to the tin metal plate to apply a high pressure and temperature to the synthesized oxide layer on the metal surface, producing nanoparticles in a low concentration of sulfuric acid. The particle size, morphology, and size distribution is controlled by the concentration of electrolytes and frequency of the power supply. The as-prepared powder of tin dioxide nanoparticles is used to fabricate a gas sensor to investigate the potential application. The particle-based gas sensor exhibits a short response and recovery time. There is sensitivity to the reduction gas for the gas flowing at rates of 50, 250, and 500 ppm of $H_2S$ gas.

• Journal of Animal Science and Technology
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• 제64권3호
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• pp.599-602
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• 2022

A new bacteriocin-producing lactic acid bacteria isolated from kimchi was identified as Lactococcus lactis JNU 534, presenting preservative properties for foods of animal origin. In this study, we present the complete genome sequence of the bacterial strain JNU 534. The final complete genome assembly consists of one circular chromosome (2,443,687 bp [base pair]) with an overall GC (guanine-cytosine) content of 35.2%, one circular plasmid sequence (46,387bp) with a GC content of 34.5%, and one circular contig sequence (7,666 bp) with a GC content of 36.2%.