• Food Science and Preservation
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• v.30 no.4
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• pp.691-702
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• 2023

This study aimed to develop high value-added mulberry (Morus alba) vinegar by fermenting mulberry with yeast and acetic acid bacteria, for using it in various foods. To select the optimal strain for mulberry fermentation, different strains were tested and Saccharomyces cerevisiae SRCM101756 and Acetobacter pasteurianus SRCM102419, exhibiting excellent alcohol and acetic acid production ability during mulberry fermentation, were selected for fermentation. Mulberry vinegar was prepared using mulberry wine and the selected acetic acid bacteria, and the physicochemical properties and physiological effects were measured. The pH was 2.98 and total acidity was 4.70% by day 9 of fermentation, establishing the possibility of developing them into vinegars for industrial use. The angiotensin-glucosidase inhibition activity of mulberry vinegar increased from 13.22% to 19.19% in the 100-fold dilution, and from 42.35% to 46.11% in the 50-fold dilution, from before fermentation to after fermentation, respectively. The angiotensin-converting enzyme inhibition activity of mulberry vinegar was found to significantly increase from 44.82% before fermentation to 63.88% after fermentation in the 25-fold dilution. Moreover, a significant increase in pancreatic lipase inhibition activity after fermentation was observed. Thus, mulberry vinegar can be used as a functional material in vinegar and other foods.

• Korean Journal of Microbiology
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• v.33 no.1
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• pp.50-54
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• 1997

이 글에서는 호수생태계에서 일어나는 변화 중 .betha.-glucosidase 활성도를 중심으로 생화학적인 분석과정을 통하여 유기물질의 분해, 생성, 소비등에 대한 과정을 설명하고자 한다. .betha.-glucosidase효소는 비교적 기질특이성이 넓고, glucose, celluhexose, carboxy-methylcellulose등의 .betha.고리를 가수분해시켜 monomer로 분해시키는 효소로서 수환경에서는 매우 중요하다. 즉 cellobiohydrolase에 의해 분해된 oligomer나 dimer를 세균의 세포막을 통과할 수 있는 크기로 분해시키는 효소이고, 이 효소의 분해 산물인 포도당은 세균에 의하여 바로 이용되고, catabolite inhibitor로 작용하므로, 이 효소 활성도의 높고 낮음은 수중생태계에서 탄소의 흐름과 세균 군집의 성장을 이해하는데 매우 중요하다(3).

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.211-214
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• 2004

MTBE로 오염된 토양에서 생태독성학적 접근 방법으로 3가지 토양 효소의 활성도를 측정해 보았다. MTBE의 잠재적 위험성으로 인한 논란은 계속되고 있으나 토양 오염에 대한 지표로써 토양 효소 활성도의 사용타당성 여부에 대한 실험은 이전에 행해지지 않았다. 따라서 중금속 오염 토양에 대해 좋은 지표로 사용되고 있는 토양 미생물 효소의 활성도를 MTBE에 적용하여 실험해 보았다. 사용한 토양 효소는 Acid Phosphotase, $\beta$-Glucosidase 그리고 Arysulfatase였다. 그러나 실험 결과 MTBE로 오염된 토양의 경우 중금속으로 오염된 토양에 비해 토양 미생물 활성도의 감소가 매우 적었다. 따라서 MTBE의 오염 토양의 경우 본 연구에서 측정된 효소의 활성도는 좋은 지표로 적합하지 않다는 것을 확인했다.

• Korean Journal of Food Science and Technology
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• v.27 no.2
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• pp.216-220
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• 1995

In order to investigate the possible use of vegetable kimchi stuff as natural preservatives for kimchi, the methanol extracts of 15 kinds of vegetable kimchi stuff were solvent-fractionated and fractions were tested for antimicrobial activities against Leuconostoc mesenteroids, Pediococcus cerevisiae, Lactobacillus plantarum and Saccharomyces cerevisiae. The neutral fractions of the extracts of garlic and leek showed strong antimicrobial activities. The extract of leek showed particularly strong antimicrobial activities against Ped. cerevisiae and L. plantarum that were known to be main microorganism of fermentation and acidification of kimchi. The results suggest the possible use of the leek extract as natural preservatives for kimchi.

• Korean Journal of Organic Agriculture
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• v.24 no.3
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• pp.497-510
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• 2016

This study was carried out to get basic resources for the industrial use of Lactobacillus bulgaricus SP5. The antibacterial activity of the supernatant obtained from Lactobacillus bulgaricus SP5 was tested against the pathogenic bacteria such as Escherichia coli KCCM 11234, Salmonella enteritidis KCCM 3313, Salmonella enteritidis KCCM 12021, and Salmonella typhimurium KCCM 40253. The supernatant of L. bulgaricus SP5 showed antibacterial activity against tested pathogenic bacteria. The antibacterial activity was examined after adjusting pH and heat treatment of supernatant. Heat treatment of supernatant had antibacterial activity against pathogenic bacteria at all temperature. However, pH changes showed no antibacterial activity. Antibacterial activity of the supernatant was confirmed to be due to organic acids (lactic, acetic, phosphoric, succinic, pyroglutamic, citric, malic, and formic acid).

• Korean Journal of Microbiology
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• v.26 no.3
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• pp.230-236
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• 1988

The distributions of bacterial numbers and activities were studied bimonthly in 1987, at 3 sites in Lade Paro for elucidating the changes by disturbance of aquatic ecosystem. The total bacterial number was $0.3\times 10^{5}-13.1\times ^{5}$ cells/ml. The geterotrophic bacterial number had the variance from $1.9\times 10^{3}$ CFUs/ml to $3.1\times 10^{4}$CFUs/ml and the variation trend was similar to that of the total bacterial number. The proportions of alpha-glucosidase or beta-glucosidase releasing bacteria showed temporal changes rather than spatial changes. The proportions of phosphatase releasing bacteria had the maximum values, 22.7-83.0%, in July. The electron transpory system activity revealed the variation from $480{\mu}gO_{2}$/l/day to $1696{\mu}gO_{2}$/l/day and hagher values at upper stream and in summer. The degradation fraction by phosphatase was 0.4-9.1%/h and increased with temperature. The maximum value of heterotrophic activity was 8.2%/h in summer. Eventhough the distributions of total bacteria and heterotrophic bacteria were affected by the water disturbance but microbial activities and proportions of the specific enzume releasing bacteria were not affected.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2003.06a
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• pp.113-116
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• 2003

• Bioindustry News
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• v.12 no.3
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• pp.36-40
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• 1999

• The Microorganisms and Industry
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• v.15 no.2
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• pp.33-39
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• 1989

본고에서는 주로 방선균의 선택분리 과정을 시료(substrate)선정, 시료 전처리(pretreatment), 배지, 배양조건, 콜로니 선정 등으로 나누어 살펴보고자 한다.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.428-435
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• 2018

In this study, we isolated and identified bacteria from freshwater and soil collected from Osang reservoir, to screen antimicrobial bacteria against various pathogenic bacteria. 38 strains were isolated and assigned to the class Proteobacteria (22 strains), Actinobacteria (7 strains), Bacteroidets (6 strains), and Firmicutes (3 strains) based on 16S rRNA gene sequence analysis. Among them, strain OS17 showed a good growth inhibition against 5 methicillin-resistant Staphylococcus aureus subsp. aureus strains and Bacillus cereus, Bacillus subtilis, Filobasidium neoformans. As a result of the 16S rRNA gene sequence analysis, strain OS17 show the high similarity with Burkholderia ambifaria $AMMD^T$, B. diffusa $AM747629^T$, B. tettitorii $LK023503^T$ 99.8%, 99.7%, 99.6%, respectively. We investigated cell growth and antimicrobial activity according to commercial culture medium, temperature, pH for culture optimization of strain OS17. Optimal conditions for growth and antimicrobial activity in strain OS17 were found to be: YPD medium, $35^{\circ}C$ and pH 6.5. When the strain was cultured in LB, NB, TSB, R2A media at $20^{\circ}C$ and $25^{\circ}C$, the antimicrobial activity did not show. Culture filtrate of strain OS17 showed antimicrobial activity against 5 MRSA strains, Bacillus cereus, Bacillus subtilis, and Filobasidium neoformans with inhibition zones from 2 to 8 mm. Optimal reaction time was 48 h in YPD medium, 100 rpm and 0.3 vvm in 2 L-scale fed-batch fermentation process for antimicrobial activity. Culture optimization of strain OS17 can be improved on antimicrobial activity. Therefore, the antimicrobial activity of Burkholderia sp. OS17 had potential as antibiotics for pathogens including MRSA.