• Journal of environmental and Sanitary engineering
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• v.14 no.1
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• pp.103-115
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• 1999

생물학적 처리공정내 미생물은 물리화학적, 생태학적으로 처리공정의 운전조건과 유입하·폐수 특성에 따라 존재량 및 반응조내 존재하는 우점종이 달라진다. 특히,폐수의 생물학적 처리시 유입수내 존재하는 독성 및 저해물질은 생물반응조내 존재하는 미생물의 양을 감소시키거나 미생물의 종류를 단순화시키거나 환경조건 및 폐수 특성변화에 능동적으로 대처할 수 있는 능력을 감소시킨다. 따라서 이러한 문제점을 극복하기 위한 방안으로 생물능력향상(bio-augmentation)이 필요하며, 여러 가지 방법으로 생물능력향상을 이룰 수 있다. 본 연구에서는 생물능력향상을 위하여 기존의 효소활성이 강한 미생물군을 투입함으로써 처리효율향상에 미치는 영향 및 제한성을 고찰하였다. 처리효율 향상을 위해서는 생존성, 폐수에 대한 순응기간 및 미생물의 체류가 매우 중요하였으며, 특히 누입된 미생물군이 처리효율을 향상시키기 위해서는 일정기간 이상의 순응기간이 필요하였다. 한편, 토착미생물군인 UB-1의 경우 기존 생물능력향상 미생물군과 거의 동일한 처리효율을 나타내고 있으며, 사전에 순양기간을 거친 UB-2의 경우도 기존 생물능력향상 미생물군과 비슷한 처리효율을 보였다. 따라서 본 결과로 볼 때 생물능력향상 미생물군 투입에 의한 처리효율의 향상은 크지 않으며, 하·폐수의 생물학적 처리공정에 적요하는데는 다소 제한성이 있은 것으로 판단되었다.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.136-140
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• 2005

Microbial cell-based UV spectrometric assay for the quantitative measurement of epoxide hydrolase activity was evaluated and optimized for the efficient screening of whole cell activity of novel epoxide hydrolase. Epoxide hydrolase activity was determined by measuring the increase of the oxidized product, benzaldehyde. The effects of the concentrations of phenyl-1,2-ethanediol, sodium metaperiodate and cells were optimized for epoxide hydrolase-catalyzed hydrolysis of styrene oxide. The relevant kinetic parameters of Km and $V_{max}$ for the hydrolysis of (R)-styrene oxide by Rhodotorula glutinis were determined from Lineweaver-Burk plot as 41.2 nmol/min$\cdot$mg dcw and 7.5 mM respectively, and coincided well with those from GC analysis.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.332-336
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• 2005

Epoxide hydrolase activities of various microbial cells were analyzed by colorimetric assay based on alkylation of epoxides with 4-(p-nitrobenzyl)pyridine (NBP). The epoxide hydrolase activity was determined by measuring the decrease of color intensity at 560 nm due to the decrease of styrene oxide substrate by epoxide hydrolase-catalyzed hydrolysis reaction. The experimental conditions of NBP colorimetric assay were optimized for the efficient measurement of epoxide hydrolase activities from various microbial cells.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.04a
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• pp.97.2-97
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• 1978

숙성한 퇴비에서 16종의 사상균을 분리하고 이들의 xylanase 및 cellulase의 활성을 측정하였다. 이 결과 효소활성이 강한 6 균주를 선별하고 이들의 형태학적 특성을 속까지 동정하고 선별된 균주가 생산하는 xylanase와 cellulase의 성질을 비교 검토하였다. 선별된 균주의 배양기질에 따른 효소생산량 산량을 비교하기 위해 cellulose와 xylan으로 배양한 후 이들을 분해하는 효소활성의 비 즉 xylanase/cellulase 비를 계산하고 이들 효소의 일반 성질을 검토하였다. 차후 연구에서 이들 효소를 분리, 정제하기 위해 acetone에 의한 침전성을 아울러 실험하였다.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1976.10a
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• pp.188.2-188
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• 1976

E. coli B 및 E. coli K-12의 Ion 변리주는 저중의 UV 조사에 의해 확산 및 단백질 합성은 그대로 지속되나 세포분열능은 상실되어 격막이 없는 다핵의 filament를 형성하므로 한무배지상에서 colony가 형성되지 않는다. 이와같은 균에 동일균 또는 타의 균체추출액을 가하어 주므로써 세포분열은 재개되며 그 활성물질중 $\beta-NAD가$ 중요한 인자로 작용함은 이미 발표되었으며 본보에서는 NAD 이외의 고분자활성물질에 대해 보고코저 한다.(중략)

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.522.1-522
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• 1986

5'-Xanthylic acid 생성균주인 Brevibacterium ammoniagenes ATCC 21263 R에 XMP에서 GMP로의 전환효소인 GMP synthetase활성을 부여하기 위해 동종간 세포융합을 시도하여 융합균주들을 얻었다. 이들 우량 융합균주들과 융합모균의 GMP synthetase 활성을 측정하여 상호 비교하였으며, pH 변화에 따른 GMP synthetase 활성과 GMP 생성량과의 관계를 검토하였다. 또한 최적 pH에서 균성장에 따른 당소모량과 GMP 생성량을 비교하였다.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1977.10a
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• pp.197.5-198
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• 1977

일반적으로 protease는 고정화되면 저분자 기질에 대하여는 높은 활성을 내 주나 고분자 기질에 대하여는 낮은 활성을 나타내 줄다. 이것은 고정화된 Pretense의 구조적인 영향으로 생각된다. 본 실험에서 polysaccharide의 표면에 ac교lamide 및 N-hydroxysuccinmidyl acrylate (NHSA)을 graft 공중합 시킴으로서 긴축쇄에 활성 ester을 가지는 새로운 carrier을 합성하여 Bacillus thermoproteolyticus가 생산하는 중성 pretense인 thermolysin을 고정화시켰으며 아울러 고정화된 thermolysin의 몇가지 효소적 성질을 조사검토 하였다.(중략)

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.4
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• pp.470-475
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• 2007

Antibacterial activities of Scutellaria baicalensis Georgi (SBG) extract were examined against spoilage bacteria isolated from commercial tofu and various pathogens such as Listeria monocytogenes ATCC 19115, Pseudomonas fluorescens ATCC 21541. Staphylococcus aureus ATCC 29737, Salmonella Typhimurium ATCC 11806, Vibrio parahaemolyticus ATCC 17802, and Aeromonas hydrophila KCTC 2358. Four kinds of spore forming organisms were isolated from commercial tofu and identified as Bacillus sp. KN-4, Bacillus sp. KN-6, Bacillus sp. KN-10 and Bacillus sp. KN-20 using API CHB kit. The SBG extract showed high antibacterial activities and significantly inhibited the growth of the isolated spoilage bacteria and pathogens. The inhibitory effects against the organisms increased as the concentration of the SBG extract increased. The antimicrobial activities of the SBG extract were maintained markedly after heat treatments $(80^{\circ}C/30\;min,\;100^{\circ}C/30\;min\;and\;121^{\circ}C/15min)$. The minimum inhibitory concentrations (MIC) of the SBG extract against the organisms ranged from 1,000 ppm to 5,000 ppm.

• The Journal of Engineering Geology
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• v.33 no.1
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• pp.15-25
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• 2023

The effects of forest fires on the activity of microbial communities in topsoil and subsoil were investigated. Samples were collected from Korean forest soils comprising mainly igneous and sedimentary rocks. Analysis of beta-glucosidase, found higher microbial activity in sedimentary rocks than in igneous rocks. Enzyme activity was not observed immediately after fire, but was restored over time. The enzyme activity of subsoil was inhibited by 33~46% compared with that in the topsoil, regardless of soil damage. The effect of fire on the availability of microbial substrate was investigated using EcoPlate. The percentages of average well color development values of damaged and normal topsoil were 52.7~56.8% and 62.3~83.6%, respectively. Forest fires appear to affect the diversity and substrate availability of the subsoil microbial community by accelerating the decomposition of soil organic matter. The Shanon index, representing microbial biodiversity, was high in the topsoil of all samples; it was higher for soil microorganisms in sedimentary rocks than in igneous rocks, and higher in topsoil than in subsoil.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.12
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• pp.973-977
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• 2013

These studies were attempted to investigate the change of microbial community of anode of microbial fuel cell using swine wastewater in the enrichment step with the lapse of time. Microbial fuel cells enriched by a 1 : 1 mixture of anaerobic digestive juices of the sewage treatment plant and livestock wastewater. Enrichment culture step was divided into three stages to indentify the microorganisms. It was separated by each lag phase, exponential phase, and stationary phase. These steps were determined by the change of the current value. The current after enrichment was generated about $0.84{\pm}0.06mA$. We were cut out the different 17 bands in the DGGE fingerprint gel to do sequencing. The bands which the concentration was increasing or newly appearing with the lapse of time were included for this study. In the lag and exponential phase, Clostridium, Rhodocyclaceae, Bacteriodetes, and Uncultured bacterium etc. were detected. There were in the stationary phase Geobacter sp., Rhodocyclaceae, Candidatus, Nitrospira, Flavobactriaceae and uncultured bacterium etc. Geobactor among microorganisms detected in this study is known as the Electrochemically active microorganisms. It may include electrochemically active microorganisms to be considered as electrical activity microorganisms.