• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1164-1169
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• 2005

Characteristics of sophorolipid and rhamnolipid were evaluated as antifungal agents against plant pathogenic fungi. Eight percent of mycelial growth of plant pathogen (Phytophthora sp. and Pythium sp.) was inhibited by 200 mg/l of rhamnolipid or 500 mg/l of sophorolipid, and zoospore motility of Phytophthora sp. decreased by $90\%$ at 50 mg/l of rhamnolipid and $80\%$ at 100 mg/l of sophorolipid. The effective concentrations for zoospore lysis were two times higher than those of zoospore motility inhibition. The highest zoospore lysis was observed with Phytophthora capsici; $80\%$ lysis at 100 mg/I of di-rhamnolipid or lactonic sophorolipid, showing the dependency of structure on the lysis. In the pot test, the damping-off disease incidence ratio decreased to $42\%\;and\;33\%$ of control value at 2,000 mg/l sophorolipid and rhamnolipid, respectively. These results showed the potential of microbial glycolipid biosurfactants as an effective antifungal agent against damping-off plant pathogens.

• 한국미생물·생명공학회지
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• 제27권3호
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• pp.236-245
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• 1999

Andong Soju is a Korean traditional distilled liquor brewed with Nuruk which is cultured with wild microorganisms. To provide useful information for scientific production and systematic quality control of traditional distilled liquor, the effects of mixed culture of the alcoholic yeasts and saccharifying molds isolated from the Nuruk, and mashes on the flavor and sensory characteristics were investigated. Distillate from mashes cocultured with Saccharomyces cerevisiae and Hansenula anomala using Mucor Nuruk was compared with distillate from mashes brewed with Andong Nuruk and with distillate from plant fermented mashes to analyze their flavor characteristics. The volatile flavor compounds in distillates were analyzed by GC and GC-MS using direct injection, solvent extraction, and purge & trap methods. Alcohols such as 3-methyl-1-butanol, 2-methyl-1-propanol, 1-propanol, and 2-phenyl ethanol; aldehydes such as acetaldehyde and 2-furancar-boxaldehyde; esters such as ethyl ester of acetic acid, hexanoic acid, octanoic acid, decanoic acid; alkanes, alkenes, ketone, sulfur, and pyrone compounds were detected. Alcohols were chief components of flavor compounds. No significant difference in overall acceptability test was shown among three experimental groups(p<0.05), but Nuruk-like aroma, Kaoliangchiew-like aroma, sweet taste, and well rounded mouthfeel showed significant differences among them(p<0.05).

• 한국정보과학회논문지:소프트웨어및응용
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• 제30권3_4호
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• pp.379-387
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• 2003

다수의 미생물 유전체 프로젝트들이 완료되면서 엄청난 양의 유전체 핵산 염기서열 데이터들이 양산되고 있다. 이러한 상황에서 전산 기법을 이용하여 유전체 DNA 염기서열 상에서 유전자의 프로모터 영역을 규명하는 문제는 최근에 상당한 연구의 관심대상으로 떠오르고 있다. 본 논문에서는 전사조절의 핵심 역할을 하는 -10 영역과 전사개시 부위를 포함한 원핵생물의 핵심 프로모터 영역에 대한 의존성 반영 분해모델 (Dependency-Reflecting Decomposition Model)을 제안한다. 이 모델은 인접한 위치에 존재하는 핵산 염기들 사이의 의존성뿐만 아니라 인접하지 않은 위치의 핵산 염기들간의 의존성까지 고려함으로써 핵산 염기서열 상에 내포되어있는 중요한 생물학적 의존성들을 함축하고 있다. DRDM 모델은 우수한 성능평가 결과를 보였으며. 미생물 유전체 Contig들 상에서 임의의 유전자 프로모터를 예측하는데 효과적으로 이용될 수 있다.

• 대한토목학회논문집
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• 제10권2호
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• pp.137-145
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• 1990

본 연구에서는 세가지 중금속 (Cd(II), Cu(II), Zn(II))에 대하여 활성슬러지 미생물 folc의 중금속 흡착 및 축적 작용에 의한 중금속 제거과정을 실험을 통해 연구하였다. 회분식 실험을 통해 pH, 중금속 농도, MLSS 농도 및 온도에 따른 반응시간별 중금속 제거율과 축적량을 측정하였다. 활성슬러지 공정에 의한 중금속제거는 흡착 및 축적에 의해 중금속이 슬러지에 고농도로 농축되어 일어났다. 회분식 실험결과 중금속의 흡착평형은 단시간내에 일어났으며, 미생물 floc과 중금속이온과의 결합세기는 Cu(II)>Zn(II)>Cd(II)의 순으로 나타났다.

• 한국유기농업학회지
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• 제24권2호
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• pp.253-262
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• 2016

친환경농자재 11종을 대상으로 황색참다래 과실무름병에 대한 항균활성 검정결과 SS (B. subtilis 10%), WS (Microbial extract 70%), DS (Sulfur 78%) 3종을 선발하였다. SS, WS, DS를 PDA 배지에 10일 동안 처리 시 B. dothidea의 균사 생장 저해 정도는 각각 94.2%, 65.2%, 58.9%였다. 선발 친환경농자재를 이용한 저장시험에서 WS와 SS가 병 방제 효과가 좋았다. 포장시험에서는 SS와 WS 단독 처리, DS-WS와 WS-SS 교호처리가 효과적이었다.

• 한국식품위생안전성학회지
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• 제9권4호
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• pp.191-198
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• 1994

The major purpose of the present study is to syrvey vegetables, meats, seafoods, processed foods and imported foods for the presence of Listeria spp. and to prevent listeriosis caused by the contamination of Listeria monocytogenes. Listeria spp. was not found in vegetables and processed foods. The optimum growth condition of isolates indentified as Listeria monocytogenes was pH 7.0 and 37$^{\circ}C$. the antimicrobial effect of grapefruit seed extract(GFSE) was observed in the level of more than 100ppm by disk method. When 1ml(2.5$\times$106 CFU/ml) of Listeria monocytogenes was inoculated and incubated for 3 days at 3$0^{\circ}C$, the total cell number of the organism was 4.5$\times$109 in the control, 7.2$\times$103 in 100 $\mu\textrm{g}$/ml of GFSE medium, and 3.5 $\mu\textrm{g}$/ml of GFSE medium. Direct visualization of microbial cells by using both transmission electron microscope and scanning electron microscope showed microbial cell membrane the function of which was destroyed by treating with the dilute solutions of GFSE. It could be confirmed that GFSE completely inhibited the growth of the test strain of Listeria monocytogenes.

• 한국물환경학회지
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• 제22권2호
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• pp.300-307
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• 2006

The combined SHARON (Single reactor system for High ammonium Removal Over Nitrite)-ANAMMOX (Anaerobic ammonium oxidation) reactor were operated in mesophilic condition ($35^{\circ}C$). In this study, microbial granulation and characteristics of SHARON and ANAMMOX sludges were investigated using settling test, Scanning Electron Microscopy (SEM) and Fluorescence In Situ Hybridization (FISH). In SHARON reactor, Aerobic granulation with diameter of 1.5~2.5 mm was accomplished but aerobic granulation was weaker than anaerobic granular sludge. Initial seed sludge of ANAMMOX reactor was used as attached media for biofilm growth. ANAMMOX sludge was more compact and rounder rather than seed sludge. Though ANAMMOX sludge has high activity, it has lower settling ability than the seed granule. The color of ANAMMOX sludge was changed from dark to redish brown granular with diameter of 1~2 mm. In FISH of ANAMMOX sludge, high fraction of Candidatus B. stuttgartiensis which paid great role of nitrogen conversion was detected. Also, FISH results reveals that ANAMMOX bacteria inhabit at inner parts near surface, having advantages in utilization of substrates and protection from oxygen inhibition.

• 한국식생활문화학회지
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• 제33권3호
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• pp.261-267
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• 2018

The sensory characteristics of a rice processed snack for 6 to 12 month old infants were investigated. The microbiological safety of all samples was also tested. The moisture content of snack of the SW snack was 6.33 significantly higher than in the other snacks (p<0.05). The sensory intensities of RW were highest in glossiness brightness, uniformity, sweet aroma, savory flavor, sweet flavor, chewiness and crispiness. In the; consumer acceptance test, RW showed significantly higher glossiness, uniformity, sweet aroma, savory flavor, sweet flavor, rancid, chewiness, adhesiveness, crispiness and overall acceptance than the other snacks (p<0.05). The aerobic plate counts were negative in all the samples tested. E. coli and pathogenic microorganisms tests were also negative or not detected, showing that all the samples tested were microbiologically safe according to the food code which applies to food manufacturers. Overall, potentially high value products of rice processed snacks for 6 to 12 month old infants were developed and tested They are expected to be utilized and in the competitive and growing infant food industry.

• KSBB Journal
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• 제18권6호
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• pp.479-484
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• 2003

염색폐수에 포함된 PVA를 생물학적으로 제거하고자 34 종의 PVA 분해용 균주를 염색폐수 및 슬러지로부터 분리하였다. 이 중 PVA 분해 시험을 거쳐 2 종의 균주를 최종분리하여 동정하여 Microbacterium barkeri LCa와 Paenibacillus amylolyticus LCb로 명명하였다. 최종분리균의 최적성장조건 및 최대분해조건을 규명해보았는데, 온도는 3$0^{\circ}C$, pH는 7, 탄소원은 starch, 그리고 질소원은 peptone으로 판명되었으며, 최적조건 하에서의 PVA 분해율은 89%를 보였다. 또한, 본 연구에서 분리한 균주는 PVA 중합도의 영향 없이 높은 분해율을 유지하는 것으로 판명되었다.

• 한국토양비료학회지
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• 제49권5호
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• pp.461-468
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• 2016

One of the important phytohormones produced by plant growth promoting bacteria is the auxin; indole-3-acetic acid (IAA), with L-tryptophan as the precursor. In this study, we focused on the investigation of optimal conditions for the production of IAA by Bacillus megaterium BM5. We investigated culturing conditions, such as incubation temperature, pH of the culture medium and incubation period, with varying media components such as inoculation volume, tryptophan concentration and carbon and nitrogen source. Besides, optimization study intended for high IAA production was carried out with fermentation parameters such as rpm and aeration. The initial yield of $42{\mu}g\;IAA\;ml^{-1}$ after 24 hr increased to $85{\mu}g\;ml^{-1}$ when 5% (v/v) of L-tryptophan was used in the culture broth. The maximum yield of $320{\mu}g\;IAA\;ml^{-1}$ was observed in trypticase soy broth (TSB) supplemented with starch and soybean meal as C and N sources with a C/N ratio of 3:1 (v/v) at $30^{\circ}C$, pH 8.0 for 48 hrs with 1.0 vvm and 250 rpm in 5 L working volume using 10 L scale fermenter. The bacterial auxin extracted from the culture broth was confirmed by thin layer chromatography and high-performance liquid chromatography and effect on plant growth was confirmed by root elongation test.