• Journal of Microbiology and Biotechnology
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• 제17권1호
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• pp.67-73
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• 2007

The present study compared the microbial diversity and activity during the application of various bioremediation processes to crude oil-contaminated soil. Five different treatments, including natural attenuation (NA), biostimulation (BS), biosurfactant addition (BE), bioaugmentation (BA), and a combined treatment (CT) of biostimulation, biosurfactant addition, and bioaugmentation, were used to analyze the degradation rate and microbial communities. After 120 days, the level of remaining hydrocarbons after all the treatments was similar, however, the highest rate (k) of total petroleum hydrocarbon (TPH) degradation was observed with the CT treatment (P<0.05). The total bacterial counts increased during the first 2 weeks with all the treatments, and then remained stable. The bacterial communities and alkane monooxygenase gene fragment, alkB, were compared by denaturing gradient gel electrophoresis (DGGE). The DGGE analyses of the BA and CT treatments, which included Nocardia sp. H17-1, revealed a simple dominant population structure, compared with the other treatments. The Shannon-Weaver diversity index (H') and Simpson dominance index (D), calculated from the DGGE profiles using 16S rDNA, showed considerable qualitative differences in the community structure before and after the bioremediation treatment as well as between treatment conditions.

• 분석과학
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• 제5권1호
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• pp.63-71
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• 1992

역상 액체 크로마토그래피에 의한 몇 가지 금속-N-Alkylisonitrosoacetylacetone imine 킬레이트의 용리거동을 Novapak $C_{18}$ 분리관을 사용하여 조사하였다. 용리액은 Acetonitrile/Water로 하였으며, 각 금속의 킬레이트의 최적 용리액 조성은 각각 70:30(Pd의 경우), 60:40(Ni의 경우) 및 50:50(Co의 경우)이었으며, 리간드의 alkyl기 종류에 따른 금속 킬레이트의 용리순서는 methyl>ethyl>propyl>butyl 유도체 순이었다. 모든 금속 킬레이트의 log k'값은 $0{\leq}log\;k^{\prime}{\leq}1$의 범위였고, log k'값과 용리액 중 물의 부피분율을 도시한 결과 직선관계가 성립되었다. 또한 뱃치법으로 측정한 분포비(Dc)값의 크기는 금속 킬레이트의 용리순서와 비교적 잘 일치할 뿐만 아니라 Dc값과 k'의 직선관계를 나타냄으로써, 금속 킬레이트의 용리 메카니즘은 주로 소용매성 효과, 즉 소수성 효과에 기인함을 확인하였다.

• Ocean and Polar Research
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• 제36권1호
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• pp.25-37
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• 2014

To understand the degradation processes of organic matter related to sulfate reduction by Sulfate Reduction Bacteria (SRB) in the tidal flat sediments of Hwang-do and Sogeun-ri, Tae-an Peninsula in Chungnam-do, biogeochemical characteristics were analyzed and highlighted using specific microbial biomarkers. The organic geochemical parameters (TOC, ${\delta}^{13}C_{org}$, C/N ratio, long-chain-n-alkane) indicate that most of the organic matter has been derived from marine phytoplankton and bacteria in the fine-grained sediment of Sogeun-ri, although terrestrial plant components have occasionally been incorporated to a significant degree in the coarse-grained sediment of Hwang-do. The concentration of sulfate in pore water is a constant tendency with regard to depth profile, while methane concentration appears to be slightly different with regard to depth profile at the two sites. Especially, the sum of bacteria fatty acid (a-C15:0 + i-C15:0 + C16:1w5) confirms that the these concentrations in Sogeun-ri are related to the degradation of Benzene, Toluene, Ethylbenzene and Xylene (BTEX) compounds from the crude oil retained in the sediments as a result of the Hebei Spirit oil-spill accident in 2007. The methane-related microbial communities as shown by lipid biomarkers (crocetane, PMI) are larger in some sedimentary sections of Hwang-do than in the Sogeunri tidal flat. These findings suggest that methane production by microbiological processes is clearly governed by SRB activity along the vertical succession in organic-enriched tidal flats.

• Asian-Australasian Journal of Animal Sciences
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• 제16권5호
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• pp.685-692
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• 2003

Information on nutrient requirements and forage intake of fallow weaner deer is required for the development of feeding strategies during the year. An experiment was conducted in which 60 fallow weaner deer (grazing on medic and ryegrass based pastures) were supplemented with a concentrated diet at three levels. The diet contained 2% minerals, 30% lupin and 68% barley grain. Twelve deer from each treatment were dosed with commercial alkane capsules in May, June, July, September and October to predict nutrient intake. The relationships between body weight gain and intake of metabolisable energy and crude protein were established using a general linear models analysis. Dry matter intake from pastures ranged from 0.137 kg to 0.304 kg in May and June and increased to 1.2 kg in October. Nutrient intake from pastures was strongly influenced by amount of supplementary feed and gender. Digestible energy intake from pastures was 1.3, 3.8 and 6.1 MJ/day higher for males than females in July, August and October, respectively. The protein and energy intake was strongly correlated with body weight gain. The energy requirement for maintenance were 7.3, 8.2, 10.2, 10.2 and 10.7 MJ DE/day and the DE required for each kg body weight gain were 19, 18, 29, 34 and 49 MJ in May, June, August and October, respectively. The protein requirement for maintenance was 12.2, 12.6, 15.0, 11.4 and $8.5g/W^{0.75}$ in May, June, July, August and October, respectively. The nutrient requirement defined from this study can be used to assist farmers to explore the possible pasture and stock management practices under southern Australian conditions. However, further research is required to develop rapid and cheap methods for estimating dry matter intake, nutritive value of pastures and to quantify the potential growth rate of fallow deer in southern Australia.

• Journal of Microbiology and Biotechnology
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• 제16권5호
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• pp.704-715
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• 2006

Oil spill was found in 1999 from a diesel storage facility located near the top of Baekun Mountain in Uiwang City. Application of bioremediation techniques was very relevant in removing oil spills in this site, because the geological condition was not amenable for other onsite remediation techniques. For efficient bioremediation, bacterial communities of the contaminated site and the uncontaminated control site were compared using both molecular and cultivation techniques. Soil bacterial populations were observed to be stimulated to grow in the soils contaminated with diesel hydrocarbon, whereas fungal and actinomycetes populations were decreased by diesel contamination. Most of the dieseldegrading bacteria isolated from contaminated forest soils were strains of Pseudomonas, Ralstonia, and Rhodococcus species. Denaturing gradient gel electrophoresis (DGGE) analysis revealed that the profiles were different among the three contaminated sites, whereas those of the control sites were identical to each other. Analysis of 16S rDNA sequences of dominant isolates and clones showed that the bacterial community was less diverse in the oil-contaminated site than at the control site. Sequence analysis of the alkane hydroxylase genes cloned from soil microbial DNAs indicated that their diversity and distribution were different between the contaminated site and the control site. The results indicated that diesel contamination exerted a strong selection on the indigenous microbial community in the contaminated site, leading to predominance of well-adapted microorganisms in concurrence with decrease of microbial diversity.

• Preventive Nutrition and Food Science
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• 제6권1호
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• pp.10-15
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• 2001

Antimicrobial activities of volatile flavor, water and methanol extracts from Agastache rugosa were investigated. The volatile flavor extract was obtained from A. rugosa by simulataneous distillation-extraction (SDE) method. Antimicrobial activity was investigated by disc diffusion method against several microorganisms, four species of Gram positive, three species of Gram negative and tow species of yeast. The volatile flavor extracts had strong antimicrobial activity againstc. utilisand S. cerevisiae. During the growth period, a difference in antimicrobial activity among volatile flavor extracts from A. rugosa was not shown. The water extract of above 10 mg/disc showed antimicrobial activity. Methanol extracts from A. rugosa harvested in June showed antimicrobial activity against tested Gram positive and Gram negative bacteria, showed weak antimicrobial activity against the bacteria from those harvested in July and August. In particular, antimicrobial activity against V. parahaemolyticus was stronger than that against other bacteria. Water and methanol extracts did not inhibit yeast. C. utilis and S. cerevisiae. To further elucidate the effective components, volatile flavor extracts was analyzed by GC/MS. harvested in June, the components included 8 phenols (93.031%), 18 terpenes (5.230%), 12 alcohols (1.300%) 8 alkanes (0.181%), 1 ester (0.056%), 2 ketones (0.033%), 2 aldehydes (0.011%) and 1 pyrrole (0.007%). In July, the components included 6 phenols (94.366%), 19 terpenes (3.394%), 11 alcohols (2.045%), 1 ester (0.039%), 2 ketones (0.028%), 1 furan (0.005%) and 1 aldehyde (0.005%). And in August, the components included 7 phenols (95.270%), 19 terpenes (2.951%), 13 alcohols (1.399%), 1 ester (0.063%), 2 aldehydes (0.016%), 2 ketones (0.011%), 1 alkane (0.006%), 1 acid (0.005%) and 1 pyrrole (0.005%). The major component of volatile flavors was estragole, a phenolic compound.

• 대한의생명과학회지
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• 제13권1호
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• pp.47-53
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• 2007

Due to wide abuse of antibiotics both in human and livestock use, the advent and spread of multidrug resistant (MDR) pathogens becomes a serious health problem all over the world. Since the development of new antibiotics is at a standstill in pharmaceutical industry, the choice of therapeutic antibiotics is getting narrower. In this study, in an effort to search new antibiotics, the antimicrobial activity of Paenibacillus DY1 isolated from Korean soil was characterized on its growth inhibition spectrum against various health threatening MDR strains, with its stability and chemical structure. Extracellular culture filtrate of Paenibacillus DY1 effectively inhibits the growth of all the tested MDR enteropathogenic Eshcherichia coli, enterohemolytic E. coli, and enterotoxigenic E. coli strains, at a similar level to that on the nonresistant control E. coli strains. It showed significant growth inhibition effect against the causative agents of class one legal communicable disease, MDR Salmonella typhi, MDR Salmonella paratyphi A, food poisoning bacteria, MDR Salmonella typhimurium, and other MDR Salmonella spp. The growth of all of 10 different MDR Shigella spp. strains and 6 different Vibrio spp. strains tested was also inhibited. The antimicrobial activity of Paenibacillus DY1 was well preserved after heat treatment, and was also stable in both alkaline and acidic environment. The antimicrobial activity was partially purified with Diaion HP20 column and TLC. By NMR study, the putative structure of the activity was postulated as an alkane having hydroxyl groups.

• 공업화학
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• 제29권5호
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• pp.620-625
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• 2018

SLES를 주성분으로 사용한 액체세정제는 공기 중에 노출하여 방치하는 경우 표면에 피막이 형성되는 경우가 있다. 이는 제형 중의 수분이 증발하면서 세정제 주성분인 계면활성제의 농도변화로 인한 미셀의 상변화로 판단된다. SLES는 30~60% 영역에서 강한 육방정계 액정상이 나타나고, 60% 이상에서는 라멜라 액정상을 보인다. 본 연구에서는 SLES 주성분으로 사용된 액체세정제의 표면 겔링 현상은 내용물에서 수분 증발로 인하여 발생하는 현상이다. 액체세정제에서 수분이 증발되면서 계면활성제의 농도가 높아지는 결과였다. 표면 겔링 상태는 편광현미경으로 관찰한 결과 혼합 계면활성제 시스템의 액정상으로 확인되었다. 결론적으로 SLES를 주성분으로 사용하는 처방에서 겔링 필름 형성을 방지하기 위하여 수용성이 좋은 AOS를 증량하고 액정형성을 방지할 수 있는 이차 계면활성제인 SAS를 도입하고, 하이드로트로프로 SXS와 PEG1500을 적용하였다. 이와 같이 개선된 액체세정제 처방4와 5는 공기 중에 노출되어도 표면에 피막이 형성되는 겔링현상을 방지할 수 있었다.

• 대한화학회지
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• 제36권5호
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• pp.744-752
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• 1992

철(III) protoporphyrin과 망간(II) tetrakis(4-N-carboxyphenyl) Porphyrin을 polystyrene divinylbenzene 공중합체 수지와 반응시켜 고분자결합 금속포피린을 합성하였다. 고분자와 결합된 포피린은 공명라만분광기를 이용, 합성과정에서 포피린과 중심금속의 산화상태 등 여러가지 화학적 성질이 변화되지 않았음으로 확인하였다. 합성된 고분자결합 금속포피린은 싸이토크롬 P-450과 같은 산화촉매효소의 모형화합물로서 과산화수소에 의한 olefin의 epoxidation과 alkane의 oxidation의 촉매로서 사용이 가능하였다. 그 효율은 고분자와 결합하지 않은 동종의 포피린에 비하여 현저히 증가되었으며, 특히 포피린이 산화제에 의해 분해되지 않아 재사용이 가능하였다. 실제 효소에서와 같이 imidazole 유도체와 같은 전자주게 배위자가 포피린 중심금속에 배위한 경우 촉매효과가 더욱 향상되었다.

• Elastomers and Composites
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• 제48권4호
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• pp.306-311
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• 2013

주 사슬의 강직그룹의 하이드로퀴논 단위에 4-클로로벤조에이트기가 결합된 액정폴리에스터가 단위체인 2,5-다이(4-클로로벤조에이트)하이드로퀴논과 4,4'-디카복시-${\alpha},{\omega}$-디페녹시 알케인의 용액중합에 의하여 합성되었다. 합성된 중합체의 구조와 성질은 $^1H$-NMR, FT-IR, DSC, TGA, POM에 의하여 조사되었다. 조사의 결과에 의하면, 중합체 사슬의 메틸렌기와 벌키한 치환기는 용해도나 열전이와 같은 성질에 큰 영향을 미쳤으며, 모든 중합체들은 편광현미경 관찰에서 약한 복굴절 현상을 갖는 네마틱 액정상의 texture를 나타내었고, 매우 좁은 액정상 온도구간을 나타내었다.