• 한국식품과학회지
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• 제22권5호
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• pp.520-525
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• 1990

포화지방산 또는 불포화지방산의 분리방법인 요소부 가법이 지닌 가메탄올 분해(methanolysis)와 농축물 회수의 곤란함 등의 문제를 해결하기 위하여 지방산과 요소의 부가화합물 형성의 반응매질로 유기용매를 사용하고 요소의 습윤제로 물을 사용한 새로운 요소부가법을 제시하였다. 어유를 원료로 제조한 지방산을 헵탄, 헥산, 이소옥탄같은 비극성 유기용매에 용해키시고 요소와 요소의 습윤제인 물을 첨가하여 부가화합물 형성을 유도한 후 요소와 부가화합물을 잘 형성하지 않는 불포화지방산 분획을 회수하여 지방산 조성을 분석한 결과 EPA, DHA 및 이들의 전구물질을 포함한 고도불포화지방산이 80%이상인 것으로 나타났다. 이 고도불포화지방산 농축물내에 EPA와 DHA 함량은 사용하는 유기용매으 종류에 따라서 변화되었는데, 헵탄과 에틸 에테르 등을 사용할 경우에는 EPA의 농축에 효과가 높았다. 이러한 특성을 이용하여 우선 펜탄을 사용하여 DHA를 농축하고 다시 헵탄을 사용하여 EPA의 농축을 시도한 바 어유 지방산으로부터 DHA가 50%인 농축물과 EPA가 53%인 분획을 각각 얻을 수 있었다.

• KSBB Journal
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• 제16권4호
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• pp.365-369
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• 2001

Serratia marcescens KY와 Serratia marcescens ATCC 27117 두 균주 모두 기본 배지에 $K_2$HPO$_4$ 농도를 0.2 g/L 농도 첨가할 경우 최대 chitinase 생성을 나타냈다. 그러나 세포 성장에 따른 균체량은 기본 배지에 $K_2$PHO$_4$ 농도 0.2 g/L 이상에서는 균체량은 약간 감소한다. 1.2% colloidal chitin과 0.2 g/L의 $K_2$PHO$_4$가 포함된 기본 배지에 MgSO$_4$를 0.2-0.25 g/L를 첨가하였을 때 최대의 chitinase 생성을 보이고, 두 균주 모두 K, P, Mg 및 기타 mineral을 영양 요구 인자로서 필요한다. Colloidal chitin을 1.2% 함유하고 있는 기본 배지에 각종 탄소원의 종류에 따른 세포 성장과 chitinase 생성은 colloidal chitin만을 첨가하였을 때가 상대적으로 가장 우수하고, 탄소원을 첨가할 경우 Serratia marcescens는 모든 탄소원에서 chitinase 생성이 억제되었다. 또한 질소원에 따른 세포 성장과 chitinase 생성은 Serratia marcescens KY와 Serratia marcescens ATCC 27117 모두 tryptone이 가장 우수하였고, 2.0 g/L의 질소원 농도까지는 질소원 농도가 증가함에 따라 chitinase 생성은 증가하다가 2.0 g/L 이상의 농도에서는 질소원 농도가 증가함에 따라 chitinase 생성은 감소하였다. 이들 질소원 중 chitinase 생성은 trypotone>yeast extract > beef extract > asparagine 순서로 chitinaserk 생성되므로, Serratia marcescens는 chitinase 생성에 있어 vitamin B군과 같은 질소원을 growth factor로 요구한다.

• 한국식품위생안전성학회지
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• 제31권6호
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• pp.465-470
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• 2016

본 연구는 전처리 방법이 새싹채소 재배에 사용되는 종자 중 식중독 세균의 검출율에 영향을 미치는지에 대해 검증하기 위해 시중 유통되고 있는 새싹채소 재배용 종자 19종을 수집하여 종자를 세척 방법과 발아 방법으로 전처리한 후 E. coli, E. coli O157:H7, Salmonella spp., L. monocytogenes의 검출율을 비교하였다. 또한 인위적으로 Salmonella enterica를 접종한 알팔파 종자에 대해서 무처리, 세척, 발아 방법으로 전처리한 후 S. enterica의 검출율을 검정하였다. 시중 유통되고 있는 종자를 수집하여 분석한 결과, 세척 방법과 발아 방법 등의 전처리 방법에 따라 E. coli 검출율과 양성시료에 차이가 있었음을 확인하였다. 인위적으로 S. enterica를 접종한 알팔파 종자에 대한 검출율 비교 검정에서도 분석시료량 대비 전처리방법별로 검출율이 차이가 나는 것으로 나타났고, 선택배지 종류에 따라서도 S. enterica의 검출율이 차이가 났다. 결론적으로 새싹채소 재배용 종자의 식중독 세균 분석에 있어서 종자의 전처리 방법, 시료당 분석시료량, 선택배지 종류 등이 검출율에 영향을 미치는 것으로 나타났다.

• BMB Reports
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• 제46권5호
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• pp.270-275
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• 2013

It is essential to analyze rare mutations in many fields of biomedical research. However, the detection of rare mutations is usually failed due to the interference of predominant wild-type DNA surrounded. Herein we describe a sensitive and facile method of detecting rare point mutation on the basis of allele-specific amplification in emulsion PCR. The identification and selective amplification of rare mutation are accomplished in one-pot reaction. The allele-specific primers coupled on magnetic beads allow the exclusive amplification and enrichment of the mutant amplicons. The productive beads bearing mutant amplicons are subsequently stained with the fluorescent dyes. Thus, the rare point mutations with a percentage as low as 0.1%, can be detected by fluorescent analysis. The relative percentages of mutation among different samples can be roughly accessed by counting the fraction of fluorescent positive beads through flow cytometry.

• Bulletin of the Korean Chemical Society
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• 제25권4호
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• pp.545-548
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• 2004

A sensitive, selective and rapid method for the determination of nickel based on the rapid reaction of nickel(II) with QADMAA and the solid phase extraction of the Ni(II)-QADMAA chelate with $C_{18}$ membrane disks has been developed. In the presence of pH 6.0 buffer solution and sodium dodecyl sulfonate (SDS) medium, QADMAA reacts with nickel to form a violet complex of a molar ratio of 1 : 2 (nickel to QADMAA). This chelate was enriched by solid phase extraction with $C_{18}$ membrane disks. An enrichment factor of 50 was obtained by elution of the chelates form the disks with the minimal amount of isopentyl alcohol. The molar absorptivity of the chelate was $1.32{\times}10^5L\;mol^{-1}cm^{- 1}$ at 590 nm in the measured solution. Beer's law was obeyed in the range of 0.01-0.6 ${\mu}$g/mL. This method was applied to the determination of nickel in water and biological samples with good results.

• Bulletin of the Korean Chemical Society
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• 제25권4호
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• pp.549-552
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• 2004

A sensitive, selective and rapid method has been developed for the determination of mercury based on the rapid reaction of mercury(II) with p-sulfobenzylidenethiorhodanine (SBDTR) and the solid phase extraction of the colored chelate with $C_{18}$ disks. In the presence of pH 3.5 sodium acetate-acetic acid buffer solution and Emulsifier-OP medium, SBDTR reacts with mercury(II) to form a red chelate of a molar ratio 1 : 2 (mercury to SBDTR). This chelate was prconcentrated by solid phase extraction with $C_{18}$ disks. An enrichment factor of 50 was achieved. The molar absorptivity of the chelate is $1.28{\times}10^5 L{\cdot}mol^{-1}{\cdot}cm^{-1}$ at 545 nm in measured solution. Beer's law is obeyed in the range of 0.01-3 ${\mu}$g/mL. The relative standard deviation for eleven replicates sample of 0.01 ${\mu}$g/mL is 1.65%. This method was applied to the determination of mercury in tobacco and tobacco additive with good results.

• Bulletin of the Korean Chemical Society
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• 제25권2호
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• pp.263-266
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• 2004

A sensitive, selective and rapid method has been developed for the determination ${\mu}$g/L level of vanadium ion based on the rapid reaction of vanadium(V) with 2-(2-quinolylazo)-5-diethylaminophenol (QADEAP) and the solid phase extraction of the colored chelate with $C_{18}$ cartridge. The QADEAP reacts with V(V) in the presence of citric acid-sodium hydroxide buffer solution (pH = 3.5) and cetyl trimethylammonium bromide (CTMAB) medium to form a violet chelate of a molar ratio 1 : 2 (V(V) to QADEAP). This chelate was enriched by solid phase extraction with $C_{18}$cartridge and the enrichment factor of 50 was obtained by elution of the chelates from the cartridge with ethanol. The molar absorptivity of the chelate is $1.28 {\times}10^5L\;mol^{-1}cm^{-1}$ at 590 nm in the measured solution. Beer's law is obeyed in the range of 0.01-0.6 ${\mu}$g/mL. The detection limit is 0.04 ${\mu}$g/L in the original samples. This method was applied to the determination of vanadium(V) in water and biological samples with good results.

• 한국미생물·생명공학회지
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• 제19권2호
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• pp.140-146
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• 1991

Mutation experiments were performed to select the mutant of Aspergillus niger 55, which had lost almost all the ability to produce transglucosidases but retained that of high productivity of raw meal saccharifying enzyme, by means of successive induction with N-methyl-N'-nitro-N-nitrosoguanidine(MNNG), ultraviolet(UV) light, and ${\gamma}$-rays. Also, we used the mutant enrichment techniques, such as liquid culture-filtration procedure and differential heat sensitivity of conidia, in order to increase the possibility of obtaining a mutant. The glucoamylase productivity of mutant PFST-38 was 11 times higher than that of the parent strain. The mutant PFST-38 was morphologically identical to the parent strain, except for the size of conidia, the tendency to form conidia and the lenght of conidiophore. Asp. niger mutant PFST-38 apeared to be useful for the submerged production of the raw corn meal saccharifying enzyme.

• 한국연소학회지
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• 제12권4호
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• pp.14-21
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• 2007

In order to enhance combustion efficiency, oxygen-enriched combustion is used by increasing the oxygen ratio in the oxidizer. However, since the flame temperature increases, NOx formation in the furnace seriously increases for low oxygen enrichment ratio. In this case, reburning is a useful technology for reducing nitric oxide. In this research, experimental studies have been conducted to evaluate the hybrid effects of reburning/selective non-catalytic reaction (SNCR) and reburning/air staging on NOx formation and also to examine heat transfer characteristics in various oxygen-enriched LPG flames. Experiments were performed in flames stabilized by a co-flow swirl burner, which were mounted at the bottom of the furnace. Tests were conducted using LPG gas as main fuel and also as reburn fuel. The paper reported data on flue gas emissions, temperature distribution in furnace and various heat fluxes at the wall for a wide range of experimental conditions. Overall temperature in the furnace, heat fluxes to the wall and NOx generation were observed to increase by low level oxygen-enriched combustion, but due to its hybrid effects of reburning, SNCR and Air staging, NOx concentration in the exhaust have decreased considerably.

• 한국미생물·생명공학회지
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• 제16권3호
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• pp.199-204
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• 1988

Naphthalene을 유일한 탄소원으로 이용하는 균을 분식 배양과 연속식 배양에 의해서 토양과 폐수로부터 분리하였다. 이 균은 Pseudomonas putida로 동정되었으며, 최적 pH와 온도는 각각 7.0과 3$0^{\circ}C$ 이었다. 분리된 균은 1,5-dihydroxynaphthalene을 naphthalene보다 더욱 잘 이용하였으며 benzoate와 salicylate도 이용하였다. 또한 catechol dl meta-분해경로를 통해서 분해되었으며, ampicillin, chloramphenicol, kanamycin, streptomycin에 대해서 강한 저항성을 지니고 있었으며, naphthalene의 분해에 관여하는 약 110kb 크기의 plasmid를 1개 지니고 있었다.