• 미생물학회지
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• 제17권3호
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• pp.97-130
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• 1979

Many industrial processes those employ bacteria are subjected to phage infestations. In L-glutamic acid fermentions using acetic acid, the phage infestations of the organisms have been recently recognized. In efforts to elucidate the sources of phage contamination involved in the abnormal fermentation, a series of study was conducted to isolate the phages both from the contents of abnormally fermented tanks and the soil or sewage samples from the surroundings of a fermentation factory, to define major charateristics of the phage isolates, and finally to determine the correlation between the phage isolates and temperate phages originating from the miscellaneous bacterial species isolated from the soil or sewage samples. The results are summarized as follows; 1) All phages were isolated from the irregular fermentation tanks and soil or sewage samples, and they were designated as phage PR-1, PR-2, PR-3, PR-4, PR-5, PR-6, and PR-7, in the order of isolation. These PR-series phages were proved to be highly specific for the variant strains of Br. lactofermentum only, namely, phage PR-1 and PR-2 for Br. lactofermentum No. 468-5 and phage PR-3~PR-7 for Br. lactofemrentum No. 2256. By cross-neutralization test, the 7 phagescould be subdivided into 3 groups, i. e., phage PR-I and PR-2 the first, phage PR-3, PR-4, PR-5, PR-6 the second, and the phage PR-7 the third. 2) The 7 phages were virulent under the experimental conditions. They produced plaques with clear and relatively sharp margins without distinct halo. The mean sizes of plaques were 1.5mm in diameter for phage PR-1 and PR-2, and 1. Omm for phages PR-3~PR-7. Double layer technique modified by Hongo and described by Adams, was applied to assay of the PR-series phages. The factors influencing the plaques were as follows;young age cells of host bacteria cultured for 3-6 hours represented the largest number and size, optimum was pH 7.0, incubation temperature was $30^{\circ}C$, and agar concentration and amount of overlayer medium were 0.6% and 0.2ml, respectively. 3) PR-series phages were stable in 0.05M tris buffer and 0.1M ammonium acetate buffer solution. The addition of $5{\times}10^{-3}M$ magnesium ion effectively increased the stability. Thermostability experiments indicated that PR-series phages were stable at the teinperture between $50^{\circ}{\sim}55^{\circ}C$ in nutrient medium, $45^{\circ}{\sim}50^{\circ}C$ in buffer solution. However, the phages mere completely inactivated at 603C and 65$^{\circ}$C within 10 minutes. The phages were stable at the range of pH6~9 in nutrient medium and of pH 8-9 in buffer solution, respectively. Exposure of the phages to UV for 25, 60 and 100 seconds resulted in the complete loss of infectivily, respectively. 4) Electron microscopy showed that PR-series phage particles exhibited rather similar morphology, differing in the size All of PR-series phages had a multilateral head and had a simple long tiil about three to five times long as compared with head. By the size, phage PR-1 and PR-2, PR-3, PR-4, PR-5, and PR-6 and PR-7 were classified into same groups, respectively. The head and tail size of phage PR-1, PR-5, PR-5(T) and PR-7 were 85nm, 74nm and 235nm and 350mm, and 72nm and 210nm, respectively. 5) Nucleic acids of PR-series phages were double stranded DNA. The G+C contents of phage PR-1, PR-5 and PR-7 were 56.1, 52.9 and 53.7, respectively. The values of G+C contents derived from the $T_m$ were in agreement with the chemically determined values. 6) PR-series phages effectively adsorbed on their host bacteria at the rate of more than 90% during 5 min. K value for phage PR-1, PR-5 and PR-7 were calculated to be $6{\times}10^9 ml$ per minute, respectiveky. The pH of the medium did effect adsorption rate, but both temperature and age of host cells did not. Generally, optimum adsorption condition of phages seemed to be almost same as optimum growth conditions of host bacteria. 7) In one-step growth experiments, the latent periods at $30^{\circ}C$ for PR-1, and PR-7 were about 70, 50 and 55 min, respectively. The corresponding average burst size was 200, 70 and 90, respectively. Lpsis period according to the multiplicity of infection and a phage series. In case of m. o. i. 100, strain No. 2256 (PR-5) and No. 468-5(PR-1) failed to grow and turbidity decreased after 50 and 70min, respectively. 8) In the lysate of a plaque purified phage PR-5 infected bacteria, there observed 2 types ofphage particles, i. e., phage PR-5 and PR-5 (T) of similar morphology but differing at the length of phage tail, and phage tail like particles. The phage taillike particles could be divided into 4 types by the length. Induction experiments of Br. lactofermentum with UV irradiation, mitomycin C or bacitracin treatment produced neither phage PR-5 (T) or phage tail-like particles. 9) No lysis occured when the growth of 7 strains of miscellaneous bacteria, isolated from soil and sewage samples, were inoculated with either phage PR-5 (T) or phage tail-like particles the inoculation of phage PR-5 pellet resulted in the growth inhibition of the orgainsms in the spot test. The lysates obtained from 3 miscellaneous soil derived bacteria following mitomycin C treatment the growth of Br. lactofermentum, but did not lyze the bacterium.

• 한국미생물·생명공학회지
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• 제7권1호
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• pp.1-8
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• 1979

혈액 및 생체반응물질등에 함유된 미량의 glucose를 효소적으로 간편하게 측량하기 위하여 먼저 고가의 glucose oxidase를 고정화 시켰다. 전리 방사선조사에 의하여 이 효소를 쉽게 고정화 시킬수 있는 방법과 그 알맞는 조건 및 높은 잔여 활성에 관한 결과는 다음과 같다. 1) 여러가지 monomer 및 polymer의 combination 중에서 AA-Bis, NK ester 23G, 물 (1:1:2)에 가용성 효소 1ml를 고정화 시켰을 경우를 비롯하여 GOD의 잔여활성이 50%이상인 여러 monomer Combination 찾았다 2) Carrier의 방사선중합에 필요한 선량은 100 krad 이상 이였으나, 400~500krad가 적당하였고, solvent는 toluene, n-haxane, petoleum ether chloroform 등을 이용할 때 고정화된 GOD의 잔여 활성 및 이화학적 성장이 좋았다. 3) GOD 고정화에 이용될 수 있는 완충 용액은 tris-glycerol buffer (pH 7.0)가 phosphate (pH 7.0) 보다 높은 활성을 보여 주었다. 4) 고정화된 GOD의 최적 pH는 6.0~6.5 또 온도는 30~4$0^{\circ}C$로서 가용성 효소보다 작용범위가 넓었고, pH 및 온도의 변화도 완만하였다. The author acknowledges with gratitude financial assistance from International Atomic Energy Agency, Vienna, Austria and also sincerely thanks Dr. K. Kawashima and his colleagues, National Food Research Institute, Tokyo, Iapan for encouragement and assistance.

• Parasites, Hosts and Diseases
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• 제56권1호
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• pp.25-32
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• 2018

Molecular techniques have been introduced for malaria diagnosis because they offer greater sensitivity and specificity than microscopic examinations. Therefore, DNA isolation methods have been developed for easy preparation and cost effectiveness. The present study described a simple protocol for Plasmodium DNA isolation from EDTA-whole blood. This study demonstrated that after heating infected blood samples with Tris-EDTA buffer and proteinase K solution, without isolation and purification steps, the supernatant can be used as a DNA template for amplification by PCR. The sensitivity of the extracted DNA of Plasmodium falciparum and Plasmodium vivax was separately analyzed by both PCR and semi-nested PCR (Sn-PCR). The results revealed that for PCR the limit of detection was $40parasites/{\mu}l$ for P. falciparum and $35.2parasites/{\mu}l$ for P. vivax, whereas for Sn-PCR the limit of detection was $1.6parasites/{\mu}l$ for P. falciparum and $1.4parasites/{\mu}l$ for P. vivax. This new method was then verified by DNA extraction of whole blood from 11 asymptomatic Myanmar migrant workers and analyzed by Sn-PCR. The results revealed that DNA can be extracted from all samples, and there were 2 positive samples for Plasmodium (P. falciparum and P. vivax). Therefore, the protocol can be an alternative method for DNA extraction in laboratories with limited resources and a lack of trained technicians for malaria diagnosis. In addition, this protocol can be applied for subclinical cases, and this will be helpful for epidemiology and control.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.639-644
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• 1998

Extracellular serine proteases were isolated from a soil bacterium, alkalophilic coryneform bacterium TU-19, which have been grown in a liquid medium optimized at 3$0^{\circ}C$ and pH 10.0. Three different sizes, 120 kDa (protease I), 80 kDa (protease II), and 45 kDa (protease III), of serine pro teases were purified using Sephadex G-150 and QAE-Sephadex chromatography (Kang et al. 1995. Agric. Chem Biotech. 38: 534-540). SDS-PAGE showed that the 120 kDa protease was degraded into the 80 kDa protease in 20 mM Tris-HCI (pH 8.0) buffer solution. This degradation was enhanced in the presence of 0.5 M NaCl and 5 mM EDTA, but was inhibited in the presence of 5 mM $CaCl_2$. These results indicated that the $Ca^{2＋}$ ion seems to stabilize the 120 kDa protease like other proteases derived from Bacillus species. The $NH_2$-terminal amino acid sequences of the 10 residues of both proteases were completely identical: Met-Asn-Thr-Gln-Asn-Ser-Phe-Leu-Ile-Lys. In contrast to this, the 80 kDa protease has 1.5 times higher specific activity than the 120 kDa protease does (Kang et al. 1995. Agric. Chern. Biotech. 38: 534-540). Therefore the C-terminal of the 120 kDa protease seems to be autolyzed to the 80 kDa protease but this autolysis did not decrease the protease activity. Optimum pH and temperature of both 80 kDa and 120 kDa proteases were pH 10.5 and $45^{\circ}C$, respectively, and pH and thermal stability were almost identical. Several divalent ions except the $Fe^{2＋}$ ion showed similar effects on activities of both proteases, which are similarly resistant to three different detergents.

• 한국식품영양과학회지
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• 제21권3호
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• pp.279-285
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• 1992

황산암모늄 분획 (35-60%) 효소액을 사용하여 Aspergillus fumigatus IFO 5840의 cytidine deaminase에 대한 효소학적 성질을 조사하였다. 효소반응의 전처리시간은 25분이었으며 본 효소의 최적pH와 최적온도는 각각 6.8-7.2와 $37^{\circ}C$부근이었다. PH에 대한 안정성은 pH7.2에서 9.0의 범위에서 안정하였으며 온도의 안정성은 4$0^{\circ}C$에서 10분 열처리시 대체로 안정하였으나 6$0^{\circ}C$에서 20분간 처리시는 77%의 효소실활을 나타내었고 7$0^{\circ}C$에서 25분간 처리하였을때 완전히 실활되었다. 본 효소의 활성화 에너지 값(Ea)은 14.190kca1/mo1이었고 온도계수 ($Q_{10}$ )는 2.163이었다.

• 전자공학회논문지SC
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• 제37권4호
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• pp.49-54
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• 2000

고분자 이온 감응막을 광도파로로 이용한 새로운 형태의 센서소자를 제작하여 칼슘이온의 농도 변화에 따른 그 특성을 평가하였다. 광도파로 소자는 실리카 유리기판에 기존의 반도체 사진식각법 (photolitho-graphy)을 이용하여 도파로가 형성되어질 부분을 에칭한 후 감지막을 스핀코팅법으로 코팅하여, 그 자체를 도파로로 이용한 고속 응답의 새로운 형태의 센서소자를 제작하였다. 도파로로 사용된 감지막은 칼슘이온에 대해 특이성을 가지는 변색성 이온감응물질인 ETH5294, 중성이온감응물질인 K23El, anionic site인 NaTm(CF/sub 3/)/sub 2/PB, 가소제인 DOP 및 PVC-PVAC-PVA 폴리머를 THF 용매에 녹여 스핀 코팅법으로 제작하였다. 여러 가지 변수에 따른 센서의 특성을 평가하기 위하여 도파로의 두께(즉, 감지막의 두께), 변색성 이온감응물질의 농도, 각 모드 변화에 따른 센서의 감응특성을 비교 평가하였다. 제작된 센서는 칼슘이온에 대해 1×10­6∼1M의 측정 범위를 가지며, 1×10­⁴∼1×10­¹M 영역에서 선형성을 가지며, 기존의 광학적 측정 방법인 분광분석법에 비해 높은 감도를 나타냄을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2523-2528
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• 2014

In the present study, at first, azo Schiff base ligand of (N,N'-bis(5-phenylazosalicylaldehyde)-ethylenediamine) ($H_2L$) has been synthesized by condensation reaction of 5-phenylazosalicylaldehyde and ethylenediamine in 2:1 molar ratio, respectively. Then, its cobalt complex (CoL) was synthesized by reaction of $Co(OAc)_2{\cdot}4H_2O$ with ligand ($H_2L$) in 1:1 molar ratio in ethanol solvent. This ligand and its cobalt complex containing azo functional groups were characterized using elemental analysis, $^1H$-NMR, UV-vis and IR spectroscopies. Subsequently, the interaction between native calf thymus deoxyribonucleic acid (ct-DNA) and CoL complex was investigated in 10 mM Tris/HCl buffer solution, pH = 7 using UV-vis absorption, thermal denaturation technique and viscosity measurements. From spectrophotometric titration experiments, the binding constant of CoL complex with ct-DNA was found to be $(2.4{\pm}0.2){\times}10^4M^{-1}$. The thermodynamic parameters were calculated by van't Hoff equation.The enthalpy and entropy changes were $5753.94{\pm}172.66kcal/mol$ and $43.93{\pm}1.18cal/mol{\cdot}K$ at $25^{\circ}C$, respectively. Thermal denaturation experiments represent the increasing of melting temperature of ct-DNA (about $0.93^{\circ}C$) due to binding of CoL complex. The results indicate that the process is entropy-driven and suggest that hydrophobic interactions are the main driving force for the complex formation.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.139-139
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• 2010

Ionic Transition Metal Complex based (iTMC) Light-emitting electrochemical cells (LEECs) have been drawn attention for cheap and easy-to-fabricate light-emitting device. LEEC is one of the promising candidate for next generation display and solid-state lighting applications which can cover the defects of current commercial OLEDs like complicated fabrication process and strong work-function dependent sturucture. We have investigated the performance characteristics of LEECs based on poly (3, 4-ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS)-incorporated transition metal complex, which is tris(2, 2'-bipyridyl)ruthenium(II) hexafluorophosphate in this study. There are advantages using conductive polymer-incorporated luminous layer to prevent light disturbance and absorbance while light-emitting process between light-emitting layer and transparent electrode like ITO. The devices were fabricated as sandwiched structure and light-emitting layer was deposited approximately 40nm thickness by spin coating and aluminum electrode was deposited using thermal evaporation process under the vacuum condition (10-3Pa). Current density and light intensity were measured using optical spectrometer, and surface morphology changes of the luminous layer were observed using XRD and AFM varying contents of PEDOT:PSS in the Ruthenium(II) complex solution. To observe enhanced ionic conductivity of PEDOT:PSS and luminous layer, space-charge-limited-currents model was introduced and it showed that the performances and stability of LEECs were improved. Main discussions are the followings. First, relationship between film thickness and performance characteristics of device was considered. Secondly, light-emitting behavior when PEDOT:PSS layer on the ITO, as a buffer, was introduced to iTMC LEECs. Finally, electrical properties including carrier mobility, current density-voltage, light intensity-voltage, response time and turn-on voltages were investigated.

• KSBB Journal
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• 제9권3호
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• pp.319-324
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• 1994

옥수수잎의 유관속초세포 내에 존재하는 malate dehydrogenase(EC 1.1.1.40)을 이용하여 malate 정량용 biosensor를 제작한 후, 기질인 malate에 대하여 여러 가지 조건하에서 측정한 결과, sodium-alginate로 고정화한 것이 하지 않은 것보다 180시 간까지 지나도 40% 이상의 activity를 가지며, 최적 pH는 8.0이었으며 pH 7.4에서 Km치는 $0.6{\times}10^{-5}M$이였다. 전극의 안정성은 연주일 이상 측정이 가능하였으며, 정량 가능한 범위는 $5.5{\times}10^{-5}M∼2.5{\times}10^{-2}M$ 이며, 감응도는 53.7mv/decade이고, 측 정소요시간은 16~18분이 소요되였다. 방해물질로서 각종 염의 영향은 크게 받지 않음을 알았다. 본 연구에서 제작한 조직 biosensor는 효소분리과정을 거치지 않고 조직을 이용하여 malate흘 정량하였다는 것과 지금까지 연구된 효소 바이오센셔와는 랄리 강산성에셔 측정하던가, 한 가지 이상의 효소를 사용하지 않고도 중성영역인 pH=8에서 측정이 가능 하였으며, malate를 탈수소화하여 정량한 연구는 많았지만, 탈탄산화하여 정량한 연구는 없었다. 본 연구에서 제작한 조직바이오센셔는 malate 측정용 sensor로 가능하리라 생각된다.

• Applied Biological Chemistry
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• 제20권1호
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• pp.26-32
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• 1977

대두(大豆)(Glycine max cultivar Gwang-gyo)의 각 성숙시기(成熟時期)에 나타나는 7S globulin을 분리하여 Davis 방법(方法)에 의한 전기영동과 PAWU용매에 의해서 유리(遊離)되는 그들의 subunit를 전기영동한 결과 7S globulin중의 복합단백질간(複合蛋白質間)에는 그 구성(構成) subunit에 유사성(類似性)이 있음을 시사하였다. 7S globulin의 복합단백질(複合蛋白質)을 DEAE-Sephadex A-50으로 크로마토그라피하여 분리하였다. 이때 pH 7.6의 인산완충액(燐酸緩衝液)에서 NaCl의 농도구배(濃度句配)가 0.28M부터 0.40M 사이에서 두 개의 분획(分劃)으로 분리되었다. 이들 명(名) 단백질(蛋白質)의 subunit를 5M urea와 1% SDS로 유리(遊離)시켜 7.5% acrylamide-PAWU gel과 5.6% acrylamide-SDS gel에서 전기영동하였다. 그 결과 subunit의 하전량(荷電量)에 의해서 분리되는 PAWU gel전기영동에서 7S globulin이 5개의 주 분리대로 분리되고 그중 2개의 분리대가 7S-A globulin과 7S-B globulin에 공유(共有)되어 있었다. 또 subunit의 분자량(分子量)에 따라서 분리되는 SDS gel 전기영동에서는 7S globulin이 7개의 주 분리대를 나타내는데 그 중에서 3개의 분리대가 7S-A와 7S-B 분획에 공유(共有)되어 있었다. 따라서 7S globulin의 복합단백질간(複合蛋白質間)에는 구성(構成) subunit간(間)에 유사성(類似性)이 있는 것으로 나타났다.