• The Korean Journal of Food And Nutrition
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• v.5 no.2
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• pp.144-149
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• 1992

Invertase was extracted from Korean ginseng(Panax ginseng C. A. Meyer) leaf with deionized water, and then prepared by ammonium sulfate(0.4~0.6 Sat.) fractionation, the enzymological properties of the invertase were investigated, and the results obtained were as follows. The optimum pH and temperature of the enzyme were pH 6.0 and 4$0^{\circ}C$ respectively. The enzyme was stable in the pH range of pH 6.0 to 8.0, and at the temperature below 4$0^{\circ}C$. The enzyme was inactivated completely by the treatment with some proteases(pepsin, trypsin, papain and ficin) and protein denaturants(8M urea and 6M guanidine-HCI), but not with glycosidases (a-amylase, $\beta$-amylase and glucoamylase). The enzyme catalyzed specifically the hydrolization of the $\beta$-fructofuranosides such as sucrose and inulin.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.143-143
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• 1993

현재 시판되고 있는 정장용 생균 제제에 함유되어있는 정장 균주의 하나인 Bifidobacterium bifidum은 항결핵제 중 rifampicin에 감수성으로 rifampicin과 병용 투여시 본래의 정장 효과를 기대할 수없다. 따라서, rifampicin에 내성인 돌연변이 균주를 얻기 위해 B. bifidum을 N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)로 처리하여 rifampicin에 내성인 30 종의 균주를 선별하였고, rifampicin에 대한 Minimal Inhibitory Concentration (MIC)를 측정해 본 결과 내성이 1,000 배 이상 상승하였다. 균주 동정을 위하여 fructose-6-phosphate phosphoketolase test를 실시해 본 결과 Bifidobacterium임이 확인되었다. 이들 내성 균주들의 유기산 생산량을 측정하여 그 생산량이 모균주와 가장 유사한 3 종의 균주를 선발하였다. 이들에 대하여 Escherichia coli 생육 억제능을 시험해 본 결과 E. coil 생육 억제능이 모균주와 유사하였다. 또, rifampicin을 함유한 배지에서 돌연변이 균주를 배양시킨 경우 rifampicin이 안정한 상태로 잔존한 것을 알 수 있었다. 이것으로 보아 돌연변이 균주들은 rifampicin을 분해 또는 변형시키는 효소를 생산하지 않는다고 볼 수 있다. 이상의 결과로 본 연구에서 개발한 돌연변이 균주들, 즉 B. bifidum RFRll, RFR21 그리고 RFR61은 rifampicin에 내성이면서 모균주와 동일한 생화학적 특성을 갖는 정장 균주로 여겨진다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.126-126
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• 1995

본 연구는 중금속에 의한 생체내 독성기전을 연구하고자 흰쥐간의 상층액에서 카드뮴과 잘 결합하는 HMWP들을 분리, 정재하고 나아가 생화학적 특성을 밝히고 이단백질이 카드뮴에 의해 생성되는 것인지 아니면 간의 기존 단백질인지를 밝히고자 함을 연구의 목적으로 하였다. CdCl %2 (3mg/kg body wt.)을 3일간 ip injection시킨 후 흰쥐의 간을 적출하고 균질화하여 원심분리한 crude extract를 직접 Sephacryl S-100에 흡착시켜 10mM phosphate buffer(pH 7.0)으로 용출시켰다. 용출된 fraction tube를 UV spectrometer로 흡광도를 측정하고 atomic absorption spectrophotometer로 카드뮴량을 측정하여 카드뮴량이 높은 분획을 모아서 ion exchange column chromatography(DEAE-Sepharose)에 흡착시켜 염농도 구배로 chromatography를 실시하고, 음이온 교환수지에서 흡착되지 않고 용출된 분획을 ultrafiltration으로 농축시킨 후 S-Sepharose에 흡착시켜 염농도 구배로 chromatography를 실시한 결과 두 종류의 카드뮴 결합 단백질(Cd-BP)를 분리, 정제하였다.

• Korean Journal of Veterinary Service
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• v.22 no.1
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• pp.79-84
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• 1999

This study was carried out to investigate isolation of Pasteurella multocida from pneumonic lungs of slaughtered animals in Kyungsan abattoir to examine the antimicrobial susceptibility and biochemical properties. The results were summarized as follows ; P multocida was isolated from 50(29.2% ) of the 171 pneumonic lungs collected individually from cattle(3/40), goats(0131) and pigs(47/100), All of the isolated P multocida showed biocemical and cultural properties similiar to reference strains. All isolates were very susceptible to AK, AM, ENR, CF, GM,07, whereas resistant to SDM.

• Korean Journal of Veterinary Research
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• v.23 no.2
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• pp.165-172
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• 1983

The distribution of slide coagulase-negative staphylococci isolated from bovine mastitic milk samples was investigated mainly according to Kloos and Schleifer's classification scheme, and toxigenic and enzymatic characteristics of these strains were also examined. One-hundred-and-twenty-one strains of coagulase-negative staphylococci isolated were classified into 8 species. Of these species, Staphylococcus epidermidis, Staph. xylosus, Staph. haemolyticus and Staph. simulans were more frequently found in bovine mastitic milk samples, and toxin and enzyme production of these species were observed in relatively high frequency. Staph. hyicus subsp. hyicus was isolated from the 4 quarters with clinical mastitis included in this investigation. By the use of Baird-Parker and Pelzer's classification system, 44.6% and 18.2% of the strains could not be classified in any subgroup, respectively.

• Journal of Life Science
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• v.11 no.3
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• pp.230-234
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• 2001

The cyclodextrin glucanotransferase(CGTase) gene of Bacillus macerans was expressed in Saccharomyces cerevisiae and the recombinant CGTase was partially purified from the yeast culture supernatant. The optimal pH and temperature of the CGTase were found to be 6.0 and 5$0^{\circ}C$, respectively. The pH and temperature stabilities of the recombinant enzyme were significantly enhanced and the half life at 55$^{\circ}C$ was about 60 hr. When the recombinant CGTase was reacted with 5% soluble starch, the conversion yield of total cyclodextrin (CD) from starch was estimated to be 41% at 48 hr, whereas the wild type enzyme showed the yield of 12%. This improvement of conversion yield and thermal stability of CGTase may be useful for the development of low-cost CD production process.

• YAKHAK HOEJI
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• v.35 no.5
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• pp.444-455
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• 1991

Two kinds of new lectin fractions (LOA-I, LOA-II) were obtained from loach (Misgurnus spp.) meat by 0.15 M NaCl extraction, salt fractionation, ion exchange and hydroxyapatite column chromatographies. On polyacrylamide gel electrophoresis, LOA-I exhibited one major and a few minor bands, but LOA-II exhibited three minor bands. The partially purified loach lectins agglutinated not only erythrocytes of human B and AB type, rabbit, dog, but also murine splenic lymphocytes. Agglutinability was relatively labile at various pH and stable at increasing temperature, but was not affected by tested several metal ions. By the sugar specificity test, D-glucosamine and metyl-$\beta$-galactopyranose inhibited agglutinating activity at a final concentration of 3 mM. The lectins contained relatively high amounts of aspartic acid, valine and leucine, but sulfur containing amino acids, cystein, methionine and isoleucine were not determined. LOA-I, LOA-II lectins were nonmitogenic toward murine lymphocytes.

• YAKHAK HOEJI
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• v.48 no.1
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• pp.13-19
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• 2004

A bacterial expression vector for the human foamy virus (HFV) integrase was constructed and expressed in Escherichia coli. By two-step purification using a nickel-chelated column and a SP-sepharose chromatography; the HFV into-grase protein of 43 kDa was purified to near homogeneity, and used to investigate biochemical characteristics of the enzymatic activities, such as endonucleolytic and disintegration activities. Oligonucleotide substrates were specifically and efficiently cleaved by the purifed HFV integrase in the presence of Mn $^{+2}$, but not in the presence of Mg $^{+2}$, indicating that the HFV integrase is not able to use Mg $^{+2}$ as a cofactor Endonucleolytic reaction was almost completed in 60 min at 37 $^{\circ}C$. In addition, the maximum enzymatic activities were observed at 5 mM Mn $^{+2}$ in the buffer of which pH was from 7.0 to 9.0. The endonucleolytic activities were dose-dependently blocked in the addition of baicalein or chicolic acid which is a well-known inhibitor of human immunodeficiency virus integrase.

• Proceedings of the Membrane Society of Korea Conference
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• 1992.10a
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• pp.10-11
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• 1992

막분리 공정의 응용범위 및 시장규모가 증가함에 따라 최근 기능성 분리막의 개발에 대한 많은 연구가 시도되고 있으나 아직까지도 매우 한정된 범위의 유기질 분리막만이 실용화되고 있을 뿐이다. 막분리 공정의 응용성은 분리막의 특성에 의하여 좌우될수 있는데 현재 주로 사용되고 있는 유기질막은 열적, 기계적, 화학 및 생화학적 안정성이 낮고 세척에 의한 재생성이 용이하지 않기 때문에 차후이들을 대체하여 모든 조업조건하에서 효율적으로 장기간 사용될 수 있는 세라믹막의 개발이 요구되고 있는 실정이다. 특히 2000년도 초반부터는 종래의 유기질막으로서는 기대할 수 없는 고기능성을 부여할 수 있는 세라믹막의 공업적 수요가 급증하여 분리막 공정에서 상당한 비중을 점유하게 될 것으로 예상되고 있으나 현재 전 세계적으로 세라믹막의 제조 및 응용에 대한 기초 및 기술이 확립되어 있지 않아서 공업적인 실용화가 이루어지지 못하고 있다.

• Korean Journal of Veterinary Service
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• v.16 no.2
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• pp.150-156
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• 1993

The present study was conducted to investigate the biochemical characteristics and anti-biotic resistance of pathogenic Escherichia coli (E. coli) isolated from piglets with diarrhea in Kyongbuk Western Area during the period from February to November 1992. 55 E. coli strains were isolated from 97 piglets with diarrhea and the biochemical and cultural reaction were compared with the classification criteria of Edwards and Ewing. The majority of E. coli were susceptible to amikacln, enrofloxacin and gentamicin. 51 (92.7%) out of 55 drug resistance stains carried R factor (R+) which were transferable to the recipients by conjugation.