• 한국미생물·생명공학회지
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• 제22권1호
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• pp.65-72
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• 1994

Purification and characterization of pectate lyase from Bacillus sp HSA-925. Bacillus sp. HSA-925 isolated from soil produced constitutively an extracellular pectate lyase when cultivated in LB broth. The pectate lyase(EC 4.2.2.2) was purified from the cuylture broth by preciptation with ammonium sulfate, followed by column chromatography on CM-cellulose C-50 and repeated gel filtration on Sephadex G-75G. The enzyme had a molecular weight of 32-33 kDa. The activity was mazimum at pH 9.5 AND 45$\CIRC $C. The enzume activity was stable at 55$\circ $C for 15 min and between pH7-12. The activation energy, Km and V$_{max}$ for the pectate lyase were 5.8779 kcal/mol, 6.33$\times $10$^{-2}$ mol/ml and 2.09$\times $10$^{2}$ $\mu $mol/min respectively. The enzyme was activated by Ca$^{2+}$, Cu$^{2+}$ and inhibited by Li$^{+}$, Hg$^{2+}$, EDTA.

• 한국식품영양과학회지
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• 제27권3호
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• pp.441-447
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• 1998

A bacterial strain No. 43 was isolated from soil samples as a levan-assimiating microorganism producing an extracellular levanase and hydrolying levan to levanbiose. According to the taxonomic characteristics of its morphological and physiological properties, the strain was idenified as Pseudomonas sp. No. 43. The optimum culura medium was composed of 10g levan, 5g(NH4)2SO4, 3g NH4Cl, 3g polypepton, 1g K2HPO4, 0.5gMgSO4.7H2O, and 0.2g MnCl2.4H2O per liter. The cultivation for levanase was carried out in pH 7.0 at 4$0^{\circ}C$ for 28hr. The reaction product was a kind of oligosaccharide and it was purified by chilled ethanol precipitation and gel filtration for evalluation of degree of polymerization (DP). The purified product was determined as levanbiose of MW 342 and DP2 by HPLC and FAB-MS.

• Journal of Microbiology and Biotechnology
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• 제1권2호
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• pp.85-89
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• 1991

The aim of this study is to elucidate characteristics of ${\beta}-lactamase$ inhibitor produced by Streptomyces sp. SMF-19 isolated from soil was found to produce proteinaceous extracellular ${\beta}-lactamase$ inhibitor. The ${\beta}-lactamase$ inhibitor was purified through ammonium sulfate fractionation, gel filtration, anion exchange chromatography and fast performace liquid chromatography. The molecular weight of the ${\beta}-lactamase$ inhibitor was estimated to be about 48,000 by SDS-PAGE. The mode of inhibition against penicillin G as a substrate was uncompetitive. The ${\beta}-lactamase$ inhibitor was stable in wide pH range but unstable at high temperature above $50^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• 제3권3호
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• pp.174-180
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• 1993

A strain SMF14 producing an extracellular $\beta$-lactamase was isolated from soil and identified to be a strain of Streptomyces aureofaciens. $\beta$-Lactamase was purified from the cell free culture broth through batchwise hydroxyapatite adsorption, anion exchange chromatography on DEAE Sephadex A-50, gel filtration on Sephadex G-75, and adsorption chromatography on hydroxyapatite. The molecular mass was estimated to be about 43 kDa by SDS-PAGE. The $\beta$-lactamase had substrate specificity to penicillins and it was inhibited by clavulanic acid, being classified to the group 2a of penicillinase.. The optimal reaction pH and temperature were pH 6.0~7.5 and $50^{\circ}C$. The $K_m, and V_{max}$ values of $\beta$-lactamase for penicillin G were calculated to be 1.72 mM and 5.4$\times$$10^5 \mu M \cdot min^{-1}$, respectively.

• 한국미생물·생명공학회지
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• 제19권5호
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• pp.439-443
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• 1991

A strain of Streptomyces sp. isolated from soil was found to produce extra-cellular $\beta$-lactamase associated partially to the cell growth. The $\beta$-lactamase was purified from the culture supernatant through anmonium sulfate fractionation, ion-exchange chromatographies and gel filtration. The final purification fold and recovery yield were 57 and 6.2%, respectively. Molecular weight of the $\beta$-lactamase was estimated to be about 67, 000 by SDS-polyacrylamide gel electrophoresis. The optimal reaction condition was at pH 7-8 and at 35-$45^{\circ}C$. The $K_m$ and $V_{max}$ values of the enzyme for penicillin G were estimated to he 3 mM and $3\times 10^3$ $\mu\textrm{M}$/min/mg protein, respectively. The purified $\beta$-lactamase was classified to the class A enzyme hydrolyzing only penicillin.

• 한국미생물·생명공학회지
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• 제24권4호
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• pp.445-451
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• 1996

The strain YCH-37, which produces yeast cell wall lytlc enzyme, was isolated from soil. From the microscopic observation, morphological and cultural characteristics, this strain was identified to fungus, Dicyma sp. So, we named this strain as Dicyma sp. YCH-37. The lytic enzyme effectively lysed Salmonella typhimurium among intact living bacteria and Torulopsis, Hansenula, Zygosaccharomyces among intact living yeast, as well as autoclaved yeast strains. The yeast cell wall lytic enzyme was succesively purified to 204 folds with 13% yields through yeast glucan affinity adsorption and DEAE-cellulose column chromatography. The enzyme was identified to monomeric protein with molecular weight of 25,000 daltons from the results of SDS-PAGE and gel filtration. The optimum pH and temperature for the yeast lytic activity were 8.0 and 50$\circ$C, respectively. The enzyme was stable up to 40$\circ$C, and between pH 4.0-pH 10.0.

• 한국식품영양과학회지
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• 제20권4호
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• pp.388-394
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• 1991

Alkaline protease producing bacteria were isolated from soil and identified as Bacillus sp. CW-1121. It was found that the production of alkaline protease reached to maximum in 5 day of fermentation at 4$0^{\circ}C$. The enzyme was purified by ammonium sulfate precipitation, gel filtration on Sephadex G-150 and DEAE-cellulose ion-exchange chromatography. The homogeneity of the purified enzyme was verified by polyacrylamide gel electrophoresis. The enzyme was purified 5.72 fold and yield of the enzyme purification was 16.71%. When the purified enzyme was applied to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the molecular weight was estimated to be 55, 000.

• 한국미생물·생명공학회지
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• 제28권4호
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• pp.233-238
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• 2000

To develop biodegradable and safe flocculant, Achromobacter sp. HY-66 were isolated from soil. The purified flocculant was composed of fructose and glucose in an approximate molar ratio of 1:24. Molecular weight was approximately 9$\times$105 dalton by Sepharose CL-4B gel filtration chromatography. Elemental analysis revealed that the contents of carbon, hydrogen and oxygen were 37.72%, 5.37% and 56.89%, respectively. The presence of O-H stretching, C-H streching, carboxy ester and C-H bending were confirmed by IR absorption spectrum analysis. We suggest that a bioflocculant produced from Achromobacter sp. YJ-66 is new and different from other bioflocculants.

• Journal of Microbiology and Biotechnology
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• 제7권6호
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• pp.386-390
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• 1997

A xylanase from the Bacillus sp. strain DSNC 101, isolated from soil, was purified to homogeneity by anion-exchange and hydrophobic interaction chromatography followed by gel filtration chromatography. The enzyme cleaved xylan, but not carboxymethyl cellulose, Avicel, soluble starch, and pNPX. The main product of oat spelts xylan hydrolysates was xylobiose. The xylanase had a molecular weight of 25 kDa determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Optimum temperature and pH for the xylanase activity were $50^{\circ}C$ and 6.0, respectively. $K_{m}\;and\;V_{max}$ of the enzyme for oat spelts xylan were 12.5 mg of xylan/ml and 869.5 unit/mg of protein, respectively. Xylanase was completely inhibited by Hg, Cu, and N-bromosuccinimide, but was stimulated by Ca, Co, and Mg.

• Applied Biological Chemistry
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• 제42권2호
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• pp.99-104
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• 1999

제주도내 25개 지점의 토양시료로부터 총 703 주의 방선균을 분리하였다. 네 종류의 배지 중 soil extract를 함유한 arginine glycerol salts agar가 다양한 방선균을 분리하는데 가장 적합하였으며, 목장초지 토양이 다른 지역의 토양에 비해서 방선균의 다양성과 밀도면에서 가장 좋은 분리원이었다 순수분리된 526개의 균주를 대상으로 Escherichia coli, Staphylococcus aureus 및 Pseudomonas solanacearum을 검정균으로 하여, 항균성 물질 생산여부를 검정한 결과, 생산균주의 발생빈도는 분리 및 배양에 사용한 배지의 종류에 따라서 $0{\sim}32.8%$로 많은 차이를 보였다. 세 종류의 검정균에 대하여 동시에 항균활성을 나타내는 10개 균주 중에서 pH 안정성과 열 안정성이 비교적 높은 물질을 생산하는 BL106Ba균주를 선택하여 등정한 결과, Streptomyces속에 속하며 S. albosporeus와 가장 유사한 것으로 추정되었다. B1106Ba의 배양액을 양이온 교환수지(AG MP-50)통과와 3차의 분자량 분획(Sephadex G-10)으로 정제하여 얻은 백색의 결정은 그람 음성균 및 양성균에 대해서는 강한 항균활성을 나타내었으나, 효모에 대해서는 약한 활성을 나타내었다. 이 결정 물질을 TLC와 HPLC로 분석한 결과 네 종류의 서로 다른 항균성 화합물이 혼합되어 있는 것으로 나타났다.