• KSBB Journal
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• 제13권2호
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• pp.162-167
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• 1998

The adsorption behaviors of two major cellulase components, endo I and exo II, from Trichoderma viride were investigated using $\alpha$-celluloses with different correlation crystallinity index(Cc) as substrates. The adsorption of cellulase enzyme components was significantly affected by the reaction condition and the physicochemical properties of the cellulose. The $\alpha$-cellulose was hydrolyzed in the presence of cellulase for various periods. The correlation crystallinity index of $\alpha$-cellulose increased with increasing the hydrolysis time. The adsorption was apparently found to obey the first-order kinetics, and the adsorption activation energy(Ea) was calculated from the adsorption rate constant(ka). The value of adsorption rate constant for endo I was larger than that of exo II. This means that endo I are adsorbed more rapidly than exo II. With the increase in correlation crystallinity index, the values of the adsorption rate constants for endo I and exo II decreased, respectively. The activation energy for the adsorption of exo II on the cellulose also was larger than that of endo I. Also adsorption activation energy of endo I and exo II increased with an increase in the crystallinity of sample cellulose.

• KSBB Journal
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• 제13권5호
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• pp.621-625
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• 1998

The raw starch hydrolysis by amylase prepared from alkaline-tolerant Bacillus sp. were investigated. Degree of hydrolysis(%) of 5%(w/v) raw rice, corn and potato starch by this enzyme were about 40, 25 and 20%, respectively. The hydrolysis action on raw starch by change of blue value was similar to the action pattern of exo ${\beta}$-amylase. The hydrolysis products of rice starch were mainly glucose and maltose. Oligosaccarides were also detected. From the above results, this enzyme was considered as exo type ${\alpha}$-amylase. This enzyme activity on the raw starch and the gelatinized starch were 28.40 and 86.60 IU/mg protein, respectively, and the ratio of raw starch-digesting activity to gelatinized starch-digesting activity (raw starch digestivity) was about 32%. The Km values for the raw and the gelatinized starch were 4.22 and 3.0mg/mL, respectively, and the VmaX values were 0.20 and 0.31mg/mL/min, respectively.

• BMB Reports
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• 제37권6호
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• pp.642-647
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• 2004

The lysine residues of Bacillus licheniformis $\alpha$-amylase (BLA) were chemically modified using citraconic anhydride or succinic anhydride. Modification caused fundamental changes in the enzymes specificity, as indicated by a dramatic increase in maltosidase and a reduction in amylase activity. These changes in substrate specificity were found to coincide with a change in the cleavage pattern of the substrates and with a conversion of the native endo- form of the enzyme to a modified exo- form. Progressive increases in the productions of $\rho$-nitrophenol or glucose, when para nitrophenyl-maltoheptaoside or soluble starch, respectively, was used as substrate, were observed upon modification. The described changes were affected by the size of incorporated modified reagent: citraconic anhydride was more effective than succinic anhydride. Reasons for the observed changes are discussed and reasons for the effectivenesses of chemical modifications for tailoring enzyme specificities are suggested.

• 한국생태학회:학술대회논문집
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• 한국생태학회 1998년도 춘계공동 학술발표대회
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• pp.62.1-62.1
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• 1998

• 한국미생물·생명공학회지
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• 제20권5호
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• pp.559-564
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• 1992

섬유소 자원의 효율적 이용을 위하여 강력한 xylan 분해효소 생산 세균을 분리 및 선발하였으며, 형태학적, 배양학적 생리학적 특성을 확인한 결과 Bacillus sp. N25로 동정하였다. 이 균주에 의해서 생산된 효소를 ammonium sulfate precipitation, DAEA-sephadex A-50, Sephadex G-100 column으로 부분 정제하여 얻은 효소의 열안정성은 $50^{\circ}C$에서 30분간 처리시 80의 역가가 잔존 했으며, pH 안정은 pH 6-8 범위에서 30'C에서 10시간 방치 후에도 안정했으며, cellulose 분해능력은 없었으며, $Hg^{2+}$, $Ag^{2+}$, $Mn^{2+}$에 의해 저해되었다. 그리고 최종분해산물은 주로 xylose이므로 exo-type xylanase로 추정된다.

• Mycobiology
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• 제29권3호
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• pp.173-175
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• 2001

The fruit body of Ramaria botrytis DGUM 29001 was used to determine enzyme activities of fruit body. The specific activity of laccase was the highest(6.5 unit/mg$\cdot$protein) and that of $\alpha$-amylase and xylanase was relatively high. However, little or no enzyme activity of $\beta$-glucosidase, CMCase, exo-$\beta$-1,4-glucanase, chitinase, lipase and protease was found.

• 한국미생물·생명공학회지
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• 제18권5호
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• pp.484-489
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• 1990

Bacillus subtilis의 세포내 이눌라아제가 부분정제되고 그의 작용 모드와 일반적 특성이 조사되었다. 이 효소는 gel filtration에 의하여 분자량을 추정하였을 때 49,000이었고, 등진점은 5.2 이었다. 기질에 대한 친화성의 지표인 Km값은 설탕에 대해서는 10mM, 라피노오스에 대해서는 18mM 이었다. 이 효소는 산성쪽에서는 불안정한 단백질로서 pH6.6에서 최대 활성을 보였으며 최적온도는 10분간 반응시켰을 때 50'C였다. 이 효소의 작용모든는 이눌린같은 구조를 가지는 과당 중합체를 과당 끝부분으로부터 하나씩 잘라가는 exo-cleavage 형이었다.

• Journal of the Korean Wood Science and Technology
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• 제25권2호
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• pp.100-109
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• 1997

The objectives of this study was to decrease pollutions of bleaching effluent and was to enhanced brightness of non-chlorine bleached pulps by xylanase treatments. Xylanase cloned Esherichacoli(E. coli) capable of each of endo, exo-xylanase and acetyl-esterase were obtained from Bacillus stearothermophillus. These xylanase was maintained high activity in alkali and high temperature. Especially endo-xylanase would be more active in $60^{\circ}C$ and pH 11. Xylanase pretreatment(X) of unbleached pulp increased brightness, and decreased the degree of delignification. The degree of increase in brightness of pulp due to xylanase pretreatment was similar to non-enzyme treated pulp, regardless of the amount of enzyme added. Therefore, the addition of xylanase of 2 unit was recommended when considering costs of enzyme. The pulp bleached XO sequence had higher brightness and lower Kappa no, than O bleached pulp, while pulp bleached XP sequence had similar brightness and Kappa no. with P bleached pulp. In XOC/D, XOZ and XOP bleaching sequences, brightness and degree of delignification were improved. The C/D and Z stage bleached pulp was good effect on rate of raise in brightness and Kappa no., but P stage bleached pulp had similar level in non-enzyme treated bleaching sequence.

• Bulletin of the Korean Chemical Society
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• 제16권6호
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• pp.498-503
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• 1995

The adsorption behaviors of two major components purified, endo Ⅱ and exo Ⅱ, from Trichoderma viride were investigated using microcrystalline cellulose with different specific surface area as substrates. Adsorption was found to apparently obey the Langmuir isotherm and the thermodynamic parameters, ΔH, ΔS, and ΔG, were calculated from adsorption equilibrium constant,K. The adsorption process was found to be endothermic and an adsorption entropy-controlled reaction. The amount of adsorption of cellulase components increased with specific surface area and decreased with temperature and varied with a change in composition of the cellulase components. The maximum synergistic degradation occurred at the specific weight ratio of the cellulase components at which the maximum affinity of cellulase components obtains. The adsorption entropy and enthalpy for respective enzyme system increased with specific surface area increase. The adsorption entropy was shown to have a larger value with enzyme mixture.

• 한국균학회지
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• 제21권2호
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• pp.106-111
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• 1993

사과 겹무늬썩음병균 Botryosphaeria dothidea에 의해 부패된 사과과실에서 pectin질 분해효소를 추출하여 그들의 활성과 pectin 성분의 변화를 조사하였다. 본 병원균은 exo-polygalacturonase(exo-PG), exo-polymethylgalacturonase(exo-PMG), polygalacturonate-trans -e1iminase(PGTE)와 pectinmethyl-trans-eliminase(PMTE)를 생산하였다. 부패된 사과 과육에서 exo-PG와 exo-PMG는 접종 후 7일째 specific activity가 각각 21.15 및 24.65 units/mg protein으로 높게 나타났다. PGTE와 PMTE의 활성은 7일째 각각 5.60과 7.90 uints/mg protein으로 나타났으나 exo-type의 효소보다는 그 활성이 낮았다. 수용성 pectin은 부패가 진행됨에 따라 14일째에 11.50 mg/100 mg-AIS이었고, versene-soluble pectin 역시 7.31 mg/100 mg-AIS로 나타나 건전과와 비교하여 각각 4.23 및 2.16 mg/100 mg-AIS 증가하였다. 부패과의 총 가용성 펙틴 함량은 총 pectin의 72.4%로서 건전과와 비교하여 24.8% 더 높았다. 불용성 pectin 함량은 부패가 진행됨에 따라 15.32 mg/100 mg-AIS에서 7.16 mg/100 mg-AIS로 현저하게 감소하였으며, 총 pectin 함량은 큰 변화가 없었다.