• Journal of Microbiology and Biotechnology
• /
• 제18권3호
• /
• pp.457-464
• /
• 2008

An extracellular enzyme (RMEBE) possessing ${\alpha}-(1{\rightarrow}4)-(1{\rightarrow}6)$-transferring activity was purified to homogeneity from Rhodothermus marin us by combination of ammonium sulfate precipitation, Q-Sepharose ion-exchange, and Superdex-200 gel filtration chromatographies, and preparative native polyacrylamide gel electrophoresis. The purified enzyme had an optimum pH of 6.0 and was highly thermostable with a maximal activity at $80^{\circ}C$. Its half-life was determined to be 73.7 and 16.7 min at 80 and $85^{\circ}C$, respectively. The enzyme was also halophilic and highly halotolerant up to about 2M NaCl, with a maximal activity at 0.5M. The substrate specificity of RMEBE suggested that it possesses partial characteristics of both glucan branching enzyme and neopullulanase. RMEBE clearly produced branched glucans from amylose, with partial ${\alpha}-(1{\rightarrow}4)$-hydrolysis of amylose and starch. At the same time, it hydrolyzed pullulan partly to panose, and exhibited ${\alpha}-(1{\rightarrow}4)-(1{\rightarrow}6)$-transferase activity for small maltooligosaccharides, producing disproportionated ${\alpha}-(1{\rightarrow}6)$-branched maltooligosaccharides. The enzyme preferred maltopentaose and maltohexaose to smaller maltooligosaccharides for production of longer branched products. Thus, the results suggest that RMEBE might be applied for production of branched oligosaccharides from small maltodextrins at high temperature or even at high salinity.

• 한국식품영양과학회지
• /
• 제22권2호
• /
• pp.240-245
• /
• 1993

정제효소의 최대활성 pH는 8.0이고, 최대활성온도는 37$^{\circ}C$였으며, pH 6.5이하 9.5이상의 영 역에서는 상당히 불안정하였고, 3$0^{\circ}C$이상의 온도에서도 불안정한 효소였다. NaCl이 첨가되지 않을 경우 효소 활성이 나타나지 않았고, NaCl 0.5M일 때 최대활성을 보였다. 미량의 CaC $l_2$ 첨가로 활성의 증대를 가져왔고, HgC $l_2$, CoC $l_2$ 및 ZnC $l_2$등에 의해서는 활성이 현저히 억제되었다. L-cysteine과 2-mercaptoethanol에 의해서는 활성이 증대되었고, ο-phenanthroilne, $\rho$-CMB, EDTA 및 iodoacetate에 의해서는 활성이 현저히 저해되었다. 정제효소의 $K_{m}$ (반응속도 정수)은 0.717%였고, $V_{max}$(최대반응속도)는 15.39U/mg 이었다. 본 정제효소는 알긴산(alginic acid)에만 특이적으로 작용하는 alginate lyase 계열의 효소였다.

• 미생물학회지
• /
• 제29권6호
• /
• pp.345-352
• /
• 1991

A serine proteinase of molecular weight 60 kd was purified from culture supernatant of P. aeruginosa using DEAE-Trisacryl M ion-exchange and AcA 54 gel filtration column chromatography, and the properties of serine proteinase were characterized. By means of SDS-polyacrylamide gel electrophoresis, the molecular weight of the enzyme was 55 kd. The optimal pH for the activity of purified enzyme was 7.5. The activity of the purified enzyme was completely inhibited by Di-isopropylfluorophosphate(DFP) and N-.alpha.-p-tosyl-L-lysine choloromethyl detone(TLCK) but not by other proteinase inhibitors such as E-64, pepstatin A, 1, 10-phenanthroline. The purified enzyme was capable of degrading type I and type IV collagen. Antisera obtained from hymans infected with Pseudomonas aeruginosa reacted to the purified serine proteinase in immunoblots. These results indicate that the purified enzyme is trypsin-like serine proteinase and this enzyme of P. aeruginosa may play an important role in tissue damage as a spreading factor and may be useful for serodiagnosis of Pseudomonas infections.

• 미생물학회지
• /
• 제26권4호
• /
• pp.362-367
• /
• 1988

The strain YL 38-3, which was capable of producing extracellular cytosine deaminase, was isolated and taxonomically examined. The isolated strain was identified to be Bacillus polymyxa YL 38-3. The optimal conditions for the enzyme production from Bacillus polymyxa YL 38-3 were investigated. The enzyme production was reached maximum level in the medium containing 0.5% glucose, 0.2% beef extract, 0.5% NaCl and 0.1% $KH_{2}PO_{4}$ (pH 6.0). And the enzyme showed the highest activity when the strain YL 38-3 was cultivated at $35^{\circ}C$ for 24 gours under the initial pH 6.0. By the additions of peptone the extracellular enzyme production was inhibited, meanwhile the intracellular enzyme production was highly stimulated. It was, therefore, deduced that peptone was related to the secretion mechanism of the enzyme from this bacterial cell.

• 한국버섯학회지
• /
• 제15권3호
• /
• pp.134-138
• /
• 2017

양송이의 국내 생산량은 9,732톤으로 5번째로 가장 많이 생산되는 버섯이다. 양송이가 속한 주름버섯속은 리그노셀룰로오스 분해력을 가진 버섯으로 알려져 있다. 양송이의 영양생장과 생식생장동안 기본적으로 셀룰로오스, 해미셀룰로오스, 리그닌 성분의 분해는 변화한다. 우리는 양송이에서 celluase, xylanase, ligninolytic enzyme의 세포외효소 활성도로 효과적인 생물학적 분해력을 가진 균주를 선발하였다. 각 효소의 생물학적 분해는 0.5% CMC-MMP ((malt-mops-peptone), 0.5% Xylan-MMP, 0.5% ligin-MMP 배지에서 14일 동안 균주들을 배양하여 측정하였다. 그리고 배양된 균사체는 0.2% trypan blue에 염색되었다. MMP배지내 각 효소의 생물학적 분해의 효율성에 따라 선발된 균주 18점은 6개로 그룹화되었다. 또한 이 균주들은 볏짚발효퇴비배지에서의 균사생장과 세포외효소 활성도의 연관성을 알아보기 위해 볏짚발효퇴비배지에서 10일, 20일 각각 배양되었다. 본 연구로 ligninolytic enzyme 활성도가 볏짚발효퇴비배지에서의 균사배양과 상관도가 가장 높아 균주내 ligninolytic enzyme의 활성도 비교로 볏짚발효퇴비배지에서 균사배양이 우수한 균주를 간단하게 선발 할 수 있다고 사료된다.

• 한국균학회지
• /
• 제26권4호통권87호
• /
• pp.496-501
• /
• 1998

송이균사(Tricholoma matsutake DGUM 26001, DGUM 26101, DGUM 26210, FRI 91024)를 사용하여 균사의 효소활성을 측정하였다. $24^{\circ}C$에서 30일간 배양후 그 여액을 조효소 용액으로 사용하였을 때, ${\alpha}-amylase$ 효소의 평균 비활성은 6142.3 unit/mg protein이었다. 배양여액 중의 xylanase의 세포의 효소활성은 상대적으로 높았으나, ${\beta}-glucosidase$, ligninase, CMCase, chitinase, pretense및 lipase의 효소활성은 낮거나 거의 없었다.

• Journal of Applied Biological Chemistry
• /
• 제59권4호
• /
• pp.373-377
• /
• 2016

An extracellular metalloprotease, Btmp, was partially purified from the culture supernatant of Bacillus thuringiensis 29-126, isolated from animal feces collected in a zoological garden in Japan, by ultrafiltration, ammonium sulfate precipitation, and a set of chromatography on Sephadex G-75 and High-Q. The molecular mass of the protease was estimated to be 60 kDa by SDS-PAGE. The enzyme showed optimum activity at $50^{\circ}C$ and pH 6.0, and had a half-life of 14 min at $50^{\circ}C$. The enzyme activity was not influenced by $Na^+$, $K^+$, $As^+$, $Mg^{+2}$, $Ca^{2+}$, $Ba^{2+}$, and phenylmethylsulfonyl fluoride, but it was moderately inhibited by $Zn^{+2}$ at a concentration of 1.0 mM, while the activity was significantly inhibited to less than 50 % by $Cu^{2+}$, $Co^{2+}$, $Cd^{2+}$, and ethylenediaminetetraacetic acid. Interestingly, the enzyme was activated to 178 % by 1.0 mM of $Mn^{2+}$. From these results, it may be suggested that the protease is a novel extracellular manganeseactivated metalloprotease.

• 미생물학회지
• /
• 제31권1호
• /
• pp.93-98
• /
• 1993

수계생태계에서 유기물질의 순환을 이해하기 위하여 팔당호에서 종속영양 활성도와 세균세포의 효소활성의 계절절 변화를 연구하였다. 팔당호 I 의 glucose 전환시간은 수층, 퇴적토에서 2-1,300 시간, 17-170 시간, protein hydrolysate 는 5-900 시간, 15-240 시간, acetic acid 는 4-350 시간, 15-230 시간으로 계절적인 변화를 나타냈다. Glucose, protein hydrolysate, acetate 각각의 호흡율은 수층에서 23-32%, 38-41%, 22-28%로 나타났고 퇴적토에서는 34%, 61% and 41% 로 나타났다. 이 결과로 3가지 유기물질 종류 모두가 수층보다 퇴적토에서는 높은 율로 호흡됨을 알 수 있었다. 한편 세균의 $\alpha$-glucosidase, $\beta$-glucosidase, N-acetyl-$\beta$-D-glucosaminidase, aminopeptidase 활성력을 살펴본 결과 수층에서는 효소 각각에 대해 32-44%, 31-32%, 18-34% 61-67% 의 범위를 나타내었고 퇴적토에서는 34%, 40%, 23% 65%로 나타났다.

• Journal of Microbiology and Biotechnology
• /
• 제17권5호
• /
• pp.745-752
• /
• 2007

A $\beta$-glucosidase from the algal lytic bacterium Sinorhizobium kostiense AFK-13, grown in complex media containing cellobiose, was purified to homogeneity by successive ammonium sulfate precipitation, and anion-exchange and gel-filtration chromatographies. The enzyme was shown to be a monomeric protein with an apparent molecular mass of 52 kDa and isoelectric point of approximately 5.4. It was optimally active at pH 6.0 and $40^{\circ}C$ and possessed a specific activity of 260.4 U/mg of protein against $4-nitrophenyl-\beta-D-glucopyranoside$(pNPG). A temperature-stability analysis demonstrated that the enzyme was unstable at $50^{\circ}C$ and above. The enzyme did not require divalent cations for activity, and its activity was significantly suppressed by $Hg^{+2}\;and\;Ag^+$, whereas sodium dodecyl sulfate(SDS) and Triton X-100 moderately inhibited the enzyme to under 70% of its initial activity. In an algal lytic activity analysis, the growth of cyanobacteria, such as Anabaena flos-aquae, A. cylindrica, A. macrospora, Oscillatoria sancta, and Microcystis aeruginosa, was strongly inhibited by a treatment of 20 ppm/disc or 30 ppm/disc concentration of the enzyme.

• Journal of Microbiology and Biotechnology
• /
• 제14권1호
• /
• pp.178-181
• /
• 2004

A gene encoding an extracellular nuclease was cloned from Aeromonas hydrophila strain ATCC14715. The gene was overexpressed and the enzyme was purified by fusing to maltose binding protein. It was shown that the protein possessed DNase activity on both single-stranded and double-stranded DNAs. It exhibited both endo- and exonuclease activities. It was also shown that the protein had an RNase activity. Possible roles of this extracellular enzyme in the A. hydrophila life cycle are discussed.