• 미생물학회지
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• 제25권2호
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• pp.157-164
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• 1987

고온 혐기성 Clostridium thermocellum의 배양액으로부터 새로운 endo-$\beta$-1, 4-glucanase를 ion exchange chromatography와 gel filtration chromatongraphy를 통하여 정제하였다. 정제된 효소의 비활성은 56배 증가하였으나 수율은 0.7%로서 매우 낮았다. SDS-PAGE, 결과, 정제된 효소는 분자량이 각각 38,000과 58,000으로 된 두 개의 subunit로 구성되어 있었다. 이 효소의 반응 최적 pH는 5.0 최적온도는 $65^{\circ}C$였으며 $70^{\circ}C$까지는 열에 안정하였으나 $80^{\circ}C$에서 거의 실활되었다. 기타 여러 가지 효소학적인 성질을 조사하였으며, 분리된 효소는 결정형 섬유소에 대한 효소활성을 나타내지 않았다.

• 미생물학회지
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• 제42권1호
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• pp.67-72
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• 2006

클로닝된 Bacillus circulans ATCC21367 유래 cellulolytic xylanase 유전자(bglBC2)의 염기서열을 결정 분석하였다. 본 유전자는 1,224 bp의 407개 아미노산을 암호하는 open reading frame (ORF)으로 구성되어 있었으며 염기서열로부터 산출된 유전자의 분자량은 45 kDa으로 효소의 SDS-PAGE로부터 측정된 분자량과 일치하였다. ATG 개시 코돈의 9bp 위쪽에 Shine-Dalgarno (SD) 서열로 추정되는 5'-AAAGGAG-3' 서열이 확인되었고 그 상단에 promoter로 추정되는 -35 서열(TTTACA)과 -10 서열(TATACT)이 위치하고 있었으며, 이는 B. subtilis promoter consensus sequence와 유사하였다. 한편, 이 효소의 아미노산 서열은 이미 보고된 B. circulans KSM-N257의 alkaline $endo-\beta-1,4-glucanase$와는 97%, B. circulans WL-12의 $endo-\beta-1,3-1,4-glucanase$와는 75%, Bacillus sp. KSM-330의 $endo-\beta-1,4-glucanase$ (cellulase)와는 45%의 유사성을 나타내었다. 또한 bglBCS 염기서 열의 정보를 GenBank에 등록하였으며 등록번호는 Ar269256이다.

• 미생물학회지
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• 제44권3호
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• pp.258-263
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• 2008

대표적인 식물병원성 곰팡이 인 Phytophthora infestans와 Fusarium oxysporum의 생장을 저해하는 근권세균들을 토양에서 분리하여 동정하였으며 이 균주들이 분비하는 항진균성 물질인 siderophore, $\beta-1$,3-glucanase, hydrogen cyanide와 chitinase의 생성능을 조사하였다. 분리균주 중 Bacilus sp. RFO41은 F. oxysporum의 생장을 가장 효율적으로 억제하였으며, siderophore 생성능과 $\beta-1$,3-glucanase의 활성이 가장 우수하였다. 또 다른 분리균주인 Bacilus sp. PS2는 P. infestans의 생장을 가장 많이 억제하였으며, chitinase 활성과 hydrogen cyanide 생성능이 가장 우수하였다. F. oxysporum과 P. infestans에 대한 항진균 효과는 근권세균이 생산하는 siderophore, $\beta-1$,3-glucanase, hydrogen cyanide와 chitinase의 활성에 따라 차이가 있음을 알 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제21권9호
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• pp.1324-1329
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• 2008

This study was conducted to evaluate the potential of the transformed Lactobacillus reuteri Pg4 (T-Pg4) harboring the ${\beta}$-glucanase gene as a poultry probiotic. The probiotic properties of the T-Pg4 strain were evaluated in vitro by their adherence capability and acid and bile salt tolerance, and were evaluated in vivo by their survival and adhesion in the gastrointestinal tract (GIT) of specific-pathogen-free (SPF) chickens. The results showed that the T-Pg4 strain exhibited resistance to acidic conditions and contact with bile salt, and adhered efficiently to the crop and intestinal epithelial cells of chickens in vitro. The T-Pg4 strain also could survive and colonize the gastrointestinal epithelium of the experimental SPF chickens in vivo. In addition, radial enzyme diffusion was used to demonstrate that the Lactobacillus spp. randomly isolated from the GIT of the SPF chickens fed T-Pg4 possessed ${\beta}$-glucanase secretion capability. These findings have demonstrated that the transformed L. reuteri Pg4 survives transit through the stomach and intestine, and may secrete ${\beta}$-glucanase in the chicken GIT. Therefore, it is suggested that this organism could be used as a multifunctional poultry probiotic.

• Applied Biological Chemistry
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• 제37권1호
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• pp.43-48
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• 1994

벼 세포 현탁배양여액으로부터 chitooligosaccharides에 의해 유도된 염기성 단백질 ICG를 순수분리하였다. 본 단백질은 chitin과 laminarin을 가수분해하므로 chitinase와 ${\beta}-1,3-glucanase$ 활성을 함께 보유하고 있는 것으로 나타났으며, 벼잎 단백질 RCG-2와는 달리 lysozyme 활성을 가지고 있지 않았다. 분자량이 52.53 kd인 본 효소의 chitinase 활성은 pH 5.0, $60^{\circ}C$, ${\beta}-1,3-glucanase$ 활성을 pH 4.0, $40^{\circ}C$의 조건에서 최대로 나타났다.$NAG_5$에 대한 $K_M$ 및 $V_{max}$ 수치는 각각 0.474 mM, 2.997 nM/min., laminarin에 대한 것은 각각 1.004 mM, 0.739 nM/min.로 나타나, ICG는 RCC-2보다 높은 기질친화성을 가지고 있으며 chitin을 chitooligosaccharide로 분해하는 endo형 chitinase로 판명되었다.

• 한국미생물·생명공학회지
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• 제23권6호
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• pp.652-658
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• 1995

We attempted simultaneous expression of genes coding for endoglucanase and $\beta $-glucosidase from Pseudomonas sp. by using a synthetic two-cistron svstem in Escherichia coli and Saccharomyces cerevisiae. Two-cistron system, 5'--tac promoter-endoglucanase gene--$\beta $-glucosidase gene-- 3', 5'-tac promoter--$\beta $-glucosidase gene--endoglucanase gene--3' and 5'-tac promoter--endoglucanase gene--SD sequence--$\beta $-glucosidase gene--3, were constructed, and expressed in E. coli and S. cerevisiae. The E. coli and S. cerevisiae contained two-cistron system produced simultaneously endoglucanase and $\beta $-glucosidase. The recombinant genes contained the bacterial signal peptide sequence produced low level of endoglucanase and $\beta $-glucosidase in S. cerevisiae transformants: Approximately above 44% of two enzymes was localized in the intracellular fraction. The production of endoglucanase and $\beta $-glucosidase in veast was not repressed in the presence of glucose or cellobiose. The veast strain contained recombinant DNA with two genes hydrolyzed carboxvmethyl cellulose, and these endoglucanase and $\beta $-glucosidase degraded CMC synergistically to glucose, cellobiose and oligosaccharide. This result suggests the possibility of the direct bioconversion of cellulose to ethanol by the recombinant yeast.

• 미생물학회지
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• 제25권4호
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• pp.339-345
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• 1987

A bacterium K-4-3, producing $\beta$-glucan hydrolyzing enzyme, was isolated from soil and identified to be Bacillus subtilis by its morpholohical and physiological characteristics. $\beta$-glucan was coloured using cibacron blue 3G-A and cross linded by the addition of 1, 4-butanedioldiglycidyl ether. This substrate was used for the isolation of $\beta$-glucanase producing microorganism. The $\beta$-glucan hydrolyzing enzyme actibity from isolated K-4-3 strain was also measured using the modified substrate. Bacillus subtilis K-4-3 produced the highest extracellular $\beta$-glucan hydrolyzing activity in the basal medium containing $\beta$-glucan as a carbon source, peptone and tryptone as a nitrogen source, and magnesium sulfate as an inorganic salt. The optimum temperature and initial pH for $\beta$-glucanase production by Bacillus subtilis K-4-3 were $37^{\circ}C$ and pH6. The highest enzyme activity was obtained at the culture age of 54 hrs with rotary shaking at $37^{\circ}C$. The crude enzyme showed the highest activity at pH 7.5-8.0 and $65^{\circ}C$.

• 한국미생물·생명공학회지
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• 제16권2호
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• pp.79-84
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• 1988

$\beta$-Glucan 분해효소의 간편하며 예민한 활성도 측정방법으로 $\beta$-glucan에 색소와 cross linking agent를 접합시키는 변형기질 제조시 영향을 미치는 조건을 조사하고 맥아와 세균의 $\beta$-glucan분해효소 측정에 적응시켜 활성도를 측정한 결과는 다음과 같다. 1.0g $\beta$-glucan은 0.1N NaOH용액에서 색소 cibacron blue 3 G-A 1.5g과 cross linking agent인 1,4-butanedioldiglycidyl ether 1.25 $m\ell$을 90분간 끓여서 색소 접합기질로 제조하였을 때 $\beta$-glucanase 활성도 측정에 최적조건이었다. 변형기질은 pH5.3 에서 안정성을 보였으며 Bacillus subtilis K-4-3에서 추출한 효소액에 변형기질을 반응시켰을 때 간편하고 정확한 효소활성 측정이 가능하였다. 또한 색소방법을 DNS방법과 비교한 결과 색소방법이 $\beta$-glucan 분해효소 측정에 적당한 방법이었음이 입증되었다.

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.467-473
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• 2010

To improve the expression efficiency of recombinant endo-$\beta$-1,4-glucanase in P. pastoris, the endo-$\beta$-1,4-glucanase (egI) gene from Aspergillus niger was synthesized using optimized codons. Fourteen pairs of oligonucleotides with 15 bp overlap were designed and the full-length syn-egI gene was generated by two-step PCR-based DNA synthesis. In the synthesized endo-$\beta$-1,4-glucanase gene syn-egI, 193 nucleotides were changed, and the G+C content was decreased from 54% to 44.2%. The syn-egI gene was inserted into pPIC9K and transformed into P. pastoris GS115 by electroporation. The enzyme activity of recombinant P. pastoris stain 2-7# reached 20.3 U/ml with 1% barley $\beta$-glucan and 3.3 U/ml with 1% carboxymethylcellulose (CMC) as substrates in shake flasks versus 1,270.3 U/ml and 220.7 U/ml for the same substrates in 50-1 fermentors. The molecular mass of the recombinant protein was approximately 40 kDa as determined by SDS-PAGE analysis, the optimal temperature for recombinant enzyme activity was $70^{\circ}C$, and the optimal pH was 5.0 when CMC was used as the substrate.

• 한국작물학회지
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• 제43권1호
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• pp.19-22
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• 1998

Effects of acute anoxia on carbohydrate hydrolytic enzyme activities and free amino acid contents in malt were examined. Malts were prepared with barley grains germinated for 7 days which contained the highest levels of amylolytic and(1-3,1-4)-$\beta$-glucanase activities. $\alpha$-Amylase and $\beta$-amylase activities in malts were not significantly affected by anoxia for 5 or 10 h.(1-3,1-4)-$\beta$-Glucanase activity, however, decreased about 7 to 10% by anoxia for 5 or 10 h. Alanine and $\gamma$-aminobutyric acid content changed drastically. Alanine contents in malts increased by 2.2- and 2-fold, and $\gamma$-aminobutyric acid contents by 1.4- and 1.9-fold under anoxia for 5 and 10 h, respectively.