• Journal of Microbiology and Biotechnology
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• 제8권2호
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• pp.141-145
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• 1998

Overproduction of intracellular ${\beta}$-glucosidase was attempted by modifying the promoter region of a ${\beta}$-glucosidase gene cloned from Cellulomonas fimi and expressing it in Bacillus subtilis DB 104. A strong engineered promoter, BJ27UΔ88, was fused to the ${\beta}$-glucosidase gene after removing its native promoter. An effective Shine-Dalgamo sequence (genel0 of phage T7) was inserted between the promoter and the ${\beta}$-glucosidase structural gene. The modified gene was overexpressed in B. subtilis and produced 1121.5 units of ${\beta}$-glucosidase per mg protein which is about $12\%$ of total intracellular protein. Secretion of overproduced intracellular ${\beta}$-glucosidase was attempted by using the signal sequence of the Bacillus endoglucanase gene as well as an in-frame hybrid protein of endoglucanase. The hybrid protein was normally secreted into the culture medium and still retained ${\beta}$-glucosidase activity.

• 산업식품공학
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• 제14권3호
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• pp.243-248
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• 2010

${\beta}$-Glucosidase 효소활성이 높은 균주를 선발하기 위하여 다양한 김치에서 분리된 젖산균의 ${\beta}$-glucosidase 활성을 탐색하였다. 김치에서 분리된 156개의 젖산균 중 134개의 균주만이 cellobiose를 탄소원으로 대사하였으며, 세포내 ${\beta}$-glucosidase 활성이 세포외 활성보다 현저히 높았다. 배추김치에서 분리된 W. cibaria KFRI88010 균주가 3.7${\pm}$0.5 unit/mg protein으로서 가장 높은 세포내 ${\beta}$-glucosidase 효소활성을 나타내었으며, 효소활성은 pH 5, ${37^{\circ}C}$ 반응조건에서 가장 높게 나타났다. $Mn^{2+}$를 비롯한 금속이온은 효소활성을 크게 저해하였다. W. cibaria KFRI88010 균주를 배양할 때 사용한 탄소원 중, fructose는 cellobiose나 glucose와 비교하여 약 2.5배 이상의 높은 세포내 ${\beta}$-glucosidase 효소활성을 나타내었다.

• 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.

• 농업과학연구
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• 제3권2호
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• pp.225-234
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• 1976

섬유소 분해균 Cellulomonas sp. CS1-1의 각종 탄소원에서의 ${\beta}$-글루코시다아제 생성을 살피기 위하여 Quickfit FVIL 발효장치를 이용하고, 뉴트리엔트 이스트브로스, 카르복시멜틸셀룰로오스, 아비셀, 셀로비오스 등을 탄소원으로 한 배지에 뱃치로 배양하여 그 배양적 특성과 세포내 또는 세포외 ${\beta}$-글루코시다아제의 분포를 검토한 결과 : i)${\beta}$-글루코시다아제는 공시한 모든 배양 조건하에서 생성되었고 세포내 효소로서 배양여액에서는 검출되지 않았다. ii) 뉴트리엔트 이스트브로스와 카르복시메틸 셀룰로오스를 탄소원으로 할 때 보다 셀로비오스 및 아비셀을 탄소원으로 하는 경우 효소의 비활성도가 높았다. iii) 공시한 모든 기질에서 공히 균의 대수기(對數期)에 극대치의 비활성도를 나타내었다.

• 미생물학회지
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• 제23권2호
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• pp.77-83
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• 1985

Sophorose에 의한 섬유소분해효소의 유도현상에 있어, Nisizawa등고 Strernbergdh Mandels가 연구보고한 상호 다른 결과들을 재규명하고, sophorose에 의한 섬유소분해효소 합성에 미치는 몇가지 요인들을 조사하고자 본 연구를 행하였다. Sophorose는 Trichoderma reesei QM914에서 CMCase와 ${\beta}-glucosidase$의 합성을 동시에 유도하며, CMCase는 pH 3.0~4.0의 완충용액을 갖는 유도배지에서, ${\beta}-glucosidase$는 pH 5.0~6.0의 K-citrate 완충용액을 갖는 유도배지에서 그 합성이 최대로 유도되었다. 또한, 세포내 ${\beta}-glucosidase$는 pH 6.5의 기질용액에 대하여, 세포의 ${\beta}-glucosidase$는 pH 5.0의 기질용액에 대하여, 각각 최대 활성도를 나타내었다. Methyl ${\beta} D glucosidase$ 는 ${\beta}-glucosidase$의 진정한 유도물질이 아닌 것으로 밝혀졌다. 포도당은 sophorose 에 의한 섬유소분해효소의 유도과정을 억제하며, 이 억제효과는 cAMP의 첨가에 의해서 영향을 받지 아니하였다.

• 한국미생물·생명공학회지
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• 제25권2호
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• pp.115-120
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• 1997

Penicillium sp.-L4, a causative fungus of rot in citrus fruits, was isolated and its mode of hydrolytic enzyme production was investigated. Carboxymethylcellulase (CMCase), polygalacturonase(PGase), extra- & intra-cellular $\beta$-glucosidase and cellobiase were produced drastically by addition of substrates in minimal media. Production of the hydrolytic enzymes were induced efficiently by cellobiose and cellooligosaccharides which were the products of cellulose hydrolysis, but repressed by addition of mono-saccharide such as glucose, raffinose, galacturonic acid. The relative activity of p-nitrophenyl-$\beta$-D-glucopyranoside(PNPG) hydrolysis was higher than that of cellobiose hydrolysis in extracellular enzymes, and reverse is true in intracellular enzymes. Intact enzyme production of P. sp.-L4 on lemon peel lesion was sequential. $\beta$-Glucosidase and CMCase were produced first and followed by PGase. The enzyme productivities and pH in lesions were coincident with optimal pH of each enzyme activities.

• 한국미생물·생명공학회지
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• 제14권5호
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• pp.377-383
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• 1986

토양으로부터 carboxymethyl cellulase 및 intra-cellular $\beta$-glucosidase생산능력이 높은 방선균 No. 109균주를 분리하고 이 균주의 배양상 내지는 형태적 특성, 생리적 특성 그리고 세포벽 구성성분 등을 조사, 균동정을 행한 결과 No. 109 분리균은 Streptomyces tanashiensis 또는 그 유연균으로 동정되었다.

• Journal of Microbiology and Biotechnology
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• 제31권7호
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• pp.1035-1043
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• 2021

Although engineered Saccharomyces cerevisiae fermenting cellobiose is useful for the production of biofuels from cellulosic biomass, cellodextrin accumulation is one of the main problems reducing ethanol yield and productivity in cellobiose fermentation with S. cerevisiae expressing cellodextrin transporter (CDT) and intracellular β-glucosidase (GH1-1). In this study, we investigated the reason for the cellodextrin accumulation and how to alleviate its formation during cellobiose fermentation using engineered S. cerevisiae fermenting cellobiose. From the series of cellobiose fermentation using S. cerevisiae expressing only GH1-1 under several culture conditions, it was discovered that small amounts of GH1-1 were secreted and cellodextrin was generated through trans-glycosylation activity of the secreted GH1-1. As GH1-1 does not have a secretion signal peptide, non-conventional protein secretion might facilitate the secretion of GH1-1. In cellobiose fermentations with S. cerevisiae expressing only GH1-1, knockout of TLG2 gene involved in non-conventional protein secretion pathway significantly delayed cellodextrin formation by reducing the secretion of GH1-1 by more than 50%. However, in cellobiose fermentations with S. cerevisiae expressing both GH1-1 and CDT-1, TLG2 knockout did not show a significant effect on cellodextrin formation, although secretion of GH1-1 was reduced by more than 40%. These results suggest that the development of new intracellular β-glucosidase, not influenced by non-conventional protein secretion, is required for better cellobiose fermentation performances of engineered S. cerevisiae fermenting cellobiose.

• 미생물학회지
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• 제27권1호
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• pp.27-34
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• 1989

In order to evaluate the applicability of enzyme electrophoresis for the identification of intra/interspecific hybride obtained by the protoplast fusion in Trichoderma, soluble proteins, intracellular soluble enzymes and extracellular $\beta$-glucosidase were analyzed by polyacrylamide gel electrophorsis. As the results, patterns of soluble protein, and isozyme patterns of peroxidase, malate dehydrogenase, and $\beta$-glucosidase in hydrids were defferent from those in parental and wild type strains. Therefore, it was established that the analysis of protein pattern by electrophoresis could be applied to isolate and identify the hybrids from the protoplast fusion.

• Journal of Microbiology and Biotechnology
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• 제27권9호
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• pp.1649-1656
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• 2017

In simultaneous saccharification and fermentation (SSF) for production of cellulosic biofuels, engineered Saccharomyces cerevisiae capable of fermenting cellobiose has provided several benefits, such as lower enzyme costs and faster fermentation rate compared with wild-type S. cerevisiae fermenting glucose. In this study, the effects of an alternative intracellular cellobiose utilization pathway-a phosphorolytic pathway based on a mutant cellodextrin transporter (CDT-1 (F213L)) and cellobiose phosphorylase (SdCBP)-was investigated by comparing with a hydrolytic pathway based on the same transporter and an intracellular ${\beta}$-glucosidase (GH1-1) for their SSF performances under various conditions. Whereas the phosphorolytic and hydrolytic cellobiose-fermenting S. cerevisiae strains performed similarly under the anoxic SSF conditions, the hydrolytic S. cerevisiae performed slightly better than the phosphorolytic S. cerevisiae under the microaerobic SSF conditions. Nonetheless, the phosphorolytic S. cerevisiae expressing the mutant CDT-1 showed better ethanol production than the glucose-fermenting S. cerevisiae with an extracellular ${\beta}$-glucosidase, regardless of SSF conditions. These results clearly prove that introduction of the intracellular cellobiose metabolic pathway into yeast can be effective on cellulosic ethanol production in SSF. They also demonstrate that enhancement of cellobiose transport activity in engineered yeast is the most important factor affecting the efficiency of SSF of cellulose.