• 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.

• Journal of Microbiology and Biotechnology
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• 제28권4호
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• pp.579-587
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• 2018

For biotechnological production of high-valued ${\beta}-{\text\tiny{D}}$-hexyl glucoside, the catalytic properties of Hanseniaspora thailandica BC9 ${\beta}$-glucosidase purified from the periplasmic fraction were studied, and the transglycosylation activity for the production of ${\beta}-{\text\tiny{D}}$-hexyl glucoside was optimized. The constitutive BC9 ${\beta}$-glucosidase exhibited maximum specific activity at pH 6.0 and $40^{\circ}C$, and the activity of BC9 ${\beta}$-glucosidase was not significantly inhibited by various metal ions. BC9 ${\beta}$-glucosidase did not show a significant activity of cellobiose hydrolysis, but the activity was rather enhanced in the presence of sucrose and medium-chain alcohols. BC9 ${\beta}$-glucosidase exhibited enhanced production of ${\beta}-{\text\tiny{D}}$-hexyl glucoside in the presence of DMSO, and 62% of ${\beta}-{\text\tiny{D}}$-hexyl glucoside conversion was recorded in 4 h in the presence of 5% 1-hexanol and 15% DMSO.

• Mycobiology
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• 제43권1호
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• pp.57-62
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• 2015

${\beta}$-Glucosidase, which hydrolyzes cellobiose into two glucoses, plays an important role in the process of saccharification of the lignocellulosic biomass. In this study, we optimized the activity of ${\beta}$-glucosidase of brown-rot fungus Fomitopsis pinicola KCTC 6208 using the response surface methodology (RSM) with various concentrations of glucose, yeast extract and ascorbic acid, which are the most significant nutrients for activity of ${\beta}$-glucosidase. The highest activity of ${\beta}$-glucosidase was achieved 3.02% of glucose, 4.35% of yeast extract, and 7.41% ascorbic acid where ascorbic acid was most effective. The maximum activity of ${\beta}$-glucosidase predicted by the RSM was 15.34 U/mg, which was similar to the experimental value 14.90 U/mg at the 16th day of incubation. This optimized activity of ${\beta}$-glucosidase was 23.6 times higher than the preliminary activity value, 0.63 U/mg, and was also much higher than previous values reported in other fungi strains. Therefore, a simplified medium supplemented with a cheap vitamin source, such as ascorbic acid, could be a cost effective mean of increasing ${\beta}$-glucosidase activity.

• KSBB Journal
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• 제15권1호
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• pp.9-13
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• 2000

Cellulose 분해에 관련된 $\beta$-Glucosidase 효소 활성의 특성 파악을 위하여 송이균사(Tricholoma matsutake DGUM 26001)의 액체 배양시 세포외로 분비되는 $\beta$-Glucosidase 효소를 부분정제하여 그 특성을 조사하였다. 효소 활성에 미치는 적정 온도는 55-$70^{\circ}C$이었고 최적 온도는 $65^{\circ}C$이었다. 적정 효소활성에 영향을 주는 적정 pH는 3.0-5.0 범위였으며 최적 pH는 4.0이었다. Salicin을 기질로 최적 조건하에서 $\beta$-Glucosidase 효소의 비활성도는 18.7 unit/mg protein이었다. 열안정성은 $60^{\circ}C$이하의 온도에 60분간 열처리시 약 90%이상의 효소활성을 유지하였다. $Fe^{++}$이온은 효소활성을 촉진하였으나, $Hg^{++}$ 및 $Cu^{++}$이온은 효소활성을 매우 억제하였다. Salicin에 대한 효소활성을 100으로 하였을 때, cellobiose는 48.6%의 상대적 효소활성을 나타내었으며, cellobiose에 대한 Km값 및 Vmax값은 각각 0.12mM과 0.02umol/min었다.

• Journal of Microbiology and Biotechnology
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• 제6권4호
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• pp.255-259
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• 1996

$\beta$-Glucosidase was known to be involved in the mutagenic activation of $\beta$-glucosides. The level of $\beta$-glucosidase in the feces of adults was 2.7 times higher than that of infants. There was no difference in the percentage of $\beta$-glucosidase positive strains among Bifidobacterium isolates between adults and infants, corresponding to 90 and 92$%$, respectively. However, the strains from adults showed 1.9 times higher enzyme activity than those from infants when grown in Brain Heart Infusion medium. $\beta$-Glucosidase negative strains could not ferment $\beta$-glucosidase substrates, such as cellobiose, salicin, naringin, esculin and arbutin. Presence of $\beta$-glucosidase in Bifidobacterium did not alter the degree of growth in reconstituted skim milk. The $\beta$-glucosidase level was much lower in milk and vegetable medium, although cells grew above $10^8$cfu/ml, than in BHI medium. This study suggests that metabolic activation of the $\beta$-glucosides by Bifidobacterium $\beta$-glucosidase varies significantly depending on types of growth medium.

• Mycobiology
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• 제35권3호
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• pp.166-169
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• 2007

A total of 106 Penicillium species were tested to examine their ability of degrading cellobiose, pectin and xylan. The activity of ${\beta}$-glucosidase was generally strong in all the Penicillium species tested. P. citrinum, P. charlesii, P. manginii and P. aurantiacum showed the higher ability of producing ${\beta}$-glucosidase than other tested species. Pectinase activity was detected in 24 Penicillium species. P. paracanescens, P. sizovae, P. sartoryi, P. chrysogenum, and P. claviforme showed strong pectinase activity. In xylanase assay, 84 Penicillium species showed activity. Strong xylanase activity was detected from P. megasporum, P. sartoryi, P. chrysogenum, P. glandicola, P. discolor, and P. coprophilum. Overall, most of the Penicillium species tested showed strong ${\beta}$-glucosidase activity. The degree of pectinase and xylanase activity varied depending on Penicillium species.

• 미생물학회지
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• 제51권1호
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• pp.68-74
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• 2015

Thermococcus pacificus P-4의 유전체 서열 분석을 통하여 예측되는 GH1 ${\beta}$-glucosidase를 암호화하는 유전자를 동정하였다. 그 유전자는 487 아미노산들을 암호화하는 1,464 bp 나타내었으며, 그 아미노산 서열은 Pyrococcus furiosus ${\beta}$-glucosidase와 77% 상동성을 나타내었다. 그 유전자는 Escherichia coli 시스템 내에서 복제 및 발현하였다. 재조합 된 단백질은 금속 친화크로마토그래피를 통하여 정제하고 특성을 분석하였다. 정제된 단백질(Tpa-Glu)은 pH 7.5와 $75^{\circ}C$에서 최적활성을 나타내었으며, 열안정성은 $90^{\circ}C$에서 약 6시간의 반감기를 보였다. Tpa-Glu는 pNP-${\beta}$-glucopyranoside, pNP-${\beta}$-galactopyranoside, pNP-${\beta}$-mannopyranoside, 그리고 pNP-${\beta}$-xylopyranoside 순으로 우수한 $k_{cat}/K_m$ 값을 나타내었다. 또한, Tpa-Glu는 ${\beta}$-1,3-linked polysaccharide (laminarin) 그리고 ${\beta}$-1,3-와 ${\beta}$-1,4-linked oligosaccharides에 대하여 exo-hydrolyzing 활성을 보였다. 본 연구는 초고온 고세균으로터 ${\beta}$-glucosidase가 exohydrolyzing 활성을 처음 확인한 것으로 이 효소는 laminarin의 당화공정에 ${\beta}$-1,3-endoglucanase와 함께 적용할 수 있을 것으로 기대된다.

• KSBB Journal
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• 제14권4호
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• pp.429-433
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• 1999

$\beta$-Glucosidaes from Cellvibrio gilvus(CG) was successfully overproduced in soluble form in E. coli with the coexpression of GroEL/ES/. Without the GroEL/ES protein, the $\beta$-glucosidase overexpressed in E. coli constituted a huge amount(80%) of total cellular protein, but was localized in the insoluble fraction, and little activity was detected in the soluble fraction. Coexpression of the E. coli GroEL/ES had a drastic impact on the proper folding of the $\beta$-glucosidase; 20% of the overexpressed enzyme was recovered in the soluble fraction in active form. Similar effects of GroEL/ES were also observed on the overexpressed $\beta$-glucosidase from Agrobacterium tumefaciens(AT). And pET28(a)-RGRAR, partially deleted mutant lacking 5-amino acid residues at carboxy teminus also could be folded into an active form when expressed with the molecular chaperonin GroEL/ES, and its activity was higher than that of the without GroEL/ES system, In addition, the synergistic effect of GroEL/ES and the low induction temperature were important factors for solubilization of the inclusion body from overproduced $\beta$-glucosidases.

• 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.

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.8-13
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• 2002

The isoflavone glycosides are hydrolyzed by ${\beta}$-glucosidase from gut microbes to the bioactive aglycones. However, the specific bacteria from the human intestinal tract that are involved in the metabolism of these compounds are not known. This study was undertaken to develop a fermented soymilk which converts isoflavones to the more bioactive aglycones form using a Bifidobacterium strain. The ${\beta}$-glucosidase activity of 15 Bifidobacterium strains were measured during cell growth. Among them, Bifidobacterium sp. Int-57 was selected for this study, because it has the highest ${\beta}$-glucosidase activity. Growth, acid development, ${\beta}$-glucosidase activity, and the hydrolysis of daidzin and genistin were investigated in four soymilks inoculated with Bifidobacterium sp. Int-57. After 12 h of fermentation, the counts of viable Bifidobacterium sp. Int-57 in all the soymilks reached a level of more than $10^8$ cfu/ml, which was then maintained. The pH of soymilks started to decrease rapidly after 6 h of fermentation and leveled off after 18 h. The titratable acidity of BL# 1 soymilk, BL#2 soymilk, and JP#l soymilk increased from 0.18 to 1.21, 1.15, and $1.08\%$ over the fermentation period, respectively. After 24 h of fermentation, the $\beta$-glucosidase activity in BL#1 soymilk, BL#2 soymilk, JP#l soymilk, and JP#2 soymilk increased to 59.528, 40.643, 70.844, and 56.962 mU/ml, respectively. The isoflavone glycosides, daidzin and genistin, in soymilks were hydrolyzed completely in the relatively short fermentation time of 18 h. These results show that Bifidobacterium sp. Int-57 can be used as a potential starter culture for developing fermented soymilk which has completely hydrolyzed isoflavone glycosides.