• Journal of Microbiology and Biotechnology
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• v.28 no.4
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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.

• Microbiology and Biotechnology Letters
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• v.23 no.6
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• pp.659-664
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• 1995

To improve stability of recombinant DNA pLC1 encoding endoglucanase gene and pGL1 encoding $\beta $-glucosidase gene, DNA fragments of genes coding endoglucanase and $\beta $-glucosidase were cloned within the recA gene on a pDR1453, and the pDRE10 and pDRG20 of recombinant plasmids were integrated into the recA gene on the E. coli 1100 chromosomal DNAs. The stability of inheritance was completely maintained in E. coli 1100; Transformants E. coli 1100/pDREIO and pDRG20 were expressed well by recA promoter and increased endoglucanase and $\beta $-glucosidase activities. This method can be used as a model to improve the stability of recombinant plasmid in large scale culture.

• Korean Journal of Microbiology
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• v.24 no.4
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• pp.335-340
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• 1986

Two kind of ${\beta}-glucosidase$, tightly-bound enzyme(TBE) and loosely-bound enzyme(LBE), were obtained from the conidia of Aspergillus nidulans. The existence of enzymes in conidia was conformed by the fact that these enzyme activities were proportional to the number of conidia. The levels of enzyme activities were independent of aging of the conidia. Enzymes were characterized partially. In spite of the physical and chemical treatments of conidia, there was no significant change in TBE activity. The optimum pH and temperature was 6.0 and $55^{\circ}C$, respectively. Thermostability of the TBE was remarkably higher than that of mycelial ${\beta}-glucosidase$. The electrophoretic pattern of LBE was identical to that of mycelial ${\beta}-glucosidase$. These results suggest that conidial ${\beta}-glucosidase$ are involved in adaptation process of the conidia to variable environments.

• KSBB Journal
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• v.5 no.2
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• pp.141-149
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• 1990

$\beta$-glucosidase derived from Aspergillus niger was immobilized by (1) covalent linkage on chitin and chitosan with glutaraldehyde, (2) adsorption on DEAE-cellulose and Amberite IRA93 after succinylation, and (3) entrapment on alginate and polyacrylamide gels with various cross linking agents. The retention yield of $\beta$-glucosidase immobilized on chitosan was 31.5% and operational stability was 69% after continuous operation at column reactor(5$0^{\circ}C$ at pH 4.8) for 15 days. The retention yield and operational stability were 24.7% and 60% respectively, in adsorption on Amberite IRA 93. On the other hand, the entrapment method by alginate and polyacrylamide gel was identified to be not appropriate due to the continuous elution of inlmobilized $\beta$-glucosidase. Optimum conditions for the immobilization on chitosan were also studied with optimum pH of 4.8 and glutaraldehyde concentration of 0.4%(w/v). The properties and stability of immobilized $\beta$-glucosidase are also investigted. The conversion yield of cellobiose to glucose was also analyzed using the column type enzyme reactor to evaluate the effectiveness of immobilized enzyme.

• Korean Journal of Microbiology
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• v.36 no.1
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• pp.8-13
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• 2000

We have examined the mode of transglycosylation, catalyzed by an extracellular $\beta$-glucosidase purified from Trichoderma koningii ATCC 26113, using cellobiose, sophorose, laminaribiose and gentiobiose as substrates. The dimers separated from the reaction mixture by HPLC were analyzed by $^(1)H$-NMR spectroscopy. When cellobiose was subjected to the action of the $\beta$-glucosidase, the products included laminaribiose, sophorose and gentiobiose. When laminaribiose, sophorose or gentiobiose was used as a substrate, the $\beta$-glucosidase accumulated transglycosylation products possessing different types of $\beta$-glycosidic linkages from the original one. The amount of dimers accumulated as reaction proceeded seemed to be dependent on the velocity of hydrolysis but not on that of formation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.439-442
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• 2004

Bacterial strains showing the firinolytic and $\beta$-glucosidase activity were screened from Doeniang. The strain of KH-15 revealed a high level of fibrinolytic and $\beta$-gluocosidase activity. The isolated bacterium was identified and desingnated as Bacillus sp. KH-15. The carbon, nitrogen and salts sgnificantly influenced te fibrinolytic enzyme and $\beta$-glucosidase production. The optimized composition of medium appeared to be 2％ glucose, 0.5% yeast extract and 0.1% calcium chloride. The optimum pH and temperature for fibrinolytic enzyme and $\beta$-glucosidase activities were pH 7∼8, 4$0^{\circ}C$ and pH 6∼8, 30∼4$0^{\circ}C$, respectively.

• Korean Journal of Microbiology
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• v.51 no.2
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• pp.141-147
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• 2015

Four halophilic bacteria were isolated from a salt water tank of more than 25% above salinity used for production of salt. HJS1 and HJS6 strains were identified as having ${\beta}$-glucosidase producing capabilities at high salinity. ${\beta}$-Glucosidase produced from these bacterial strains showed the best activity at 56-79 U/ml in NaCl (0-5%), showing the highest ${\beta}$-glucosidase activity at NaCl 3%. A salt tolerant ${\beta}$-glucosidase can maintain at least 75% activity of the enzyme in 0-20% NaCl concentration. The 16S rRNA gene sequences of strains HJS1 and HJS6 shows 99.8% similarity with Roseivivax roseus $BH87090^T$. Those sequences were registered as AB971835 and AB971836 in the NCBI GenBank. DNA-DNA hybridization test revealed that both strains showed 90.1 to 90.3% hybridization values with R. roseus $BH87090^T$, which was the closest phylogenetic neighbor. Major Cellular fatty acids of strains HJS1 and HJS6 were $C_{16:0}$, $C_{18:1}$ ${\omega}7c$, $C_{19:0}$ cyclo ${\omega}8c$ and 11-methyl $C_{18:1}$ and the major quinone was Q-10. Their fatty acid composition and quinone were very similar to Roseivivax roseus $BH87090^T$. Meanwhile, Roseivivax roseus $BH87090^T$ did not produce any ${\beta}$-glucosidase. Based on the molecular and chemotaxonomic properties, strains HJS1 and HJS6 were identified as members of Roseivivax roseus.

• Research in Plant Disease
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• v.18 no.3
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• pp.186-193
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• 2012

Biotransformation is an eco-friendly and efficient method for enhancing the bioavailability of biopesticide. To increase the antifungal activity of the crude extract of Cynanchum wilfordii roots against barely powdery mildew, we performed biotransformation of wilfoside C1G using ${\beta}$-glucosidase (cellobiase from Aspergillus niger). The mixture (G sample) of partially purified wilfoside C1G and cynauricuoside A (K1G) was treated with ${\beta}$-glucosidase to remove a glucopyranosyl moiety. The enzyme completely converted C1G to C1N and K1G to K1N. Optimal conditions for enzymatic biotransformation of G sample were determined to be 10% ethanol, 1,555 ${\mu}U$ ${\beta}$-glucosidase/ml, pH 5, and $45^{\circ}C$. In in vivo experiment, the G sample transformed by ${\beta}$-glucosidase showed stronger antifungal activity against barley powdery mildew than the non-treated G sample. These results suggest that ${\beta}$-glucosidase biotransformation can be applied to increase the antifungal activity of the crude extract of C. wilfordii roots against powdery mildews.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.3
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• pp.210-212
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• 2003

Recombinant $\beta$-glucosidase from Thermus caldophilus GK24 was easily purified partially by a heat treatment procedure, resulting in 8-fold and recovery yield of 80% from crude enzyme. When the $\beta$-glucosidase was incubated with a 80% glucose solution (w/w), gentiobiose ($\beta$1,6-glucobiose) was the major product in the reaction mixture. The optimal conditions for producing gentiobiose (11% yields of total sugar) were pH 8-9 and 7$0^{\circ}C$ for 72 h.

• Mycobiology
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• v.43 no.1
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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.