• Proceedings of the Korean Society of Crop Science Conference
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• 2020.11a
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• pp.127-127
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• 2020

• Proceedings of the Korean Society of Crop Science Conference
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• 2021.10a
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• pp.195-195
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• 2021

• Korean Journal of Microbiology
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• v.51 no.1
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• pp.68-74
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• 2015

Based on the genomic analysis of Thermococcus pacificus P-4, we identified a putative GH1 ${\beta}$-glucosidase-encoding gene (Tpa-glu). The gene revealed a 1,464 bp encoding 487 amino acid residues, and the deduced amino acid residues exhibited 77% identity with Pyrococcus furiosus ${\beta}$-glucosidase (accession no. NP_577802). The gene was cloned and expressed in Escherichia coli system. The recombinant protein was purified by metal affinity chromatography and characterized. Tpa-Glu showed optimum activity at pH 7.5 and $75^{\circ}C$, and thermostability with a half life of 6 h at $90^{\circ}C$. Tpa-Glu exhibited hydrolyzing activity against various pNP-glycopyranosides, with kcat/Km values in the order of pNP-${\beta}$-glucopyranoside, pNP-${\beta}$-galactopyranoside, pNP-${\beta}$-mannopyranoside, and pNP-${\beta}$-xylopyranoside. In addition, the enzyme exhibited exo-hydrolyzing activity toward ${\beta}$-1,3-linked polysaccharide (laminarin) and ${\beta}$-1,3- and ${\beta}$-1,4-linked oligosaccharides. This is the first description of an enzyme from hyperthermophilic archaea that displays exo-hydrolyzing activity toward ${\beta}$-1,3-linked polysaccharides and could be applied in combination with ${\beta}$-1,3-endoglucanase for saccharification of laminarin.

• Journal of Microbiology and Biotechnology
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• v.26 no.10
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• pp.1661-1667
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• 2016

The ginsenoside-hydrolyzing β-glucosidase gene (bgy2) was cloned from Lactobacillus brevis. We expressed this gene in Escherichia coli BL21(DE3), isolated the resulting protein, and then utilized the enzyme for the biotransformation of ginsenosides. The bgy2 gene contains 2,223 bp, and encodes a protein of 741 amino acids that is a member of glycosyl hydrolase family 3. β-Glucosidase (Bgy2) cleaved the outer glucose moieties of ginsenosides at the C-20 position, and the inner glucose at the C-3 position. Under optimal conditions (pH 7.0, 30℃), we used 0.1 mg/ml Bgy2 in 20 mM sodium phosphate buffer (PBS) for enzymatic studies. In these conditions, 1.0 mg/ml ginsenoside Rb1 and ginsenoside F2 were converted into 0.59 mg/ml ginsenoside Rd and 0.72mg/ml compound K, with molar conversion productivities of 69% and 91%, respectively. In pharmaceutical and commercial industries, this recombinant Bgy2 would be suitable for producting ginsenoside Rd and compound K.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.554-562
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• 2021

Lactobacillus plantarum SM4, a strain producing β-glucosidase, was isolated from kimchi and fermented with white Taraxacum coreanum to enhance the production of bioactive compounds. The total polyphenol content(TPC), total flavonoid content(TFC), radical scavenging activity(RSA), tyrosinase inhibitory activities(TIA), and collagenase inhibitory activities(CIA) were measured to evaluate the skin whitening and anti-wrinkle effects of the fermented product. The TPC of fermented white T. coreanum was 41.8±0.26 mg GAE/g DW, which was approximately two times higher than the hot-water extraction of 21.4±0.67 mg GAE/g DW. RSA, an indicator of antioxidant activity, was 65.6±4.7% in fermentation, which is four times higher than that of the hot-water extract. TAI and CAI, which are indicators of the whitening and anti-wrinkle effects, were 87.9±4.73% and 66.7±3.48%, respectively, which were 2.4 and 1.5 times higher than those of hot-water extraction. When comparing the UVA(320 nm) protection effects of fermented and hot-water extraction, the fermented white T. coreanum showed higher protection with an absorption rate of 64.7% and 15.2%, respectively. The white T. coreanum fermented product showed higher bioactive properties and improved skin whitening, anti-wrinkle, and UV protection effects through the production of β-glucosidase from L. plantarum SM4.

• Journal of Life Science
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• v.20 no.11
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• pp.1589-1594
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• 2010

Glutaraldehyde was used to cross-link chitosan beads to immobilize the crude enzyme $\beta$-glucosidase from Exiguobacterium sp. DAU5. The conditions for preparing cross-linking chitosan beads and immobilization such as concentration of glutaradehyde, cross-linking time, immobilization pH and time were optimized. The chitosan beads were cross-linked with 1.5% glutaraldehyde for 1.5 hr. The immobilized $\beta$-glucosidase had an overall yield of 20% and specific activity of 5.22 U/g. The optimized pH and temperature were 9.0 and $55^{\circ}C$, respectively. More than 80% of its activity at pH 7.0-10.0, 80% at $40^{\circ}C$ for 2 hr and 48% at $50^{\circ}C$ for 1 hr, were retained. However, the immobilization product showed higher pH and thermal stabilities than free enzymes. It also showed high hydrolyzing activity on soybean isoflavone glycoside linkage. These results suggest the broad application prospects of immobilization enzymes.

• 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.

• Journal of Life Science
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• v.30 no.5
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• pp.452-459
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• 2020

This study was conducted to investigate the total lignin content and anti-oxidant activity in extracts of defatted sesame seeds (DSS) fermented with 15 strains of Bacillus subtilis. The anti-oxidant activities of DSS were analyzed both before and after fermentation. The total lignan content of the DSS extracts fermented with BCH3678 (1,613.8 mg/l) and BCH3572 (1,599.5 mg/l) were relatively high compared to other strains. Anti-oxidant activity was determined according to phenolic compound and flavonoid content and DPPH radical scavenging rate; the highest total phenolic compound content was provided by the DSS with SRCM103716 at 2,803.3 mg GAE/g which returned total flavonoid content of 1,553.1 mg/g as strong correlation of its anti-oxidant activity. The DSS extract fermented by SRCM103716 at 37℃ for 24 hr showed the highest DPPH scavenging rate at 66.5%. The fermented DSS extracts, regardless of strain, demonstrated higher anti-oxidative activity than the unfermented control, and these results suggest that such extracts could be useful as a potential source of bioactive compounds.

• Journal of Life Science
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• v.31 no.2
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• pp.183-191
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• 2021

Euglena gracilis is a microalga of great biotechnological interest that can create high levels of bioactive compounds, such as tocopherol, paramylon, and folic acid. The objective of this study was to investigate the biological activities of extracts from E. gracilis, especially those focused on immunological activity. E. gracilis biomass was extracted with hot water (HWE) and the remaining pellet was continuously extracted with methanol (HWME). First, we examined the effect of two extracts from E. gracilis on the production of nitric oxide (NO) and the expression of pro-inflammation cytokines, including IL-1β, IL-6, and TNF-α in murine macrophage RAW 264.7 cells. HWE treatment dose-dependently increased the production of IL-1β and TNF-α. On the other hand, treatment with HWME significantly decreased the generation of NO and pro-inflammatory cytokines (IL-6 and TNF-α) in lipopolysaccharide (LPS)-stimulated macrophage cells. In addition, other biological activities of the extracts were further analyzed: α-glucosidase inhibition, protein tyrosine phosphatase (PTP1B) inhibition, tyrosinase inhibition, xanthine oxidase (XO) inhibition, and angiotensin-converting enzyme (ACE) inhibition. Analysis of these biological activities showed that HWE has more inhibitory effects than HWME against α-glucosidase, tyrosinase, and XO agents. However, the inhibition of PTP1B and ACE with HWME were higher than with HWE. Taken together, the results suggested that E. gracilis possesses various biological activities―especially immunological capabilities―through regulation of cytokine production. Therefore, E. gracilis extract may be potentially useful for food material with immune-regulating effects.

• Journal of Environmental Science International
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• v.31 no.3
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• pp.227-235
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• 2022

In this study, a biodegradation model of based on molecular cellulose was established. It is a mathematical, kinetic model, assuming that two major enzymes randomly break glycosidic bonds of cellulose molecules, and calculates the number of molecules by applying the corresponding probability and degradation reaction coefficients. Model calculations considered enzyme dose, cellulose chain length, and reaction rate constant ratio. Degradation increased almost by two folds with increase of temperature (5℃→25℃). The change of degradation was not significant over the higher temperatures. As temperature increased, the degradation rate of the molecules increased along with higher production of shorter chain molecules. As the reaction rates of the two enzymes were comparative the degree of degradation for any combinations of enzyme application was not affected much. Enzyme dose was also tested through experiment. While enzyme dose ranged from 1 mg/L to 10 mg/L, the gap between real data and model calculations was trivial. However, at higher dose of those enzymes (>15 mg/L), the experimental result showed the lower concentrations of reductive sugar than the corresponding model calculation did. We determined that the optimal enzyme dose for maximum generation of reductive sugar was 10 mg/L.