• Applied Biological Chemistry
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• v.40 no.2
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• pp.163-166
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• 1997

A yeast, Torulopsis bombicola, was cultured in the media fortified with soybean oil as a additional carbon source for 7 days with reciprocal shaking. From the culture broth, sophorose-lipid was isolated and treated with alkali to afford sophorose. The sophorose contained in the medium was acetylated and isolated through silica gel column chromatography. The aceylated sophorose was hydrolyzed with 5% KOH at room temperature to give rise to sophorose. Meanwhile, the MeOH extracts obtained from the pod of Sophora japonica was solvent-fractionated with n-BuOH and $H_2O$, and butanolic layer was chromatographed on silica gel column to afford a flavonoide-glycoside. The glycoside was hydrolyzed with 0.02 N $H_2SO_4$ to yield sophorose.

• Applied Biological Chemistry
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• v.39 no.6
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• pp.512-516
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• 1996

Sophorose $(2-O-{\beta}-D-glucopyranosyl-D-glucopyranose)$ was chemically synthesized from D-glucopyranose through six steps of chemical reactions with the yield of 21%. The chemical structures of sophorose and some compounds obtained during reactions were confirmed by interpretations of spectral data, NMR, IR, etc.

• Korean Journal of Microbiology
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• v.23 no.2
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• pp.77-83
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• 1985

The aim of this investigation was to resolve the contradiction between the results of Sternberg and Mandels (1980, 1982)and those of Nisizawa et al., (1971) in cellulase induction by sophorose, and furthermore to study the conditional effects in sophorose-induced cellulase induction in Trichoderma reesei QM 9414. Sophorose could induce the synthesis of CMCase and ${\beta}-glucosidase$ simultaneously. Optimal induction medium by sophorose had the potassium citrate buffer solution of pH 3.0-4.0 for CMCase, but one of pH 5.0-6.0 for ${\beta}-glucosidase$. At this time, two different types of ${\beta}-glucosidase$ could be induced by sophorose: one was extracellular and had maximum at pH 5.0, the other was intracellular and had maximum activity at pH6.5. Induction study showed that $methyl-{\beta}-glucoside$ was not a true inducer of ${\beta}-glucosidase$ and that large ${\beta}-glucosidase$ induction could be obtained only by the addition of sophorose into the induction medium. Glucose repressed the induction of cellulase by sophorose. The repression of glucose could not be overcome by the addition of cyclic AMP into the induction medium.

• 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.

• KSBB Journal
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• v.8 no.4
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• pp.364-369
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• 1993

The biodegradability of some anionic surfactants were investigated using biological oxygen consumption measurement at different temperatures. As test surfactants, soap, alkyl sulfate (AS), alpha olefin sulfonate (AOS), alkyl polyoxyethylene sulfate (AES), linear alkylbezene sulfonate(LAS), microbial surfactants such as sophorose lipid (sopholipid) and spiculisporic acid (S-acid), were used. The test solution were incubated at $5^{\circ}C$, $18^{\circ}C$ and $32^{\circ}C$, respectively. The comparative rates of biodegradation were in accordance with the results obtained from the surface tension measurement and methylene blue method. The results of comparative blodegradabilities of the surfactants were as follows; soap, AS>AES>AOS>LAS at $18^{\circ}C$ and $32^{\circ}C$. However, at$ 5^{\circ}C$, the biodegradation rate of soap was better than other surfactants. Considering the actual environment of the river, it was concluded that the biological oxygen consumption rate method at lower temperature was more practical than the current method such as methylene blue assay with adapted shaking flask culture at $25^{\circ}C$

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.2
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• pp.106-111
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• 2003

A novel carbohydrolase, which is a DXAMase, containing both dextranase and amylase equivalent activities, was purified from Lipomyces starkeyi KSM22. The purified DXAMase was also found to hydrolyze cellobiose, gentiobiose, trehalose and melezitose, while disproportionation reactions were exhibited with various di- and tri-saccharides, such as maltose, isomaltose, gentiobiose, kojibiose, sophorose, panose, maltotriose, and isomaltotriose with various kinds of oligosaccharides produced as acceptor reaction products. Furthermore, the purified DXAMase hydrolyzed raw waxy rice Starch and produced maltodextrin to the extent of 50% as a glucose equivalent.

• Journal of the Korean Wood Science and Technology
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• v.35 no.5
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• pp.100-108
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• 2007

$\beta$-Glucosidase from Laetiporus sulphureus among the enzymes related to lignocellulosic biomass degradation to sugars for using alternative bioethanol production was characterized. The highest activity of $\beta$-glucosidase was obtained on cellobiose at shaking culture. For the characterization and purification of $\beta$-glucosidase culture solution was concentrated and then purified by FPLC using ion exchange and size exclusion column. According to the results of SDS-PAGE, native PAGE and microfluidic system of purified enzyme, protein band was observed at about 132 kDa. Optimal pH and temperature of purified $\beta$-glucosi-dase were 5.0 and $60^{\circ}C$, respectively. In the kinetic properties of $\beta$-glucosidase on various substrates such as sophorose, gentiobiose and cellobiose, $K_m$ was 0.81, 1.07 and 1.70 mM, respectively.

• Korean Journal of Microbiology
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• v.27 no.1
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• pp.35-42
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• 1989

The mode of transglycosylation reaction observed during the action of low-molecular-weigh $\beta$-D-glucosidase ($\beta$-D-glucoside glucohydrolase, EC3.2.1.21) purified from Trichoderma koningii ATCC 26113 was investigated using $^{1}H$-NMR spectroscopy. The enzyme was purified by the series of procedures including ammonium sulfate precipitation, and fractionations by column chromatographies on Bio-Gel P-150, DEAE-Sephadex A-50, and SP-Sephadex C-50. The final purification was performed by the band eluation after preparative polyacrylamide gel electrophoresis. The enzyme showed its molecular size of 78,000 through the analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and its isoelectric point of 5.80 through the analysis of analytical isoelectric focusing. The H-1 proton resonances were analyzed. After the reaction of the enzyme with cellobiose, the reaction products were separated by high performance liquid chromatography using refractive index detector. H-1 resonances of the products were consisted with those of gentiobiose [$\beta$-D-glucopyranosyl--(1,6)-D-glucopyranose], and cellotriose [$\beta$-D glucopyranosyl-(1,4)-$\beta$-D-glucopyranosyl]-(1,4)-D-glucopyranose] with minor resonances of sophorose [$\beta$-D-glucopyranosyl-(1,2)-D-glucopyranose], respectively.

• Korean Journal of Microbiology
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• v.24 no.3
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• pp.251-262
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• 1986

High-molecular-weight ${\beta}-glucosidase$ (EC 3.2.1.21) was purified from the culture filtrate of Trichoderma koningii through a four-step procedure including chromatography on Bio-Gel P-150, DEAE-Sephadex A-50 and SP-Sephadex C-50; and chromatofocusing on Polybuffer exchanger PBE 94. The molecular weight of the enzyme was determined to be about 101,000 by SDS-polyacrylamide gel electrophoreses, and the isoelectric point was estimated to be 4.96 by analytical isoelectric focusing. The temperature optimum for activity was about $55^{\circ}C$, and the pH optimumwas 3.5. The enzyme was considerably thermostable, for no loss of activity was observed when the enzyme was preincubated at $60^{\circ}C$ for 5h. Km values for cellobiose, gentiobiose, sophorose, salicin and $p-nitrophenyl-{\betha}-D-glucoside$ were 99.2, 14.7, 7.09, 3.15 and 0.70 mM, respectively, which indicates that the enzyme has much higher affinity towards $p-nitrophenyl-{\betha}-D-glucoside$ than towards the other substrates, especially cellobiose. Substrate inhibition by $p-nitrophenyl-{\betha}-D-glucoside$ and salicin was observed at the conecntrations exceeding 5mM. Gluconolactone was a powerful inhibitor against the action of the enzyme on $p-nitrophenyl-{\betha}-D-glucoside\;(K_i\;37.9\;{\mu}M)$, wherease glucose was much less effective ($K_i$ 1.95 mM). Inhibition was of the competitive type in each case. Transglucosylation activity was detected shen the readtion products formed from $p-nitrophenyl-{\betha}-D-glucoside$ by the enzyme were analysed using high-performance liquid chromatography.

• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.454-460
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• 2007

Enzymatic properties and substrate specificity of recombinant $\beta-glycosidases$ from a hyperthermophilic archaeon, Sulfolobus shibatae (rSSG), were analyzed. rSSG showed its optimum temperature and pH at $95^{\circ}C$ and pH 5.0, respectively. Thermal inactivation of rSSG showed that its half-life of enzymatic activity at $75^{\circ}C$ was 15 h whereas it drastically decreased to 3.9 min at $95^{\circ}C$. The addition of 10 mM of $MnCl_2$ enhanced the hydrolysis activity of rSSG up to 23% whereas most metal ions did not show any considerable effect. Dithiothreitol (DTT) and 2-mercaptoethanol exhibited significant influence on the increase of the hydrolysis activity of rSSG rSSG apparently preferred laminaribiose $(\beta1\rightarrow3Glc)$, followed by sophorose $(\beta1\rightarrow2Glc)$, gentiobiose $(\beta1\rightarrow6Glc)$, and cellobiose $(\beta1\rightarrow4Glc)$. Various. intermolecular transfer products were formed by rSSG in the lactose reaction, indicating that rSSG prefers lactose as a good acceptor as well as a donor. The strong intermolecular transglycosylation activity of rSSG can be applied in making functional oligosaccharides.