• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.751-758
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• 2004

The NCS(Non-Cariogenicity Sugar) from Bacillus sp. S-1013 was purified by cold acetone and methanol precipitation, and DEAE-cellulose ion-exchange and Sephadex G-100 column chromatographies, to yield an amorphous yellow syrup. The melting point and $[\alpha]_D^{20}$ were 155-$157^{\circ}C$ and +53, respectively. Instrumental analyses such as FT-IR, $^1H-NMR, and ^{13}C-NMR$ showed that the NCS contained an O-H group, C-H, C=O, $NH_2$, anomeric carbon, anomeric proton, N-acetylgalactose, fucose, and neuramic acid, thus, the NCS was determined to be a trisaccharide of Fuc($1\longrightarrow4$)GalNAc($2\longrightarrow6$) NeuAc.

• The Plant Pathology Journal
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• v.20 no.1
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• pp.1-6
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• 2004

The diseases caused by Xylella fastidiosa are associated with aggregation of the bacteria m xylem vessels, formation of a gummy matrix and subsequent blockage of water uptake. In the closely related pathogen, Xanthomonas campestris, xanthan gum is known to be an important virulence factor, probably contributing to bacterial adhesion, aggregation and plugging of xylem. Xanthan gum, produced by X. campestris, is an extra-cellular polysaccharide consisting of a cellulose backbone ($\bate$-1,4-linked D-glucose) with trisaccharide side chains composed of mannose, glucuronic acid and mannose attached to alternate glucose residues in the backbone. We had constructed a mutant of X. campestris lacking gumI gene that is responsible for adding the terminal mannose for producing modified xanthan gum which is similar to xanthan gum fromX. fastidiosa. The modified xanthan gum degrading endgphytic bacterium Acineto-bacter johnsonii GX123 isolated from the oleander infected with leaf scorch disease.

• Journal of Microbiology and Biotechnology
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• v.8 no.5
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• pp.484-489
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• 1998

Galactooligosaccharides (GalOS) were efficiently produced by partially purified $\beta$-galactosidase from the yeast strain Bullera singularis ATCC 24193. Ammonium sulfate precipitation and ultrafiltration methods were used to prepare the enzyme. The enzyme activity decreased at $50^{\circ}C$ and above. A maximum yield of 40% (w/w) GalOS, corresponding to 120 g of GalOS per liter, was obtained from 300 g per liter of lactose solution at $45^{\circ}C$, pH 3.7 when the lactose conversion was 70%. The yield of GalOS did not increase with increasing initial lactose concentration but the total amounts of GalOS did. Volumetric productivity was 4.8 g of GalOS per liter per hour. During this reaction, the by-products, glucose and galactose, were found to inhibit GalOS formation. Reaction products were found to be comprised of disaccharides and trisaccharides according to TLC and HPLC analyses. We propose the structure of the major product, a trisaccharide, to be ο-$\beta$-D-galactopyranosyl-(l-4)-ο-$\beta$-D-galactopyranosyl-(l-4)-$\beta$-D-glucose (4'-galactosyl lactose).

• KSBB Journal
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• v.5 no.2
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• pp.101-106
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• 1990

The aspects of pullulan production by Aureobasidium pullulans were investigated under various initial pH, carbon source and nitrogen source conditions. The resulting pullulan fermentation broths were analyzed by using GC, LC and GPC techniques. The maximum pullulan production was obtained in the culture medium containing 5% sucrose at pH 6, 28$^{\circ}C$ after 7 days of cultivation. Under the pH 3, pullulan was almost not produced although the total cell mass of A. pullulans was increased, and the case on using (NH4)SO4 as a nitrogen source, which usually cause the fermentation medium under pH 3, also gave the similar phenomena. Sucrose was believed to converted to trisaccharide and glucose extracellulary and polymerization of glucose was proceeded intracellulary.

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1755-1760
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• 2008

Energy minimization and conformational studies of molecular ions generated by ESI (electrospray ionization) tandem mass spectrometry (MS/MS) can be used for the discrimination of stereoisomeric permethylated and sodium cationized trisaccharides. Sets of fucose-containing trisaccharides having different internal and terminal linkages have been synthesized to analyze the reducing terminal linkage positions using BT and IT fusion approaches. A detailed investigation has been undertaken on the conformational behaviors of four trisaccharide fragments from human milk and blood group determinants of Type 1 and Type 2, namely Fuc($\alpha$1- 3)Gal($\beta$1-3)GalNAc and Fuc($\alpha$1-3)Gal($\beta$1-X)GlcNAc where X = 3, 4 and 6 using molecular modeling methods. Three dimensional rigid and adiabatic phi-psi-energy maps (Surfer program) describing the energy as a function of rotation around corresponding glycosidic linkages were calculated by SYBYL molecular modeling and MM4 force field programs conjunction with cleavage energies of ESI MS/MS for the side group orientations. This approach predicted conformational behaviors exhibited by isomer saccharides for future applications on biologically active glycoconjugates and to exploit a faster method of synthesizing a series of structural isomeric oligosaccharides.

• Journal of the Korean Chemical Society
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• v.42 no.1
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• pp.78-83
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• 1998

It's necessary to develope a facile methodology forming ${\alpha}$-altropyranosidic linkage, for the synthesis of trisaccharide repeating unit of O-antigenic part of Campylobacter jejuni gram negative bacteria. In this paper, the effective synthesis of disaccharides containing ${\alpha}$-altropyranosidic linkage by 1,2-trans glycosidation of allal derivatives was discussed. 4, 6-O-Benzylidene-3-O-(t-butyldimethylsilyl)-D-allal was treated with DMDO (3,3-dimethy ldioxirane) to yield 1,2-anhydro-4, 6-O-benzylidene-3-O-(t-butyldimethylsilyl)-${\beta}$-D-altropyranose. The reaction of 1,2-anhydro-4, 6-O-benzylidene-3-O-(t-butyldimethylsilyl)-${\beta}$-D-altropyranose with allyl alcohol gave allyl 4, 6-O-benzylidene-3-(t-butyldimethylsilyl)-${\alpha}$-D-altropyranoside quantitatively, and reactions with glucals were also successful to prepare ${\alpha}$-altropyranosodic disaccharides. It is convinced that 1,2-trans glycosidation of allal derivatives should be an attractive choice for preparing oligosaccharides containing ${\alpha}$-altropyranosidic linkages.

• KSBB Journal
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• v.11 no.3
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• pp.317-322
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• 1996

Galactooligosaccharlde (GOS) is a kind of functional oligosaccharides that can be used as a food ingredient and a cosmetic additive. In this paper, characteristics of GOS synthesis by cellulase, using lactose as a substrate, were investigated. Penicillium funiculosum cellulose was found to be the most efficient for GOS production among six cellulose tested. The optimum pH and temperature for GOS production were 5.0 and $50^{\circ}C$, respectively. There was an optimum ratio of lactose concentration to enzyme loading; the value was 10 (w/w). The reaction pattern of P. funiculosum cellulase is consistent with that of microbial ${\beta}$-galactosidase which shows transgalactosylation activity. Amounts of GOS produced from 20% (w/v) lactose after 6 h incubation at $50^{\circ}C$, were 23% (w/w) based on total saccharide in the reaction medium. The GOS % increased with initial lactose concentration in the range of 5 to 20%. The products mainly consisted of a trisaccharide and tetrasaccharide from HPLC and TLC analysis. Among enzymes involved in transgalactosylation reaction, high molecular weight fractions over 50,000 Da, presumably ${\beta}$-glucosldase, were considered to be responsible for GOS production. Using this cellulose, a direct synthesis of galactosyl g1ucoside including GOS could be readily achieved with lactose as a galactosyl donor.

• Journal of Microbiology and Biotechnology
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• v.28 no.8
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• pp.1282-1292
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• 2018

The exopolysaccharide (EPS) produced by Bacillus amyloliquefaciens GSBa-1 was isolated and purified by ethanol precipitation, and DEAE-cellulose and Sepharose CL-6B chromatographies. The molecular mass of the purified EPS was determined to be 54 kDa. Monosaccharide analysis showed that the EPS was composed of predominantly glucose, and it was further confirmed by NMR spectroscopy to be ${\alpha}-glucan$ that consisted of a trisaccharide repeating unit with possible presence of two ${\alpha}-(1{\rightarrow}3)$ and one ${\alpha}-(1{\rightarrow}6)$ glucosidic linkages. Microstructural analysis showed that the EPS appeared as ellipsoid or globose with a smooth surface. The EPS had a degradation temperature at $240^{\circ}C$. Furthermore, the EPS had strong DPPH and hydroxyl radical scavenging activities, and moderate superoxidant anion scavenging and metal ion-chelating activities. This is the first characterization of a glucan produced by B. amyloliquefaciens with strong antioxidant activity. The results of this study suggest the potential of the EPS from B. amyloliquefaciens GSBa-1 to serve as a natural antioxidant for application in functional products.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.484-492
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• 2022

Lichenase is an enzyme mainly implicated in the degradation of polysaccharides in the cell walls of grains. Emerging evidence shows that a highly efficient expression of a thermostable recombinant lichenase holds considerable promise for application in the beer-brewing and animal feed industries. Herein, we cloned a lichenase gene (CelA203) from Bacillus subtilis B110 and expressed it in E. coli. This gene contains an ORF of 729 bp, encoding a protein with 242 amino acids and a calculated molecular mass of 27.3 kDa. According to the zymogram results, purified CelA203 existed in two forms, a monomer, and a tetramer, but only the tetramer had potent enzymatic activity. CelA203 remained stable over a broad pH and temperature range and retained 40% activity at 70℃ for 1 h. The K_m and V_max of CelA203 towards barley β-glucan and lichenan were 3.98 mg/ml, 1017.17 U/mg, and 2.78 mg/ml, 198.24 U/mg, respectively. Furthermore, trisaccharide and tetrasaccharide were the main products obtained from CelA203-mediated hydrolysis of deactivated oat bran. These findings demonstrate a promising role for CelA203 in the production of oligosaccharides in animal feed and brewing industries.

• Korean Journal of Food Science and Technology
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• v.48 no.1
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• pp.1-8
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• 2016

Sugar profiles of 45 Korean honey samples (15 acacia, 15 multi-floral, 10 chestnut, and 5 artificial honey samples), which are commercially available in the Korean markets, were analyzed using gas chromatography/mass spectrometry (GC/MS) through TMS-oxime and TMS-methoxime derivatization. The average invert sugar contents in acacia, multi-floral, chestnut, and artificial honey samples were $71.2{\pm}1.05$, $68.7{\pm}3.26$, $63.2{\pm}1.85$, and $68.0{\pm}2.10%$, respectively. Fourteen disaccharides were detected from the samples, and the average content of major disaccharides was higher in order of turanose, maltulose, maltose, trehalulose, kojibiose, isomaltose, and nigerose. The average content of total disaccharides was highest in chestnut and lowest in acacia. Seven trisaccharides were detected from the samples, and the average content of trisaccharides was the highest in artificial honeys, which had high erlose content. The total content of disaccharides and trisaccharides was highest ($16.0{\pm}2.03%$) in chestnut honey and lowest ($9.70{\pm}1.75%$) in acacia honey.