• Journal of Microbiology and Biotechnology
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• v.31 no.3
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• pp.387-397
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• 2021

There is growing interest in the production of microalgae-based, high-value by-products as an emerging green biotechnology. However, a cultivation platform for Oocystis sp. has yet to be established. We therefore examined the effects of bacterial culture additions on the growth and production of valuable compounds of the microalgal strain Oocystis sp. KNUA044, isolated from a locally adapted region in Korea. The strain grew only in the presence of a clear supernatant of Sphingomonas sp. KNU100 culture solution and generated 28.57 mg/l/d of biomass productivity. Protein content (43.9 wt%) was approximately two-fold higher than carbohydrate content (29.4 wt%) and lipid content (13.9 wt%). Oocystis sp. KNUA044 produced the monosaccharide fucose (33 ㎍/mg and 0.94 mg/l/d), reported here for the first time. Fatty acid profiling showed high accumulation (over 60%) of polyunsaturated fatty acids (PUFAs) compared to saturated (29.4%) and monounsaturated fatty acids (9.9%) under the same culture conditions. Of these PUFAs, the algal strain produced the highest concentration of linolenic acid (C18:3 ω3; 40.2%) in the omega-3 family and generated eicosapentaenoic acid (C20:5 ω3; 6.0%), also known as EPA. Based on these results, we suggest that the application of Sphingomonas sp. KNU100 for strain-dependent cultivation of Oocystis sp. KNUA044 holds future promise as a bioprocess capable of increasing algal biomass and high-value bioactive by-products, including fucose and PUFAs such as linolenic acid and EPA.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.212-218
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• 2015

Fucosyltransferases (FucTs) catalyze fucosyl transfer from guanosine-diphosphate fucose (GDP-β-L-fucose) to acceptor molecules to form fucosyloligosaccharides with α-glycosidic linkages. However, when FucT genes have been expressed in Escherichia coli, most cases have resulted in the production of inclusion bodies. In this study, to overcome this drawback, molecular chaperones were co-expressed with α1,2-fucosyltransferase (FucT2) in E. coli. For this, the pACYC184 vector, having genes for chaperones such as GroEL, GroES, DnaK, DnaJ, and GrpE, were transformed into E. coli BL21 (DE3) star harboring pHFucT2, including the FucT2 gene from Helicobacter pylori 26695. The results from SDS-PAGE showed that 5 chaperones were successfully expressed and the soluble fraction of FucT2 was also increased. HPLC analysis revealed that the coexpression of chaperone proteins resulted in a 5-fold increase in the total activity of fucosyltransferase in E. coli. In conclusion, the FucT2 expression system developed in this study can be used as a useful tool for the synthesis of fucosyloligosaccharides.

• The Korean Journal of Mycology
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• v.27 no.1 s.88
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• pp.76-81
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• 1999

Exo-polysaccharide obtained from the submerged cultivation of Ganoderma lucidum mycelium was fractionated. The structural analysis of the acidic exo-polysaccharide fraction (BWS-DA-GI), showing high antitumor activity, was carried out and compared to the mycelial acidic fraction (MWS-DA-GI). The major sugar constituents of the fraction of BWS-DA-GI were glucose, galactose and mannose in the molar ratio of 2.5 : 2.1 : 2.5. The minor components in this fraction were xylose and fucose. While the major sugar constituents of the mycelial acidic fraction of MWS-DA-GI were galactose, fucose, mannose and glucose. The trace components in this fraction was xylose. From the results of periodate oxidation, Smith degradation, affinity chromatography and methylation analysis, the chemical structures of the two fractions, BWS-DA-GI and MWS-DA-GI were both determined as ${\beta}-1,3$ glucans. It was also estimated that BWS-DA-GI had a $1{\rightarrow}6$ glucosidic linkage and MWS DA-GI had $1{\rightarrow}4$ and $1{\rightarrow}6$ glucosidic linkages. The molecular weights of these fractions, MWS-DA-GI and MWSDA-GI were estimated as $1.2{\times}10^6\;and\;1.0{\times}10^6$ dalton, respectively.

• ALGAE
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• v.21 no.1
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• pp.157-160
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• 2006

Three different forms of Undaria pinnatifida, the southern form (U. pinnatifida f. typica), the northern form (U. pinnatifida f. distans), and Samcheok form (recently cultivated strain), were examined for the contents and compositions of fucoidans. Fucoidans were extracted from the dried edible portions of three forms of U. pinnatifida in low pH condition, mainly by ethanol precipitation and CaCl2 treatment. It was shown that Samcheok form contains 1.8 and 3.5 times more fucoidans than the northern and the southern forms, respectively. The monosaccharide compositions of individual fucoidans were also varied. The fucoidans from the southern and the northern forms were shown to be composed of mainly fucose and galactose with the molar percentage ratios of 83.5%:16.5% and 87.4%:12.6%, respectively, indicating that these are F-type fucoidans. The fucoidan from Samcheok form, however, consisted of fucose (62.7%), galactose (32.9%), and small amount of glucose (4.4%). The results of this study showed that both amount and monosaccharide compositions of fucoidans are variable depending on U. pinnatifida forms.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.5
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• pp.665-671
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• 2020

The chemical and rheological properties of fucoidan and alginate prepared from different parts of Undaria pinnatifida (sporophyll, frond, stipe) were investigated. The algal materials were extracted with HCl (pH 2.0, 3 h at 70℃) to prepare fucoidan, and the remaining solid was continuously re-extracted with Na₂CO₃ (pH 10.0, 70℃, 3 h) to prepare alginic acid. The fucoidan and alginic acid contents in the sporophyll, frond, and stipe were 11.14%, 3.84%, and 1.73% and 22.04%, 37.14%, and 31.74%, respectively. The content of fucoidan and alginate depends on the part extracted. The fucoidan extracted from the sporophyll mainly consists of fucose and galactose, but the fucoidan extracted from frond and stipe contains mannose in addition to fucose and galactose. Fourier-transform infrared spectroscopy analysis of fucoidan and alginate suggests the presence of sulfate groups (1261 and 840 cm^-1) and carboxyl groups (1626 and 1419 cm^-1), respectively. Alginate solutions (5%) had a low viscosity of 10.84-31.63 mPa·s. The activation energies of fucoidan and sodium alginate were 14.45-18.38 kJ/mol and 18.61-22.06 kJ/mol, respectively. The D-mannuronic acid/L-guluronic acid (M/G) ratios of alginate showed a relatively high (frond, 3.72; stipe, 2.88; and sporophyll, 1.80).

• The Korean Journal of Mycology
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• v.40 no.2
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• pp.109-113
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• 2012

We have isolated an anti-complementary polysaccharide from the hot water extracts of Phellinus linteus mycelia. Anti-complementary polysaccharide, PL-5-IIIa, was purified by ultrafiltration, gel permeation chromatography using Sepharose CL-4B. GPC (Sepharose CL-4B) and its homogenicity was demonstrated by HPLC. Using gel permeation chromatography with standard dextrans, its molecular weight was determined as about 800,000 dalton. The purified PL-5-IIIa was identified as a protein bound polysaccharide comprising of 29.6% protein and 64.2% carbohydrate which was composed of fucose(15.8%), galactose(43.1%) and mannose(40.6%).

• Food Science and Biotechnology
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• v.16 no.2
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• pp.270-274
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• 2007

To characterize the polysaccharides which exist as soluble forms in fruit wines, crude polysaccharides were isolated from red, white, raspberry, wild grape, and pear wine, respectively. Among them, the crude polysaccharide (RW-0) in red wine showed the highest yield and considerable amounts of thiobarbituric acid (TBA)-positive materials. The pectic polysaccharide RW-2 was purified to homogeneity from RW-0 by subsequent size-exclusion chromatography using Sephadex G-75 and its structure was characterized. RW-2 consisted of 14 different monosaccharides which included rarely observed sugars in general polysaccharides, such as 2-O-methyl-fucose, 2-O-methyl-xylose, apiose (Api), 3-C-carboxy-5-deoxy-L-xylose (aceric acid, AceA), 3-deoxy-D-manno-2-octulosonic acid (Kdo), and 3-deoxy-D-lyxo-2-heptulosaric acid (Dha). Methylation analysis indicated that RW-2 comprised at least 20 different glycosyl linkages such as 3,4-linked fucose, 2,3,4-linked rhamnose, 3'-linked apiose, and 2,3,3'-linked apiose, being characteristic in rhamnogalacturonan II (RG-II). High performance size-exclusion chromatography indicated that RW-2 mainly comprised RG-II of higher molecular weight (12,000), and that the changes of molecular weight to apparent 7,000 under less than pH 2.0 were observed. These analyses indicated that the higher molecular weight polysaccharide in RW-2 was mainly present as a RG-II dimer.

• Journal of the Korean Chemical Society
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• v.13 no.1
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• pp.96-101
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• 1969

Jalapin purified from the tubers of the sweet potato (Ipomoea batatas) was deacylated and subjected to structural elucidation. Complete and degraded acid hydrolyses indicated the presence of L-rhamnose, D-fucose and D-glucose in the molar ratio of 1: 1: 1 and in the increasing order of acid-stability. While two moles of periodate were consumed per mole of the product, D-glucose survived in the oxidation. The following structure was, therefore, proposed tentatively for the deacylated jalapin: L-$Rha_f$-(1${\to}$4)-D-$Fuc_p$-(1${\to}$3)-D-$Glu_p$-(1${\to}$11)-jalapinolic acid.

• 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.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.3
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• pp.191-196
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• 1989

Monosaccharide content of four forest soils were analyzed. Two soils under coniferous forest trees and another two under duciduous forest trees of Mts. Zeombong and Odae in Kangweon-Do were sampled from the surface horizon down into the subhorizons. 1. The largest amount of monosaccharide is found in the surface organic horizon of each soil and with increasing depth the amount decreases as might be expected considering total organic matter content. 2. Hexoses (galactose, glucose, mannose) predominate over pentoses (arabinose, ribose, xylose) and deoxyhexoses (fucose, rhamnose), the latter being in the smallest amount. Glucose is the most abundant monosaccharide in all samples regardless of vegetation of soil or depth. In general the content of each monosaccharide follows the order of glucose > manrtose > galactose > arabinose > xylose > rhamnose > fucose > ribose. 3. Very little amount of ribose is present even in organic horizons of coniferous forest soils. In samples taken from deciduous forest soils ribose is virtually absent. 4. The relative proportion of monosacchaiide to the total soil organic matter decreases with increasing depth, which may be resulted from the effect of prolonged humification. The total monosaccharide in the organic surface layer amounts to 27-50% of the total organic carbon or 15.7-29% of the total organic matter. Hexoses alone take the largest share of 20-38% of the carbon, or 12-22% of the organic matter.