• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.160-166
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• 2008

A DNA fragment containing 2,079 base pairs from Bacillus circulans CGMCC 1416 was cloned using degenerate PCR and inverse PCR. An open reading frame containing 981 bp was identified that encoding 326 amino acids residues, including a putative signal peptide of 31 residues. The deduced amino acid sequence showed the highest identity (68.1%) with $endo-{\beta}-1,4-D-mannanase$ from Bacillus circulans strain K-1 of the glycoside hydrolase family 5 (GH5). The sequence encoding the mature protein was cloned into the pET-22b(+) vector and expressed in Escherichia coli as a recombinant fusion protein containing an N-terminal hexahistidine sequence. The fusion protein was purified by $Ni^{2+}$ affinity chromatography and its hexahistidine tag cleaved to yield a 31-kDa ${\beta}$-mannanase having a specific activity of 481.55U/mg. The optimal activity of the purified protein, MANB48, was at $58^{\circ}C$ and pH 7.6. The hydrolysis product on substrate locust bean gum included a monosaccharide and mainly oligosaccharides. The recombinant MANB48 may be of potential use in the feed industry.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.61-70
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• 2020

A eukaryotic microalga was isolated from seawater in Janghang Harbor, Korea and its morphological, molecular, and physiological characteristics were investigated. Due to its simple morphology, no distinctive characters were found by morphological observation, such as light microscope or scanning/transmission electron microscopy (S/TEM). However, molecular phylogenetic evidence inferred from the concatenated small subunit (SSU) 18S rRNA and internal transcribed spacer (ITS) sequence data indicated that the isolate belonged to the newly described Micractinium singularis. Furthermore, it was clustered with Antarctic Micractinium strains and it also showed a psychrotolerant property, surviving at temperatures as low as 5℃. However, its optimal growth temperatures range from 15℃ to 25℃, indicating that this microalga is a mesophile. Additionally, gas chromatography-mass spectrometry (GC/MS) analysis showed that the isolate was rich in nutritionally important omega-3 polyunsaturated fatty acid, and high-performance liquid chromatography analysis (HPLC) revealed that the high-value antioxidant lutein was biosynthesized as an accessory pigment by this microalga, with glucose as the major monosaccharide. Therefore, in this study, a Korean marine M. singularis species was discovered, characterized, and described. It was subsequently added to the national culture collections.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.3
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• pp.52-58
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• 2011

Proton-NMR spectroscopic method was applied to kinetic study of concentrated sulfuric acid hydrolysis reaction, especially focused on 2nd step of acid hydrolysis with deferent reaction time and temperature as main variables. Commercial xylan extracted from beech wood was used as model compound. In concentrated acid hydrolysis, xylan was converted to xylose, which is unstable in 2nd hydrolysis condition, which decomposed to furfural or other reaction products. Without neutralization steps, proton-NMR spectroscopic analysis method was valid for analysis of not only monosaccharide (xylose) but also other reaction products (furfural and formic acid) in acid hydrolyzates from concentrated acid hydrolysis of xylan, which was the main advantages of this analytical method. Higher temperature and longer reaction time at 2nd step acid hydrolysis led to less xylose concentration in xylan acid hydrolyzate, especially at $120^{\circ}C$ and 120 min, which meant hydrolyzed xylose was converted to furfural or other reaction products. Loss of xylose was not match with furfural formation, which meant part of furfural was degraded to other undetected compounds. Formation of formic acid was unexpected from acidic dehydration of pentose, which might come from the glucuronic acid at the side chain of xylan.

• Journal of Plant Biotechnology
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• v.39 no.3
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• pp.212-218
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• 2012

Glycosyltransferases are enzymes (EC 2.4) that catalyze the transfer of monosaccharide moieties from activated nucleotide sugar to a glycosyl acceptor molecule which can be a carbohydrate, glycoside, oligosaccharide, or a polysaccharide. In this study, a UDP-glucosyltransferase cDNA was isolated from Brassica rapa using a rapid amplification of cDNA ends (RACE) and subsequently named BrUGT. It has a full-length cDNA of 1,236 bp with 119 bp 5'-untranslated region (UTR), a complete ORF of 834 bp encoding a polypeptide of 277 amino acids (31.19 kDa) and a 3'-UTR of 283 bp. BLASTX analysis hits a catalytic domain of Glycos_transf_1 super family (cl12012) that belongs to the Glycosyltransferases group 1 with tetratricopeptide (TPR) regions located between 165 to 350 bp. Expression analysis showed high mRNA transcripts in pistil, followed by petal, seed and calyx of flower. Moreover, expression analysis of BrUGT in Chinese cabbage seedlings under stresses of cold, salt, PEG, $H_2O_2$, drought and ABA showed elevated mRNA transcript. Furthermore, when BrUGT gene was transformed into rice using pUbi-1 promoter, overexpression was evident among the $T_1$ plants. This study provides insights into the function of BrUGT in plants.

• The Korean Journal of Mycology
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• v.16 no.3
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• pp.162-174
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• 1988

To separate and quantitate antitumor protein-bound polysaccharides of Coriolus versicolor, the constituents were obtained from the submerged culture of the mycelia(C) and from the extract of the carpophores of the wild fungus(N). The polysaccharides were degraded by methanolysis. The neutral monosaccharides were separated and quantitated by HPLC using microbondapak carbohydrate analysis column, refractive index detection and water-acetonitrile acetic acid elution. The analyses of these constituents by HPLC showed that the natural constituent(N) consisted of glucose, xylose and mannose, the average amount being 96.44, 2.16 and 1.73%, respectively. The fermentation constituent(C) consisted of mannose, glucose, xylose and galactose, the average amount being 61.30, 14.00, 12.95, and 11.75%, respectively. The analyses of these constituents by an amino acid analyzer showed that both C and N contained 17 amino acids.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.296-299
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• 1990

As an improved preparation method of Shikhae, a tea-bag system containing malt and amylolytic enzymes was developed in which extraction of malt enzymes and saccharification occured efficiently. The amylolytic activity of the malt was increased by adding the mixture of ${\alpha}-amylase$, glucoamylase and glucoisomerase. Malt and the mixture of enzymes were placed in tea-bag $(16{\times}20cm)$, extracted in water at $30-40^{\circ}C$ for 1-2 hours and followed by saccharification of the cooked rice at $60-70^{\circ}C$ for 3-4 hours. In the conventional Shikhae, content of maltose was about 50% and that of oligosaccharides larger than trisaccharides was about 40% of total sugar. The content of monosaccharides such as glucose and fructose was about 95% and this improved method would be effective for increasing the sweetness and the monosaccharide contents in the product.

• Journal of the Korean Wood Science and Technology
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• v.37 no.4
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• pp.381-387
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• 2009

Enhancing enzymatic saccharification of corn stover by aqueous ammonia soaking pretreatment was investigated on chemical compositional changes and enzymatic hydrolysis characteristics. At three different levels of aqueous ammonia soaking temperature and time ($140^{\circ}C$-1 h, $90^{\circ}C$-16 h and $50^{\circ}C$-6 days), higher temperature and shorter treatment time led to more xylan and lignin removal based on overall composition analysis and carbohydrate compositional analysis. More xylan and lignin removal in higher temperature treatment led to higher enzymatic saccharification of cellulose and xylan to monosaccharide by commercial cellulase mixtures (Celluclast 1.5L and Novozym 342 from Novozyme, Denmark).

• Ocean and Polar Research
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• v.38 no.2
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• pp.129-137
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• 2016

This study aimed to isolate and characterize sulfated polysaccharides (SPs) from Iridaea cordata and evaluate their anticancer activity. SPs of the Antarctic red seaweed were obtained by $CaCl_2$ (SP1) and ethanol precipitations (SP2) following diluted acid extraction at room temperature. Yields of SP1 and SP2 were approximately 14% and 23%, respectively, of the dry weight of red seaweed. The average molecular mass of the SP1 and SP2 was estimated about $1.84{\times}10^3$ and $1.42{\times}10^3kDa$, respectively, by size-fractionation High-Performance Liquid Chromatography (HPLC). From the High-Performance Anion-Exchange Chromatography-Pulsed Amperometric Detection (HPAEC-PAD) analysis, the main monosaccharide was galactose with glucose and fucose as minor components. The sulfate content of SP2 (40.4%) was slightly higher than that of SP1 (33.8%). The FT-IR spectra also showed characteristic band of carrageenan-like sulfated polysaccharides. Taken together the SPs are thought to be carrageenan-like sulfated galactan. The polysaccharides (SPs) from I. cordata exhibited weak antitumor activity against PC-3 (prostate cancer), HeLa (cervical cancer), and HT-29 (human colon adenocarcinoma). To our knowledge, this is the first data on biological activity of the Antarctic red seaweed I. cordata.

• 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 the East Asian Society of Dietary Life
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• v.26 no.5
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• pp.450-456
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• 2016

Allulose, a monosaccharide isomer of fructose, was evaluated as a sucrose replacer for healthy cookie production with benefits such as low glycemic impact and low calorie content. Sucrose (as a reference), fructose, glucose, and allulose were used to explore the effects of sugar-replacer type on solvent retention capacity (SRC), differential scanning calorimetry (DSC), rapid visco-analyzer (RVA), and wire-cut cookie baking. SRC results indicated the lowest swelling of solvent-accessible arabinoxylans in allulose compared to that in other sugar solutions. DSC and RVA results showed retardation of starch gelatinization and onset of starch pasting, respectively, in the following order: water < allulose < fructose < glucose < sucrose. Among sugars, wire-cut cookies formulated with glucose showed the least desirable attributes with respect to cookie diameter and thickness. Although the baking response of allulose was slightly inferior to that of the sucrose control, the sugar exhibited a superior baking response to that of fructose, suggesting it could be used successfully as a fructose alternative or sucrose alternative for producing wire-cut cookies with reduced calorie content and low glycemic impact.