• Food Science and Preservation
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• v.9 no.4
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• pp.429-433
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• 2002

The D-xylulokinase from Candida sp. L-16 was purified through a sequence of ammonium sulfate fractionation, DEAE-cellulose chromatography, Sephadex G-100 and Sephadex G-200 gel filtration. The specific activity of the purified Dxylulokinase was increased to 23.2 fold and the yield was 11.2%. The enzyme was showed to be a single protein band by SDS-PAGE. The molecular weight of the enzyme was 150,000 dalton, this enzyme was identified to be a dimer with two subunits. The optimum conditions of the enzyme were pH 8.0 and 40$\^{C}$, respectively. The enzyme was relatively stable between pH 7.0 to pH 9.0, but it was unstable over 30$\^{C}$. The enzyme showed substrate specificity on D-xylulose, D-arabinose and D-ribose, Km value and Vmax for D-xylulose were 0.042 mM and 117 units/ml, respectively. The activation energy of the enzyme was 4.75 Kcal/mol. The one was inhibited by metabolic intermediates such as 6-phosphogluconic acid, 2-keto-gluconic acid. The enzyme was activated by EDTA and thiol compounds such as cysteine-HCI, DTT and glutathione.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.2
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• pp.215-221
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• 2011

The goal of this study was to evaluate the quality characteristics of various beans in distribution. The quality characteristics investigated were proximate composition, color, free sugars, organic acids, amino acids, and minerals. Bean samples analyzed were white soybeans (Glycine max. (L.) Merrill), kidney beans (Phaseolus vulgaris var. humilis), black soybeans (Glycine max (L.) Merr.), black small soybeans (Rhynchosia nulubilis), sword beans (Canavalia gladiata), and green beans (Phaseolus vulgaris). The highest contents of crude fat and crude protein were 17.60${\pm}$0.14% for white soybeans, and 42.38${\pm}$0.15% for black soybeans, respectively. Higher color values compared to the other samples were $L^*$ (64.07${\pm}$0.97) for sword beans, $a^*$ (15.64${\pm}$0.48) for kidney beans, and $b^*$ (22.92${\pm}$0.09) for white soybeans. The highest contents of sucrose, oxalic acid, and malic acid in black small soybeans were 54.23 mg/g, 23.26 mg/100 g and 18.24 mg/100 g, respectively. Xylose, galactose, lactose, malonic acid, succinic acid, and lactic acid were not detected in the soybeans studied, whereas the glutamic acid content of soybeans ranged from 2.68 to 6.18 g/100 g. Levels of K and Mg contents in soybean were higher than those of the other minerals.

• Journal of Life Science
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• v.17 no.10
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• pp.1341-1346
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• 2007

An intracellular ${\beta}-xylosidase$ from Paenibacillus sp. DG-22 was purified to homogeneity by ion-exchange, hydrophobic interaction and gel-filtration chromatography. The molecular weight of the enzyme was measured to be 156,000 by gel filtration and 80,000 by SDS-PAGE, indicating that the enzyme consisted of two identical subunits. The purified enzyme exhibited maximum activity at $65^{\circ}C$ and pH 5.5. It retained 89% of its initial activity up to 60 min at $60^{\circ}C$ and had a half-life of 25 min at $65^{\circ}C$. The enzyme was highly specific for pNPX as the substrate. It showed little or no activity against other p-nitrophenyl glycosides and xylans. The $K_m\;and\;V_{max}$ for pNPX was 0.53 mM and 3.18 U/mg protein, respectively. The ${\beta}-xylosidase$ was strongly inhibited by $Ag^+,\;Fe^{2+},\;Hg^{2+}\;and\;Zn^{2+}$ and slightly activated by DTT. The hydrolysis product from xylobiose, xylotriose, and xylotetraose was xylose.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.339-345
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• 2009

Two lactic acid bacteria (LAB) with high ornithine-producing capacity were isolated from kimchi. Examination of the biochemical features using an API kit indicated that the strains belonged to the members of Weissella genus. They were gram positive, short rod-type bacteria, and able to grow anaerobically with $CO_2$ production. The isolates grew well on MRS broth at $25\sim37^{\circ}C$ and pH of 6.0~7.0. The optimum temperature and pH for growth are $30^{\circ}C$ and pH 6.5. The isolates fermented arabinose, ribose, xylose, glucose but not cellobiose, galactose, raffinose, or trehalsoe. The 16S rDNA sequences of isolates showed 99.6% and 99.7% homology with the Weissella koreensis S5623 16S rDNA (access no. AY035891). They were accordingly identified and named as Weissella koreensis OK1-4 and Weissella koreensis OK1-6, and could produce ornithine from MRS broth supplemented with 1% of arginine at a productivity of 27.01 and 31.41 mg/L/h, respectively. This is the first report on the production of ornithine by the genus Weissella isolated from kimchi.

• KSBB Journal
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• v.10 no.5
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• pp.589-597
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• 1995

Protein-bound polysaccahrides(PBP) were isolated, purified, and characterized from the sawdust media after harvesting the fruit body of Flammulina velutipes. The yield of the crude PBP(Fr.CA) extracted from the sawdust media, was 0.367% relative to the original sawdust media. The total sugar and protein contents of Fr.CA were 19.8% and 23.8% respectively. Using the membrane filtration, the fraction of which the molecular weight is over 300 kDa(Fr.A) was isolated from the Fr.CA and the yield was 44.6% relative to the Fr.CA. This result indicates that high molecular PBP is the dominant components of the Fr.CA. The Fr.A was separated into three fractions (Fr.A-1, Fr.A-2 and Fr.A-3) whose yields are 5.8%, 8.5% and 13.2% respectively. These fractions were further purified using gel filtration, obtaining a single peak in each fraction that considered as pure PBP Among them, the yield of Fr.A-1-${\alpha}$ was 20.9% relative to the Fr.A-1, and the molecular weight was 800 kDa. Monosaccharide components such as glucose, galactose, mannose, xylose and fucose could be detected all fractions by a HPLC analysis. Especially in the Fr.A-1-${\alpha}$ fraction, the content of glucose and galactose appeared to be high.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.229-239
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• 2018

The purpose of this study was to effectively produce the biosugar from cell wall of lipid extracted microalgae (LEA) by using microwave-assisted pretreatment without enzymatic hydrolysis process. Response surface methodology (RSM) was applied to optimization of microwave-assisted pretreatment conditions for the production of biosugar based on enzyme-free process from LEA. Microwave power (198~702 W), extraction time (39~241 sec), and sulfuric acid (0~1.0 mol) were used as independent variables for central composite design (CCD) in order to predict optimum pretreatment conditions. It was noted that the pretreatment variables that affect the production of glucose (C6) and xylose (C5) significantly have been identified as the microwave power and extraction time. Additionally, the increase in microwave power and time had led to an increase in biosugar production. The superimposed contour plot for maximizing dependent variables showed the maximum C6 (hexose) and C5 (pentose) yields of 92.7 and 74.5% were estimated by the predicted model under pretreatment condition of 700 w, 185.7 sec, and 0.48 mol, and the yields of C6 and C5 were confirmed as 94.2 and 71.8% by experimental validation, respectively. This study showed that microwave-assisted pretreatment under low temperature below $100^{\circ}C$ with short pretreatment time was verified to be an effective enzyme free pretreatment process for the production of biosugar from LEA compared to conventional pretreatment methods.

• Journal of Microbiology and Biotechnology
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• v.16 no.10
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• pp.1554-1560
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• 2006

A Gram-positive, aerobic or facultative anaerobic, non motile, endospore-forming bacterial strain, designated Gsoil $114^T$, was isolated from a soil sample of a ginseng field in Pocheon Province (South Korea), and was characterized taxonomically by using a polyphasic approach. It grew well on nutrient agar medium and utilized a limited number of organic substrates as sole carbon sources, including D-xylose and some other carbohydrates, but did not utilize L-amino acids and organic acids. The isolate was positive for oxidase test but negative for catalase, and negative for degradation of macromolecules such as starch, cellulose, xylan, casein, chitin, and DNA. The G+C content of the genomic DNA was 41.8 mol%. The predominant isoprenoid quinone was menaquinone 7 (MK-7). The major fatty acids were $anteiso-C_{15:0}$ (32.1%), $iso-C_{15:0}$ (30.5%), and $anteiso-C_{17:0}$ (30.2%). Comparative 16S rRNA gene sequence analysis showed that strain Gsoil $114^T$ fell within the radiation of the cluster comprising Bacillus species and joined Bacillus shackletonii LMG $18435^T$ with a bootstrap value of 95%. The highest 16S rRNA gene sequence similarities were found with Bacillus shackletonii LMG $18435^T$ (97.6%), Bacillus acidicola DSM $14745^T$ (96.9%), Bacillus sporothermodurans DSM $10599^T$ (96.5%), and Bacillus oleronius DSM $9356^T$ (96.5%). The phylogenetic distance from any other validly described species within the genus Bacillus was less than 96%. DNA-DNA hybridization experiments showed that the DNA-similarities between strain Gsoil $114^T$ and closest phylogenetic neighbors were less than 39%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil $114^T$ (=KCTC $13944^T$=DSMZ $18134^T$) was classified in the genus Bacillus as the type strain of a novel species, for which the name Bacillus ginsengihumi sp. nov. is proposed.

• Microbiology and Biotechnology Letters
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• v.48 no.2
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• pp.215-222
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• 2020

The marine microorganism PX-1, which can hydrolyze xylan, was isolated from coastal sea water of Jeju Island, Korea. Based on the 16S rRNA gene sequence and chemotaxonomy analysis, PX-1 was identified as a species of the genus Aestuariibacter and named Aestuariibacter sp PX-1. From the culture broth of PX-1, an extracellular xylanase was purified to homogeneity through ammonium sulfate precipitation and subsequent adsorption chromatography using insoluble xylan. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration chromatography estimated the molecular weight of the purified putative xylanase (XylA) as approximately 64 kDa. XylA showed xylanase activity toward beechwood xylan, with a maximum enzymatic activity at pH 6.0 and 45℃. Through thin-layer chromatographic analysis of the xylan hydrolysate produced by XylA, it was confirmed that XylA is an endo-type xylanase that decomposes xylan into xylose and xyloligosaccharides of various lengths. The K_m and V_max values of XylA for beechwood xylan were 27.78 mM and 78.13 μM/min, respectively.

• Applied Biological Chemistry
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• v.11
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• pp.49-53
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• 1969

Some properties of glucose isomerizing enzyme which produced by the strain K-17 in xylose containing nutrient broth medium were investigated. The optimal pH for enzyme reaction was indicated about 7.2 and optimal temperature was about $75^{\circ}C$. The same optimal temprature was indicated by both cell free extract and acetone dried cells using as enzyme. The glucose isomerizing enzyme from strain K-17 was not inhibited by the high concentration of substrate even in a suturated glucose solution, but most enzyme was inactivated by the heat treatment at $80^{\circ}C$. The maximum fructose forming ratio from glucose was about 50 percents.

• The Korean Journal of Mycology
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• v.23 no.4 s.75
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• pp.340-347
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• 1995

Polysaccharide FHW was extracted from the fruiting bodies of Fomitella fraxinea with hot-water treatment and then fractionated into FHW-I and FHW-II on DEAE-Cellulose chromatography. FHW-I and FCW-II were further purified into FHW-Ia and Ib, FHW-IIa and IIb on gel permeation chromatography, respectively. A small amount of uronic acid was detected and glucose, galactose, fucose, and mannose were found to be main sugars in the polysaccharides. Protein was detected in FHW-Ia, FHW-IIa, and FHW-IIb, but not in FHW-Ib. FHW-Ia was identified to be a fuco-gluco-mannogalactan with molecular weight of 19,000 and FHW-Ib was a gluco-fuco-mannogalactan of 15,000. FHW-IIa and FHW-IIb were galacto-mannoglucan and their molecular weights were estimated to be 31,000 and 9,000, respectively. Both FHW-Ib and FHW-IIb did not show an absorption band characteristic of the ${\beta}-glycosidic$ linkage in IR spectra. FHW-IIb showed a strong immuno-stimulating activity but the other three polysaccharides showed a weak activity.