• Microbiology and Biotechnology Letters
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• 제43권1호
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• pp.9-15
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• 2015

The seaweed, Gracilaria verrucosa, was fermented to produce bioethanol. Optimal pretreatment conditions were determined to be 12% (w/v) seaweed slurry and 270 mM sulfuric acid at 121℃ for 60 min. After thermal acid hydrolysis, enzymatic saccharification was carried out with 16 U/ml of mixed enzymes using Viscozyme L and Celluclast 1.5 L to G. verrucosa hydrolysates. A total monosaccharide concentration of 50.4 g/l, representing 84.2% conversion of 60 g/l total carbohydrate from 120 g dw/l G. verrucosa slurry was obtained by thermal acid hydrolysis and enzymatic saccharification. G. verrucosa hydrolysate was used as the substrate for ethanol production by separate hydrolysis and fermentation (SHF). Ethanol production by Candida lusitaniae ATCC 42720 acclimated to high-galactose concentrations was 22.0 g/l with ethanol yield (Y_EtOH) of 0.43. Acclimated yeast to high concentrations of specific sugar could utilize mixed sugars, resulting in higher ethanol yields in the seaweed hydrolysates medium.

• Microbiology and Biotechnology Letters
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• 제34권3호
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• pp.196-203
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• 2006

Three slime-forming lactic acid bacteria were isolated from Kimchi and shown to produce viscous exopolysaccharides (EPS) in sucrose media. The isolated strains, GJ2, C3 and C11, were identified as Leuconostoc kimchii, Leuconostoc citreum and Leuconostoc mesenteroides, respectively, by examining their metabolic characteristics and determining their 16S rDNA sequences. Leu. kimchii GJ2, Leu. citreum C3 and Leu. mesenteroides C11 exhibited high viability (maintained initial viable cell count of $10^8$ CFU/ml) in 0.05 M sodium phosphate buffer (pH 3.0) for 2 h, in artificial gastric juice for 2 h and in 0.3% oxgall for 24 h. When tested, Leu. kimchii GJ2, in particular, displayed antimicrobial activity against pathogenic microorganisms. Leu. kimchii GJ2, Leu. citreum C3 and Leu. mesenteroides C11 produced 21.49 g/l, 16.46 g/l and 22.98 g/l EPS, respectively, in sucrose (5%) medium. The amount of purified EPS extracted from Leu. kimchii GJ2, Leu. citreum C3 and Leu. mesenteroides C11 was 14.61 g/l, 7.73 g/l and 4.77 g/l, respectively. Although the EPS produced by Leu. kimchii GJ2, Leu. citreum C3 and Leu. mesenteroides C11 differed in viscosity, TLC and HPLC analysis revealed that each contained only one type of monosaccharide, glucose. The average molecular mass of EPS produced by Leu. kimchii GJ2 was 306,606 Da.

• Journal of the Korean Wood Science and Technology
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• 제42권6호
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• pp.740-746
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• 2014

The unripe fruit of cudrania tricuspidata was extracted with 50% ethanol. The crude water-soluble extracts were separated by liquid-liquid separation with n-hexane, ethyl acetate and butanol followed by precipitation with ethanol, and then the water-soluble polysaccharide (F1) was isolated by the fractionation through gel permeation chromatography using preparative PLaquagel-OH column with water. The structure was characterized by monosaccharide composition with HPAEC-PAD, methylation analysis with GC-MS, FT-IR and HPLC. According to the data, F1 was com posed of glucose (22.84 mM), galactose (13.75 mM), arabinose (45.87 mM), xylose (7.49 mM). It was revealed which uronic acid and acetyl group were not attached in F1. And it is constituted of 1-linked arabinose, 1,4-linked arabinose, 1,3-linked glucose, 1,4-linked galactose, 1,4-linked glucose, 1,3,6-linked galactose, 1,3,6-linked glucose and the ratio was showed 1.1 : 1.0 : 4.9 : 7.5 : 3.0 : 3.1 : 1.4 : 1.5.

• Korean Journal of Microbiology
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• 제42권4호
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• pp.326-331
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• 2006

In the present study, we examined biosorption characteristics of heavy metals onto the extracellular polysaccharide (EPS) produced by the purple nonsulfur photosynthetic bacteria Rhodopseudomonas sp. KH4, which was isolated from a stream in Anyang, Kyonggi-Do. When Cd (100 mg/L) and Cu (100 mg/L) were added to EPS (1.0 g/L) in the optimal condition (Cd; pH 8, Cu; pH 5, $40^{\circ}C$), 84.2 mg/L of Cd and 70.0 mg/L of Cu were adsorbed within 30 min and 10 min, respectively. When 100 mg/L of Cd and Cu were present as mixture, 16.8 mg/L of Cd and 48.7 mg/L of Cu were adsorbed at $25^{\circ}C$, pH 5. The maximum adsorption capacity determined by fitting Langmuir isotherms model was suitable for describing the biosorption of Cd (76.9 mg/g) and Cu (67.1 mg/g) by EPS. The neutral monosaccharide in the EPS determined by GC consisted of arabinose (2.4%), glucose (7.1%) and mannose (90.5%).

• KOREAN JOURNAL OF CROP SCIENCE
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• 제52권4호
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• pp.421-428
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• 2007

Eight varieties of milled rice showing different palatabilities were studied in order to identify the relationship between physicochemical properties of carbohydrate components and their fine structure. Gopumbyeo showed the highest palatability value among the eight varieties tested. Both peak viscosity and breakdown were hightest in Hitomebore, and lowest in Mihyangbyeo. No relationship was indicated between the palatability and gelatinization properties. The amylose content of starch showed a significant difference among the varieties tested. However, no relationship was found between the structure of amylose and the palatability of milled rice. The degree of branching(B/A value) was highest in Saechucheongbyeo, and lowest in Palgongbyeo in fine structure of amylopectin. But no relationship was indicated between the B/A values and the palatability of milled rice. Difference was indicated in properties of gelatinization of starch by differential scanning calorimetry. The enthalphy for gelatinization showed a significant difference among the varieties. However, no relationship was found between the enthalphy for gelatinization and the palatability of milled rice. Monosaccharide in endosperm was composed of rice were compound of rhamnose, fucose, ribose, arabinose, and xylose. The total content of monosaccharides was highest in Saechucheongbyeo, and lowest in Palgongbyeo. However, 7 varieties of milled rice, expect Palgongbyeo, showed no relationship between the palatability and monosaccharides contents.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제16권3호
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• pp.202-210
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• 1983

In order to elucidate the taste compounds of Korean catfish, Parasilurus asotus, free amino acids, nucleotides and their related compounds, organic bases, sugars, organic acids and minerals in the extracts of Korean catfish were analyzed, and then evaluated by sensory test of synthetic extract prepared on the basis of the analytical data. Taste panel assessments of synthetic extracts prepared with each extractive component omitted were carried out by a triangle difference test, and changes in taste profile were assessed. In free amino acid composition, glycine was dominant occupying $25\%$ of total free amino acids. The other abundant free amino acids were lysine, taurine and alanine. Judging from the result of analysis of nucleotides, IMP was dominant showing about $70\%$ of total nucleotides while ATP, ADP, AMP, inosine and hypoxanthine were low in content. Among organic bases, total creatinine was abundant and its nitrogen content occupied more than $50\%$ of the total extractive nitrogen. The amount of betaine was 18mg/100g and trace amount of trimethylamine and trimethylamine oxide were detected. The main organic acids were succinic, butyric, propionic and valeric acid. On the other hand, oxalic, fumaric, maleic, tartaric and citric acids were analyzed in trace. As for the sugars, glucose was found to be the most abundant monosaccharide. Extremely small amounts of fructoae, inositol were also detected and ribose and arabinose were trace in content. $K^+,\;Na^+,\;PO_{4}^{3-}$ and $Cl^-$ were found to be the major ions and small amount of $Ca^{2+}$ were defected. The synthetic extract, prepared with about 40 pure chemicals based on the analytical data satisfactorily revealed the natural taste of the original extract except slight difference in meaty taste and mildness. From the results of omission test the major components which contribute to produce the taste were serine, IMP, succinic acid and $PO_{4}^{3-}$.

• Korean Chemical Engineering Research
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• 제51권5호
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• pp.561-567
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• 2013

Mixed hardwood chips were pre-pulping extracted with green liquor prior to kraft pulping in order to recover hemicelluloses for use as biofuels. This green liquor solution containing mainly sodium sulfide and sodium carbonate was applied at different alkali charges (expressed as $Na_2O$) of 0, 1, 3, and 5% on dry wood weight. The extractions were performed at $160^{\circ}C$ for residence times ranging from about 1-2 h to determine the effect of extraction severity on composition of the pre-pulping extract. The severity of hemicellulose extraction time and green liquor charge controls the concentration of acetic acid and monosaccharide sugars available for downstream processing, the accumulation of degradation products such as organic acids and furans in the extract. As the alkali charge was increased, the amount of acetate side chains on the hemicelluloses and the dissolved lignin in the extract increased but the carbohydrate and sugars in the extract decreased appreciably. Hot water extraction (0% alkali addition) released the greatest amount of carbohydrates, up to 29.80 g/L measured as component sugars, but resulted in the greatest decrease in pulp yield. Meanwhile, pre-pulping extraction with 3% green liquor increased the pulp yield while greatly reducing the component sugars to 7.08 g/L. Fundamental data obtained in this study will allow selection of optimum hemicellulose extraction conditions for integrating the extraction operation into the Kraft pulping process.

• Korean Journal of Food Science and Technology
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• 제37권5호
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• pp.741-745
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• 2005

Pectin was dissolved in HCl, citric acid, and deionized distilled water (DW, 2%, v/v) and irradiated at different irradiation doses (2.5-50 kGy) by gamma ray to investigate its physicochemical characteristics and biological activity. Viscosity of pectin solution was significantly decreased by irradiation up to 10 kGy, then remained constant thereafter. Gamma-irradiation increased monosaccharide and polysaccharide levels up to 30-40 kDa. Electron donating ability of pectin solution was highest when DW was added and was increased by increasing irradiation dose (p<0.05). ${\beta}-Carotene$ bleaching assay revealed irradiation resulted in development of antioxidantive activity in pectin solution. Growth inhibition of cancer cell lines was observed in irradiated pectin solution in dose-dependent manner, with G36l showing the highest. Results suggested irradiation of pectin solution could be effective for preparation of functional pectin oligomer.

• Korean Journal of Food Science and Technology
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• 제38권2호
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• pp.153-158
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• 2006

Changes in contents of amino acids, caffeine, trigonelline, chlorogenic acid, and monosaccharides in green coffee beans during roasting were investigated. During roasting, amino acid contents of Arabica and Robusta coffees decreased by 30%, among which cysteine, serine, lysine, and arginine contents markedly decreased, whereas those of glutamic acid, glycine, alanine, valine, isoleucine, leucine, and phenylalanine slightly decreased or increased. Caffeine contents of Arabica and Robusta were 1 and 2%, respectively, and remained unchanged during roasting. Trigonellin content of Arabica (0.87%-0.90%) was slightly higher than that of Robusta (0.74%), and 50 to 65% trigonellin degraded when green beans were heavily roasted. Chlorogenic acid levels of Robusta and Arabica were 4.82, and 4.38-4.66%, respectively. About 90% chIorogenic acid degraded with heavy roating. Total monosaccharide contents of Arabica and Robusta were 38.1-38.7 and 37.7%, respectively, and gradually decreased with roasting.

• KSBB Journal
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• 제10권5호
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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.