• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.960-968
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• 2003

A bacterial isolate showing a strong endochitosanase activity was isolated from soil and then characterized. The isolate was identified and designated as Bacillus cereus P16, based on morphological and biochemical properties, assimilation tests, cellular fatty acids pattern, along with 16S rRNA gene sequence. The optimized medium for producing extracellular chitosanase in a batch culture contained 1% tryptone, 0.5% chitosan, and 1% NaCl (pH 7.0). Powder chitosan and tryptone served the best as carbon and nitrogen sources, respectively, for the chitosanase production. Chitosanase activity was the highest when culture was completed at $37^{\circ}C$ among various temperatures ($20-42^{\circ}C$) tested in a shaking incubator (200 rpm). The levels of chitosanase activity in the culture fluid were 2.0 U/ml and 3.8 U/ml, respectively, when incubated in a flask for 60 h and in a jar fermenter for 24 h. The culture supernatant showed a strong liquefying activity on the soluble chitosan. The viscosity of 1% chitosan solution, that was incubated with the culture supernatant, was rapidly decreased, suggesting the secretion of endochitosanolytic enzymes by P16. The culture fluid revealed six endo-type chitosanase isozymes, two major (38 and 45 kD), and four minor (54, 65, 82, and 96 kD) forms by staining profile. The crude enzymes were very stable, and full activity was maintained for 4 weeks at $4^{\circ}C\;or\;-20^{\circ}C$ in the culture supernatant, suggesting a highly desirable stability rate for making an industrial application of the crude enzymes. The supernatant also cleaved the insoluble chitosan powder, but the hydrolysis rate was much lower. The enzymic degradation products of chitosan contained $(GlcN)_n$ (n=2-8). The concentration of chitosan in the reaction mixture of the crude enzyme affected the chitooligosaccharides composition of the hydrolysis products. When the higher concentration of chitosan was used, the higher degree of polymerized chitooligosaccharides were produced. By comparison with other commercial chitosanase preparations, P16 was indeed found to be a valuable enzyme source for industrial production of chitooligosaccharides from chitosan.

• Microbiology and Biotechnology Letters
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• v.43 no.2
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• pp.134-141
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• 2015

An agarolytic marine bacterium (H9) was isolated from the coastal seawater of the West Sea, South Korea. The isolate, H9, was gram-negative and rod-shaped with a smooth surface and polar flagellum. Cells grew at 20-30℃, between pH 5.0 and 9.0, and in ASW-YP (Artificial Sea Water-Yeast extract, Peptone) media containing 1-5% (w/v) NaCl. The G+C content was 41.56 mol%. The predominant isoprenoid quinone in strain H9 was ubiquinone-8. The major fatty acids (>10%) were C_16:1ω7c (34.3%), C_16:0 (23.72%), and C_18:1ω7c (13.64%). Based on 16S rRNA gene sequencing, and biochemical and chemotaxonomic characterization, the strain was designated as Pseudoalteromonas sp. H9 (=KCTC23887). In liquid culture supplemented with 0.2% agar, the cell density and agarase activity reached a maximum level of OD = 4.32 (48 h) and OD = 3.87 (24 h), respectively. The optimum pH and temperature for the extracellular crude agarases of H9 were 7.0 and 40℃, respectively. Thin-layer chromatography analysis of the agarase hydrolysis products revealed that the crude agarases hydrolyze agarose into neoagarotetraose and neoagarohexaose. Therefore, the new agar-degrading strain, H9, can be applicable for the production of valuable neoagarooligosaccharides and for the complete degradation of agar in bio-industries.

• Journal of Conservation Science
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• v.36 no.3
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• pp.213-224
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• 2020

This research conducted a component analysis and conservation treatment of "Sangryangmun," a material which had been written in 1965 and was discovered during the repair project for "Jinnamgwan" in Yeosu. The "Sangryangmun" has been stored in a cylindrical metal storage; however, defects, discolorations, hardening, and damages caused by pollutants were found. Based on the XRF analysis, rust in the cylindrical metal storage, which was made of Cu, was stuck on the surface of the "Sangryangmun". Using FT-IR and Pyrolysis-GC/MS analyses, carbonyl and compounds of fatty acids were detected; the organic material on the surface of the "Sangryangmun" was identified to have belonged to oil-based components. Therefore, it was presumed that the bast fibers of a mulberry was used in the paper. To determine the conservation materials, component analysis, condition survey, and preliminary test on adhesives were conducted. Moreover, the missing parts and partial linings were filled using mulberry-fiber paper, methyl cellulose, etc.

• Applied Biological Chemistry
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• v.30 no.1
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• pp.46-53
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• 1987

For the effective utilization of Korean Crnciferal seeds, the chemical characteristics, lipid composition and amino acid composition were analysed in six kinds. The content of crude lipid was 39.1% to 46.5% in Korean Cruciferal seeds. The iodine value, saponification value and acid value were 93.4 to 107.2, 170.4 to 185.0 and 0.7 to 1.2 in Cruciferal seed oils, respectively. The content of neutral lipids was 95.3% to 96.4% to total lipid, while that of compound lipids was 3.6% to 4.2%. The content of erucic acid teas 33.4% to 51.5% to total fatty acid in Gerg-gac, Chin-ju Daepung, Seoul-cabbage, and that of Mok-po 71 was only 0.8%. The content of erucic acid was decreased with increasing amount of oleic acid, Among the amino acid in defatted seed meals, glutamic acid, leucine, lysine, arginine and proline showed high quantity and the sum of these amino acids occupied 50% to total amino acid. While cystine and methionine were poor in content.

• Applied Biological Chemistry
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• v.42 no.3
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• pp.256-261
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• 1999

This study was conducted to investigate the effect of barley tea with roasted grains and barley tea with a tea bag on the reduction of chlorination by-product(CBP) levels in chlorinated drinking water. Since the concentrations of six volatile compounds of eight CBPs were blow their respective detection limits after 10 minute heating, two nonvolatile CBPs dichloroacetic acid and trichloroacetic acid, and total chlorine were compared between tap water and two kinds of barley tea. No significant differences were observed in the relative changes of the amounts of the above three items, and new peaks which were not found in the original water appeared in the chromatograms of gas chromatograph/electron capture detector(GC/ECD). Thirty three organic compounds were identified in the extracts of barley tea with roasted grains, barley tea with a tea bag, corn tea, and Cassia tora seed tea which were prepared with distilled/deionized water, using gas chromatography/mass selective detection(GC/MSD). Exclusive of fatty acids, most of the compounds were aromatic compounds such as phenols, furans, and pyrroles.

• Journal of Applied Biological Chemistry
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• v.60 no.2
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• pp.179-184
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• 2017

Tolaasin, a 1.9 kDa peptide toxin, is produced by Pseudomonas tolaasii and causes the brown blotch disease of cultivated oyster mushroom. It forms pores on the membrane and thus destroys cellular membrane structure, seriously reducing the productivity of mushroom cultivation. The mechanism of tolaasin-induced cytotoxicity is not known in detail. However, it has been reported to form a pore structure in the cytoplasmic membrane through the molecular multimerization. Therefore, food additives which can interact with tolaasin molecules may inhibit the pore formation by hydrophobic interactions with tolaasin molecules. In this study, various food additive materials have been identified as inhibitors of the tolaasin activity and named tolaasin-inhibitory factors (TIF). Most of TIFs are emulsifying agents for food processing procedures. Among various TIFs, polyglycerol and sucrose esters of fatty acids blocked effectively the cytotoxicity of tolaasins at the concentrations $10^{-4}-10^{-5}M$. These TIFs also successfully suppressed the blotch disease development in the shelf cultivation of oyster mushroom.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.1
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• pp.11-19
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• 2018

The gut microbiome has been studied extensively over the past decade with most scientific reports focused on the adverse role of the gut microbiome on gastrointestinal diseases. For example, the altered gut microbiome exacerbates the development of immune system-mediated damage in many diseases. The most studied pathologies include irritable bowel syndrome, inflammatory bowel diseases, and colitis-associated cancer. On the other hand, intestinal microflora is also beneficial and contributes to the intestinal physiology by the synthesis of vitamins, production of short chain fatty acids and bile acid metabolism, thereby maintaining gut homeostasis. Therefore, the balance between commensal and pathogenic bacteria populations influences mainly the maintenance of intestinal health. Changes in the intestinal microflora have been suspected to be the underlying causes of multiple diseases. Despite the immense amount of published data, the optimal gut microbiome composition is still controversial. This review briefly outlines the connection between the gut microbiome and critical gastrointestinal diseases focusing on three prominent intestinal disorders: irritable bowel syndrome, inflammatory bowel diseases, and colitis-associated cancer disorders. Finally, intervention strategies using natural products for the alleviation of these diseases and the maintenance of a health gut microbiome are suggested.

• Korean Journal of Food Science and Technology
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• v.14 no.2
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• pp.151-155
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• 1982

Effects of vitamins, metabolic intermediates and several inorganic mineral salts on the biomass and lipid accumulation of Mucor plumbeus were investigated after 15 days of incubation at $37^{\circ}C$ under static culture condition. The optimum concentrations of various vitamins were ${\gamma}/l$ for biotin, and 0.01 g/l for nicotinic acid, pyridoxine, thiamine and riboflavin. Among them pyridoxine was the most stimulatory. The maximum felt weight and lipid content per 50ml medium were $2.82{\pm}0.14\;g$ and 62.8%. Triglyceride content of neutral lipid produced under this condition was 64.9%. The major fatty acids were oleic acid (50.0%), linoleic (23.8%) and palmitic acid (13.9%). Malonic acid was considered not to be desirable even though it stimulated the biomass and lipid accumulation because triglyceride content was lowered considerably comparing with control. $MgSO_4{\cdot}7H_2O$ was the most stimulatory among the various magnesium salts and its optimum concentration was 5 g/l. Mucor plumbeus did not require $NaH_2PO_4$ for the stimulation of felt and lipid production. However, the addition of $MnCl_2$ at the concentration of 2 g/l was stimulatory to show $2.76{\pm}0.28\;g$ of felt/50 ml and 56.4% lipid content, and 73.9% triglyceride in the neutral lipid.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.2
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• pp.93-101
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• 2000

The objective of this study was to evaluate the possibility of co-digestion of food waste and sewage sludge mixture using anaerobic system. The Biochemical methane Potentials of cabbage and food waste were $297ml\;CH_4/g$ VS and $306.7ml\;CH_4/g$ VS, respectively. The biodegradability of food waste was 60%. The concentrations of acetate, propionate, and isobutyrate produced during the aerobic acidogenesis of food waste for 36 hours were 7,000~7,200 ppm, 260~280 ppm, 380~400 ppm, and 40~50 ppm, respectively, of which acetate was over 85%. The concentrations of acetate, propionate, and isobutyrate produced during the anaerobic acidogenesis for 36 hours were 1,400~1,600 ppm, 30~40 ppm, 220~250 ppm, and 260~300 ppm, respectively, of which acetate was over 70%. The biodegradabilities of aerobic and anaerobic acidogenesis were 30% and 25%, respectively. Methanogensis could be activated under 1 % of NaCl and 1,000 ppm of volatile fatty acids at the range of pH 6.8~7.2. The maximum mixture ratio of food waste and sewage sludge in the present study was 2:8 by the result of VS removal rate and Methane production.

• Journal of Microbiology and Biotechnology
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• v.13 no.3
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• pp.348-353
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• 2003

Generally, two different types of fructose polymer are found in nature. One is inulin, whose fructosyl residues are linked mainly by a ${\beta}-(2,1)-linkage$, while the other is high-molecular-weight levan, whose fructosyl residues are linked mainly by a ${\beta}-(2,6)-linkage$. In contrast to the extensive studies on the prebiotic properties of inulin, there has been no report on the effect of levan on the large bowel microflora in viva. Therefore, to examine whether dietary levan can be used as a prebiotic, Sprague-Dawley male rats were fed one of two diets for 3 weeks: 1) basal diet plus sucrose; 2) basal diet plus 10% (wt/wt) levan. The cecal bowel mass, cecal and colon short-chain fatty acids (SCFAs), pH, and microflora were then compared. The intake of the levan-containing diet significantly increased the total cecal weight and wall weight. The analyses of the SCFAs in the cecal and colonic contents revealed that levan was converted into acetate, butyrate, and lactate, which resulted in acidic conditions. The intake of levan also significantly increased the total number of microorganisms by 5-fold and lactic acid-producing bacteria (LAB) 30-fold in the feces. Accordingly, the current work shows that levan can be used as a prebiotic for stimulating the growth of LAB in an animal model.