• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.1
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• pp.90-96
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• 2000

The composition of leachates varies depending on the waste characteristics, landfill age and landfilling method. Generally, leachates contain high dissolved organic substance and ammonia nitrogen whereas phosphorus concentration was very low. Leachate A produced from young landfill is characterized by high BOD5/COD ratio (0.8) whereas leachate C produced from old landfill has lower BOD5/COD ratio (0.1). Maximum biochemical methane potential of leachate A, B (from medium landfill) and C were 271,106 and 4 ml CH4/g-COD, respectively. On the other hand, the maximum biodegradability of leachate A, B, and C were 75,30, and 1%, respectively. These results indicated that anaerobic treatment of leachate from young landfill was effective in removing organic pollutants. In case of leachate C, carbon might reside in the form of large molecular weight organic compounds such as lignins, humic acids and other polymerized compounds of soils, which are resistant to biodegradation. The lag-phase period increased with the increasing organic concentration in leachate. In case of leachate A of concentration greater than 25%, the lag-phase period increased sharply. This implied that the start-up period of anaerobic process using an unacclimated inoculum could be extended due to the higher concentration of leachate. This relatively long lag-phase is probably related to the fact that most of the inhibitory compounds have been diluted beyond their inhibitory concentrations of less than 50%. Furthermore, the ultimate methane yield and methane production rate decreased as leachate concentration increased. It was anticipated the potential inhibition was related with the steady-state inhibition as well as the initial shock load.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.325-334
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• 1995

The early senescence mutant induced from Gihobyeo by $\gamma-ray$ irradiation was determined. The mutated gene expression was identified with comparing the characteristic of original cultivar. The mutant had so similar the morphological characteristics to original cultivar that it couldn't be distinguished until senescence occurred at about 20 days after heading. Suddenly yellow leaves were observed within a few days due to great decreases in total chlorophyll and various carotenoid contents. Transmission electron microscopy showed the formation of starch granules, distortion of fine structure of leaf cell organelles, especially grana structures, and the decrease in grain filled after senescence occurred. But banding patterns of total proteins and isozymes have not show any differences, The early senescence mutant will be very useful for study material not only on physiological and biochemical properties of plant senescence but also on gene expression regulating senescence which gives great influence on yield potential and its stability.

• Journal of Life Science
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• v.31 no.10
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• pp.922-928
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• 2021

To profile the microbial compositions of Korean traditional fermented paste made from whole soybeans, Doenjang and Cheonggukjang, and compare their taxonomic differences, we analyzed the V3-V4 region of 16S rRNA of naturally fermented foods by using next generation sequencing. α-Diversity results showed that values indicating bacterial community abundances (OTUs) and richness (ACE, Chao1) were statistically significant (p=0.0001) in Doenjang and Cheonggukjang. Firmicutes was the most common phylum in both groups, representing 97.02% and 99.67% in the Doenjang and Cheonggukjang groups, respectively. Bacillus was the most dominant genus, accounting for 71.70% and 59.87% in both groups. Linear discriminant (LDA) effect size (LEfSe) analysis was performed to reveal the significant ranking of abundant taxa in different fermented foods. A size-effect threshold of 2.0 on the logarithmic LDA score was used for discriminative functional biomarkers. On the species level, Bacillus subtilis, Tetragenococcus halophilus, and Clostridium arbusti were significantly more abundant in Doenjang than in Cheonggukjang, whereas Bacillus thermoamylovorans, Enterococcus faecium, and Lactobacillus sakei were significantly more abundant in Cheonggukjang than in Doenjang. Permutational multivariate analysis of variance (PERMANOVA) showed that the statistical difference in microbial clusters between the two groups was significant at the confidence level of p=0.001. This research could be used as basic research to identify the correlation between the biochemical characteristics of Korean fermented foods and the distribution of microbial communities.

• Journal of fish pathology
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• v.20 no.1
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• pp.33-40
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• 2007

Biochemical characteristic of Streptococcus iniae and Streptococcus parauberis that are pathogens of streptococcosis of cultured flounder, Paralichthys olivaceus, in Jeju area was examined. The result of experiments on the grow according to temperatures showed that only S. parauberis grew at 10℃, the result of hemolysis test showed that only S. iniae bacteria showed β hemolysis. Only S. parauberis were positive in VP test and HIP test, both bacteria used α-D-glucose, D-mannose, D-psicose, D-trehalose, pyruvatic acid methyl ester, and glycerol as substrates. L-lactic acid was used only S. iniae bacteria, and β-methyl-D-glucosid was used only by S. parauberis. S. iniae exhibited acute infection patten, differently S. parauberis exhibited chronic infection patten in pathogenic test.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.959-967
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• 2004

To screen probiotic lactic acid bacteria with potent adhesive property on human colonic mucosa, colonic mucin-binding assay was introduced. This colonic mucin-binding assay actually measures the binding activity of surface lectin-like protein (SLP) on colonic mucin, and the optimal conditions were examined. The optimal pH for colonic mucin coating on plate wells was 4.8, and ${\times}24,000$ diluted solution of commercially available horseradish peroxidase (HRP) conjugated streptoavidin yielded good results, for rapid screening, $5.0\;{\mu}g/mL$ of biotinylated SLP from lactic acid bacteria was optimal, and optimal scintillation time of 3,3',5,5'-tetramethyl benzidine (TMB) was 10 min. These conditions were useful for both rapid selection and quantitative analysis of lactic acid bacteria that have high adhesion property to human intestinal tract. Among 50 strains of lactic acid bacteria, including 32 type culture strains and 18 isolated strains from infant feces, Lactobacillus species FSB-1 isolated from kimchi showed the highest binding activity to colonic mucin. From taxonomical viewpoints based on morphological study, physico-biochemical study, partial 16S rDNA seguencing, and phylogenetic analysis, L. species FSB-1 was identified as Lactobacillus brevis.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.393-401
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• 2014

A bacterium producing antimicrobial substance was isolated from cheonggukjang. The bacterium was identified as a strain of Bacillus subtilis by 16S rDNA sequencing and designated as Bacillus subtilis HH28. The antimicrobial substance produced from Bacillus subtilis HH28 was purified by 0-80% ammonium sulfate precipitation, DEAE-sepharose FF column chromatography, and Sephacryl S-200 HR gel chromatography. The molecular weight of the purified antimicrobial substance was estimated to be approximately 3,500 Da using Tricine sodium dodecyl sulfate-polyacrylamide gel electrophoresis and direct detection analysis. Antimicrobial substance from B. subtilis HH28 not only inhibited B. cereus, but also Listeria monocytogenes and Vibrio parahaemolyticus. The purified antimicrobial substance was stable at $40-80^{\circ}C$, and between pH 2 and 8. Antimicrobial activity of the purified substance was completely destroyed by treatment of protease, proteinase K, and pronase E, indicating that it is proteinaceous.

• Journal of radiological science and technology
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• v.31 no.4
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• pp.355-365
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• 2008

Purpose : This study isto determine the grade of brain tumor and compare the characteristics in each grade using in MRS (MR Spectroscopy). Method : STEAM (Stimulated Echo Acquisition Method) and protocol of PRESS (Point Resolved Spectroscopy) were used in the levels of tumor grade. We classified the pattern of tumor and analysis of the spectrum signals quantitatively from voxel in the brain tumor grade. In accordance with the result, we calculated the accuracy of biochemical. Result : In high-grade tumor, the NAA/Cr showed the signal reduction of 29.4% and 53.9%. However Cho/Cr increased 570% and 711%. However, in low-grade tumor, NAA/Cr downed to 42.6% and 58.1%. Cho/Cr increased to 188% and 195%. Conclusion : The study suggests that the comparative analysis of signals from MR spectroscopy could be useful to evaluate the grade of tumor and find out the characteristics of it. By extension, MR spectroscopy can be used for research with other organs in the human.

• The Korean Journal of Mycology
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• v.25 no.2 s.81
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• pp.152-160
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• 1997

In order to compare collected strains of Naematoloma sublateritium, electrophoretic isozyme and RAPD band patterns of DNA from mycelia were studied. The two characteristics of the strain, ASI 11010 were much different from those of ASI 11005 and 11006. These patterns may be used as valuable criteria for identifying strains of N. sublateritium. Optimal conditions on the vegetative growth of N. sublateritium using sawdust media were favourable on alder sawdust media added with 30% beer waste. Optimal water content was 70%.

• Journal of fish pathology
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• v.26 no.2
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• pp.77-88
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• 2013

Starry flounder, Platichthys stellatus (body length $4.4{\pm}0.51cm$) that became sick during an outbreak of disease at mariculture facilities at Ulsan, Korea in August of 2012, were examined to identify the cause of the disease. Diseased fish didn't show a unique sign, but the oxidase-positive and gram negative rod was isolated from moribund fish. The bacterium was revealed as Photobacterium damselae subsp. piscicida by biochemical analysis and sequence analysis of the 16S rRNA and capsular polysaccharide (CPS) genes. The isolates (AD5) was carrying susceptible to ofloxacin and gentamycin and showed high growth value at $18^{\circ}C$ and $25^{\circ}C$ compared to four other P. damsela strains.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.158-163
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• 2014

In the acidic LB plate, a bacterial strain was isolated from homemade soybean paste as a producer of the extracellular mannanase. The isolate YB-1402, which was a Gram-positive rod-shaped bacterium with spore, has been identified as Bacillus amyloliquefaciens on the basis of its 16S rDNA sequence and biochemical properties. Maximum mannanase productivity of the isolate YB-1402 was reached approximately 150 U/ml in LB broth supplemented with konjac (3.0%). The molecular mass of YB-1402 mannanase was estimated to approximately 38.0 kDa by zymogram of the culture filtrate on SDS-PAGE. The mannanase of culture filtrate was the most active at $55^{\circ}C$ and pH 5.5. The mannanase activity was completely maintained after pre-incubation at pH 3.0 to 10.0 for 1 h. The predominant products resulting from the mannanase hydrolysis were mannose, mannobiose and mannotriose for LBG or mannooligosaccharides. The enzyme could hydrolyze mannooligosaccharides larger than mannobiose.