• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.3
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• pp.166-170
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• 2004

Gluconobacter oxydans that produces the cellulose was isolated. In order to confirm the chemical features of cellulose, various spectrophtometeric analysis were carried out using electron microscopy, X-ray diffractogram, and CP/MAS $\^$13/C NMR. The purified cellulose was found to be identical to that of Acetobacter xylinum. For effective production of cellulose, the various carbon and nitrogen sources, mixture of calcium and magnesium ions, and biotin concentration were investigated in flask cultures. Among the various carbon sources, glucose and sucrose were found to be best for the production of cellulose, with maximum concentration of 2.41 g/L obtained when a mixture of 10 g/L of each glucose and sucrose were used. With regard to the nitrogen sources, when 20 g/L of yeast extract was used, the maximum concentration of bacterial cellulose was reached. The concentration of cellulose was increased with mixture of 2 mM of each Ca$\^$2+/ and Mg$\^$2+/. The optimum biotin concentration for the production of cellulose was in the range of 15 to 20mg/L. At higher biotin concentration (25-35mg/L). the bacterial cellulose production was lower.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.796-801
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• 2000

Kimchi is the Korean traditional food which is fermented properly from salted Korean cabbage of raddish with other various supplements. Kimchi therefore can be the major sources for various kinds of nutrients and other biological substances. The fermentation process accompanies with complicated reaction mechanism which bacteria, fungi and yeast are involved and they produced aroma, taste and bioactive components. To identify nucleoside, this study was conducted with freeze-dried mustard leaf, mustard leaf kimchi and fermented mustard leaf kimchi. Hexane, CH$_2$Cl$_2$, EtOAc and BuOH was used in order to extract their components. The isolated compounds I and II from mustard leaf and mustard leaf kimchi were identified as adenosine and uracil using UV, $^{1}H$-NMR, $^{13}C$-NMR and LC-MS, respectively. Compound I, II and nucleosides are the first report of its occurrence from mustard leaf and their kimchi, the standardized ratios of ingredients for kimchi were 10 of anchovy juice, 8 of red pepper powder, 3 of garlic, 1.5 of ginger, 6 of paste of glutinous rice. The nucleoside of mustard leaf and their kimchi was determined and compared. The order of nucleosides contents of mustard leaf was uridine>cytosine>uracil>adenine>guanosine>guanin, that of fresh mustard leaf kimchi was uridine>uracil>cytosine>guanine>adenosine>adenin>guanosine and that of fermented mustard leaf kimchi (5days at 15$^{\circ}C$) was guanine>adenine>adenosine>guanosine. The differences of nucleoside contents from those were due to various supplements and fermentation process.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.807-813
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• 2000

One hundred fifty grams of Korean fermented soybean paste and hot pepper-soybean paste were packaged in glass jar of 232 mL and Sotred at 5, 13, 22 and 30℃. During the storage, the changes in their microbial flora and quality attributes were monitored. Carbon dioxide production rate from the stored pastes were also determined from initial change of CO₂concentration in headspace of the pack. Hot pepper-soybean pate showed much higher CO₂ production rate higher dependence of CO₂ production on temperature compared to soybean paste. Total aerobic bacteria count and lactic acid bacteria count did not change significantly through the storage. Yeast count in soybean paste decreased slowly after initial uprise while that of hot pepper-soybean paste steadily decreased. Surface color of hot pepper paste changed to dark red with slight decrease in 'L' value and slight increase in 'a' and 'b' values, whereas any significant color change was not observed in soy paste. Titratable acidity increased with time with higher increase in soybean paste, but pH stayed at constant level for both pastes. All the rates of quality change were higher with higher temperature. Pressure buildup due to CO₂ production needs to be considered first in designing the packages of the fermented pastes before their color changes and other chemical quality changes.

• Advances in nano research
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• v.13 no.4
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• pp.325-339
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• 2022

Endophytes ascertain a symbiotic relationship with plants as promoters of growth, defense mechanism etc. This study is a first report to screen the endophytic population in Waltheria indica, a tropical medicinal plant. 5 bacterial and 3 fungal strains in leaves, 3 bacterial and 1 yeast species in stems were differentiated morphologically and identified by biochemical and molecular methods. The phylogenetic tree of the isolated endophytes was constructed using MEGA X. Silver nanoparticles were biosynthesized from a rare endophytic bacterium Cupriavidus metallidurans isolated from the leaf of W. indica. The formation of silver nanoparticles was confirmed by UV-Visible spectrophotometer that evidenced a strong absorption band at 408.5 nm of UV-Visible range with crystalline nature and average particle size of 16.4 nm by Particle size analyzer. The Fourier Transform Infra-Red spectrum displayed the presence of various functional groups that stabilized the nanoparticles. X-ray diffraction peaks were conferred to face centered cubic structure. Transmission Electron Microscope and Scanning Electron Microscope revealed the spherical-shaped, polycrystalline nature with the presence of elemental silver analyzed by Energy Dispersive of X-Ray spectrum. Selected area electron diffraction also confirmed the orientation of AgNPs at 111, 200, 220, 311 planes similar to X-ray diffraction analysis. The synthesized nanoparticles are evaluated for antimicrobial activity against 7 bacterial and 3 fungal pathogens. A good zone of inhibition was observed against pathogenic bacteria than fungal pathogens. Thus the study could hold a key aspect in drug discovery research and other pharmacological conducts of human clinical conditions.

• Food Science and Preservation
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• v.20 no.3
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• pp.424-428
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• 2013

Microbiological contamination of 4 vegetables (garlic, red pepper, perilla leaf and lettuce) collected from 10 restaurants around university was examined. The vegetables were evaluated for total plate count, coliforms, psychrophiles, yeast, and Staphylococcus aureus. The results of total plate count showed the highest value as $5.4{\pm}0.69$ log CFU/g in lettuce, following by $4.8{\pm}1.53$ log CFU/g in red pepper, $4.5{\pm}1.65$ log CFU/g in perilla leaf and $3.4{\pm}1.27$ log CFU/g in garlic. The contamination level of coliforms and psychrophiles were highest in red pepper with maximum as 4.7 log CFU/g and 8.2 log CFU/g, respectively. Red pepper of psychrophiles showed the highest average value as $5.0{\pm}1.82$ log CFU/g followed by $4.2{\pm}1.91$ log CFU/g in lettuce, $4.7{\pm}1.55$ log CFU/g in perilla leaf and $2.4{\pm}2.10$ log CFU/g in garlic. The average number of yeasts were highest in perilla leaf with $4.4{\pm}1.41$ log CFU/g and were lowest in garlic with $0.9{\pm}1.41$ log CFU/g. The contamination level of S. aureus was detected in 27 samples among the total 40 samples with the range of 0.5-5.2 log CFU/g. In conclusion, the microbial quality of the fresh vegetables evaluated in this study was not very good. Therefore, it needs to be enhanced through the good sanitation management and production and distribution methods to improve the safety of fresh vegetables.

• Applied Biological Chemistry
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• v.19 no.2
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• pp.82-92
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• 1976

The study was carried out to investigate the changes of the various chemical components and the microflora during the aging period of Korean navive Kochuzang. (Red pepper soybean paste) Korean native maeju loaves were separated into surface and inner parts. Three kinds of Korean native Kochuzang were prepared from surface part, inner part, and ordinary of maeju. The selection and the indentification of the high enzyme producing strains from the microflora and characteristics of their enzymes were studied. I. The changes of the various chemical components during the aging period of Kochuzang. 1) The changes of pH in the 3 kinds of Kochuzang displayed rapid decrease for the first 10 days after preparing and gradual curve of decrease until 60 days, but slight increase for the next 30 days. The pH of the surface part Kochuzang was lower than that of inner part or ordinary Kochuzang. 2) The total acid contents in the 3 kinds of Kochuzang showed gradual increase until the 60 days but it slowly reduced after this time. 3) The total nitrogen contents in the 3 kind of Kochuzang showed gradual inerease up to the 60 days, but slight decrease after this time. 4) The changes of trichloroacetic acid soluble nitrogen in the 3 kinds of Kochuzang showed a remarkable increase for the first 10 days, however gradual increase after this time. 5) The increase of amino nitrogen contents in the 3 kinds of Kochuzang seemed to be remarkable until the first 30 days, however to be less remarkable after this time. 6) The contents of reducing sugar in the 3 kinds of Kochuzang showed remarkable increase until the first 50 days and it slowly reduced after this time. II. The changes of microflora during the aging period of Kochuzang. 1) Aerobic, anaerobic bacteria and mold in the 3 kinds of Kochuzang were increased until the first 30 to 40 days, but they were reduced after this time. 2) No yeast in the three kinds of Kochuzang appeared until the first 20 days. Yeast were proved to grow, when the pH value was decreased below 5.4 after the 30 days. Yeasts in the surface part and ordinary Kochuzang were gradually increased and those in the inner part Kochuzang were decreased as aging. III. The selection and identification of high amylase and protease producing strains from the microflora during the aging period of Kochuzang. 1) The amylase and protease highly producing strains from microflora were identified as Bacillus subtilis-P, Bacillus subtilis-G, Bacillus licheniformis-K, Aspergillus oryzae-B. 2) Amylase activity of Aspergillus oryzae-B was highest among the strains and the strains in order of the higher activity to the lower one were Bacillus subtilis-P Bacillus licheniformis-K, Bacillus subtilis-G. Protease activities of Aspergillus oryzae-B and Bacillus subtilis-P were about the same and the strains in order of the higher activity to the lower one were Bacillus licheniformis-K, Bacillus subtilis-G. 3) Amylase activity was inhibited more than protease activity was with NaCl concentration. Amylase activity was inhibited by 45 to 65 percent and protease activity by 40 to 46 percent at the concentration of 15 percent NaCl, which was the average concentration of NaCl in Kochuzang.

• Progress in Medical Physics
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• v.18 no.2
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• pp.81-86
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• 2007

The cone-beam CT (CBCT) which is acquired using on-board imager (OBI) attached to a linear accelerator is widely used for the image guided radiation therapy. In this study, the effect of respiratory motion on the quality of CBCT image was evaluated. A phantom system was constructed in order to simulate respiratory motion. One part of the system is composed of a moving plate and a motor driving component which can control the motional cycle and motional range. The other part is solid water phantom containing a small cubic phantom ($2{\times}2{\times}2cm^3$) surrounded by air which simulate a small tumor volume in the lung air cavity CBCT images of the phantom were acquired in 20 different cases and compared with the image in the static status. The 20 different cases are constituted with 4 different motional ranges (0.7 cm, 1.6 cm, 2.4 cm, 3.1 cm) and 5 different motional cycles (2, 3, 4, 5, 6 sec). The difference of CT number in the coronal image was evaluated as a deformation degree of image quality. The relative average pixel intensity values as a compared CT number of static CBCT image were 71.07% at 0.7 cm motional range, 48.88% at 1.6 cm motional range, 30.60% at 2.4 cm motional range, 17.38% at 3.1 cm motional range The tumor phantom sizes which were defined as the length with different CT number compared with air were increased as the increase of motional range (2.1 cm: no motion, 2.66 cm: 0.7 cm motion, 3.06 cm: 1.6 cm motion, 3.62 cm: 2.4 cm motion, 4.04 cm: 3.1 cm motion). This study shows that respiratory motion in the region of inhomogeneous structures can degrade the image quality of CBCT and it must be considered in the process of setup error correction using CBCT images.

• Korean Journal of Agricultural Science
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• v.5 no.2
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• pp.136-144
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• 1978

A series of experiments over three years was planned for practical application of rhizobia in farms and grass lands in Korea. This is the report for the studies of the first year mainly on the isolation and characterization of rhizobial strains, and on the assessment of their nodulation abilities and nitrogen fixation capacities. 1. Total number of 88 strains for soybean group and 22 st ra ins for pea and vetch group was isolated from nodules which were taken from legumes grown in Daekwanyong, Cheju and various places in Korea. 2. Morphological and cultural characteristics of the strains were studied, and attempts were also made to investigate their antigenic properties and to demonstrate lysogenic strains in these groups. The results were : i) the isolates varied in cultural characteristics on yeast mannitol broth and agar, and in degree of congo reel absorption ; ii) similarities in their antigenic properties were found between/among the strains: G-3/G-9/D216, G-20/G-52 in soybean group; iii) no lysogeny was found in the strains of these groups. 3. Plant infection tests by test tube and bottle method in light room were carried out to elucidate the ability of the strains to nodulate specific legumes and of the capacity of such nodules to fix atmospheric nitrogen. The isolates were grouped into non- invasive, ineffective, or effective to the legumes. Those strains which produced effective nodules, supporting similar level of growth as nitrate control, were: P-3, 4 and 8 in pea and vetch group; G-23, 27, and, D-216 in soybean group.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.5
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• pp.671-676
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• 2008

Forty-eight Naemi lambs (avg. BW 31.7 kg) were transported by truck for a distance of 1,450 km from Al-Jouf to Riyadh, Saudi Arabia. On arrival day, the lambs were randomly allocated to four groups receiving diets supplemented with 0.0, 0.3, 0.6 and 0.9 ppm organic chromium (Cr). Each group consisted of four separately housed replicates of three lambs each. The animals were fed ad libitum on a grower diet for 84 days. Blood samples were obtained shortly before transportation, upon arrival and at weekly intervals thereafter from all lambs for analysis of plasma and serum. Plasma glucose and serum cortisol, total protein, albumin, urea-N and total cholesterol concentrations were determined. A cursory clinical examination of the lambs, along with rectal temperature, was undertaken at different intervals during the experiment. The lambs were inoculated each with 2 ml i.v. chicken red blood cells (CRBC) on days 0, 21, and 42. Serum total, IgG and IgM antibody titers were determined at weekly intervals post-immunization. An in vivo intradermal hypersensitivity test was carried out on 6 lambs from each group on days 10 and 70. Transportation of the lambs resulted in a significant (p<0.001) elevation of serum cortisol, total protein and albumin levels, as well as increased plasma glucose concentration, with corresponding decrease in total cholesterol, while blood urea-N remained largely unchanged. These constituents returned to normal levels during subsequent weeks, with no significant differences in their concentrations being observed between the Cr-supplemented groups and controls. Rise in rectal temperature after transportation was reduced to a greater extent (p<0.05) in Cr-supplemented versus control lambs. Total, IgG and IgM antibody titers against CRBC rose significantly (p<0.05) during immunizations in all groups, with significantly and linearly higher (p<0.05) total and IgG titers in Cr-supplemented versus control lambs. By contrast, no significant effect due to Cr supplementation was recorded in IgG titers, which increased equally in Cr-fed and control groups. Skin thickness in response to intradermal inoculation of phytohaemagglutinin (PHA) was also significantly (p<0.01) increased as a result of Cr supplementation. These results indicate that dietary Cr supplementation might be useful during stress especially for enhancing immune responses in transport-stressed lambs.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.273-278
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• 2015

The purpose of this study was to evaluate the in-vitro efficacy of PDT using red light emitting diode (LED) with Radachlorin for biofilm inhibition of clinical Candida albicans isolates. The suspensions containing C. albicans at $9{\times}10^8CFU/mL$ were prepared on yeast nitrogen base containing 5% glucose. The biofilm formation was grown for 3 h after seeding suspensions each 100 ul on a 96-well plate and then supernatant was discarded. Each well was treated with $0.39{\mu}g/mL$ from $50{\mu}g/mL$ concentrations of Radachlorin on adherent biofilm. After a 30-minute incubation, light was irradiated for 30, 60, or 90 minutes using the following light source of wavelength 630 nm LED, at energy densities of 14, 29, and $43J/cm^2$. Afterwards, all supernatant was removed and dried. Adherent cells were stained with safranin O and dried. The cell viability was measured using a microplate reader at 490 nm. Also, a fluorescent signal on C. albicans was observed by saturation of a photosensitizer. In conclusion, a significant inhibition of 72.5% was observed to C. albicans on biofilm at the Radachlorin dose of $50{\mu}g/mL$ with 630 nm LED. The Photosensitizer (Radachlorin) was adequate at 30 minuttes for C. albicans. Overall, the results showed that inhibition of biofilm formation was Radachlorine dose-dependent. The results suggest that PDT, using Radachlorin with 630 nm LED, is able to decrease biofilm formation of C. albicans.