• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.369-373
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• 1988

The gene for thermostable alpha-amylase from the thermostable bacterium Bacillus licheniformis has been cloned and expressed in Escherichia coli. The Alpha-amylase producing E. coli cells contained a 7.4 kb chimeric plasmid (pTA 322) which was composed of the vector pBR322 and a 3.1 kb EcoRI fragment of B. licheniformis DNA. The alpha-amylase from cloned fragement was shown to be indistlnguishable from that of B. licheniformis in the optimum temperature of 9$0^{\circ}C$, heat stability and the pH stability. The foreign gene was expressed efficiently in E. coli and stably maintained.

• Applied Biological Chemistry
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• v.45 no.2
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• pp.71-76
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• 2002

Several antagonistic bacteria, SD-1, 4, 10, 11, 14, 15, and 16, which have strong CMCase and amylase activities, were isolated from the fermented mushroom media. Among them, SD-1, 10, 11, and 15 have strong antibacterial activities against the mushroom pathogenic bacteria Pseudomonas sp., and SD-1, 10, 11, 14, and 16 have strong antifungal activities against the mushroom pathogenic fungi, Trichoderma sp. SD-14, 15, and 16 did not inhibit the growth of mushroom Pleurotus eryngii ASI-2302, and Pleurotus ostreatus ASI-2042 and ASI-2180. When the culture broth mixture of the seven bacterial strains was applied to the mushroom media, the growths of pathogens, Pseudomonas sp. and Trichoderma sp., were inhibited.

• Korean Journal of Optics and Photonics
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• v.18 no.6
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• pp.452-460
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• 2007

Ultra-low loss ZERODUR and fused silica mirrors were manufactured and their light scattering characteristics were investigated. For this purpose, ZERODUR and fused silica substrates were super-polished by the bowl feed method. The surface roughness were 0.292 ${\AA}$ and 0.326 ${\AA}$ in rms for ZERODUR and fused silica, respectively. To obtain the high reflectivity, 22 thin film layers of $SiO_2$ and $Ta_2O_5$ were deposited by Ion Beam Sputtering. The measured light scattering of ZERODUR and fused silica mirror were 30.9 ppm and 4.6 ppm, respectively. This shows that the substrate surface roughness is not the only parameter which determines the light scattering of the mirror. In order to investigate the mechanism for additional light scattering of the ZERODUR mirror, the surface roughness of the mirror was measured by AFM and was found to be 2.3 times higher than that of the fused silica mirror. It is believed that there is some mismatch at the interface between the substrate and the first thin film layer which leads to the increased mirror surface roughness. To clarify this, the contact angle measurements were performed by SEO 300A, based on the Giriflaco-Good-Fowkes-Young method. The fused silica substrates with 0.46 ${\AA}$ in its physical surface roughness shows lower contact angle than that of the ZERODUR substrate with 0.31 ${\AA}$. This indicates that the thin film surface roughness is determined by not only its surface roughness but also the surface energy of the substrate, which depends on the chemical composition or crystalline orientation of the materials. The surface energy of each substrate was calculated from a contact angle measurement, and it shows that the higher the surface energy of the substrate, the better the surface roughness of the thin film.

• Journal of the Korean Magnetics Society
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• v.15 no.6
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• pp.315-319
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• 2005

To obtain low switching field ($H_{SW}$) we introduced amorphous ferromagnetic $Co_{70.5}Fe_{4,5}Si_{15}B_{10}$ single and synthetic antiferromagnet (SAF) free layers in magnetic tunnel junctions (MTJs). The switching characteristics for MTJs with structures $Si/SiO_2/Ta$ 45/Ru 9.5/IrMn 10/CoFe 7/AlOx/CoFeSiB 7 or CoFeSiB (t)/Ru 1.0/CoFeSiB (7-t)/Ru 60 (in nm) were investigated and compared to MTJs with $Co_{75}Fe_{25}$ and $Ni_{80}Fe_{20}$ free layers. CoFeSiB showed a lower saturation magnetization of $560 emu/cm^3$ and a higher anisotropy constant of $2800\;erg/cm^3$ than CoFe and NiFe, respectively. An exchange coupling energy ($J_{ex}$) of $-0.003erg/cm^2$ was observed by inserting a 1.0 nm Ru layer in between CoFeSiB layers. In the CoFeSiB single and SAF free layer MTJs, it was frond that the size dependence of the $H_{SW}$ originated from the lower $J_{ex}$ experimentally and by micromagnetic simulation based on the Landau-Lisfschitz-Gilbert equation. The CoFeSiB SAF structures showed lower $H_{SW}$ than that of NiFe, CoFe and CoFeSiB single structures. The CoFeSiB SAF structures were proved to be beneficial far the switching characteristics such as reducing the coercivity and increasing the sensitivity in micrometer to submicrometer-sized elements.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.2
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• pp.153-156
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• 1986

A pot (1/200a) experiment was conducted to find out the changes of soil and water temperature on the several paddy soil weeds (Duck weed, Algae and Floatin fern) growing condition. The results obtained were shown as follows; 1. Diurnal maximum soil and water temperature were lowered by 2 to $3^{\circ}C$ under duck weed growing condition while minimum soil and water temperature were higher in $0.5^{\circ}C$ and/or similar tendency than that of bare paddy soil condition. 2. The changes of soil and water temperature were lowered by 0.1 to $0.3^{\circ}C$ at sunny day under Duck weed growing condition but was higher in 0.1 ta $0.4^{\circ}C$ at rainy, cloudy and after rainy day than that of bare paddy soil. 3. Soil and water temperature were higher about 0.3 to $1.0^{\circ}C$ under algae growing condition than that of bare paddy condition. 4. The effects of keeping warm efficiency were high in order of Duck weed > Duck weed with algae > algae > bare paddy soil condition.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.254-260
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• 2016

Doenjang samples were prepared by inoculation of multiple starters consisting of two Bacillus spp., one yeast, and one fungus. Doenjang A was fermented with Bacillus amyloliquefaciens EMD17, B. amyloliquefaciens MJ1-4, Pichia farinosa SY80, and Rhizopus oryzae. Doenjang B and C were fermented with the same yeast and fungus but different Bacillus strains; namely, B. amyloliquefaciens EMD17 and B. subtilis CH3-5 for doenjang B, and B. amyloliquefaciens MJ1-4 and B. subtilis CH3-5 for doenjang C. Doenjang D was fermented with microorganisms present in rice straw (control). The doenjang samples were spiked with B. cereus ATCC14579 at two different levels, 10⁴ CFU/g doenjang (I) and 10⁷ CFU/g doenjang (II). All eight doenjang samples were fermented for 70 days at 25℃. Growth of B. cereus was inhibited in doenjang A, B, and C, with the bacterial cell count after 70 days being less than the initial 10⁴ CFU/g added, whereas B. cereus was not inhibited in doenjang D. Doenjang B showed the strongest inhibitory activity against B. cereus, with a cell count of less than 10³ CFU/g after 42 days, even when B. cereus was initially added at 10⁷ CFU/g. Some properties of the doenjang samples, such as pH, TA, and amino-type nitrogen content, were similar to those of doenjang fermented with starters only. The results indicate that carefully selected starters can effectively prevent the growth of B. cereus during doenjang fermentation.

• Food Science and Preservation
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• v.18 no.2
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• pp.143-148
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• 2011

This study was conducted to investigate the effect of CA(4% $O_2$ and 7.5% $CO_2$) storage on the quality characteristics and chilling injury in 'Nanko' prunus mume fruits at 1, 5, and $9^{\circ}C$. CA storage reduced production of $CO_2$ and $C_2H_4$ significantly. Hue values of fruit skin were significantly higher in fruits stored at $1^{\circ}C$ and $5^{\circ}C$ than $9^{\circ}C$. Weight loss was much lower in fruits stored under CA storage. Soluble solids content (SSC) titratable acids (TA), and firmness were maintained and electrolyte leakage was lower in fruits stored under CA storage. Ratios of chilling injury and decay were increased faster at $5^{\circ}C$ and $9^{\circ}C$ than $1^{\circ}C$. The chilling injury was suppressed in fruits of CA storage compared with control fruits during cold storage. These results indicate that CA storage at $1^{\circ}C$ of prunus mume fruits extended the storage life up to 30 days without quality deterioration. effectively.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.87-93
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• 1998

The tannic acid (0.5 mg/ml, 1.0 mg/mi, 2.0 mg/ml) and/or cadmium (20 mg/kg) were administered by oral administration. The results were as follows: 1. There were adverse effects on the weight changes and water consumption. But, the extent of adverse changes were decreased by tannic acid administration. 2. Also, there were some significant changes in organ weight, especially relative liver weight and relative brain weight by cadmium administration, but Ta1.0 group was significant changes in relative liver weight, relative lung weight and relative thymus weight compared with control group. 3. In the hematological patterns of administered mice, there were significant changes between cadmium treated groups and control group. Hemoglobin contents, packed cell volume, platelet count and neutrophill count were significantly change compared with control group. These changes were not shown in tannic acid treated group. 4. There were serological enzymatic changes in the cadmium treated mouse. In the tannic acid treated group 0.5, 1.0, 2.0 mg/ml, ALT, AST, BUN and creatinine were recovered to the extent of control group. From the above results, the tannic acid has some possible alleviative effects of cadmium toxicity upto the 2.0 mg/ml/day of oral dose for 4 weeks. But we need further study of mechanism for toxicty alleviating action of tannic acid to the heavy metals like cadmium.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1228-1235
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• 1997

This study was conducted to standardize the proper ingredient ratios of chinese cabbage kimchi by the sensory evaluation, chemical properties, and functional properties of antimutagenic effect and inhibitory effect on the growth of cancer cells from the ratios obtained from literatures. The standardized ratios of ingredient from the literatures was 13.0 of radish, 2.0 of green onion, 3.5 of red pepper powder, 1.4 of garlic, 0.6 of ginger, 2.2 of anchovy juice, 1.0 of sugar and the final salt concentration 2.7 in the proportion of 100 salted chinese cabbage. The standardized ratio of the ingredients exhibited better overall acceptability and less moldy smell and moldy flavor than any other ratio of ingredient in the sensory evaluation. The standardized kimchi with the above ratios of the ingredients, at final salt concentration of 2.5%, showed high reducing sugar contents and Leuconostoc sp. counts. All juices of the chinese cabbage kimchi showed not only high antimutagenicity against aflatoxin $B_1$ in Salmonella typhimurium TA100 but also strong inhibitory effect on the growth of AGS human gastric adenocarcinoma cells in SRB assay, especially these functional properties were the most effective at each standardized ratio of the ingredients. From the taste, chemical and functional properties, the standardized ratios of ingredients was 13.0 radish, 2.0 green onion, 3.5 red pepper powder, 1.4 garlic, 0.6 ginger. 2.2 anchovy juice, 1.0 sugar and the final salt concentration 2.5 in the proportion of 100 salted chinese cabbage.

• The Korean Journal of Mycology
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• v.38 no.1
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• pp.34-39
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• 2010

We have attempted to verify 30 strains of Hypsizigus marmoreus from various mushroom stocks in Korea using random amplified polymorphic DNA (RAPD) methodology. Chromosomal DNAs of them were extracted and subjected to PCR analyses with 3 random primers. Each PCR produced approximately 30 distinct PCR bands with the size from 200 bp to 3000 bp. A dendrogram was acquired using the unweighted pair-group method with arithmetic average (UPGMA) clustering methodology on the basis of the DNA band pattern. The analysis revealed that 30 strains of H. marmoreus were clustered into two distinct clusters. Cluster 1 contained 3 subgroups while the cluster 2 consisted of rather diverse strains. Interestingly, Hm3-10, a wild strain collected from Deog-Yu mountain, was not included in either clusters, indicative of uniqueness of this strain. We nextly attempted to develop strain-specific DNA markers to verify a specific strain. A unique band in the RAPD gel lane of Hm0-4 was extracted and its sequence was determined. PCR with a primer set from the determined sequence revealed that the primer set gave a 250 bp DNA band only for Hm0-4, indicating that this approach works well for the strain-specific identification of H. marmoreus.