• Korean Journal of Soil Science and Fertilizer
• /
• v.42 no.4
• /
• pp.307-316
• /
• 2009

Soil microbial activity and diversity are affected by organic sources applied to improve soil quality and fluctuate seasonally. We investigated the effects of municipal compost (MC), poultry litter (PL), and cover crops of spring oats and red clover (RC) on soil enzyme activities, and soil bacterial community-level physiological profiling (CLPP) in a Mexico silt loam in North Central Missouri, USA. Temporal patterns of these parameters were observed by periodic five soil sampling from spring to fall over a two year period. MC increased soil dehydrogenase (DH) activity consistently beginning about three months after MC application; fluorescein diacetate (FDA) hydrolytic activity significantly began to increase by the September of the first year but fluctuated during the following period. DH activity responded more directly to the amount or properties of organic residues in soils while FDA hydrolysis and CLPP were generally influenced by composition of organic sources, and enzyme activities and CLPP showed seasonal variation, which depended on organic sources and soil moisture. MC and cover crops may be useful organic sources for enhancing general soil microbial activity and altering soil microbial diversity, respectively. Because microbial activities and diversity are dynamic and subject to seasonal changes, the effects of organic amendments on these parameters should be investigated frequently during a growing season.

• Clean Technology
• /
• v.14 no.3
• /
• pp.193-203
• /
• 2008

A surfactant is used to assist the effect of cleaning, dispersibility and adhesion during leather manufacturing process. Existing surfactant for that process includes many hydrophilic groups that may cause problem such as stain, bad water resistance and poor durability, etc. It is potential problem to make high-performance property for future leather market. In this study, we have synthesized the fluorinated surfactant of which property decreases surface tension, increases dispersion, cleaning effect and the better chrome absorption by the high bond energy of C-F to complement weakness that the present alkyl derivative surfactants have. Using fluorinated surfactant, we can confirm that dispersion is increased, chrome absorption ratio is augmented with high osmosis and coherence, chrome content in the tanning waste water is reduced, BOD and COD contents are diminished and physical characteristics are improved.

• Korean Journal of Microbiology
• /
• v.39 no.4
• /
• pp.230-234
• /
• 2003

An extracellular protease of Bacillus amyloliquefaciens S94 was purified to apparent homogeneity. The enzyme activity was strongly inhibited by general inhibitor for serine protease, PMSF, suggesting that the enzyme is a serine protease. The purified enzyme activity was inhibited by leucine peptidase inhibitor, bestatin, suggesting that the enzyme is a leucine endopeptidase. When the enzyme was chemically modified with PMSF, which specifically reacted with serine residue on the enzyme, the activity was eliminated. The endopeptidase activity was inhibited by the modifier which chemically modified carboxyl group of aspartate and glutamate. PLP, which would modify lysine residue, did not affect the endopepetidase activity to a greater extent. This demonstrates that serine and aspartate (or glutamate) residues of enzyme would participate in a important function of the endopeptidase activity.

• KSBB Journal
• /
• v.14 no.4
• /
• pp.465-469
• /
• 1999

Horseradish peroxidase(HRP) in organic solvent can be reactivated by evaporation. In order to measure the evaporation effect, the enzyme solutions were obtained by evaporation and dilution of organic solvent, respectively. Although two situations were thermodynamically identical, the activity from evaporation was higher than that from dilution. From the UV absorbance and the fluorescence intensity mesurements, it can be explained that reactivation of enzyme activity might be caused by reversible folding, and the enzyme obtained by evaporation was more refolded than that obtained by dilution.

• Food Engineering Progress
• /
• v.15 no.4
• /
• pp.346-354
• /
• 2011

This study was carried out to fortify the antimicrobial activity of yoghurt by adding liquorice extract to it. The liquorice extracts (1 mg/mL) showed relatively high antibacterial activity against H. pylori KCCM 40449 (p < 0.05). The solvent liquorice extracts of minimal inhibitory concentrations (MIC) against H. pylori KCCM 40449 were 25- 100 ${\mu}g$/mL. Lactobacillus amylovorus DU-21 with high EPS production ability were inoulated to milk after the addition of different amounts of liquorice extracts (0.0%, 0.05%, 0.1% and 0.2%). The physico-chemical characteristics of yoghurts added with liquorice extracts were examined. The initial pH, titratable acidity, viscosity and viable cell counts of the yoghurt added liquorice extracts were 3.41-3.51, 1.021-1.091%, 1,686-1,930 cp and 9.41-9.38 Log CFU/mL, respectively. The viscosity and syneresis of yoghurt were better than that of the control. Antimicrobial activity against H. pylori KCCM 40449 increased with increasing addition of liquorice extract. However, the sensory score of yoghurt added with different amounts of liquorice extracts was lower than that of the control (p < 0.05). As a result of the sensory evaluations, the flavor, taste, texture, color and overall acceptability of the yoghurt with 0.05% liquorice extract were found to be much better than those of the other groups (p < 0.05). Overall, the optimal amount of liquorice extract added in the manufacture of yoghurt was 0.05% of the total weight. Further studies on increment of antimicrobial activity and palatability of liquorice extract added yoghurt are necessary.

• Proceedings of the KAIS Fall Conference
• /
• 2001.05a
• /
• pp.84-86
• /
• 2001

본 논문에서는 고성능 활성탄의 악취 및 유해가스 흡착효율과 멜트브로운(M/B)부직포의 여과성능에 의한 복합적인 고기능 방진특성을 갖는 활성탄 부착 M/B 국산화 여과재를 제조개발하였다. 고성능 활성탄은 고순도의 일반활성탄에 금속염, 유기물 등을 담지시켜 활성화시킨 활성탄이고, M/B여과재의 웹(web)제조조건은 M/B 방사기에서 방사온도 250℃, 방사속도 150m/sec, 고온공기온도 250℃ 그리고 DCD(die to collector distance) 20cm가 적합함을 알 수 있었다. 또한 M/B 여과재에 활성탄 부착은 열롤러시스템에 의한 열적결합방법을 이용하여 균일한 분포의 점접착결합구조를 갖도록 하였고, 개발된 복합기능 여과재가 방진마스크용 여과재로의 이용이 가능하다는 것을 분진포집효율, 투과율, 흡기저항 등 여과재 성능기준실험 결과를 통해 확인하였다.

• Investigative Magnetic Resonance Imaging
• /
• v.16 no.2
• /
• pp.124-135
• /
• 2012

Purpose : The objective of this study was to investigate the differences of hippocampal volume and shape as well as the functional change between long life experienced taxi drivers and controls of Korean population. Materials and Methods: Three-dimensional T1-weighted images and blood oxygen level dependent functional MRI(fMRI) were obtained from 8 subjects, consisting of 4 experienced (20-30 years) taxi drivers and 4 age-matched controls. The hippocampal volume and shape were analyzed with three-dimensional T1-weighted images. In addition, neuronal activities of brain were analyzed using a blood oxygen level dependent fMRI between the two groups. Results: The hippocampal volume showed no statistically significant difference between the two groups (p > 0.05). The left hippocampi of the taxi drivers were slightly elongated with larger head and tail portions than those of the controls (p < 0.05, uncorrected). For the functional MRI, fusiform gyrus was specifically activated in taxi drivers, compared with the control group. Conclusion: The structural and functional changes of taxi driver's hippocampus indicate the functional differentiation as a result of occupational dependence on spatial navigation. In other words, the continuous usage of spatial navigation performance may diminish degeneration of hippocampus and the related brain regions.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.21 no.5
• /
• pp.573-579
• /
• 1992

The influence of succinylation on several functional properties of fungal protein (Aspergillus fumigatus) was investigated. Fungal protein was succinylated to 20.7 and 85.3% by addition of 2.5 and 10% succinic anhydride, respectively. Succinylated fungal protein decreased the absorbance at 260nm, nucleic acid and carbohydrate, but increased the proteinous nitrogen and protein extraction in fungal protein. Succinylation had an enhancing effect on the functional properties as much as the degree of it was increased. Oil retention of succinylated fungal protein was higher about from two to five times than those of milk casein. Nitrogen solubility of succinylated fungal protein was increased to 32 and 51% than that of milk casein and soy flour. Emulsifying activity and stability were increased in proportion to the succinylated degree of fungal protein. As the result of succinylation increase more than 80%, emulsifying activity increased about 8.4 times. In conclusion, succinylated fungal protein improved functional properties, compared with nonsuccinylated fungal protein, milk casein and soy flour.

• Korean Journal of Food Science and Technology
• /
• v.30 no.3
• /
• pp.693-696
• /
• 1998

Chitosan is the deacetylated product of chitin. Chitosan and its derivatives have many properties that make them attractive for a wide variety of health applications. This study was performed to investigate some effects of water soluble chitooligosaccharides on liver function in the mouse. The animals given the sterol diet containing 3% cholesterol for 6 weeks showed increase in plasma cholesterol level, which were lowered by 23% when they were fed on 1% chotooligosaccharide. While there was no significant change in liver cholesterol and plasma HDL-cholesterol levels. Continuous administration of 15% ethanol via drinking water to mice for 8 weeks elicited pathological alterations such as inflammation, necrosis, accumulation of lipid droplets in the liver and increase in GPT activity, while simultaneous administration of ethanol and chitooligosaccharide prevented remarkedly ethanol-induced liver injury; there was no observable lipid droplet and GPT activity was decreased by 25% in the liver. These results suggest that chitooligosaccharide play some roles in liver function, such as reducing the plasma cholesterol level and preventing alcoholic liver disease.

• Food Science and Preservation
• /
• v.10 no.2
• /
• pp.241-245
• /
• 2003

To develope tea-fungus beverage(TB), media added various kinds of ingredients including black tea, persimmon leave tea, pine needle, mugwort mycelia and fruiting body of Cordyceps spp. were prepared fur fermentation. Tea-fungus beverage(TB) was prepared with tea-fungus by fermentation for 2 weeks at 30 $^{\circ}C$. Functional properties of antibacterial activity, electron donating ability and nitrite scavenging ability were investigated in tea-fungus beverage(TB) and 5 times diluted tea-fungus beverage(DTB). Antibacterial activity against pathogenic E. coli and S. aureus was excellent in TB added pine needle, mycelia and fruiting body of Cordyceps japonioa while no activity in TB added persimmon leave tea. Electron donating ability of TB were ranged from 41％ to 87% in TB and were ranged from 11% to 63％ in DFB, high ability was in TB and DTB added pine needle and persimmon leave tea, while low ability in FB and DTB added mycelia and fruiting body of C. militaris. Nitrite scavenging ability was 63% in TB added black tea and 44% in TB added persimmon leave tea. Other ingredients added TB had weak nitrite scavenging ability.