• Applied Biological Chemistry
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• v.49 no.4
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• pp.328-333
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• 2006

Many plant extracts are known to have antioxidative effects. However, their activities can be reduced or disappeared during mass production process. The purpose of this study is to compare antioxidative effects of edible plant extracts distributed in Korea. forty three kinds of edible plant extracts commercially available in Korea were selected and investigated for their total phenolics contents and antioxidative potentials(DPPH radical and superoxide anion radical scavenging activities). In contents of total phenolics, the commercial plant extracts from Artemisia annua(whole plant), Ilex paraguariensis(leaf, Silybum marianum(fruit and leaf, Ulmus pumila(bark), Coliolus versicolor(fruit), and Curcuma longa(root and stem) contained over 70 mg/g of powder, DPPH radical scavenging activities($SC_{50}$, 50% scavenging concentration) of A. annua, I. paraguariensis, Pinus densiflora(leaf),S. marianum, U. pumila, and C. longa were $53.96{\pm}0.81\;ppm,\;24.61{\pm}2.12\;ppm,\;35.96{\pm}1.11\;ppm,\;57.46{\pm}2.13\;ppm,\;55.25{\pm}1.65\;ppm\;and\;12.99{\pm}1.67ppm$, respectively, while that of positive control(vitamin C) was $3.86{\pm}0.81\;ppm$. $SC_{50}$ values against superoxide anion radical of A. annua, Cinnamomum zeylanicum(bark), I. paraguariensis, Rubus coreanus(fruit and leaf), Morus alba(leaf), P. densiflora, S. marianum, U. pumila, C. versicolor, C. longa, Perilla frutescens var. acuta(leaf), and H. sabdariffa(leaf and newer) were $53.21{\pm}1.83ppm,\;50.12{\pm}2.12ppm,\;5.59{\pm}0.84ppm,\;41.60{\pm}8.93ppm,\;20.19{\pm}0.97ppm,\;15.19{\pm}1.66ppm,\;21.20{\pm}1.88ppm,\;15.71{\pm}0.91ppm,\;55.48{\pm}2.42ppm,\;52.12{\pm}2.44ppm,\;23.80{\pm}1.98ppm\;and\;11.14{\pm}0.51ppm$, respectively($SC_{50}$ value of vitamin C: $9.61{\pm}0.93ppm$). In particular, both 1 paraguariensis and P. densiflora had high content of phenolics as well as high scavenging activities of DPPH radical and superoxide anion radical. Consequently, above two commercial extracts may be useful as a source of antioxidative nutraceutics.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.07b
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• pp.37-54
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• 2003

It has been recognized that the hen. like its mammalian counterparts. provides young chicks with antibodies as protection against hostile invaders. This system facilitates the transfer of specific antibodies from serum to egg yolk. and provides a supply of antibodies called immunoglobulin Y(IgY) to the developing embryo and the hatched chick. The protection against pathogens that the relatively immuno-incompetent newly hatched chick has. is through transmission of antibodies from the mother via the egg. Egg yolk. therefore. can be loaded with a large amount of IgY against pathogens which can immobilize the existing or invading pathogens during the embryo development or in day-old chicks. Thus. the immunization of laying hens to various pathogens results in production of different antigen-specific IgY in eggs. Egg yolk contains 8~20 mg of immunoglobulins (IgY) per $m\ell$ or 136~340 mg per yolk suggesting that more than 30 g of IgY can be obtained from one immunized hen in a year. By immunizing laying hens with antigens and collecting IgY from egg yolk. low cost antibodies at less than ＄10 per g compared to more than ＄20.000 per g of mammalian IgG can be obtained. This IgY technology opens new potential market applications in medicine. public health veterinary medicine and food safety. A broader use of IgY technology could be applied as biological or diagnostic tool. nut-raceutical or functional food development. oral-supplementation for prophylaxis. and as pathogen-specific antimicrobial agents for infectious disease control. This paper has emphasized that when IgY-loaded chicken eggs are produced and consumed. the specific antibody binds. immobilizes and consequently reduces or inhibits the growth or colony forming abilities of microbial pathogens. This concept could serve as an alternative agent to replace the use of antibiotics. since today. more and more antibiotics are less effective in the treatment of infections. due to the emergence of drug-resistant bacteria.

• Korean Journal of Organic Agriculture
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• v.9 no.2
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• pp.101-115
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• 2001

Nitrogen applied as fertilizer for crop production is partly absorbed by plant , and the remaining nitrogen in soil might be leached out through complicated processes to the subsoil layer Especially, NO$_3$-N in leachate causes environmental pollution. The purpose of this study was focused on understanding of uptake of nutrients by plants, the behaviors of nutrients in soil and the possibility of leaching loss when nitrogen fertilizer and completely decomposed compost were applied. Lysimeters(Volume 0.15㎥, Diameter 62cm, Height 62.8cm) were installed for collecting leachate in the Jeju volcanic ash soils. Lysimeter study consisted of thirteen treatments : fallow, fallow with weeding, cropping without fertilizer and compost, three N fertilizer soil surface applications(16, 32, 64kg/10a), three N fertilizer and compost soil surface applications(16+800, 32+1600, 64+32kg/10a), two water dissolved N fertilizer applications(16, 32kg/10a), and low and high plant densities. N fertilizer was applied as urea. The growth of com(preceding crop) and potatoes(succeeding crop) and leaching loss were determined during the experimental period. The results obtained were summarized as follows ; With Increased N, pH of leachate tended to decrease and NO$_3$-N concentration of leachate increased. NO$_3$-N leaching loss was remarkably greater in soil from the bare plot without fertilization and the weed control than from plots with medium N rate and was least in the cropping plot without fertilization. NO$_3$-N concentration in leachates from the water dissolved N fertilizer application plots was 64% of that from the soil surface application plots. The concentration of Ca and K ions and the leaching loss of these ions were least from the cropping plot without fertilization and were greatest from bare plots(T1 and T2) without fertilization. The proportion of leaching and residual N in soil increased as N rate increased indicting that higher N rates increase the possibility of N leaching to subsoil layer The proportion of N leaching losses was lower at the low N rate and the high plant density. In future, fertilization prescription which can maximize fertilizer use efficiency and minimize the pollution of ground water will be needed for conserving the environments.

• Journal of Wetlands Research
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• v.12 no.3
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• pp.1-13
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• 2010

Most of investigations about the effects of dam construction on the surrounding environments have focused mainly on the change of climate conditions and crop production. In order to research the effect of dam construction on the surrounding vegetation, we chose the Soyanggang dam whose storage capacity is the largest in Korea, and was built 33 years ago. We surveyed and analyzed the surrounding vegetation by using quadrat method and measured the soil moisture content among floodplain (FP), 5m above the flood plain (AFP) and control group (CG) which is 3km far from the lake through ridge. The largest value of mean importance percentage of the canopy~understory layer at FP was Salix koreensis (87.9%) and those of AFP and CG was Quercus mongolica (38.9% and 40.4% respectively) and the largest important percentage of the herb layer at FP was Artemisia capillaris (34.2%) and those of AFP and CG was Oplismenus undulatifolius var. undulatifolius (9.4% and 24.6% respectively). The Shannon-Wiener diversity index of shrub~canopy layer at FP (0.26) was lower than AFP (2.34) and CG (2.23) and there was not any significant difference in the herb layer among three groups. The S${\o}$rensen similarity index between FP and AFP, FP and CG was 0, and that of AFP and CG was relatively high. The highest density of tree and subtree with the DBH level of FP was S. koreensis of 5~10cm (240/ha), and that of AFP and CG was Quercus spp. of 15~20cm (400/ha and 466/ha respectively). And the highest density of seedlings of FP was Pinus densiflora (7,040/ha), and that of AFP and CG was Quercus spp. (720/ha and 400/ha respectively). The soil water content of FP (6.28%) was relatively lower than AFP and CG (11.13% and 10.14% respectively; p<.01). These results indicated that construction of Soyanggang dam changed the vegetation of the floodplain, without showing a change in its upland areas.

• Journal of Mushroom
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• v.9 no.2
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• pp.59-62
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• 2011

To develop a new cultivar of King oyster mushroom(Pleurotus eryngii), G09-21 as parental strain was selected by the method of Di-mon crossing between monokaryotic strains derived from ASI 2824(Keunneutari No.2) and dikaryotic strain ASI 2887(Aeryni 3). The Pe21-51($G09-21-10{\times}2844-11$) was shown the best cultural characteristics, selected to be a new cultivar and named as 'Song-A'. The 'Song-A' was formed incompatibility line distinctly in the confrontation growth of parental strains Keunneutari No.2, Aeryni 3 and ASI 2844. The optimum temperature for mycelial growth, fruiting body development and pH arrange were $25{\sim}30^{\circ}C$, $14{\sim}16^{\circ}C$ and pH5~8, respectively. Fruiting body production per bottle was about $94.7{\pm}29.5$ g which is almost 106% quantity compared to that of other cultuvar Keunneutari No.2. And also the stip is thick and long but the number of available stipe is few. Analysis of the genetic characteristics of the new cultivar 'Song-A' showed a different DNA profile as that of the control strains, Keunneutari No.2, Aeryni 3 and ASI 2844, when RAPD(Random Amplified Polymorphic DNA) primers URP4 and 7 were used. This new cultivar 'Song-A' of Pleurotus eryngii is characterized by a small number of primordia formation and the stip is thick and long. Therefore, we expect that this new strain will save of labor and cost by without culling work.

• Korean Journal of Microbiology
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• v.51 no.1
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• pp.7-13
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• 2015

Hydrotrope-combined copper (HCC) is a copper ($Cu^{2+}$)-based algicide, which is combined with a hydrotrope that keeps copper ion in solution to improve performance. This study assessed the growth inhibition effect of HCC against Microcystis aeruginosa which is one of the most common toxic cyanobacterium in eutrophic freshwater environment. Various HCC doses, ranging from 5.5 to $550{\mu}g/L$ as $Cu^{2+}$, were applied to either BG-11 or 1/4 diluted medium with low- or high-inoculum density of M. aeruginosa. Growth inhibition was monitored based on a decrease in chlorophyll-a content in culture medium during the incubation. Results showed that HCC significantly inhibited the growth of M. aeruginosa in a dose-dependent manner. In case of 1/4 diluted BG-11 medium, HCC dose as low as $5.5{\mu}g$ $Cu^{2+}/L$ completely inhibited the production of chlorophyll-a by M. aeruginosa. It was found that HCC did not induce any significant release of microcystin-LR from M. aeruginosa. Acute toxicity of HCC was tested using Daphnia magna, and the 24-h $EC_{50}$ value was 0.30 mg/L as $Cu^{2+}$ which was much higher than the actual inhibition dose. Ames test was performed using Salmonella enterica serovar Typhimurium TA100, and HCC showed no increase in the number of revertant colonies. The result suggested that HCC does not have any mutagenic potential in the aquatic environment. In addition, no genotoxic effect of HCC was also confirmed based on the SOS ChromoTest using Escherichia coli PQ37. Therefore, HCC could be used as a relatively safe and effective pre- and post-treatment agent to control hazardous algal blooming in aquatic environments.

• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.51-67
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• 1996

There are three main rice-growing regions in the United States: the prairie region along the Mississippi River Valley in eastern Arkansas; the Gulf Coast prairie region in southwestern Louisiana and southeastern Texas; and the Central Valley of California. The Central Valley of California is producing about 23% of the US rice(Fig. 1). In California. most of the crop has been produced in the Colusa, Sutter, Butte, Glenn Counties of the Sacramento Valley since 1912, when rice was commercially grown for the first time in the state(Fig. 2). Roughly speaking, the average annual area sown to rice in California is about 300,000 acres to 400,000 acres during the last forty years(Fig. 3). California rice is grown under a Mediterranean climate characterized by warm, dry, clear days, and a long growing season favorable to high photosynthetic rates and high rice yields. The average rice yield per acre is probably higher in California than in any other rice-growing regions of the world(Fig. 4). A dependable supply of irrigation water must be available for a successful rice culture. Most of the irrigation water for California rice comes from the winter rain and snow-fed reservoir of the Sierra Nevada mountain ranges. Less than 10 percent of rice irrigation water is pumped from wells in areas where surface water is not sufficient. It is also essential to have good surface drainage if maximum yields are to be produced. Rice production in California is highly mechanized, requiring only about four hours of labor per acre. Mechanization of rice culture in California includes laser-leveler technology, large tractors, self-propelled combines for harvesting, and aircraft for seeding, pest control, and some fertilization. The principal varieties grown in California are medium-grain japonica types with origins from the cooler rice climates of the northern latitudes (Table 1). Long-grain varieties grown in the American South are not well adapted to California's cooler environment. Nearly all the rice grown recently in California are improved into semidwarf varieties. Choice of variety depends on environment, planting date, quality desired, marketing, and harvesting scheduling. The Rice Experiment Station at Biggs is owned, financed, and administered by the rice industry. The station was established in 1912, as a direct result of the foresight and effort of Charles Edward Chambliss of the United States Department of Agriculture. Now, The station's major effort is the development of improved rice varieties for California.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.1
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• pp.30-39
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• 2020

A new silicate coating technology was developed which reduces the impact of dust and loosening during seeding compared to existing silicate-coatings (Seed/Si/Zeolite), and therefore can lower the production costs of rice cultivation. In this method, 100 g of rice seed is coated with 18 mL of liquid silicic acid and then dressed with a mixture containing 80 g of dolomite and 5 g of iron. To determine the most effective method of application and ensure that seedlings developed healthily, a series of experiments were carried out. Infected seeds scattered in seedling boxes and pots (soil and hydroponic) were coated dry, without disinfection. In comparison to the seed which were not treated with the silicate-coating, the new seed (A) were 1.84 times heavier in weight, and were also improved in terms of coating strength and coating color. Compared to the seedlings grown from the non-coated seed, those grown from the new silicate-coated seed were of significantly higher quality (weight/length) and had erect, dark greenish leaves, which are ideal plant characteristics. This was most likely due to increased silicate uptake. The symptoms of bakanae disease in the non-coated seed peaked after 38 days to 54.2%, whereas the control value was 68.8% in the new silicate-coated seed (A). In the infected seedlings grown from the new silicate-coated rice seed, subnormal macro-conidia, namely, a sickle shape spore without a septum; a straight oblong shape spore without a septum and with a thick cell wall; and inter-septal necrosis of a normal spore were detected. It is believed that the strong alkalinity of silicic acid have acted as unfavorable conditions for pathogenicity. In seedlings grown from the new silicate coated rice seed under hydroponic conditions without nutrients, normal root activity and growth was maintained without leaf senescence. Therefore, it was possible to reduce the rate of fertilization. In the future, a new silicate-coated rice seed was required for the study of minimal nutrition for anti-aging of seedlings.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.435-440
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• 2008

Bovine mastitis is an important disease causing serious economic loss in dairy production and food poison in public health. The major causative agents of bovine mastitis include Escherichia coli (E. coli), Streptococcus agalactiae (S. agalactiae), Staphylococcus aureus (S. aureus). These bacteria were found in milk and environmental condition such as feces, water, soil and so on. Recently, many cases of mastitis are derived from environmental contamination of micro-organisms, which important factors for the spread of this disease in farm. Ultraviolet irradiation (UV) has been used as disinfection for waste and water in clinical and industrial facilities. Moreover the UV irradiation has been used as useful bactericidal agents to remove bacterial biofilms in environmental condition. In this study, we determined the bacterial replication in different percentage of water content (PWC) in sterilized saw dust and feces complexes from farm, and results showed that slightly decreased growth pattern of E. coli and S. agalactiae but increased growth pattern of S. aureus in various PWC (200, 400 and 600%) until 144 h incubation. In the bacteriocidal effect of UV irradiation to bacteria in saw dust and feces complex, the results showed that bacteriocidal effect was depended on the UV irradiation time, irradiation distance and PWC. Especially the antibacterial activity of UV irratiation is stronger in low PWC (50%), long time irradiation (50 sec), and short distance (5 cm) than other condition of this study. Furthermore UV irradiation with stirring showed increased the bactericidal effect compared without stirring. These results suggested that bovine mastitis causing agents may survive long time in environmental condition especially saw dust and feces complexes in farm and can cause a various disease including mastitis. Moreover, these data can be used as basis for application and development of UV disinfection to control of bovine mastitis from environmental contaminated bacteria in dairy farm.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.103-108
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• 2010

To obtain the best yield of the beneficial ingredients in green tea, such as catechins, green tea powder is most often prepared by ethyl alcohol extraction. However, the taste, cost and composition of ethyl alcohol extract is different from aqueous spray-dried green tea extract (aq-GTE). Specifically, aq-GTE has a better flavor, lower production costs and higher purity when compared to ethyl alcohol extract. In this study, we elucidated the effect of aq-GTE on diet-induced obesity in male C57BL/6J mice following dose-dependent oral administration of aq-GTE. After eight weeks, the body weight was reduced by 13-17% in mice fed 200 mg/kg bw aq-GTE ($12.468{\pm}0.45\;g$; p<0.05) and 20-25% in mice fed 400 mg/kg bw aq-GTE ($11.259{\pm}0.61\;g$; p<0.05) when compared with the high-fat diet (HFD) control group mice ($14.714{\pm}0.95\;g$; p<0.05). The correlation between epididymal fat accumulation and body weight also decreased by approximately 26.6% (p<0.05) in mice fed a HFD with aq-GTE 400 mg/kg bw. Finally, serum parameters such as the triglyceride, glucose and cholesterol levels in the HFD groups were reduced by the aq-GTE 400 mg/kg bw diet. Analysis on glutamic-pyruvic transaminase, blood urea nitrogen and development of hepatic steatosis revealed no histologic evidence of hepatotoxicity in HFD mice fed aq-GTE. Overall, our results imply that aq-GTE is able to regulate body weight and fat accumulation in mice.