• Journal of Life Science
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• v.19 no.10
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• pp.1478-1483
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• 2009

A solid-state culture based on grain materials was attempted to produce a fibrinolytic enzyme for blood circulation improvement using Bacillus subtilis BK-17. The spore, rather than vegetative cell inoculation, of B. subtilis BK-17 on the solid-state culture was effective in the production of a fibrinolytic enzyme. Maximum spore production was obtained with a SFM medium (0.8% nutrient broth, 0.05% yeast extract, $10^{-1}$ M $MgCl_2$, $10^{-3}$ M $FeCl_3$, $10^{-4}$ $MnCl_2$, $10^{-5}$ M dipicolic acid, pH 6.5). Optimal pH and temperature were pH 6 and $30^{\circ}C$, respectively. The spore production reached a maximum at 60 hours of incubation. Bacillus subtilis BK-17 on the mung bean solid-state culture produced greater fibrinolytic activity, and less activity was seen in other grains such as kidney bean, soybean and corn. Protein and lipid contents of fermented soybeans were about 10 - 30% more than those of unfermented soybeans. Amino acid content was also 5 - 20% more than that of unfermented soybeans. These results indicated that fermented solid-state culture medium, fermented soybean in this case, can be utilized as a food supplement.

• Toxicological Research
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• v.20 no.2
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• pp.101-108
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• 2004

The different social reflections about the benefits and the potential risks of genetically modified (GM) crops have evolved with .different reactions in different countries. Many countries including Korea are working toward setting down new guidelines. Korea requires companies to label all food that contains more than 3% GM ingredients. One of the rapid and convenient detection methods of GM ingredients is amplification of the introduced DNAs by polymerase chain reaction (PCR). Many PCR kits for this purpose are commercially available. The objective of this study was to evaluate performance of commercialized GM crop detection kits. The results showed that 6 out of 15 kits tested did not meet the requirements even purposed by the manufacturers themselves in terms of stability, reproducibility, and detection limits, suggesting a potential quality control problem in their design stage or production line. The evaluation also suggests that, although the duplex and triplex detection kits allowed unambiguous detection in a single PCR reaction, the monoplex detection kits were the most sensitive to the detection of GM ingredients. The detection limits also differ between soybean and corn. Results from this study will be useful in the development of sound qualitative tracking systems of GM ingredients for monitoring throughout the cultivation of GM crops, their trans-boundary movement, and food production using GM grains as well as for complying with government guidelines associated with GM crops.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.4
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• pp.327-337
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• 1996

A field experiment was conducted at SNU Experimental Livestock Farm, Suweon in 1995 to determine effect of planting date on forage performance of wm hybrids of four different maturity groups. A split-plot design replicated three times was used, with com hybrids representing four maturity groups (115, 118, 121 and 125 days) being the main plots and planting dates (3124, 415, 415, 425, 515 and 5/15) the sub-plots. 1. Days to emergence and percent emergence from the March 24 planting were, on the average, 36 days and 58%, respectively, but those from the April 5 to May 15 planting averaged 12 days and 92%, respectively. 2. Plant and ear heights increased gradually as the dates of planting were delayed except the May 15 planting, however, percent ear was decreased as the dates of planting were delayed. There was a trend for the mean lodging percentage of the hybrids to be higher as the planting date was delayed. 3. The 115-and 118-day mediumearly maturing hybrids harvested on August 18 produced silages with a dry matter content between 27 and 30% at all planting dates except the May 15 planting, while the 121-and 125-day medium-late maturing hybrids produced silages with a dry matter wntent less than 27% regardless of any planting dates. 4. There were no significant differences in mean dry matter yield among the hybrids, but significant mean TDN yield differences were found. The 115-, 118- and 125-day hybrids had significantly higher mean TDN yield than the 121-day hybrid. There were significant differences in mean dry matter and TDN yields among the planting dates. The mean dry matter and TDN yields from the April 5, 15 and 25 plantings were significantly higher than those of other plantings, however, there were no significant differences in mean TDN yield among the April 5, April 15 and April 25 plantings. No significant planting date $\times$ maturity interactions were found for both the dry matter and TDN yields. 5. Mean stover NDF and ADF contents of the 115- and 118day hybrids were higher than those of the 121- and 125-day hybrids, but the reverse was true for mean stover IVDMD and RFV. Mean stover NDF an ADF contents increased with earlier plantings, but mean stover IVDMD and RFV increased when planting was delayed. Results of this experiment indicate that for corn planting in central and northern areas of Korea, early to mid-April may be the right time with the 115-to 118-day maturity hybrids when silage making before August 20 is taken into consideration.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.4
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• pp.315-322
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• 1997

Sixteen cultivars of corn(Zea mays L.) hybrids have been recommended as the government recommended corn hybrids since 1984, however, their forage performances have been mostly tested at two locations, such as Suweon and Sunghwan in the Middle parts of Korea. Therefore, the objective of this experiment was to retest the agronomic characteristics and yield of eleven of sixteen government recommended corn hybrids at five scattered locations, such as Icheon, Suweon, Sunghwan, Keonpan and Kwangju in 1993 and 1995 with the intention of improving recommendations to dairy farmers. Among the corn hybrids tested, 'Suweon 19' was susceptible to foliar diseases and poor stay green at all locations in 1993 and 1995. Generally, all hybrids have less lodging and infection rate of rice black streaked dwarf virus(RBSDV) varied by location but mostly not exceed 10%. Infection rate at Sunghwan and Kwangju among locations was the highest as 13.5 and 15.3% respectively. Among the corn hybrids tested, 'Suweon 19' was the highest RBSDV infection rate, but that of 'Kwanganok' and '3282' was lower than other hybrids. At all locations, '3352' and '3394' were the earliest in growth stage, but 'Kwanganok', '3282', 'DK729', 'G4624' and 'DK713' were the latest among the corn hybrids. Ear percentage in total DM of '3352', '3394' and 'G4624' was higher than other hybrids, but that of 'DK713' was the lowest among the corn hybrids. '3352' and '3394' showed the most suitable DM content for silage production at harvest. Among the corn hybrids tested, 'Suweon 19' and '3282' were the lowest DM yield at all locations in 1993 and 1995, but the highest DM yield varied by location. At Icheon, '3144W' and 'G4743', at Suweon, '3352' and '3144W, at Sunghwan, 'DK729' and '3144W', at Keongsan, '3352' and 'DK729', and at Kwangju, '3352' and 'DK689' were the highest DM yield in 1993 and 1995, respectively. Then, '3394' was higher than other hybrids at all locations in 1995. The government recommended corn hybrids tested were generally adapted across the country. However, in forage production situations where wrn should be harvested before the rainy season in late summer, earlymedium maturing corn hybrids, '3352' and '3394' might be preferred.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.3
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• pp.209-218
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• 2007

This experiment was conducted to investigate effect of plowing frequency and sowing dates on the agronomic characteristics, feed value, weed yield and palatability of silage corn. Treatments were a basal treatment(C: May 5 seeding, plowing once, weeding control once), T1(May 12 seeding, plowing twice, weeding control 0 time), T2(May 19 seeding, plowing three times, weeding control 0 time, T3(May 26 seeding, plowing four times, weeding control 0 time) and T4(June 2 seeding, plowing five times, weeding control 0 time). The experiment was performed at the College of Life and Natural Sciences of Sangju University in Sangju in 2006. The plant height and ear height showed highly in order to C > T1 > T2 > T3 > T4 treatment, leaf length was the highest at T2 (96.0cm). Leaf width and number of dead leaf were the highest at C and T3 (11.2cm), C, C and T1 (4.6), respectively. Stem diameter was the highest at T3 as 31mm, while T2 was the lowest as 25mm (p<0.05). Ear circle showed highly in order of C > T1 > T4 > T3 > T4 (p<0.05), and tip filling degree was the highest at C treatment as 8.8, while T4 treatment was the lowest as 6.0 (p<0.05). The stem hardness and grain hardness were C < T1 < T2 < T3 < T4 (p<0.05). Stem saccharinity was T1(6.1%) was the highest, while T2(3.0%) was the lowest(P<0.05). Fresh yield of weed was the lowest at C treatment as 500 kg/ha, but T1 treatment was the highest as 44,100 kg/ha (p<0.05). Weed coverage rate showed highly in order of T1 > T2 > T3 > T4 > C treatment (p<0.05). Fresh yield of corn was the highest at C treatment as T3,550 kg/ha, but T4 treatment was the lowest as 65,500 kg/ha (p<0.05). Dry matter yield of corn showed highly in order of C(26,978 kg/ha) > T1(26,130 kg/ha) > T2(20,255 kg/ha) > T3(20,255 kg/ha) > T4(17,508 kg/ha) treatment (p<0.05). Crude protein content was T1(7.69%) > T4(7.42%) > T2(6.34%) > T3(5.99%) > C(5.91%) treatment (p<0.05), and Crude fat content showed highly in order of C (2.13%) > T1(2.04%) > T2(1.96%) > T3(1.95%) > T4(1.84%) treatment. Relative palatability of Holstein, Korean native goat and spotted deer was the highest at C treatment, but Korean native cattle was the highest at T1 treatment.

• Korean journal of applied entomology
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• v.30 no.2
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• pp.103-137
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• 1991

The developmental period(mean $\pm$ SE) of the red flour beetle, Tribolium castaneum was studied on brown rice at four constant temperature(25, 28, 34, $36^{\circ}C$ $\pm$ $0.5^{\circ}C$, RH 70%)conditions. Based on the results, the lower and the upper developmental threshold temperature for the beetle were also estimated. The duration of the egg stage was estimated to be 7.6 $\pm$ 0.25, 4.8 $\pm$ 0.10, 3.0 $\pm$ 0.03 and 2.5 $\pm$ 0.09 days at 25, 28, 34, $36^{\circ}C$, respectively. That of the larval stage was estimated to be 53.3 $\pm$ 1.49, 33.4 $\pm$ 0.57, 30.6 $\pm$ 0.70, 31.0 $\pm$ 1.18; that of the pupal stage to be 12.1 $\pm$ 0.17, 7.8 $\pm$ 0.09, 5.7 $\pm$ 0.09, 5.0 $\pm$ 0.07 ; that of the overall period which spans from eggs to the adult emergence to be 72.3 $\pm$ 1.67, 46.0 $\pm$ 0.55, 39.4 $\pm$ 0.64, 38.7 $\pm$ 1.15 days at 25, 28, 34, $36^{\circ}C$, respectively. The duration of the egg and the pupal stage were similar to those of the results reared on other diets such as wheat and maize. Fed on brown rice, however, the duration of the larval stage was significantly retarded than on wheat. The mortality of the beetle during ,development was higher on brown rice than on wheat reported, indicating that brown rice is a poor diet compared with wheat. The lower developmental threshold temperature was estimated to be $20.0^{\circ}C$ for all stages of the beetle. The upper one was estimated to be $40.2^{\circ}C$ for the overall stage. The modal value of the moulting times during the larval stage was 7. However, as temperature increased,.the frequency of the beetle that moulted more than 7 times became higher. The sex ratio of the beetle was not affected by temperature.

• Korean Journal of Poultry Science
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• v.38 no.2
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• pp.137-144
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• 2011

The current work was carried out to investigate the effect of crossbred Korean native chickens (KNC) on fatty acid, amino acid and nucleotide-related compounds contents of chicken meat. A total of 360 male chicks (1d of age) was used in this work and were divided 4 groups as A) (KNC egg-meat type C strains ${\times}$ KNC meat type S strains) ${\times}$ Ross broiler, B) (KNC egg-meat type C strains ${\times}$ KNC meat type H strains) ${\times}$ KNC meat type S strains, C) (KNC native R strains ${\times}$ KNC meat type S strains) ${\times}$ KNC meat type H strains and D(White Semibroiler Chickens) strains for 5 weeks at the flat house. Palmitic acid and vaccenic acid were highest in C strain meat, and myristic acid and linolenic acid were lowest in A strain meat (p<0.05). Saturated fatty acid was lowest in C strain meats (p<0.05). Valine, leucine, phenylalanine and lysine of essential acid were low in A strain meat. Cystine, aspartic acid, glycine, alanine and proline were also low in A strain meat. Hypoxanthin (Hx) was high compared other strains at 5 weeks and low at 10 weeks. IMP was high compared other strains at 5 and 10 weeks. AMP has not significant difference among strains at 5 weeks but B strain was high other strains at 10 weeks. These results showed that C stain was excellent on the fact of nutrients compared to other strains. Consequently, the result of this work gave the basic data that needed to develope the new strains.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.1
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• pp.2-15
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• 1982

In this report, a total domestic demand for major commercial fertilizer for crop production in Korea up to 1996 was estimated. The agricultural products and area for demand for both 1982 and 1986 was quoted from the estimate of the 5th Five-year Economic plan. And the demands estimated for 1991 and 1996 reflected possible changes of diet from cereal to meat and their indirect effects on the increase of cereal consumption. As the advanced countries followed, consequently, the demands for soybean, corn and other feed grains were expected to be increased as well as the land for growing those crops. 1. Total annual demands for nitrogen, phosphorus and potassium fertilizers were estimated 1,050,000M/T, 1,110,000M/T, 1,280,000M/T and 1,010,000M/T for the year 1982, 1986, 1991, and 1996 respectively. 2. It was assumed that there would be difficulties in self-sufficiency of grains at the cost of the maximum utilization of land and fertilizers in 1996. 3. It was clear that the increase of the productivity per unit area is possible by improving the conditions of arable land which could resulted a self-sufficiency of food in Korea. As a consequence, the demand for fertilizers at that time would exceed the level of estimates. 4. The recent decrease in demand for commercial fertilizers (currently estimated 850,000M/T) was due to an inadequate application of fertilizers for respective crop reqirement. This inadequacy should be checked and encouraged the consumptions of fertilizers to be increased by supporting the price of grain.