• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.212-220
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• 1983

In order to improve the quality of sweet potato silage by adding some additives. sweet potatos (80%) were ensiled with one (20%) of the followings ; wheat bran, layer waste, swine waste or cow waste. The chemical composition, pH and acid contents of silages were determined. In addition, the silage intakes by Korean native goats were measured to estimate the palatability. The results were summarized as follows. 1. The pH of silages were decreased from the criginal 6.95 to 4.00 for WBAS (wheat bran added silage), to 4.50 for LWAS (layer waste added silage), to 4.40 for SWAS (swine waste added silage) and to 4. 10 for CWAS (cow waste added silage) after 40 days ensiling. 2. The contents of total acid and latic acid were 3.50% and 3. 32% for WBAS, 9.55% and 9.23% for LWAS, 8.51% and 8.50% for SWAS and 0.93% and 0.90% for CWAS, respectively. Therefore, good results for acid content were abtained from WBAS, LWAS and SWAS. 3. The bacterial counts were $2.6{\times}10^7/g$ for WBAS, $2.8{\times}10^7/g$ for LWAS, $2.6{\times}10^7/g$ for SWAS and $1.9{\times}10^7/g$ for CWAS. The number of lactic acid bacteria were $4.0{\times}10^7/g$ for WBAS, $5.5{\times}10^7/g$ for LWAS, 4.6{\times}10^7/g$ for SWAS, and $4.2{\times}10^7/g$ for CWAS. 4. The content of crude protein was highest in LWAS, that of crude fat was highest in SWAS and that of crude fiber was highest in CWAS. The contents of crude protein and crude fat in the silages were slightly increased while the moisture contents decreased as the fermentation was progressed. 5. The silage intakes by Korean native goat were slightly lower for animal-wasie-added silages than wheat-bran-added silage. Among the animal-added silage, the intakes of LWAS and SWAS were slightly higher than CWAS.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.10-10
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• 2017

Rice consumption has been continuously decreasing as the eating habits of Koreans have become westernized and diversified. The per capita annual rice consumption in Korea has dropped sharply from 136.4 kg in 1970 to 61.9 kg in 2016. The Korean government, therefore, has been trying to promote rice consumption by invigorating the processed food industry using rice flour. To facilitate the market for processed rice foods, it is essential to develop proper milling technology in terms of flour particle size and damaged starch content to produce high quality rice flour at competitive cost. Dry milling and wet milling are the two major processes used to produce rice flour. Although the dry milling process is relatively simple with a lower production cost, damaged starch content increases because of the high grain hardness of rice. In wet milling, the quality of rice flour is improved by reducing flour particle size as well as damaged starch content through soaking procedures. However, the production costs are high because of the additional expenses associated with the disposal of waste water, sterilization and drying of the wet flour. Recently developed technologies such as jet milling and cryogenic milling also require expensive investment and production. Therefore, developing new rice cultivars with dry milling adaptability as well as good processing properties is an important goal of rice breeding in Korea. 'Suweon 542' is a floury endosperm mutant line derived from sodium azide treatment on a high-yield, early maturing, and non-glutinous japonica rice cultivar, 'Namil'. Compared with the wild type, after dry milling process, the grain hardness of 'Suweon 542' was significantly lower because of its round and loosely packed starch granules. Also, the flour of 'Suweon 542' had significantly smaller particles and less damaged starch than 'Namil' and other rice cultivars and its particle size distribution was similar to a commercial wheat cultivar. Recently, through collaborations with nine universities and food companies, a total of 21 kinds of processed prototypes, using the dry milling flour of 'Suweon 542', were evaluated. In the production of major rice processing products, there was no significant quality difference between the flours prepared by wet milling and dry milling. Although the amount of water added to the dough was slightly increased, it was confirmed that the recipe applying the wet flour could be used without significant change. To efficiently transfer the floury endosperm characteristics of 'Suweon 542' to other commercial rice cultivars, it is essential to develop DNA marker tightly linked to the target gene. Association analysis using 70 genome-wide SSR markers and 94 F2 plants derived from 'Suweon 542'/'Milyang 23' showed that markers on chromosome 5 explained a large portion of the variation in floury grains percentage (FGP). Further analysis with an increased number of SSR markers revealed that the floury endosperm of 'Suweon 542' was directed by a major recessive locus, flo7(t), located in the 19.33-19.86 Mbp region of chromosome 5, with RM18639 explaining 92.2% of FGP variation in the F2 population. Through further physical mapping, a co-segregate and co-dominant DNA marker with the locus, flo7(t) was successfully developed, by which, thereby, breeding efficiency of rice cultivars having proper dry milling adaptability with high yield potential or useful functional materials would be improved. 'Suweon 542' maintained the early maturity of the wild type, Namil, which can be used in rice-wheat double cropping systems in Korea not only for improved arable land but also for sharing flour production facilities. In addition to the high susceptibility against major rice diseases, nevertheless, another possible drawback of 'Suweon 542' is the high rate of viviparous under prolonged rainfall during the harvesting season. To overcome susceptibility and vivipary of 'Suweon 542', the progeny lines, derived from the crosses 'Suweon 542' and 'Jopyeong', an early maturing rice cultivar with multiple resistance against rice blast, bacterial blight, and rice strip virus, and 'Heugjinju', a anthocyanin pigment containing black rice cultivar, were intensively evaluated. As the outputs, three dry milling suitable rice elite lines, 'Jeonju614', 'Jeonju615', and 'Jeonju616' were developed.

• Korean Journal of Environmental Biology
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• v.34 no.4
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• pp.304-313
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• 2016

One of the issues currently facing nuclear power plants is how to store spent nuclear waste materials which are contaminated with radionuclides such as $^{134}Cs$, $^{135}Cs$, and $^{137}Cs$. Bioremediation processes may offer a potent method of cleaning up radioactive cesium. However, there have only been limited reports on $Cs^+$ tolerant bacteria. In this study, we report the isolation and identification of $Cs^+$ tolerant bacteria in environmental soil and sediment. The resistant $Cs^+$ isolates were screened from enrichment cultures in R2A medium supplemented with 100 mM CsCl for 72 h, followed by microbial community analysis based on sequencing analysis from 16S rRNA gene clone libraries(NCBI's BlastN). The dominant Bacillus anthracis Roh-1 and B. cereus Roh-2 were successfully isolated from the cesium enrichment culture. Importantly, B. cereus Roh-2 is resistant to 30% more $Cs^+$ than is B. anthracis Roh-1 when treated with 50 mM CsCl. Growth experiments clearly demonstrated that the isolate had a higher tolerance to $Cs^+$. In addition, we investigated the adsorption of $0.2mg\;L^{-1}$ $Cs^+$ using B. anthracis Roh-1. The maximum $Cs^+$ biosorption capacity of B. anthracis Roh-1 was $2.01mg\;g^{-1}$ at pH 10. Thus, we show that $Cs^+$ tolerant bacterial isolates could be used for bioremediation of contaminated environments.

• Korean Journal Plant Pathology
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• v.3 no.3
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• pp.180-186
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• 1987

Cell suspensions of two isolates of Pseudomonas syringae. PS8401 from sweet persimon and PS8402 from tea plant, were active in ice nucleation at -2.5 and $-3.8^{\circ}C$, respectively. Ice nucleation at those temperature was, using micropipette method, detected in suspensions ($10^8$ olony forming unit/ml of distilled water) of cells that had been grown on nutrient agar supplemented with $2.5\%$ glycerol. Using the same method, on the other hand, the freezing temperature of distilled water only was approx. $-21.8^{\circ}C$, and those of various plant saps including corn were lower than $-11.6^{\circ}C$. Corn seedlings sprayed with cell suspensions $(10^8\;cfu/ml)$ of nutrient broth) of PS8401 began to be damaged at $-2^{\circ}C$ and were almost completely damaged at $-4^{\circ}C$, whereas seedlings sprayed with nutrient broth only were not injured until the temperature down to $-9^{\circ}C$. Amounts of frost damage measured 48 hr after application of PS8401 suspensions increased as applied bacterial cell densities were increased. Ice-nucleation activity of the cell suspensions in vitro increased with increasing the number of cells in suspension. The activity also affected by growth-medium composition or growth-temperature. Ice nucleation thus occured at -4.0, -4.4 and $-7.2^{\circ}C$ in suspensions $(10^2\;cfu/ml)$ of PS8401 that had been grown at$25\%$ nutrient agar with $2.5\%$ glycerol, nutrient agar with $2.5\%$ glucose and nutrient agar only, respectively, and occured at -4.0 and $-7.6^{\circ}C$ in suspensions $(10^2\;cfu/ml)$ of PS8401 hat had been grown on nutrient agar with $2.5\%$ glycerol at $15\~25^{\circ}C$ and $30^{\circ}C$, respectively.

• Research in Plant Disease
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• v.16 no.1
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• pp.27-34
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• 2010

This study was performed to develop a formulation using an antagonistic bacterium Bacillus amyloliquefaciens A-2 to control tomato leaf mold caused by Fulvia fulva. B. amyloliquefaciens A-2 was grown in a medium with rice oil and mixed with various carrier and additives. One of the formulations, A2-MP, showed the best disease control value among the tested formulations. The disease control value of A2-MP at 100-fold and 500-fold diluted treatment was not significantly different from that of chemical fungicide triflumizole in a growth chamber. Although disease control effect was decreased by serial diluted treatment of the prepared A2-MP, 1,000-fold diluted treatment of A2-MP still showed high disease control value of 72.0%. For the green house experiments, the disease control values of A2-MP was indicated as 79.4% which is similar to that of chemical fungicide, triflumizole showing 79.6%. When the disease control activity of the formulation A2-MP was compared in tomato production conditions, disease control values of 100-fold diluted A2-MP and 3,000 fold diluted triflumizole exhibited 60%, 81.6%, respectively. The disease control efficiency by A-2MP was 73% of the disease control value of chemical fungicide. The formulation A-2MP maintained the stable bacterial viability and disease control activity when stored at $4^{\circ}C$. This result suggested that A-2MP develped from B. amyloliquefaciens A-2 could be used to control tomato leaf mold.

• Pediatric Infection and Vaccine
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• v.17 no.1
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• pp.30-35
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• 2010

Purpose : We investigated the causative organism and its antibiotic susceptibility of community acquired urinary tract infection (UTI) in children at a secondary hospital to test the adequacy of the current guidelines. Methods : Children diagnosed with UTI at the Department of Pediatrics, Kwandong University MyMyongji Hospital by pyuria and bacterial growth of greater than $1.0{\times}10^5CFU/mL$ on clean catch midstream urine from January 2005 to December 2008 were studied retrospectively. The epidemiologic data, causative organism, and the antibiotic susceptibility were analyzed. Results : Sixty two children were diagnosed with sixty four cases of UTI's. Two bacteria were isolated in one case and thus data on 65 urine cultures were analyzed. The male:female ratio was 1.6:1 and 78.1% were less than 12 months of age. Escherichia coli was the predominant cause consisting of 53 cases (82.8%) of the cases. K. pneumoniae (5), Enterobacter (4), Enterococcus (1), $\beta$-streptococcus (1), Diphtheroides (1) were isolated. The antibiotic resistance of E. coli were as follows; ampicillin 69.8%, cefotaxime 1.9%, gentamicin 15.1%, amikacin 0.0%, levofloxacin 1.9%, and trimethoprim/sulfamethoxazole 26.4 %. Only one case of the E. coli was extended spectrum $\beta$-lactamase (ESBL) positive. Conclusion : Compared to prior reports from other tertiary hospitals in Korea, E. coli was the predominant cause in childhood UTI and the rate of ESBL positivity was low. The antibiotic resistance was also different compared to prior reports. We conclude that a difference in the cause and antibiotic resistance of childhood UTI exists between centers and this should be taken into consideration when prescribing antibiotics for childhood UTIs.

• Pediatric Infection and Vaccine
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• v.21 no.2
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• pp.96-103
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• 2014

Purpose: The aim of this study is that the prevalence of rotavirus infection was evaluated by each group and clinical features of group A, B and C rotaviruses infections were described respectively to compare one with another. Methods: Between January 2010 and December 2010, we enrolled a group of children below 10 years of age admitted for management of acute diarrhea at the Catholic University of Korea Bucheon St. Mary's Hospital. A total of 310 stool samples documented to be free of common bacterial pathogens were collected from children with diarrhea. The presence of group A, B or C rotavirus is indicated by amplification of DNA segments of the expected lengths after the first and second PCRs Results: In a total of 310 stool specimens, 40 (12.9%) specimens were positive for rotaviruses. These included 23 (7.4%) positive for group A, 5 (1.6%) for group B and 12 (3.9%) for group C rotaviruses. Group B rotavirus infected patients had significantly less diarrheas per day (group A: P =0.01, group C: P =0.01) and shorter duration of vomiting days (group A: P =0.03, group C: P =0.03) than those with group A and C rotaviruses infection respectively. All the group B rotaviruses had been isolated in March and October. Group C rotavirus infections were prevalent during late summer and early winter and peaked in October. Conclusion: These findings indicate that group B and C rotaviruses are notable causes or the contributing causes of diarrhea among infants and children in Korea.

• Pediatric Infection and Vaccine
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• v.21 no.2
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• pp.129-138
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• 2014

Purpose: Streptococcus pyogenes is an important cause of invasive diseases in children. We aimed to describe the clinical characteristics of invasive infections due to S. pyogenes in children in Korea. Methods: A retrospective study of children under 18 years of age with invasive infections due to S. pyogenes at Seoul National University Children's Hospital between March 1992 and December 2012, and Seoul National University Bundang Hospital between March 2003 and December 2012 was conducted. Demographic factors, clinical characteristics, laboratory findings, treatment, mortality and morbidity of all patients were reviewed. Results: A total of 30 among 36 cases identified as invasive disease due to S. pyogenes were available for review. There was a predominance for male subjects (male:female=2.75:1). The median age was 50 months (range 12 days to 15 years) and 53.3% were under 5 years of age. Skin and soft tissue infections (9/30, 30.0%), bacteremia without identified focus (4/30, 13.3%) and bone and joint infections (6/30, 20.0%) were the most frequent clinical presentations. Streptococcal toxic shock syndrome (3/30, 10.0%) pulmonary, abdomen and central nervous system infections (2/30, 6.7%) were also seen. There was a peak in number of patients in year 2012 (9/30, 30.0%). There were no cases of mortality. Erythromycin and clindamycin resistance rates were low by 3.8% and 7.5%, respectively. Conclusion: We studied the clinical presentations of invasive infections due to S. pyogenes during the past 20 years in Korean children. The findings of this study help us understand the characteristics of the disease, enhancing early recognition and prompting adequate antibiotic therapy which is important in reducing morbidity and mortality.

• Korean Journal of Weed Science
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• v.32 no.2
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• pp.98-106
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• 2012

This research has been carried out to find out the highest effect on insecticidal, fungicidal and herbicidal activities in leaves, stem and tuber extracts of yacon (Smallanthus sonchifolius) and extraction methods such as water, boiling water and methanol. Characteristics of potential herbicidal components among extraction methods were investigated by solvent fractions such as hexane, chloroform, ethyl acetate, butanol, and water. Generally, methanol extract was the best on inhibition of germination rate, plant height, and root length in cucumber and barley. On the other hand, the inhibition effect on growth in cucumber and barley was the best in tuber among plant parts of yacon. Inhibition of germination rate, plant height, and root length in cucumber and barley in solvent fractions was the best in water fraction, but there were no differences in other fractions. Digitaria sanguinalis L. and Solanum nigrum L. by 5 and 10% extractions of yacon tuber were controlled by more than 70~80% and 95~100%, respectively. However, there was no inhibition effect on foliar treatment in cucumber and barley as affected by 5 and 10% extractions of yacon tuber. Mortality of green peach aphid (Myzus persicae Sulzer) was 50% at 3 days after treatment of 5% extracts of yacon leaves. Mortality of brown plant hopper (Nilaparvata lugens Stal) was only 24% in 5% extracts of stems and leaves with midrib, but was 57% in 5% extracts of leaves without midrib. There was no fungicidal effect on anthracnose (Colletotrichum truncatum), wilt disease (Fusarium oxysporum), verticillium wilt (Verticillium dahliae), bacterial blight (Xanthomonus oryzae) in 5% extracts of yacon leaves.

• Journal of Food Hygiene and Safety
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• v.19 no.2
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• pp.60-65
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• 2004

120 samples of ready-to-eat salad product were purchased at department stores, marts and family restaurants in metro area. Coliform bacteria and food borne pathogenic bacteria were isolated from these samples. In 73 samples among the 120 salad product samples, coliform bacteria and food borne pathogenic bacteria were detected by 60.8％ of isolated rate. Salad were classified into organic and non-organic salad. According to a salad type, salad were classified into vegetable salad and mixed vegetable salad with fried chicken and extra food. According to a packing type, packed salad product and salad-bar product were classified. After the classification, the results of each cases were compared. There is no statistical relation between cultivation or packing methods and contaminated bacteria. But the incidence number of microbial strains was significantly different between vegetable salad and mixed vegetable salad(p＜0.005). In vegetable salad, more various strains were detected. E. coli was isolated in 10 cases among the 90 cases in non-organic vegetable and in 7 cases among the 30 cases in organic salad. Food borne pathogenic bacteria were isolated in non-organic vegetable salad product. Staphylococcus aureus was isolated in 4 cases of vegetable salad product and Salmonella spp. isolated in 1 case. After 5 times examination of each 4 market products, the total number of aerobic bacteria was average 4.8$\pm$0.19 log cfu/g. One sample from this product, saline and a detergent for vegetable were used for 3 minutes to notice the effect. As a result, when saline was used 5 times and detergent for vegetable was used 1 time, bacterial contamination was decreased up to 95.5％.