• The Korean Journal of Mycology
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• v.40 no.2
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• pp.124-126
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• 2012

Stem rot symptoms of Eupatorium lindleyanum occurred sporadically in the herb exhibition field at Hamyang-gun Gyeongsangnam-do Agricultural Research and Extension Services in Korea. The typical symptom included water-soaking on the main stem, rotting, wilting, and blighting, which eventually leads to death of the plant. The sclerotia, white to brown, globoid with size of 1-3 mm, were formed over lesions and surface soil line. The optimum temperature for mycelial growth and sclerotia formation was $30^{\circ}C$ on PDA. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. Mycological characteristics and pathogenicity to host plants indicated that the infected fungus was Sclerotium rolfsii Saccardo. This is the first report of stem rot on Eupatorium lindleyanum caused by S. rolfsii in Korea.

• Journal of Species Research
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• v.7 no.1
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• pp.36-49
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• 2018

During a study to discover indigenous prokaryotic species in Korea in 2016, a total of 42 actinobacterial isolates were recovered from various environmental samples collected from natural cave, squid, sewage, sea water, trees, droppings of birds, freshwater, eelgrass, mud flat, sediment and soil. On the basis of a tight phylogenetic clade with the closest species and high level of 16S rRNA gene sequence similarity, it was shown that each isolate was assigned to independent and previously described bacterial species which were assigned to the phylum Actinobacteria. The following 42 species have not been reported in Korea: eight species in two genera n the order Corynebacteriales, 26 species of 16 genera in the Micrococcales, one species of one genus in the Micromonosporales, one species of one genus in the Propionibacteriales, four species of two genera in the Streptomycetales and two species of two genera in the Streptosporangiale. Cell morphology, Gram staining reaction, colony colors and features, the media and conditions of incubation, physiological and biochemical characteristics, origins of isolation and strain IDs of 42 unrecorded actinobacterial species are presented in the species description.

• Journal of Microbiology and Biotechnology
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• v.23 no.12
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• pp.1673-1682
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• 2013

Citrobacter sp. is a cause of significant opportunistic nosocomial infection and is frequently found in human and animal feces, soil, and sewage water, and even in industrial waste or putrefaction. Biofilm formation is an important virulence trait of Citrobacter sp. pathogens but the process and characteristics of this formation are unclear. Therefore, we employed in vitro assays to study the nutritional and environmental parameters that might influence biofilm formation of C. werkmanii BF-6 using 96-well microtiter plates. In addition, we detected the relative transcript levels of biofilm formation genes by RT-PCR. Our results indicated that the capacity of C. werkmanii BF-6 to form biofilms was affected by culture temperature, media, time, pH, and the osmotic agents glucose, sucrose, NaCl, and KCl. Confocal laser scanning microscopy results illustrated that the structure of biofilms and extracellular polysaccharide was influenced by 100 mM NaCl or 100 mM KCl. In addition, nine biofilm formation genes (bsmA, bssR, bssS, csgD, csgE, csgF, mrkA, mrkB, and mrkE) were found to contribute to planktonic and biofilm growth. Our data suggest that biofilm formation by C. werkmanii BF-6 is affected by nutritional and environmental factors, which could pave the way to the prevention and elimination of biofilm formation using proper strategies.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.1
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• pp.13-19
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• 2014

The management of non point sources was marked by the need for clean water environments. It was proposed the fundamentals to promote the reasonable land management in this study. We monitored rainfall events at two non point sources with different crop cultivations such as a sweet potato and a cherry tree for three years. Because the most important factor was rainfall, the rainfall runoff and pollutant loads were generated 100% in the case of rainfall ranges with 50 < rainfall (mm). However the frequency of rainfall runoff was interacted with the crop cultivation and soil characteristics in the case of rainfall ranges such as 30 < rainfall (mm) ${\leq}50^a$ and 10 < rainfall (mm) ${\leq}30^b$. The frequency of rainfall runoff was a : 60% and b : 5% in the cherry tree cultivation with growing significantly and pollutant loads were lower than that of the sweet potato cultivation. Meanwhile the frequency of rainfall runoff was a : 60% and b : 5% in the sweet potato cultivation.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.E4
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• pp.177-186
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• 2003

The total of 1,454 aerosol samples were collected by high volume tape sampler at the Gosan Site in Jeju Island from 1992 to 1999, and the major water-soluble ionic components were chemically analyzed. The mean concentrations of nss-S $O_4$$^{2-}$, N $H_4$$^{＋}$, and N $O_3$$^{[-10]}$ showed high values, which were 6.73, 1.45, and 1.45 ${\mu}{\textrm}{m}$/㎥, respectively, while $Ca^{2+}$ and $K^{+}$ concentrations were low with the values of 0.49 and 0.42 $\mu\textrm{g}$/㎥. The concentrations of most components increased in spring but decreased in summer, especially with the remarkable increase of $Ca^{2+}$ and N $O_3$$^{[-10]}$ concentrations in spring. The seasonal comparison of nss-S $O_4$$^{2-}$ concentrations showed higher values with the order of spring > fall 〉 winter〉 summer, but spring 〉 winter〉 fall 〉 summer for N $O_3$$^{[-10]}$ Meanwhile, the concentration levels of N $a^{+}$ and C $l^{[-10]}$ increased more in winter season. According to the investigation of wind direction effect, the concentrations of most aerosol ionic components showed higher values consistently at the westerly and northerly wind conditions. Based on the factor analysis, the atmospheric aerosols in the Gosan Site are considered to be largely affected by marine sources, followed by anthropogenic and soil sources.urces..

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.2
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• pp.179-184
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• 1995

This study was carried out to characterize sources of suspended particulate matter(SPM) in Mt. Soback area from January to Novembver in 1993. The collection and major water soluble ion analysis of SPM were conducted by using a High Volumn Air Sampler(HVAS; W&A Inc., PM-10) and ion chromatograph(DIONEX 4000i), respectively. The variations of SPM and major ion concentrations were found to be 9. sim. 156.mu.g/ $m^{3}$, $F^{-10}$ 0.00 .sim. 0.15.mu.g/ $m^{3}$, C $l^{-10}$ 0.06 .sim. 3.79.mu.g/ $m^{3}$, N $O_{3}$$^{-10}$ 0.90 .sim. 6.85.mu.g/ $m^{3}$, S $O_{4}$$^{2-}$ 1.99 .sim. 9.36.mu.g/ $m^{3}$ N $a^{+}$0.00 .sim. 0.27.mu.g/ $m^{3}$, N $H_{4}$ $^{+}$0.72 .sim. 5.77.mu.g/ $m^{3}$, $k^{+}$0.03 .sim. 0.88.mu.g/ $m^{3}$ and $Ca^{2+}$0.12 .sim. 2.76.mu.g/ $m^{3}$. Tree sources were identified by Principal Component Amalysis(PCA) using a SPSS/P $C^{+}$. The explanation ability of forst, second and third Principal Component were 60.8%, 13.6%, 8.2%, of total variance. The sources classfied by PCA were found to be secondary aerosol/fuel combustion, soil dust related cement production/yellow sand and aerosol related waste burning.related waste burning.g.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.4
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• pp.420-431
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• 2010

The water-soluble components have been analyzed from the total suspended particulate (TSP) collected at Gosan site of Jeju Island for ten years (1997~2006), and the long-term variations of ionic constituent concentrations have been investigated in order to understand the pollution characteristics of atmospheric aerosols. Their mean concentrations were in the order of nss-${SO_4}^{2-}$ > $Na^+$ > ${NO_3}^-$ > $Cl^$ > ${NH_4}^+$ > nss-$Ca^{2+}$ > $K^+$ > $Mg^{2+}$. The ${NO_3}^-$ concentrations had increased somewhat smoothly compared to those of ${SO_4}^{2-}$ for the past 10 years, possibly indicating the recent energy consumption pattern changes in China. The concentrations of ionic aerosol components showed mostly higher values during the Asian Dust storm periods, and the concentration ratios of nss-$Ca^{2+}$, ${NO_3}^-$, and nss-${SO_4}^{2-}$ between the Asian Dust and Non-Asian Dust periods were 6.9, 2.4, and 1.3, respectively. The anthropogenic nss-${SO_4}^{2-}$, ${NO_3}^-$, ${NH_4}^+$ and the soil originated nss-$Ca^{2+}$ components showed high concentrations as the air parcels were moved from the Asia continent, on the other hand, their concentrations were relatively low as moving from the Northern Pacific into the Gosan area.

• Journal of Korean Society of Rural Planning
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• v.19 no.4
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• pp.319-327
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• 2013

The objective of this research was to develop a relational database management system(RDBMS) to collect, manage and analyze data on agricultural non-point source(NPS) pollution. The system consists of the relational database for agricultural NPS data and data process modules. The data process modules were composed of four sub-modules for data input, management, analysis, and output. The data collected from the watershed of the upper Cheongmi stream and Geunsam-Ri were used in this study. The database was constructed using Apache Derby with meteorological, hydrological, water quality, and soil characteristics. Agricultural NPS-Data Management System(ANPS-DMS) was developed using Oracle Java. The system developed in this study can deal with a variety of agricultural NPS data and is expected to provide an appropriate data management tool for agricultural NPS studies.

• Research in Plant Disease
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• v.12 no.1
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• pp.55-57
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• 2006

Stem rot of Houttuynia cordata occurred in the experiment field of Research Institute of Natural Product, Uiseong, Gyeongbuk, Korea in July 2003. The typical symptoms of the disease were water-soaking, stem rot, necrotic tuber. White mycelial mats were spread over lesions and sclerotia were formed on died plant and near soil line. The sclerotia were spherical and irregular, 1-2.5 mm on potato dextrose agar (PDA), white to brown in color, The optimal temperature for hyphal growth was $28{\sim}30^{\circ}C$ and the hyphal diameter was $3{\sim}9{\mu}m$. Clamp connections were observed on PDA. Pathogenicity of the casual organism was provided on H. cordata according to Koch's postulate. The fungus was identified as Sclerotium rolfsii Saccardo on the basis of mycological characteristics and pathogenicity test to host plants. This is the first report on the stem rot of H. cordata caused by S. rolfsii in Korea.

• Research in Plant Disease
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• v.11 no.2
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• pp.201-203
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• 2005

The stem rot disease was found on Hosta longipes that planted in the flower beds along the Namgang riverside in Jinju city, Korea. The disease occurred first time in July, 2004 and sporadically occurred in 2005. The typical symptom of the disease is water-soaking, dark brown spot on the stem, and getting wilt. The infected plants were mostly died. White mycelial mats were spread over lesions and sclerotia were formed on stems and near soil line. The sclerotia were globoid in shape, $1\~3$ mm in diameter and white to brown in color, The optimum temperature for mycelial growth of the fungus on PDA was $30^{\circ}C$ and the hyphal width was $4\~8{\mu}m$. Clamp connections were observed in the hyphae of the fungus grown on PDA. Pathogenicity of the causal organism was proved on Hosta longipes according to Koch,s postulate. On the basis of mycological characteristics and pathogenicity to host plants, the fungus was identified as Sclerotium rolfsii Saccardo. This is the first report on the stem rot of H. longipes caused by S. rolfsii in Korea.