• Korean Journal of Ecology and Environment
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• v.44 no.3
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• pp.253-263
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• 2011

This study was conducted to gain preliminary data for restoration and management of constructed small-scale ponds in paddy fields through analysis of their physicochemical and biological properties. A field survey was performed at 13 small-scale ponds located in paddy fields from August 2009 to October 2010. Structural properties, water quality, soil characteristics and fish fauna were measured. Results showed that small-scale ponds without frames might lose their function over time because of crumbling walls. Therefore, it is necessary for these ponds to have frames for soil protection and sustainable maintenance. Chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) concentration were higher than the water quality standard for agricultural water in small-scale ponds. In particular, TN concentration was 8.03 mg $L^{-1}$ and over 8 times the water quality standard because of the presence of livestock such as cows and pigs in the study areas. Sand, organic matter and available phosphorus contents of soil in small-scale ponds was 53.4${\pm}$16.6%, 21.8${\pm}$9.74 g $kg^{-1}$ and 12.8${\pm}$7.59 mg $kg^{-1}$, respectively indicating that sand and available phosphorus contents were suitable for plants in small-scale ponds, but organic matter contents was somewhat low in newly constructed small-scale ponds, and would take some time to stabilize for plant growing. Fish fauna was not diverse with only 4 species at all sites surveyed. Collected fishes share a common feature that they all inhabit paddy fields or canals with shallow water depth. In this study, all ponds were not linked to the streams and canals around them. It appears that connection to adjacent streams was the major factor controlling fish fauna in small-scale ponds. The results of statistical analysis were classified into three groups. Factor 1 was 26.3%, which shows a structural properties such as area and depth of small-scale pond. As for factor 2, it appears on 20.1%, showing water quality like a TP, suspended solids (SS) and COD. Small-scale ponds were classified into three groups by factor scores. Group I consisted of 6 small-scale ponds, which were larger than the others. Group III had higher water quality than the others. We conclude that the most important points to be considered for restoration and management of small-scale ponds is connection with adjacent streams or ditches and depth and size of the small-scale pond.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.1
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• pp.47-52
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• 2010

Physical, chemical and biological properties of soils and cadmium(Cd) content of Artemisia princeps var. orientalis collected from 10 metalliferous mines were analysed. Cd contents of unplanted soils and rhizosphere soils were not significantly different(p < 0.05), and mean values were 5.92 and 5.91 mg/kg, respectively. In addition, Cd content of rhizosphere soils were correlated with Cd content of Artemisia princeps (p < 0.05, ${R^2}_{shoot}$ = 0.3120, ${R^2}_{root}$ = 0.4177). Minimum data set(MDS) of soil quality parameters for statistical assessment of Cd uptake was established by principal component analysis, and it was identified as organic matter(OM), dehydrogenase activity(DHA), pH, exchangeable Mg. According to multiple regression analysis using the MDS, coefficients of determination ($R^2$) for Cd uptake of shoot and root of Artemisia princeps were found to be 0.3418 and 0.5121, respectively. This suggests that statistical soil quality assessment using the MDS seems a useful tool to interpret heavy metal uptake of plant.

• Applied Biological Chemistry
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• v.12
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• pp.115-118
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• 1969

In a series of studies on the formation processes and chemical properties of humic substances from paddy soils the photoabsorption spectra of hymatomelanic and humic acids were recorded in the visible, ultraviolet and infrared regions. The spectra patterns of both fractions in the visible range were indicative of the decrease in optical density with the rise of wavelength and the UV-spectra showed the maximum peak at $235\;m{\mu}$, the minimum at $395\;m{\mu}$. The IR-spectra indicate a typical pattern showing a few sharp peaks in both fractions. The spectra of both fractions were compared and discussed.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.968-975
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• 2018

In the course of screening for microbes with nematicidal activity, we found that Enterobacter asburiae HK169 displayed promising nematicidal activity against the root-knot nematode Meloidogyne incognita, along with plant growth-promoting properties. Soil drenching of a culture of HK169 reduced gall formation by 66% while also increasing root and shoot weights by 251% and 160%, respectively, compared with an untreated control. The cell-free culture filtrate of the HK169 culture killed all juveniles of M. incognita within 48 h. In addition, the nematicidal activity of the culture filtrate was dramatically reduced by a protease inhibitor, suggesting that proteolytic enzymes contribute to the nematicidal activity of HK169. In order to obtain genomic information about the HK169 isolate related to its nematicidal and plant growth-promoting activities, we sequenced and analyzed the whole genome of the HK169 isolate, and the resulting information provided evidence that the HK169 isolate has nematicidal and plant growth-promoting activities. Taken together, these observations enable the future application of E. asburiae HK169 as a biocontrol agent for nematode control and promote our understanding of the beneficial interactions between E. asburiae HK169 and plants.

• Applied Biological Chemistry
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• v.28 no.2
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• pp.68-75
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• 1985

Laboratory experiments were conducted to investigate the effect of compost and humic acid treatment on adsorption of Cd, Zn, and Cu in soils. Three soils differing in physical and chemical properties used in this experiments were Bonyrang (Typic Udifluvents) SL, Gangseo (Aquatic Eutrochrepts) L, and Gyorae (Typic Distrandepts) SiL. Adsorption of Cd, Zn, ana Cu on the soils followed Langmuir isotherm up to 75 ppm of initial concentration. The adsorption maxima of Cd, Zn, and Cu for the Bonryang soil, the lowest in pH, organic matter content, and CEC, were the lowest of the three soils. Although the Gyorae soil derived from volcanic ash was the highest in organic matter content and CEC, the adsorption maxima of heavy metals for the Gyorae soil were lower than those for the Gangseo soil of which organic content and CEC were intermidiate. The adsorption maxima/CEC ratios for the Bonryang, the Gangseo, the Gyorae soils were found to be in the range of $23{\sim}27%,\;28{\sim}57%$, and $11{\sim}14%$ respectively The bonding energy constants of Cd, Zn, and Cu for the soils were in the order of Gangseo>Bonryang>Gyorae soils. The adsorption maxima of Cd, Zu, and Cu for the Bonryang soil increased with compost treatment by $100{\sim}210%,\;90{\sim}230%$, and $130{\sim}290%$ respectively, while little difference was observed when the soil was treated with humic acid Bonding energy constants of Cd, Zn, and Cu for the Bonryang soil increased significantly with compost treatment, and showed insignificant correlation with humic acid treatment.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.185-190
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• 2005

An experiment was conducted to know the effects of crab shell, sericite ore, and charcoal powders on the growth, yield, and grain quality of rice. After application of 110-40-57 kg/ha of $N-P_2O_5-K_2O$, 3,000 kg/ha of crab shell and charcoal powders and 5,000 kg/ha of sericite ore powder were applied and incorporated into soil before transplanting of rice seedlings. The number of tillers and panicles, leaf area index at heading stage, N concentration of plants, and protein content and chalkiness of rice grains were increased with the application of crab shell powder, while the percentage of ripened stains and head rice and Toyo taste value were decreased. The yield of milled rice and other grain appearance and chemical and physical properties of rice grains were not affected by the application of crab shell powder. The sericite ore and charcoal powders increased protein content decreased Toyo taste value, but did not affect on the growth, yield and yield components and other grain qualities.

• Applied Biological Chemistry
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• v.23 no.2
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• pp.131-139
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• 1980

TOK (2,4-Dichlolo-4'-nitrodiphenyl ether) was applied to two Korean soils possessing different physico-chemical properties at a certain concentration and incubated for a certain time under flooded conditions. The metabolites and the soil microorganisms involved in the degradation of TOK are studied. Chong Ju and Chung Ju soils treated with TOK at a concentration of 500 ppm and incubated for two, four, and six months at $30^{\circ}C$ yielded 4-chloro-4'-amino diphenyl ether, 2, 4-dichloro-4'-amino diphenyl ether(amino-TOK), N-[4'-(4-chloro-phenoxy)] phenyl acetamide, and N-[4'-(4-chloro-phenoxy)] phenyl formamide as the major metabolites. TOK underwent the reduction of nitrogroup to amino group, dechlorination, acetylation, and formylation. No cleavage at the ether linkage was recognized. TOK was more readily degraded in Chung Ju soil which is characterized by the higher pH (PH 6.43), clay loam in textural class, and the higher cation exchange capacity. The toxicity of TOK as a possible environmental contaminant is expected to be considerably reduced as a result of the above degradation Twelve strains of soil bacteria were isolated from the TOK-treated Chong Ju and Chung Ju soils. As a result of the incubation of TOK in pure cultures of the isolates, T-1-1 strain isolated from Chong Ju soil had almost no degradability, whereas T-2-3 strain turned out to be the most potent. The degradation of TOK by the isolates constituted mostly the reduction of the nitro group to amino group. The citrate buffer extract of Chung Ju soil reduced TOK more readily to amino-TOK than that of Chong Ju soil.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1126-1135
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• 2012

In order to produce high-quality fermenting composts, bacteria strains with high activities of extracellular enzymes (cellulase, chitinase, amylase, protease and lipase) were isolated from the soils in 6 provinces of Korea, and characterized by 16S rRNA gene sequence analysis and properties. The selected 7 stains inoculated to livestock manure for 2' fermenting time, and experimental treatment divided into 3 groups, B1, B2 and B3, according to microbial activity and enzyme type. Our results showed that microbe applications (B1, B2 and B3) can increase (p<0.05) both rhizomes (17-38%) and enzyme activities (50-81%) in compost after fermenting time, respectively, compared to non-microbe treatment (control). The microbe application also decreased significantly (p<0.05) the $NH_3$ and $H_2S$ gas contents 13.4 and 27.3% compared with control, and the Propionic acid and Butyric acid gas contents 14.5 and 19.6%, respectively, as compared to the control. The microbial degradation rate (%) of pesticides and heavy metals increased significantly (p<0.05) after fermenting time, respectively, as compared to the control. Especially, microbe applications were more effective in total rhizomes yields and bioactivities than non-microbe treatment. Thus the results of this study could help in development of potential bioinoculants and composting techniques that maybe suitable for crop production, and protectable for earth environment under various conditions.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.428-433
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• 1993

A strain that inhibited the growth of Pellicularia sasakii was isolated from the soil and identified as Pseudomonas aeruginosa 3120. A dark brownish antibiotic, MRL3120 isolated and purified from the culture broth of P. aeruginosa 3120 was soluble in ethylacetate, chloroform and methanol, and it was active against gram-positive and negative bacteria as well as fungi. The structure of MRL3120 was identified as a chelate compound consisting of two N-methyl-N-thioformyl-hydroxylamine and a copper ion by the analysis of UV, IR, and EI-MS spectra and other physico-chemical properties and supposed to have a structure of fluopsin C related compound. Addition of $CuSO_4$ into the fermentation medium containing soybean meal increased antifungal activity but no activity was found in the presence of EDTA (0.1%, v/v). However antibiotic MRL3120 was not produced in the fermentation medium containing soytone instead of soybean meal but it was rapidly produced by the addition of $CuSO_4$.

• Applied Biological Chemistry
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• v.43 no.1
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• pp.34-38
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• 2000

To investigate the effects of chitosan on growth and quality improvement of vegetables, we utilized cabbage as a model plant system and SL-chitosan as a chitosan fertilizer. The chitosan fertilizer treatment increased the leaf lengths of cabbage seedlings compared with those of control groups. In addition, the content of ${\gamma}-aminobutyric$ acid (GABA) in the fertilizer-treated cabbage seedlings was higher than that in the control group. Peripheral lengths and head weights of cabbages along with their GABA contents were also measured during the growth of cabbages in field. The fertilizer treatment, without changing the physico-chemical properties of main field soil after the cultivation of cabbage, significantly increased the peripheral length, average weight and GABA content compared with control treatment. These results may suggest that the quality and quantity of cabbage can be improved by chitosan treatments.