• Korean Journal of Microbiology
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• v.43 no.4
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• pp.273-278
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• 2007

As a model compound of PAHs (polycyclic aromatic hydrocarbons) phenanthrene has been regarded as a toxic material, mutagen and carcinogen in various animals. Biodegradation conditions of phenanthrene such as pH, temperature, shaking speed, stabilizer and cofactor of degrading enzymes were investigated with Trametes versicolor and its transformant T. versicolor MrP1 in YMG medium, minimal medium and soil microcosm. T. versicolor MrP1 can overexpress mrp gene encoding Mn-repressed peroxidase that is involved in fungal degradation. Biodegradations of phenanthrene by T. versicolor and T. versicolor MrP1 were optimally performed in conditions of weak-acid (pH 6.0), $30^{\circ}C$, shaken culture and medium containing 5 mM veratryl alcohol or tryptophan. In these optimal conditions, biodegradation of phenanthrene by T. versicolor MrP1 is 31% higher than that of wild type strain in a minimal medium for 20 days. Biodegradation of phenanthrene by T. versicolor MrP1 was also higher than that of wild type in soil microcosm. T. versicolor MrP1 can be a excellent candidate for the bioremediation of PAHs contaminated environments.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.3
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• pp.1-17
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• 1999

The purpose of this study is to evaluate the creation techniques of artificial wetland, one of biotopes developed to promote biodiversity in urban areas, and to look for improvement steps. Specifically, artificial wetland creation techniques were categorized into living environment and living creature classification. Being living conditions for creations, habitat environment was reviewed with a focus on water and soil environments. Living creatures were classified into plants, insects, fish, and birds. The evaluation of creation techniques was done in post-construction evaluation while considering the creation of habitats for living creatures. Intervention by users, changes in living environment and living species, and relevance of creation techniques were reviewed. Key results of this study are as follows. (1) Water environment for the living environment of creatures provides a suitable environment conditions for the living of creatures through a process easing the use of piped water. Various water depths and embankment appear to have a positive impact on the living of aquatic life. In particular, embankment covered in soil naturally played an important role as a place for the activities of aquatic insects and young fish as well as the growth of aquatic plants. (2) Various aquatic and ground plants to promote insect-diversity, shallow water, and old-tree logs had contributed greatly in increasing the types and number of insects. Aquatic insects. Aquatic insects were seen much particularly in areas where aquatic plants are rich but water is shallow than any other areas. (3) A space piled with stone to provide habitats for fish was not much used. However, it was observed that fish used embankment built with natural stones and embankment using logs in areas where water is deep. In addition, it was confirmed that 1,500 fish that had been released propagated using various depths and places for birth. (4) It was analyzed that techniques (creation of island, log setting, and creation of man-made bird nests) to provide habitats and to attract birds are not serving their roles. In such a case, it is believed that species had not increased due to the smallness as well as isolated features of the area. Based on theoretical review, they are judged to be areas that are likely to be used when a greater variety of birds is introduced. It is judged that attracting and keeping more birds at the site, such spaces need to be linked systematically in the future in terms of building eco-network while ensuring an adequate living areas. (5) In the study areas, users intervened greatly. As a result, a blockage was created preventing the normal growth of plants and non-indigenous plants were introduced. In order to limit the intervention by users, setting enough buffer zones, and environment education programs were urgently required. D/H=1>Hyangkyo> houses on the river>temples>lecture halls. D/H ratio of the backside areas is as follows. D/H=1>Hyangkyo>houses on the river>lecture halls. 4. Inner garden were planted deciduous than evergreen trees with Lagerstroemia indica. Enclosed dominant trees were planted by Pinus densiflora, Querces seuata. construct GEM strain, and examined for the expression and functional stability in microcosms.

• Korean journal of applied entomology
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• v.35 no.3
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• pp.221-227
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• 1996

Four strains of Beauveria bassiana F101, F587, F9 and FJ8, were received from Forestry Research Institute,Seoul. The strain, B. bassiana F101, was the most active in the enzymatic activity and spore production. Whenspores of B. bassiana FlOl were sprayed on the female larva of the black tipped sawfly with various concentrationsof 6 xl 0'~-10s~p ores/ml, insects started to die from 5-7 days, and were covered with mycelia andspores in 24-28 days at 25"C, while the insect did not show visible symptoms even after 50 days at 4'C. Theinsect injected with 5 pl of spore solution (3X l0'~-10s~p oreslml) died within 30-98 and 38-218 hours at25$^{\circ}$C and 4"C, respectively. About 3 days (60 hours) after the injection with a concentration of 3 x lo9 spores1ml, at the point of the insect's death, lots of proteins started to disappear '||'&'||' the hemolymph, fat body and carcaseat 25'C. Esterase activity in the tissues was gone suddenly after that time. Six days after the spray, manyprotein and esterase bands were lost in the hemolymph, but not those in the fat body and carcase. When thefungi growing in the host were exposed in the air, they put energy for spore production, while numerous longand thin mycelia branched out from the host body in the soil.e host body in the soil.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.2
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• pp.138-145
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• 1989

Little information is available on the effects of low pH on nodulation and growth of subterranean clover cultivars. Plants of 11 cultivars were inoculated with an acid-tolerant strain of Rhizobium trifolii and grown for 28 days in continuously flowing nitrogen-free nutrient solutions maintained at six constant pH values from 4.0 to 6.5. At pH 4.0, 4 cultivars failed to nodulate and the remainder formed only a few nodules; nodulation was delayed by 2 to 3 days in this treatment. All cultivars nodulated at pH 4.5 but, with the exception of cv. Dwalganup, nodule numbers were significantly less than at $pH{\geq}5.0$. Only in cvv. Clare and Woogenellup were nodule numbers significantly greater at pH 6.5 than at 5.0. Whole plant dry matter yields were strongly depressed at pH 4.0(21 to 33% of maximum). At pH 4.5, relative yields of all cultivars except Dwalganup were significantly depressed without significant reductions in nodule dry weights, suggesting that nodule function was inhibited by acidity. These results are consistent with the view that nodulation and growth of plants dependent on symbiotic nitrogen fixation are much more sensitive to low pH per se than is host plant growth in the presence of adequate mineral nitrogen.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.77-88
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• 1992

Effective strains of cowpea bradyrhizobia JB7 $nal^rspe^r$ and CB756 $str^rrif^r$, antibiotic-resistant variants of JB7 and CB756, respectively, were used to examine changes of rhizosphere populations and nodule occupancy. Populations of each strain increased gradually in the rhizosphere, reaching a maximum of about $10^8$ cells per root system. Nodule number increased as the density of inoculum increased from $10^2$ cells to $10^8$ cells per seed. Inoculation with liquid suspension resulted in the formation of more nodules than the peat slurry or granule inoculation. When JB7 $nal^rspe^r$ and CB756 $str^rrif^r$ were introduced in equal numbers in inoculum mixtures the former consistantly occupied the majority of nodules with all three groundnut cultivars used. There was no difference in yield between nitrogen treatments and inocultation treatments.

• Research in Plant Disease
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• v.19 no.1
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• pp.21-24
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• 2013

White rot caused by Sclerotium cepivorum was reported to be severe soil-born disease on garlic. Disease progress of white rot of garlic (Allium sativum L.) was investigated during the growing season of 2009 to 2011 at Taean and Seosan areas. The white rot disease on bulb began to occur from late April and peaked in late May. The antifungal bacteria, Burkholderia pyrrocinia CAB08106-4 was tested in field bioassay for suppression of white rot disease. As a result of the nucleotide sequence of the gene 16S rRNA, CAB008106-4 strain used in this study has been identified as B. pyrrocinia. B. pyrrocinia CAB080106-4 isolate suppressed the white rot with 69.6% control efficacy in field test. These results suggested that B. pyrrocinia CAB08106-4 isolate could be an effective biological control agent against white rot of garlic.

• International Journal of Highway Engineering
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• v.8 no.2 s.28
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• pp.1-12
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• 2006

An existing Steel pipe, Cast iron pipe and Concrete pipe is can not escaped from aging, specially Metal tube is causing many problems that the quality of water worse is concerned about many rust and mike efficient use of preservation of water. The use of Glassfiber Reinforced Plastic Pipe(GRP PIPE) should be one of the possible scheme to get over these problems. The GRP PIPE has an excellent resistance power and the life is lasting from 50 to 100 years roughly. It's to be useful as a result of high durability and a good construction work also it is a light weight therefore can be expected to short the time of construction and man power. In this research, to executed the small-scaled model test, in-situ model test using CLSM of in-situ soil and to evaluated the stress - strain of the pipe also try to estimated how useful is. From the model test in laboratory, the vertical and horizontal deformation of the GRP PIPE measured in six instance using 200mm and 300mm in diameters. The value of experimentation, theory, analysis got the same results of the test, but the vertical and horizontal deformation gauged in small and the earth pressure was almost zero using CLSM of in-situ soil..

• Korean Journal of Environmental Biology
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• v.27 no.2
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• pp.198-204
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• 2009

From leaf mold and reclamation site soil of the Capital area of Korea, 3 poly(butylene succinate-co-butylene adipate: PBSA)-degrading strains were isolated through the clear zone test. The PBSA-degrading activities of the strains were assessed by means of a modified Sturm test using 0.01% of PBSA film as a sole carbon source. After the modified Sturm tests for 40 days at the respective isolation temperatures, the 3 strains degraded 30%, 55% and 43% of PBSA, respectively. The isolated strains were identified to be Burkholderia cepacia PBSA-4, Bacillus licheniformisPBSA-5 and Burkholderia sp. PBSA-6 through the 16S rDNA gene sequence analysis. Among them, PBSA-5 degraded both PBSA and Poly(vinyl alcohol). The degradation activity of the PBSA degrading strains appeared to be high at moderate temperatures such as $27^{\circ}C$ and $37^{\circ}C$, and initial inoculum size of $10^{10}cfu\;mL^{-1}$ degraded PBSA 1.2~1.3 more times than that $10^9cfu\;mL^{-1}$. Addition of 0.1 or 0.5% (w/w) of gelatin, yeast extract and ammonium sulfate raised the PBSA degrading activity, and especially addition of 0.1% (w/w) of gelatin enhanced the PBSA degrading activity by more than 33%. The mixed strains degraded PBSA faster than the single strain.

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.377-383
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• 1992

Seven strains of Bacillus thuringiensis were isolated from soil in Korea and characterized. The isolates were named HL-8, 10, 12, 13, 14, 15 and 16 which produced parasporal crystals and endospores in their cells. The biochemical characteristics of the seven isolates were only minor different in specific chracteristics to the known serotypes of Bacillus thuringiensis. The number of the plasmid DNA elements from the isolates were studied. The computerized molecular weights of the six plasmid elements in the HL-8 and HL-lO strains were from 3.01 to 15.1 Md, four plasmid elements in the HL-12 were from 5.4 to 21.9 Md, four plasmid elements in HL-13 were from 5.1 to 20 Md, three plasmid elements in HL-15 were from 3.4 to 11.3 Md and three plasmid elements in the HL-16 were from 2.4 to 20.1 Md. The seven isolates showed resistances to ampicillin, bacitracin, cephalothin, methicillin and penicillin G. The strains of HL-8, HL-lO, HL12, HL-14, HL-15 and HL-16 showed lethalities against Culex pipiens 3rd instar larvae. The HL8 and 14 strains showed 100% lethality to the larvae within 48 hours. HL-13 strain did not have toxicity against the larvae.

• Journal of the Korean Geotechnical Society
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• v.31 no.3
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• pp.51-62
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• 2015

Shear behavior obtained by direct shear tests is dependent on shear box and boundary condition. The objective of this study is to analyze problems of conventional direct shear test (type-A) and provide the reliable results by developing type-C direct shear apparatus. Experimental tests are carried out for Ulleung sand by using type-A and -C direct shear devices. The soil specimens, which are prepared at the relative density of 60%, and are applied to vertical confining stresses of 50, 100, 200, 300, and 400 kPa, are sheared at a constant shear strain rate of 0.5 mm/min. By comparing the results obtained by type-A and -C direct shear apparatus under constant normal load (CNL) condition, the performance of new one is verified. In addition, two constrained conditions including constant normal load (CNL) and constant pressure (CP) are applied to type-C one. Experimental results show that type-A direct shear apparatus has some problems such as rotating of loading plate and upper shear box, and the frictional forces between soil and inner wall of upper shear box. Thus, the shear strengths obtained by type-A device are overestimated or underestimated depending on shear box and boundary condition. On the other hand, type-C device produces clear and consistent test results regardless of constrained conditions. This study represents that type-C direct shear apparatus not only can solve the problems of type-A direct shear apparatus but provide the reliable results.