• 한국토양비료학회지
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• 제48권1호
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• pp.36-43
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• 2015

Excess use of chemical fertilizer causes soil acidification and accumulation of salt, and thus might bring to desertification of soil. To overcome this problem, it needs limited usage of chemical fertilizer and increased usage of natural fertilizer as an alternative. In this study, dry soil-borne Bacillus sp. SHL-3, which was isolated from arid and barren soil, with plant growth promoting activity was isolated for identification and to determine optimal culture condition. A bacterial strain SHL-3 had the IAA productivity ($5.16{\pm}0.10mg\;L^{-1}$), ACC deaminase activity ($0.36{\pm}0.09$ at 51 hours) and siderophore synthesis. It was identified as genus Bacillus sp.. Also, optimal culture condition of SHL-3 were $20^{\circ}C$ and pH 7 in LB medium. Bacillus sp. SHL-3 had up to 4% salt tolerance in the medium. We evaluated the plant growth promotion ability of SHL-3 using yam (Dioscorea japonica Thunb.). As a result, Bacillus sp. SHL-3 was effective on the increase of the shoot length (202.4% increase for 91 days). These results indicate that Bacillus sp. SHL-3 can serve as a promising microbial resource for the biofertilizers of soil.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.888-897
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• 2009

Lipase diversity in glacier soil was assessed by culture-independent metagenomic DNA fragment screening and confirmed by cell culture experiments. A set of degenerate PCR primers specific for lipases of the hormone-sensitive lipase family was designed based on conserved motifs and used to directly PCR amplify metagenomic DNA from glacier soil. These products were used to construct a lipase fragment clone library. Among the 300 clones sequenced for the analysis, 201 clones encoding partiallipases shared 51-82% identity to known lipases in GenBank. Based on a phylogenetic analysis, five divergent clusters were established, one of which may represent a previously unidentified lipase subfamily. In the culture study, 11 lipase-producing bacteria were selectively isolated and characterized by 16S rDNA sequences. Using the above-mentioned degenerate primers, seven lipase gene fragments were cloned, but not all of them could be accounted for by the clones in the library. Two full-length lipase genes obtained by TAIL-PCR were expressed in Pichia pastoris and characterized. Both were authentic lipases with optimum temperatures of ${\le}40^{\circ}C$. Our study indicates the abundant lipase diversity in glacier soil as well as the feasibility of sequence-based screening in discovering new lipase genes from complex environmental samples.

• 한국지하수토양환경학회지:지하수토양환경
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• 제24권5호
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• pp.42-54
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• 2019

Biodegradation of an explosive compound, glyceryl trinitrate (GTN), was studied with a denitrifying microbial culture grown in a sequencing batch reactor and a GTN acclimated denitrifying culture. The GTN acclimated culture, which were fed on GTN for 1 month, degraded GTN regioselectively via denitration on C1 position as compared to C2 position denitration by denitrifying culture that has never been exposed to GTN. Accumulation of two isomeric glyceryl dinitrates (GDNs) in both culture medium suggests that GDN denitration is the rate-limiting step in GTN biodegradation. The first order GTN degradation rate normalized to cell concentration of the acclimated culture was calculated to be 0.045 (${\pm}0.002$) L/g-hr. Increasing concentration of electron acceptor(nitrate) resulted in discouraged GTN degradation. According to microbial community analysis, prolonged GTN exposure resulted in 25% increase in the genus level of the GTN acclimated culture with the disappearance of two dominating denitrifying microbial species of Methyloversatilis universalis and Hyphomicrobium zavarzinii in the denitrifying culture.

• Journal of Plant Biotechnology
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• 제30권2호
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• pp.167-172
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• 2003

Immature zygotic embryos of Eleutherococcus senticosus seeds matured rapidly within one month when the seeds comprising zygotic embryos were pieced to small size and cultured on 1/2 MS medium. Frequency of somatic embryos formation was declined rapidly when the zygotic embryos germinated and grew to plantlets. Embryogenic cells were induced by consecutive subculture of somatic embryos on MS medium with 1.0mg/L2,4-D. After heart-shaped somatic embryos were induced by suspension culture, these embryos were plated onto petri dish to support maturation of embryos. Germination of embryos occurred on medium with 5mg/L GA$_3$and transferred to culture bowl to stimulate the further growth. Frequency of soil survival of plantlets was influenced by soil mixture (perlite and peatmoss). The suitable combination of perlite and peatmoss was 1:5, and the soil survival rate was 78% after 4 months. The soil transferred plantlets were over-wintered in field condition after defoliation. New year sprouting of plants was achieved successfully and they grew to adult plants. These results indicate that the systematic procecure of plant production in E. senticosus for micro propagation.

• 한국작물학회지
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• 제46권1호
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• pp.47-52
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• 2001

In order to develop more stable seedling stand method in wet direct rice seeding culture, the effect of making the drainage ditches was studied in both methods of broadcast seeding on floody paddy surface and puddled-soil drill seeding. In a broadcast seeding on floody paddy surface, the ditching after seeding using a tractor or small ditch maker improved the seedling stand, and reduced the floating seedling and herbicide injury by accelerating the drainage. Suitable ditching time was at 2 days after seeding (DAS) for the tractor and at 3 DAS for the ditch maker. In the puddled-soil drill rice seeding culture, the ditching before seeding with a ditch maker at 3 days after draining effectively improved the seedling stand due to quick draining through well formed the seeding furrows. In the puddled-soil drill seeding, seedling stand number showed higher in both ditching plots synchronized with seeding compared with both only draining treatment at 1 DAS without ditching and the flooding plot condition for 6 DAS. And the suitable ditching depth was 6 cm, as considered the ditching status and drained status. These results suggest that the ditching in wet direct rice seeding is an resonable practice for improving the seedling stand through the accelerating drainage of field.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.337-345
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• 2005

The degradation of phenanthrene, a model PAH compound, by microorganisms either in the mixed culture or individual strain, isolated from oil-contaminated soil in oil refmery vicinity sites, was examined. The effects of pH, temperature, initial concentration of phenanthrene, and the addition of carbon sources on biodegradation potential were also investigated. Results showed that soil samples collected from four oil refinery sites in Korea had different degrees of PAH contamination and different indigenous phenanthrene-degrading microorganisms. The optimal conditions for phenanthrene biodegradation were determined to be 30$^{circ}C$ and pH 7.0. A significantly positive relationship was observed between the microbial growth and the rate of phenanthrene degradation. However, the phenanthrene biodegradation capability of the mixed culture was not related to the degree of PAH contamination in soil. In low phenanthrene concentration, the growth and biodegradation rates of the mixed cultures did not increase over those of the individual strain, especially IC10. High concentration of phenanthrene inhibited the growth of microbial strains and biodegradation of phenanthrene, but was less inhibitory on the mixed culture. Finally, when non-ionic surfactants such as Brij 30 and Brij 35 were present at the level above critical micelle concentrations (CMCs), phenanthrene degradation was completely inhibited and delayed by the addition of Triton X100 and Triton N101.

• 한국자원식물학회지
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• 제6권2호
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• pp.171-179
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• 1993

This study was conducted to investigate the effect of growth regulators and medium composition on the growth of each stage in apical meristem culture for mass propagation of Zanthoxylum piperitum var. inerme Makino. The source material, shoot tip segments were taken from three-years old graft trees. Apical meristems were cultured in vitro on basal MS, GD, WS, half strength MS(1/2MS) and half strength GD(1/2GD) media supplemented with various concentrations for growth regulators(BA, IBA) and inorganic nutrients. The results summarized are as follows: 1. In culture establishment stage, ratio of culture establishment was 96.7% and the best resuit was obtained using MS medium supplemented with 1.0mg/l BA and 0.2mg/l IBA. 2. In shoot multitication stage, both shoot multiplication and growth were achieved in average 5.6cm. These results were obtained on in MS medium supplemented with 1.0mg/l BA and 0.2mg/l IBA. 3. In roothing stage, phloroglucinol(PG) acted as IBA synergist in root initiation. The most faverable combinations for root development was half-strength MS medium supplemented with 162mg/l PG and 0.2mg/l IBA, and ratio of rooting was 58.0%. 4. In Vitro formed plantlets were transplanted to paper pots in greenhouse with 85% of relative humidity. 96% of survival rate was obtained from artificial soil mix having same volume of sand, vermiculite, peat, and soil.

• 한국환경농학회지
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• 제25권4호
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• pp.382-385
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• 2006

정수장슬러지의 수도육묘용 상토로서의 사용 가능성을 검토하기 위하여 정수장슬러지와 모래의 비율을 달리하는 상토들을 조제 후 시판용 상토를 대조로 수도유묘의 생육 및 무기성분흡수 특성을 조사하였다. 정수장슬러지 이용 상토는 시판용 상토에 비해 수도유묘 지상부의 신장 및 생중량이 다소 부진하고 인의 흡수량이 낮았던 반면, 지하부의 신장 및 생중량은 현저한 증가를 보여 정수장슬러지가 수도유묘의 뿌리발달에 탁월하고 뿌리의 매트형성이 우수하였다. 따라서 비록 정수장슬러지 이용 상토가 시판용 상토에 비해 수도유묘의 지상부 생장이 부진하고 인의 흡수가 다소 낮다 할지라도, 상토의 필수 조건인 뿌리의 매트형성이 탁월하고 단간의 지상부가 직립으로 매우 건실하며, 높은 pH에도 불구하고 입고병과 같은 병 발생이 없어 수도육묘용 상토로 이용 가능성이 높은 것으로 판단된다. 정수장슬러지 첨가에 따른 이러한 수도육묘의 뿌리생장 증가 효과는 정수장슬러지와 모래를 50:50 비율로 혼합한 상토에서 가장 우수하였다.

• 한국농공학회지
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• 제37권1호
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• pp.55-64
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• 1995

This paper presents analytic results of energy sequestered for the forcing cultural Cu- cumber and the others production system with the input-output tables method in the suthern parts of Korea. In this study an attempt is made to evaluate input of direct and indirect energy, output of yield energy and net energy in order to achieve increased energy productivity under P E greenhouse. Cultural practices were grouped soil and soilless with perlite for vegetable production. The results from this study are summarized as follows : 1. Total energy inputs in cucumber production were calculated to be 510 GJ/l0a(di- rect energy : 480 GJ/lOa, indirect energy : 30 GJ/lOa) from soil culture and 440 GJ/ 10a(direct energy : 420 GJ/lOa, indirect energy : 20 GJ/lOa) from soilless culture in perlite hydroponics. 2. Energy outputs from cucumber and biomass were 7 GJ/lOa and 120 GJ/lOa at a uniform rate respectively. 3. Heating fuel as diesel is a major energy inputs approaching 90% of the total energy requirements for cucumber production. 4. Net energy in cucumber production was calculated to be 503 GJ/lOa from soil cul- ture and 431 GJ/lOa from soilless culture. Net energy productivity was maintained costantly as 0.98. 5. Energy productivity in cucumber was calculated to be 0.029 kg/MJ from soil culture and 0.043kg/MJ from soilless culture, while energy efficiency was 0.012 and 0.015 respectively. It is expected that a soilless cultural production system seems to be reduc- tive in seguestered energy input by 13%.

• International Journal of Advanced Culture Technology
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• 제3권1호
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• pp.78-85
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• 2015

In Thailand, the electricity consumption is very high with the intention of reduce high temperature in the building. Since 2000, a lot of people paying attention to Green-Building concept. A similar concept is natural building, which is usually on a smaller scale and tends to focus on the use of natural materials that are available locally. Therefore, the Earth-Block (EAB) product is appropriated approach to reduce energy consumption in the buildings. The EAB is produced with environmentally friendly process, which does not release harmful pollution and effective cost. The main significant character is durable materials for building construction. This study aims to develop the new thermal insulation by using soil-cement with vetiver grass fibre. Additionally, it describes the innovative systems used in production of EAB materials by mixing the soil-cement with vetiver grass fibre. This paper reveals lowest costs, space configurations changing and greater design flexibility for constructing the building.