• Journal of Soil and Groundwater Environment
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• v.20 no.3
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• pp.15-24
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• 2015

The soil ecosystem is a complex system performing particularly complicated and varied functions, such as providing a habitat for organisms, acting as a medium for plant cultivation and growth, and functioning as a buffer against external materials in the environment. To assess whether these important functions of the soil ecosystem are executed appropriately, the concept of soil ecosystem health has been introduced, which is defined as the ability to perform the specific functions of the soil ecosystem. Understanding soil properties and soil indicators related to soil functions is essential to assess the soil health. In this study, systems, the indicators, and evaluation factors for assessing soil ecosystem health employed in a number of countries were investigated and discussed. In particular, it is necessary to introduce a technique for the evaluation of soil ecosystem health in Korea and to develop techniques and indicators appropriate to the soil ecosystem and status in Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1286-1290
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• 2004

This study was carried out to screen yeasts effective in reducing odor from pig feces. Three isolates from soil and compost sources were selected to treat pig feces. On the basis of morphological and biochemical characteristics, one isolate from compost was Candida rugosa, and two isolates from soil were Candida rugosa and Candida maris. These isolates showed deodorizing activity by reducing the concentration of ${NH}_3$ and R-${NH}_2$. Volatile fatty acids (VFA) are the specific malodorous compounds of pig feces, and the Candida maris from soil showed a 100% reduction of butyric, iso-butyric, and iso-valeric acid in 10% pig slurry medium. However, the Candida rugosa from compost showed a 100% reduction of butyric and iso-butyric acid while that from soil showed a 100% reduction of propionic, butyric acid and iso-valeric acid in the medium. Also, these yeasts were effective in reducing $NH_{4}-N$, soluble-N, and biological oxygen demand (BOD).

• Land and Housing Review
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• v.1 no.1
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• pp.59-65
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• 2010

The paper presents a comparison between a semi-implicit time integration linear finite element implementation and fully-implicit nonlinear Newton-Raphson finite element implementation of a triphasic small strain mixture formulation of an elastic partially saturated porous medium. The pore air phase pressure pa is assumed atmospheric, i.e., $p_a$ = 0, although the formulation and implementation are general to handle increase in pore air pressure as a result of loading, if needed. The solid skeleton phase is assumed linear isotropic elastic and partially saturated 'consolidation' in the presence of surface infiltration and traction is simulated. The verification of the implementation against an analytical solution for partially saturated pore water flow (no deformation) and comparison between the two implementations is presented and the important of the porosity-dependent nature of the partially saturated permeability is assessed on comparison with a commercial code for the partially saturated flow with deformation. As a result, the response of partially saturated permeability subjected to the porosity influences on the saturation of a soil, and the different behaviors of the partially saturated soil between staggered and monolithic coupled programs is worth of attention because the negative pore water pressure in the partially saturated soil depends on the difference.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.456-460
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• 2016

Biofertilizers are increasingly available in the market as one of the alternatives to chemical fertilizers. The supply of a high number of viable microorganisms is important for farmers. Lysobacter capsici YS1215 producing chitinases and gelatinases, isolated from soil in Korea, was evaluated for the establishment of an optimal medium condition of its shelf life under an in vitro condition. In this study, the population density of a biofertilizer (L. capsici YS1215) in media containing crab shell and gelatin powder (M1, M2, M3 and M4) was observed to be higher than that of populations grown in TSB (Tryptic soy broth) media (M5, M6 and M7) during experimental period. In addition, the population density at 11 months was over $10^6\;CFU\;mL^{-1}$ in M1, M3 and M4, but under $10^6\;CFU\;mL^{-1}$ in M2, M5, M6 and M7. The best optimal medium for the shelf life was M1 ($2.6{\times}10^6\;CFU\;mL^{-1}$) containing both chitinous and gelatinous materials at 11 months. Therefore, this study provided results of the appropriate medium composition for the enhancement of the shelf life of L. capsici YS1215.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.6
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• pp.389-393
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• 2013

The purpose of this study is to investigate the biodegradation characteristics of the xylene by BTEX-degrading bacteria, Pseudomonas putida BJ10, isolated from oil-contaminated soil and bio-degradation pathway of the xylene. The removal efficiencies of o, m, p-xylene in mineral salts medium (MSM) by P. putida BJ10 were 94, 90 and 98%, respectively for 24 hours. It shows clear difference compared with the control groups which were below 3%. The removal efficiencies of BTEX by P. putida BJ10 in gasoline-contaminated soil were 66% for 9 days. They were clearly distinguished from the control groups (control and sterilized soil) which were 32 and 8%. 3-methylcatechol and o-toluic acid were detected after 6 and 24 hours during the o-xylene biodegradation pathway. Therefore, we confirmed o-toluic acid as the final metabolite. And intermediate-products were somewhat different with previously published studies of the transformation pathway from o-xylene to 3-methylcatechol.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.447-453
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• 1999

Salt accumulation is one of themajor problems in soils under protected cultivation . Since protected cultivation does not have rainfall or excessive irrigation, salt accumulaiton inthe soils is inevitable. In this study, characteristics of salt accumulation in soil column were ivestigated, and a salt-extracting method was tested to see its effectiveness. The results showed that the concentration of salt in top soil layers increased and electrical conductivity as thesalt concentration decreased especially in the top soil layer .When extraction medium was applied.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.69-76
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• 1999

Because of the limited land in Korea most of the projects require large-scale reclamation. The hydraulic-filled soil deposits are usually loose and susceptible to be liquified during earthquake. The dynamic deformation characteristics which expressed by shear modulus and damping ratio are important to analyze the earthquake ground motion. In this paper resonant column tests were performed on five hydraulic filled soil in Korea and the deformational characteristics at both small and medium strains were investigated. The coefficients in the Hardin equation to predict the representative maximum shear modulus and modulus reduction cure are also proposed.

• Korean Journal of Plant Tissue Culture
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• v.21 no.4
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• pp.233-237
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• 1994

Plant regeneration system via somatic embryogenesis in leaf explant cultures of Gentiana scabra var. buergeri has been established. Leaf segments formed calli when cultured on MS medium supplemented with 0.5 mg/L 2,4-D and 2 mg/L BAP After transferred to SH medium supplemented with 0.5 mg/L 2,4-D, 2 mg/L CPA and 0.5 mg/L kinetin, the callus became embryogenic. The embryogenic callus was subcultured every 3 to 4 weeks. Upon transfer onto SH basal medium the embryogenic callus gave rise to numerous somatic embryos, which subsequently developed into plantlets. The regenerated plants were potted in an artificial soil with mixture (peatmoss : pearlite : vermiculite : 2 : 1 : 1) and transplanted to the soil after kept under a high humidity for two weeks. A total of 78 plants out of 105 regenerated plants survived in the soil. Phenotypic variations in height, number of stems and the flowering time were observed in tile regenerated plants. Cytogenetical analyses showed no chromosomal variation.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.454-461
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• 2017

This study was conducted to investigate the optimal conditions for spore germination, prothallus propagation, sporophyte formation, and seedling growth in Polystichum braunii (Spenn.) $F{\acute{e}}e$. The rate of spore germination and early prothalium development was high in Knop (41.2%), which had low mineral content. The optimal medium for prothallus propagation and sexual organ formation was 2MS medium (2% sucrose). Among the various mixtures of cultivation soil (bedding soil, peat moss, perlite, and decomposed granite), a mixture of bedding soil and decomposed granite at a ratio of 2:1 (v:v) had a positive effect on sporophyte formation (276.3 ea/$7.5m^2$). The most efficient conditions for promoting the growth of sporophytes were pots filled with only bedding soil.

• Journal of Microbiology and Biotechnology
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• v.28 no.7
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• pp.1156-1167
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• 2018

The aim of this study was to isolate and characterize lead (Pb)-solubilizing bacteria from heavy metal-contaminated mine soils and to evaluate their inoculation effects on the growth and Pb absorption of Brassica juncea. The isolates were also evaluated for their plant growth-promoting characteristics as well as heavy metal and salt tolerance. A total of 171 Pb-tolerant isolates were identified, of which only 15 bacterial strains were able to produce clear haloes in solid medium containing PbO or $PbCO_3$, indicating Pb solubilization. All of these 15 strains were also able to dissolve the Pb minerals in a liquid medium, which was accompanied by significant decreases in pH values of the medium. Based on 16S rRNA gene sequence analysis, the Pb-solubilizing strains belonged to genera Bacillus, Paenibacillus, Brevibacterium, and Staphylococcus. A majority of the Pb-solubilizing strains were able to produce indole acetic acid and siderophores to different extents. Two of the Pb-solubilizing isolates were able to solubilize inorganic phosphate as well. Some of the strains displayed tolerance to different heavy metals and to salt stress and were able to grow in a wide pH range. Inoculation with two selected Pb-solubilizing and plant growth-promoting strains, (i.e., Brevibacterium frigoritolerans YSP40 and Bacillus paralicheniformis YSP151) and their consortium enhanced the growth and Pb uptake of B. juncea plants grown in a metal-contaminated soil. The bacterial strains isolated in this study are promising candidates to develop novel microbe-assisted phytoremediation strategies for metal-contaminated soils.