• 한국약용작물학회지
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• 제26권3호
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• pp.248-253
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• 2018

Background: Dazomet are widely used as soil fumigant to solve soilborne problems, and the degradation intermediates are toxic to nematodes, fungi, bacteria, insects and weeds. Methods and Results: The effects of cultivation of green manure crop, maize before and after soil fumigation on the control of ginseng root rot disease were compared using soil where 6-years-old ginseng was harvested. Fumigant (dazomet) were used for soil fumigation in May and September, respectively. Maize was grown for soil management before and after soil fumigation. After May fumigation, the sowing date of maize was delayed by 15 days and thus its dry weight was decreased significantly. Maize cultivation after May fumigation increased pH but decreased EC, $NO_3$, $P_2O_5$, and K significantly. Maize cultivation after May fumigation decreased fungi population and the ratio of fungi and bacteria. Growth of 2-years-old ginseng was improved and the incidence of ginseng root rot was significantly decreased by maize cultivation after May fumigation. After harvesting 2-years-old ginseng, the population of Cylindrocarpon destructans was not different between treatment of May and September, but Fusarium solani showed a significant increase in September fumigation after maize cultivation. Conclusions: Maize cultivation after soil fumigation was effective in inhibiting ginseng root rot by the amendment of mineral composition and microorganism in fumigated soil.

• 한국토양비료학회지
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• 제46권6호
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• pp.579-584
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• 2013

The study was conducted to investigate changes in the characteristics of inorganic components during fermenting process of organic liquid fertilizers according to the type and ratio of microorganism and the amount of molasses when producing organic liquid fertilizers using sesame oil cake and rice bran. To select appropriate microorganisms, liquid fertilizers were produced through a 90-day fermentation process by adding mag-ggeo-li, yogurt, dried yeast, and leaf mold. The pH in liquid fertilizer was decreased, and then increased in all microorganism samples except the mag-ggeo-li sample. The EC was rapidly increased in all samples until the $10^{th}$ days after production, and showed no changes after the $60^{th}$ days in dried yeast and after the $30^{th}$ days in the other samples. The concentration of $NH_4$-N was generally increased with time. The concentration of $P_2O_5$ was rapidly increased until the $10^{th}$ days after production and was maintained at about 1% regardless of the type of microorganism. In terms of the characteristics of liquid fertilizers according to the ratio of selected dried yeast, the pH was decreased until the $30^{th}$ days after producing the liquid fertilizers, and then was increased regardless of the ratio of dried yeast. The EC was increased with time and showed no differences depending on the amount of dried yeast. The concentration of $NH_4$-N was increased with time and in proportion to the amount of dried yeast. In terms of the characteristics of liquid fertilizers according to the ratio of molasses, the pH was decreased with increasing the molasses. The EC and concentration of $P_2O_5$ were no differences according to the amount of molasses. When 3% molasses was added, the content of $NH_4$-N was 2.6 mg $L^{-1}$ at the beginning and was at 3,025 mg $L^{-1}$ on the $90^{th}$ days.

• The Korean Journal of Ecology
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• 제24권1호
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• pp.1-7
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• 2001

침엽수림과 활엽수림의 산불지역에서 토양환경의 회복과정을 살펴보기 위해, 산불발생 후 시간이 경과함에 따른 토양화학적 성질과 토양미생물 변화를 조사하였다. 활엽수림인 삼신봉 지역 산화지에서의 산불직후 토양의 화학적 성질은 pH 5.8, 유기물량 7.42%, 전질소량 0.37%, 유효인산량 28.5 mg/kg, 치환성양이온인 $K^{＋}$이 1.3 me/100g, $Ca^{＋＋}$이 13.3 me/100g, $Mg^{＋＋}$이 2.2 me/100g로 나타났으나 시간이 경과할수록 감소하는 경향이었으며, 비산화지에서는 시간 경과에 따른 변화폭이 적었다. 침엽수림인 촛대산 산불지역에서 산불직후 토양의 화학적 성질은 pH 5.3, 유기물량 6.42%, 전질소량 0.25%, 유효인산량 24.4 mg/kg, 치환성양이온인 $K^{＋}$이 0.7 me/100g, $Ca^{＋＋}$이 3.7 me/100g, $Mg^{＋＋}$이 2.1 me/100g로 각각 나타났으며, 시간이 경과할수록 역시 감소하는 경향 이었다. 활엽수림 인 삼신봉 산불지역의 토양미생물은 호기성균 291$\times$$10^4$ CFU균, 방선균 523$\times$$10^4$ CFU균, 진균 691$\times$$10^4$ CFU균으로 진균의 개체수가 비교적 높게 나타났으며, 비산불지역에서는 호기성균 160$\times$$10^4$ CFU균, 방선균 745$\times$$10^4$ CFU균, 진균 594$\times$$10^4$ CFU균으로 방선균의 개체수가 높게 나타났다. 침엽수림인 촛대산 산불지역에서는 호기성균 350$\times$$10^4$ CFU균, 방선균 434$\times$$10^4$ CFU균, 진균 676$\times$$10^4$ CFU균으로 진균의 개체수가 비교적 높게 나타났으며, 비산불지역에서는 호기성균 328$\times$$10^4$ CFU균, 방선균 319$\times$$10^4$ CFU균, 진균 461$\times$$10^4$ CFU균으로 진균의 개체수가 높게 나타났다. 토양미생물은 호기성균, 방선균, 진균 모두 비산불지역 보다 산불지역에서 많이 나타났다. 본 조사지역에서 호기성균은 활엽수림보다 침엽수림에서 많게 나타났으며, 방선균과 진균은 침엽수림보다 활엽수림에서 많이 나타났다.

• The Plant Pathology Journal
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• 제37권6호
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• pp.596-606
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• 2021

Soil-borne diseases are the major problems in mono cropping. A mixture (designated LTM-m) composed of agricultural wastes and a beneficial microorganism Streptomyces saraceticus SS31 was used as soil amendments to evaluate its efficacy for managing Rhizoctonia solani and root knot nematode (Meloidogyne incognita). In vitro antagonistic assays revealed that SS31 spore suspensions and culture broths effectively suppressed the growth of R. solani, reduced nematode egg hatching, and increased juvenile mortality. Assays using two Petri dishes revealed that LTM-m produced volatile compounds to inhibit the growth of R. solani and cause mortality to the root knot nematode eggs and juveniles. Pot and greenhouse tests showed that application of 0.08% LTM-m could achieve a great reduction of both diseases and significantly increase plant fresh weight. Greenhouse trials revealed that application of LTM-m could change soil properties, including soil pH value, electric conductivity, and soil organic matter. Our results indicate that application of LTM-m bio-organic amendments could effectively manage soil-borne pathogens.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.162-166
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• 2004

This study investigated tile effect of ozonation on indigenous microorganisms distributed in different size fractions of soil aggregates. Soil was ozonated from 0 to 300 minutes. The treated soils were fractionated into 3 groups (small, <53 $\mu$m; medium, 53-500 $\mu$m; and large, 2000-500 $\mu$m) and total heterotrophic bacteria in the soils were enumerated. Cell number decreased rapidly within 120 minute ozonation and showed slow decrease upon longer ozonation. Abundance of total heterotrophic bacteria in each fraction was in the following order regardless of ozonation time: small>medium>large fractions. Difference in microbial abundance among the fractions was smaller as ozonation time increased.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.297-300
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• 2004

The various microbial tests were performed to determine bioremediation agent capacity for eight strains isolated from the oil contaminated regions. Two tests for isolated strains were conducted such as cell hydrophobicity and emulsifying activity. The biodegradation of SHM (saturated hydrocarbon mixture) and AHM (aromatic hydrocarbon mixture) with the strains also was carried out. The strains having higher cell hydrophobicity and emulsifying activity degraded petroleum oil effectively. The degradation capacity for SHM was represented more than 90% in YS-7 and WLH-1 of isolated strains, and KH3-2 were capable of degrading AHM. Especially, WLH-1 as yeast was shown more than two or three times in the degradation capacity of automobile engine lubricants and the biomonitoring results of contaminated soil for residual oil degrading test showed that the hydrocarbon biodegradation was increased in the second treatment by this strain.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.91-94
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• 2003

A field pilot-scale demonstration of an enhanced SVE using hot air injection and extraction was conducted to remove diesel range compounds from subsurface soils at a site in J-city, Korea. The objective of demonstration was to evaluate field ISR by intrinsic microorganism after an application study of hot air-SVE technology and to calculate each first-order kinetic with soil temperature. TPH concentration of contaminated soil at the site was approximately 2, 000~11, 000 mg/kg (average 6, 900 mg/kg) with depths greater than 5 m bgs. The 1st-order reaction rate constants, k were 0.0438(@about5$0^{\circ}C$), 0.0564(@4$0^{\circ}C$), and 0.0685(@33$^{\circ}C$) d-1 respectively.

• Journal of Microbiology and Biotechnology
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• 제22권4호
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• pp.563-566
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• 2012

To investigate the possibility of horizontal gene transfer between agricultural microorganisms and soil microorganisms in the environment, Bacillus subtilis KB producing iturin and the PGPR recombinant strain Pseudomonas fluorescens MX1 were used as model microorganisms. The soil samples of cucumber or tomato plants cultivated in pots and the greenhouse for a six month period were investigated by PCR, real-time PCR, Southern hybridization, and terminal restriction fragment length polymorphism (T-RFLP) fingerprinting. Our data from Southern blotting and T-RFLP patterns suggest that the model bacteria do not give significant impacts on the other bacteria in the pots and greenhouse during cultivation.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1996년도 경북지부 결성 및 추계학술발표회 논문집
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• pp.114-117
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• 1996

Biodegradation potential of crude oil has been studied in liquid and soil slurry culture. Studies were performed to optimize the factors affecting metabolic activity. Arabian Light(sulfur content 1%) was used as a representative crude oil and Nocardia sp. was selected as an oil degrading microorganism based on its ability to degrade and emulsify Effects of various nutritional and environmental conditions as well as emulsification and surface tension were observed. Tentative optimization of environmental and nutritional condition were as follow; pH 8, sodium nitrate as inorganic nitrogen source, yeast extract 0.05%, phosphate concentration 0.25% and glucose addition of 1.0% (w/v basis), extent of degradation to 78 %.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.673-679
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• 2004

A microbial cryoprotectant formulation using a W/O/W multiple emulsion system was developed. The psychrotolerant microorganism, B4, isolated from soil in South Korea, was observed by the drop freezing method, in which the microorganism sample inhibited ice nucleation activity. The antifreeze activity was eliminated when the microorganism sample was treated with protease, indicating that the antifreeze activity was due to the presence of antifreeze protein. The result of the l6S rDNA sequencing indicated the B4 strain was most closely related to a species of the genus Bacillus. Culture broth of B4 strain (Bacillus sp.) and rapeseed oil containing 1 % polyglycerine polyricinolate (PGPR) were used as core and wall material, respectively. The most stable W/O emulsion was prepared at a core/oil ratio of 1:2. The highest W/O/W emulsion stability was achieved when the primary emulsion to external aqueous phase containing 0.5% caster oil polyoxyethylene ether $(COG25^{TM})$ ratio was 1:1. Microcrystalline cellulose showed better W/O/W emulsion stability than other polymer types. The viability of cells in a W/O/W emulsion was higher than free cells during storage at $37^\circ{C}$. An acidic pH and UV exposure decreased the viability of free cells, but cells in W/O/W emulsion were more stable under these conditions.