• 한국유기농업학회지
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• 제12권4호
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• pp.427-436
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• 2004

This study was conducted to investigate the effect of microbial product on microorganisms in soil and the growth of leaf lettuce. The test material were treated with chitosan, wood vinegar and EM activity liquid, and treatment concentration was 50 times solution and 100 times solution level with foliar application. The results were summarized as follows : Among foliar application of microorganisms treatments diluted by chitosan 100 times solution level was effective considering growth of leaf lettuce as compared other dilutions and control plot. Change of microorganism number in the soil for cultivation of chinese cabbages and leaf lettuce was increased with microorganism treatment plot as compared with control plot. Specially chitosan 100 times solution level showes the most significant effect.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.28-30
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• 2005

Because of high population diversity in soil microbial communities, it is difficult to accurately assess the capability of biodegradation of toxicant by microbes in soil and sediment. Identifying biodegradative microorganisms is an important step in designing and analyzing soil bioremediation. To remove non-important noise information, it is necessary to selectively enrich genomes of biodegradative microorganisms fromnon-biodegradative populations. For this purpose, a stable isotope probing (SIP) technique was applied in selectively harvesting the genomes of biphenyl-utilizing bacteria from soil microbial communities. Since many biphenyl-using microorganisms are responsible for aerobic PCB degradation In soil and sediments, biphenyl-utilizing bacteria were chosen as the target organisms. In soil microcosms, 13C-biphenyl was added as a selective carbon source for biphenyl users, According to $13C-CO_2$ analysis by GC-MS, 13C-biphenyl mineralization was detected after a 7-day of incubation. The heavy portion of DNA(13C-DNA) was separated from the light portion of DNA (12C-DNA) using equilibrium density gradient ultracentrifuge. Bacterial community structure in the 13C-DNAsample was analyzed by t-RFLP (terminal restriction fragment length polymorphism) method. The t-RFLP result demonstates that the use of SIP efficiently and selectively enriched the genomes of biphenyl degrading bacteria from non-degradative microbes. Furthermore, the bacterial diversity of biphenyl degrading populations was small enough for environmental genomes tools (metagenomics and DNA microarrays) to be used to detect functional (biphenyl degradation) genes from soil microbial communities, which may provide a significant progress in assessing microbial capability of PCB bioremediation in soil and groundwater.

• 한국연초학회지
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• 제21권2호
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• pp.136-143
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• 1999

This study was conducted to evaluate the degradation characteristics of waste cigarette filters under 0, 5, 10, and 15cm in depth from soil surface by environmental conditions. Weather was the most important factor during degradation of waste cigarette filters in this study. Bulking of cellulose acetate filaments exposed on soil surface was observed after 2 months, but the form of filter was kept up after 12 months. The treated cigarette filters in soil landfill revealed a little different degradation pattern at each soil landfill depth, The sample in 5cm depth of soil was more degraded then other site. A fluffy appearance of cellulose acetate filaments in the control filter rods was also developed more strongly in soil landfill then on soil surface. From the observation of waste cigarette filters by scanning electron microscopy, much degradation of the fiber of waste cigarette filters could be ascertained in soil landfill. The weight of waste cigarette filters under 5cm from soil surface was reduced about 50%, and the tensile strength of the samples in soil surface and under 5cm from soil surface were reduced 66.0% and 92.4%, respectively. The microbial experiment date that the viable cell number in microbial population and cellulolytic microorganisms showed the maximum values under 5cm from soil surface, suggest that microorganisms in soil play an important roll in the degradation of acetate cigarette filters.

• Journal of Microbiology and Biotechnology
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• 제31권1호
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• pp.104-114
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• 2021

Petroleum-contaminated soil is considered among the most important potential anthropogenic atmospheric methane sources. Additionally, various rhizoremediation factors can affect methane emissions by altering soil ecosystem carbon cycles. Nonetheless, greenhouse gas emissions from soil have not been given due importance as a potentially relevant parameter in rhizoremediation techniques. Therefore, in this study we sought to investigate the effects of different plant and soil amendments on both remediation efficiencies and methane emission characteristics in diesel-contaminated soil. An indoor pot experiment consisting of three plant treatments (control, maize, tall fescue) and two soil amendments (chemical nutrient, compost) was performed for 95 days. Total petroleum hydrocarbon (TPH) removal efficiency, dehydrogenase activity, and alkB (i.e., an alkane compound-degrading enzyme) gene abundance were the highest in the tall fescue and maize soil system amended with compost. Compost addition enhanced both the overall remediation efficiencies, as well as pmoA (i.e., a methane-oxidizing enzyme) gene abundance in soils. Moreover, the potential methane emission of diesel-contaminated soil was relatively low when maize was introduced to the soil system. After microbial community analysis, various TPH-degrading microorganisms (Nocardioides, Marinobacter, Immitisolibacter, Acinetobacter, Kocuria, Mycobacterium, Pseudomonas, Alcanivorax) and methane-oxidizing microorganisms (Methylocapsa, Methylosarcina) were observed in the rhizosphere soil. The effects of major rhizoremediation factors on soil remediation efficiency and greenhouse gas emissions discussed herein are expected to contribute to the development of sustainable biological remediation technologies in response to global climate change.

• 한국유기농업학회지
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• 제21권4호
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• pp.647-657
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• 2013

시설재배지 토양에 녹비작물의 재배가 Biomass-C와 토양 양분의 변화에 미치는 영향을 평가하고자 pot(${\phi}$10-cm)에 헤어리벳치, 호밀, 발랭이를 70일간 재배 후 식물체와 토양을 분리하여 분석한 결과가 다음과 같다. 녹비작물의 생육량은 호밀이 가장 많았으며, 질수흡수량은 헤어리벳치가 가장 높게 나타났다. 호밀 재배구가 토양의 인산함량은 가장 낮았으며, biomass C는 가장 높게 나타났다. 시험 후 토양의 질소함량과 식물체 질소 흡수량은 고도의 부의 상관을 보였다. T-N 함량은 헤어리벳치 시험구에서는 증가하였지만, 호밀과 바랭이 재배구에서는 감소하는 경향을 보였다. 이상의 결과를 요약해볼 때 시설재배지에서 가장 중요한 것이 토양의 염류집적(EC) 인데 시험 후 토양에서 대조구에 비해서 콩과인 헤어리벳치는 EC가 약간 증가했고 다른 무기성분은 큰 변화가 없으며, 화본과인 호밀은 EC와 다른 무기성분도 약간 감소하는 경향으로 시설연작재배지에서는 화본과 작물이 염류집적 경감을 위해서 유리하다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1998년도 한국생물과학협회 학술발표대회
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• pp.167.1-167
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• 1998

No Abstract, See Full Text

• The Plant Pathology Journal
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• 제18권1호
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• pp.30-35
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• 2002

The hyphal growth and biocontrol efficacy of Trichodemo harzianum in soil may depend on its interactions with biotic components of the soil environment. The effect of soil microbial biomass on growth and biocontrol efficacy of T. hanianum isolate ThzIDl-M3 (green fluorescent protein transformant) was investigated using artificially prepared different levels of soil microbial biomass (153,328, or 517ug biomass carbon per g of dry soil; BC). The hyphal growth of T. harzanum was significantly inhibited in the soil with 328 or 517 $\mu$g BC compared with 153 ug BC. When ThzIDl-M3 was added to the soils as an alginate pellet formulation, the recoverable population of ThzIDl-M3 varied, but the highest population occurred in 517ug BC. Addition of alginate pellets of ThzIDl-M3 to the soils (10 per 50 g) resulted in increased indigenous microbial populations (total fungi, bacterial fluorescent Pseudomonas app., and actinomycetes). Furthermore, colonizing ability of ThzIDl-M3 on sclerotia of Sclerotinia sclerotiorum was significantly reduced in the soil with high revel of BC. These results suggest that increased soil microbial biomass contributes to increased interactions between introduced T. harzianum and soil microorganisms, consequently reducing the biocontrol efficacy of 1T. harzianum.

• 한국유기농업학회지
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• 제6권1호
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• pp.133-149
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• 1997

Recently, the importance of management and cultivation of grasses has been increased in Korea. Among these cultural practices, the appropriate control of diseases is considered more important than other cultivation techniques such as fertilization and irrigation. The damages of brown patch and large patch caused by Rhizoctonia spp. and Pythium blight caused by Pythium spp. are serious in the major cultivation area of turfgrass in Korea. Since these diseases are difficult to control by agrochemicals, the damages are very serious if these are occured. The periodic spray of agrochemicals, to protect and control these diseases could make some problems of toxicity and environmental pollution as well as rising of non-target diseases. Therefore, the biological methods to control diseases have been required to decrease problems resulted from overuse of agrochemicals, to conserve natural ecosystem, and to control effectively diseases of grasses in the long period. The number of studies about biological control using antagonistic microorganisms have been increased for last half century. However, the application of biological control method has been very limited. In this study, thirteen isolates of R. cerealis, 8 isolates of R. solani and 3 isolates of Phthyn spp. have been isolated from diseased turfgrass in golf course and grass-culture area that have patch and wilting symptoms of zoysia grass and creeping bentgrass. Isolation frequency of R. cerealis and R. solani was high in especially zoysiagrass, while Pythym spp. was isolated from bent grass at low frequency but showed high pathogenicity. Totally, 205 isolates of soil microorganisms were isolated in this study as primary antagonistic microorganism by Herr's triple agar layer plate and dual culture method using rhizosphere of grasses, soil of crop field as the source of antagonistic microorganisms. Among the 205 isolates, 23 isolates were actinomycetes and 182 isolates were bacteria. All of the actinomycetes were isolated by Herr's method. Antagonistic effect of primary isolated microorganisms was tested for in vitro mycelial growth inhibition against pathogenic fungi isolated from grasses and for inhibition of disease occurrence in 24 well tissue culture plate and pot experiment. Then, four isolated of bacteria which are BG23, BG74, BG136 and BG171 were selected as antagonistic microorganisms against soil-born pathogenic fungi of bentgrass.

• 한국유기농업학회지
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• 제8권3호
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• pp.131-146
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• 2000

화학비료와 농약의 대용으로 가축분의 발효퇴비 및 미생물 발효퇴비를 시용하여 토양의 이화학적 성질 변화와 배추의 생육 및 체내 성분변화을 알아보기 위하여 본 시험을 수행하였던바 결과는 다음과 같다. 1. 유기농 자재를 시용한 토양의 화학적 성질을 보면 pH 및 유기물함량은 화학비료 처리구에서는 거의 변화가 없었던 반면 발효퇴비 및 미생물 발효퇴비 처리구에서는 약간 증가하였고, 인산, 칼슘 및 칼리 성분은 발효퇴비 및 미생물 발효퇴비 처리구에서 화학비료 처리구보다 증가하였으며, 특히 계분+미생물 발효퇴비 처리구에서 가장 높았다. 2. 유기농 자재를 시용한 토양의 미생물상의 변화는 화학비료 처리구에서는 세균 및 방선균수는 거의 일정한 경향을 보였고 사상균수는 약간 감소하는 경향을 보인 반면 발효퇴비 및 미생물 발효퇴비 처리구에서는 세균, 방선균 및 사상균수가 모두 증가하는 경향을 보였으며, 특히 미생물 발효퇴비 처리구에서는 세균수가 상당히 증가하였다. 3, 유기농 자재의 시용에 따른 배추의 생육은 화학비료 처리구> 미생물 발효퇴비 처리구> 발효퇴비 처리구순으로 높았고, 체내 NO$_3$$^{-}$ 함량은 내엽보다 외엽에서 많았고, 처리간에는 화학비료 처리구에서 내.외엽 모두 가장 많았으며, 미생물 발효퇴비 처리구에서 다소 적었다. 4. 유기농 자재의 시용에 따른 배추의 체내성분은 처리간 뚜렷한 차이는 나타나지 않았다.

• 한국토양비료학회지
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• 제45권2호
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• pp.169-176
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• 2012

Among the major nutrients, phosphorus is by far the least mobile and available to plants in most soil conditions. A large portion of soluble inorganic phosphate applied to soil in the form of phosphate fertilizers is immobilized rapidly and becomes unavailable to plants. To improve the plant growth and yield and to minimize P loss from soils, the ability of a few soil microorganisms converting insoluble forms into soluble forms for phosphorus is an important trait in several plant growth-promoting microorganisms belonging to the genera Bacillus and Pseudomonas and the fungi belonging to the genera Penicillium and Aspergillus in managing soil phosphorus. The principal mechanism of solubilization of mineral phosphate by phosphate solubilizing bacteria (PSB) is the release of low molecular weight organic acids such as formic, acetic, propionic, lactic, glycolic, fumaric, and succinic acids and acidic phosphatases like phytase synthesized by soil microorganisms in soil. Hydroxyl and carboxyl groups from the organic acids can chelate the cations bound to phosphate, thereby converting it into soluble forms.