• 농약과학회지
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• 제17권4호
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• pp.371-378
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• 2013

토양에 서식하는 다양한 미생물 중에서 식물 근권에 서식하는 미생물들은 식물과 상호작용하며 독특한 군집을 형성한다고 알려져 있다. 본 연구에서는 비료 연용 논토양과 무비 논토양에서 재배된 벼(Oryza sativa L.)의 근권으로부터 배양적 접근을 통해 다양한 방선균을 분리하여 항균활성을 조사하였다. 방선균의 선택적 배양을 위해서 4종류의 선택 배지를 이용하였고, 전체 152균주를 분리할 수 있었다. 분리된 균주들의 분류를 위해서 16S rRNA 유전자의 염기서열을 결정하여 표준균주와의 상동성을 비교하였다. 모든 균주들이 기존에 보고된 표준균주들과 99.0~100.0%의 높은 상동성을 나타내었으며, Dactylosporangium, Micromonospora, Kitasatospora, Promicromonospora, Streptomyces, Streptosporangium 등의 6개 속(genus)로 분류되었다. 그 중 Streptomyces 속에 포함되는 균주가 143균주 (94%)로 가장 많았다. 항균활성을 조사한 결과 대다수의 분리 균주들이 식물병원균에 항균성을 나타내는 것을 확인할 수 있었다. 특히 벼 도열병균(Magnaporthe oryzae)에 우수한 항균활성을 보였다. 이와 같은 연구 결과는, 벼의 근권이 다양한 방선균을 분리할 수 있는 우수한 분리원이며, 분리된 방선균에서 다양한 생리활성 물질을 생산할 수 있음을 제시하여 준다. 또한 추후 연구를 통해 친환경 농업을 위한 유용한 미생물 제제로 활용할 수 있을 것으로 기대한다.

• 한국균학회지
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• 제13권4호
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• pp.195-201
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• 1985

전(全) 세균(細菌)과 균류(菌類)는 금산(錦山)의 재작(再作) 이병포(罹病圃) 토양(土壤)에 많이 분포(分布)하였고 반면(反面) 방선균(放線菌)의 수(數)는 괴산(塊山)의 초작건삼포(初作健蔘圃) 토양(土壤)에 많이 분포(分布)하였다. 재료(材料) 토양(土壤)을 여러가지 식물질(植物質)로 개량처리(改良處理) 후에 토양중(土壤中)의 미생물(微生物) 수(數)의 변동(變動)을 조사한 결과, 괴산(塊山) 지역(地域)의 토양(土壤)을 제외하고 다른 토양(土壤)에서는 세균(細菌)의 수(數)가 감소(減少)하였고, 반대로 균수(菌數)는 2개(個) 지역(地域) 토양(土壤)에서 양파와 감자줄기를 처리한 토양조건(土壤條件)에 수(數)가 증가(增加)하였다. 또한 개량(改良) 처리(處理)한 토양(土壤)에서 일반적으로 균류(菌類)가 증가하였다. 세균(細菌)과 균수(菌數)는 이병(罹病) 재작지(再作地)에서 일반적으로 증가(增加)하였다. 균(菌)의 포자(胞子) 발아(發芽)는 미생물(微生物)의 분포수(分布數)가 많을수록 낮아졌다. A. panax는 자연토양조건(自然土壤條件)에서 포자(胞子) 발아(發芽)가 적게 영향을 받았으나, Fusarium속(屬)은 영향을 받았다. 자연(自然) 토양(土壤)은 4가지 균(菌)의 포자(胞子) 발아력(發芽力)에 대해 정균현상(靜菌現象)을 나타내었다.

• 한국토양비료학회지
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• 제46권6호
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• pp.474-481
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• 2013

Understanding the microbial community structure of agricultural soils is important for better soil management in order to improve soil quality. Phospholipid fatty acid analysis has been popularly used in determining the microbial community structure in different ecosystems. The microbial community structure of paddy soil under long-term fertilizer treatments was investigated after 45 years using PLFA analysis. Treatments were control (no fertilization, Con), compost (COM), NPK, NPK+compost (NPKC), PK, NK, and NP. Soil chemical properties were mainly affected by the addition of compost and inorganic P fertilizer. Total nitrogen and organic matter contents were significantly higher in treatments with compost while available $P_2O_5$ and exchangeable calcium were significantly higher in treatments with added inorganic P fertilizer. It was found that microbial communities were responsive to the different fertilizer treatments. PLFA results showed that the soils were dominated by gram-negative bacteria, followed by the actinomycetes, then gram-positive bacteria, and fungi. Principal component analysis of the soil chemical properties and PLFA composition proved to be a more reliable tool because it was more responsive to the changes in soil chemical properties.

• Journal of Plant Biotechnology
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• 제44권2호
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• pp.156-163
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• 2017

A greenhouse experiment was conducted for evaluation of ecological effects of transgenic melon plants in the rhizospheric soil in terms of soil properties, enzyme activities and microbial communities. Organic matter content of soil under transgenic melon plants was significantly higher than that of soil with non-transgenic melon plants. Significant variations were observed in organic matter, total P and K in soil cultivation with transgenic melon plants. There were also significant variations in the total numbers of colony forming units of fungi, actinomycetes and bacteria between soils treated with transgenic and non-transgenic melon plants. Transgenic and non-transgenic melon significantly enhanced several enzymes activities including urease, acid phosphatase, alkalin phosphatase, arysulphtase, ${\beta}$ glucosidase, dehydrogenase, protease and catalase. Soil polyphenoloxidase activity of $T_1$ transgenic melon was lower than that of $T_0$ transgenic melon and a non-melon plant during the same period. The first generation transgenic melon plants ($T_0$) showed significantly greater (p<0.05) effect on the activitiy of arylsulfatase, which increased from $2.540{\times}10^6CFU\;g^{-1}$ (control) to $19.860{\times}10^6CFU\;g^{-1}$ ($T_0$). These results clearly indicated that transgenic melon might change microbial communities, enzyme activities and soil chemical properties.

• 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.

• 한국토양비료학회지
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• 제46권3호
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• pp.182-186
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• 2013

In this study, we examined the chemical properties and microbial community characteristics in 25 controlled horticultural soils (CHS) sampled from Gyeongnam Province by fatty acid methyl ester (FAME) method. The electrical conductivity of watermelon CHS was significantly (p < 0.05) higher than those of red pepper CHS, pumpkin CHS, and strawberry CHS. The amounts of total FAMEs, total bacteria, gram-negative bacteria, gram-positive bacteria, and fungi were significantly (p < 0.05) higher in red pepper CHS than those in strawberry CHS and pumpkin CHS. In addition, higher (p < 0.05) ratios of cy19:0 to $18:1{\omega}7c$ were detected in tomato CHS than those in watermelon CHS, pumpkin CHS, and red pepper CHS. This implied that microbial communities of tomato CHS were stressed more than other species of cultivation soils. Actinomycetes community in red pepper CHS was significantly (p < 0.05) higher than those in tomato CHS, strawberry CHS, and watermelon CHS. Differences in soil microbial community composition were highly associated with cultivated crop species which might result from the management inputs such as fertilizer, herbicide, and irrigation.

• 한국토양비료학회지
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• 제36권3호
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• pp.127-133
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• 2003

토양미생물의 생태적 특성을 평가하기 위해 화강암, 석회암 및 현무암을 모재로 한 12개의 토양통의 미생물적 특성을 조사하였다. 토양미생물상은 토양화학성과 유의한 상관관계를 보였는데, 특히 토양 pH는 형광성 슈도모나스와, 토양 EC는 방선균, 사상균, 중온성 Bacillus 및 호알카리성균과 정의 관계를 보였다. 포자형성균인 Bacillus는 화강암과 현무암에 비해 석회암토양에서 높은 균수를 보였으나, 그람음성균은 모암간에 비슷한 수준을 유지하였다. 화강암유래 토양에서는 Burkholderia, Pseudomonas, Ralstonia가, 석회암토양에서는 Pseudomonas, Burkholderia, Phyllobacterium가, 현무암토양에서는 Burkholderia속이 우점적으로 분포하고 있었다.

• 한국토양비료학회지
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• 제44권3호
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• pp.492-497
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• 2011

경남지역 과수원 토양 25개소를 대상으로 2010년에 미생물 군집을 분석하고 토성, 지형 및 작물별 주요 변동요인을 주성분 분석으로 해석하였다. 경남지역 과수원 토양 평균값은 총 FAME 함량이 $332nmol\;g^{-1}$이었으며 총 세균 함량은 $94nmol\;g^{-1}$, 그람음성 세균 함량은 $46nmol\;g^{-1}$, 그람양성 세균은 $42nmol\;g^{-1}$, 방선균 함량은 $4.8nmol\;g^{-1}$, 곰팡이 함량은 $54nmol\;g^{-1}$, 내생균근균 함량은 $9.1nmol\;g^{-1}$ 이었다. 미생물의 환경스트레스 지수인 토양 cy19:0과 18:$1{\omega}7c$ 비율은 사양토에서 0.36으로 양토 0.80 보다 유의적으로 낮아 (p<0.05) 토양 미생물의 스트레스가 적었다. 과수원 토양 평균 미생물은 총 세균이 28.1%, 곰팡이 15.9%, 그람음성 세균은 13.6%, 그람양성 세균은 12.5%, 내생균근균 2.8%, 방선균 1.4%의 비율을 나타냈다. 복숭아 재배지의 토양 그람음성 세균 군집은 15.2%로서 배 재배지 12.8%에 비해 유의적으로 높은 비율을 나타냈다 (p<0.05). 주성분 분석결과 지형, 토성, 작물별 유의적인 차이가 없었으며 토양 미생물 군집의 다양성을 관리하기 위해 지속적인 모니터링이 필요할 것으로 생각된다.

• The Plant Pathology Journal
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• 제21권3호
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• pp.244-251
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• 2005

The induction of growth promotion on numerous crops by rhizobacteria is a well documented phenomenon. In case of tomato (Lycopersicon esculentum), fruit yield is higher in replant soil than that in fresh soil. To investigate what kind of rhizobacterium is involved, microbial community in rhizosphere and on rhizoplane of tomato plants from each soil was analyzed by dilution plating on selective media. Many Gram-negative bacteria and actinomycetes were isolated from tomato in replant soil. One Gram-negative rhizobacterium isolated was identified as Pseudomonas putida based on its biochemical characteristics, fatty acid methyl ester analysis and 16S rDNA sequence. This bacterium designated strain 17 inhibited the growth of Pseudomonas corrugata, and increased growth of tomato seedlings. In addition, its culture filtrate inhibited conidial germination of plant-pathogenic fungi such as Fusarium oxysporum f. sp. radicis-lycopersici, F. oxysporum f. sp. cucumerinum, and Nectria radicicola. Scanning electron microscopy revealed strain 17 colonized and persisted on the epidermal surfaces of tomato radicles and roots. These results suggest that P. putida strain 17 may serve as a biological control agent to suppress multiple soil-borne diseases for tomato plants. Increased microbial populations that suppress deleterious microorganisms including pathogens could be one of the major factors in increased tomato yield in replant soil.

• 한국토양비료학회지
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• 제8권3호
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• pp.113-119
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• 1975

Volcanic Ash Soils are widely distributed in Jeju island, and constitute the important upland soils which are either presently being cultivated or are suitable for reclaiming. The characteristics of Volcanic Ash Soils according to data made available by previous studies in Jeju and the outside of the country are as following: The most conspicuous mineralogical property is the presence of amorphous mineral colloids. The colloids have large and highly reactive surface to which the common physical and chemical properties are related. Soils are low in bulk density and higher both in porosity and permeability. Accumulation of humus in the upper part of soil is found in great quantity. Cation exchange capacity is high mainly due to high humus content, but the absorbing intensity of ammonium and potassium is weaker than that of crystalline clays. The phosphate absorption coefficient is extremely high and deficiency of minor element may occur both crops and animals. Soils are densely populated with actinomycetes and anaerobic bacteria. Nitrification and activity of urease are distinctly stronger than that of non-Volcanic Ash Soils.