• 한국균학회지
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• 제46권1호
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• pp.83-90
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• 2018

Podosphaera fusca에 의한 멜론 흰가루병은 우리나라에서 멜론의 심각한 식물병 중의 하나이다. 본 연구에서는 선발한 길항세균의 다양한 식물병원균에 대한 균사 생육 억제 및 메론 흰가루병 방제에 대한 효과를 평가하였다. 16S rDNA 및 gyrA 유전자의 염기서열을 바탕으로 선발한 길항세균 Bacillus sp. M09, M70 및 M99-1을 동정한 결과 B. velezensis로 동정되었다. B. velezensis M09, M70 및 M99-1는 다양한 식물병원균에 47~69%의 균사생육 억제 효과를 보였을뿐만 아니라 흰가루병균의 발생을 현저히 감소시켰다. 본 연구에서 선발한 3균주는 멜론 흰가루병뿐만 아니라 다양한 식물병에 대한 잠재적인 생물방제제로 활용될 수 있을 것으로 생각되었다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.87.2-87
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• 2003

Long-term repeated culturing of biocontrol agents on a certain medium often results in reduced biocontrol efficacy and altered physiology. Effect of culturing media on biocontrol ability and physiological state of Burkholderia gladioli strain B543 was investigated. Over 20 times repeated cultivation of B. giadioli strain B543 on Kings B medium or nutrient agar medium showed improved biological control of cucumber damping-off caused by Pythium ultimum, while one time cultivation on KB or NA did not. The repeated cultivation also induced the physiological changes of the biocontrol agent such as antifungal activity and the production of protease and siderophore. Our result indicates that adaptation to proper culturing medium can alter biocontrol ability and must consider in optimizing the use of biocontrol agents.

• 한국식물병리학회지
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• 제11권4호
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• pp.287-291
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• 1995

Biocontrol agents, Gliocladium virens G872B and Pseudomonas putida Pf3, were compatible each other in colonizing cucumber rhizosphere, which contributed to a long-term inhibition of cucumber Fusarium wilt. G872B colonized successfully on the cucumber root system, irrespective of the introduction of Pf3. Pf3 also colonized well in the cucumber rhizosphere regardless of the presence of G872B. The individual strains effectively suppressed cucumber wilt up to 56 days after transplanting. The combined treatment of G872fB and Pf3 provided a long-term protection of about 80 days with the efficacy greater than that obtained by any individual strains under greenhouse conditions. These results suggest that the colonization of the biological control agents in the rhizosphere could be correlated directly to Fusarium wilt-suppressive potentials.

• 대한화학회지
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• 제47권1호
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• pp.47-58
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• 2003

알킬화제로 작용할 수 있는 naphthoquinones인 fibrostatin이 Streptomyces catanulae subsp. griseospora 배양액으로부터 추출되었다. 이들 quinone 화합물의 합성은 이 화합물들의 생물학적 반응성 연구에 매우 중요하다. 본 논문에서는 효과적으로 치환체들의 위치를 조절할 수 있는 방법인 Hooker oxidation을 이용하여 fibrostatin B를 합성하였다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제3권2호
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• pp.133-137
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• 2003

Various bioinformatics tools for biological data processing have been developed and most of them are available in public. Most bioinformatics works are carried out by a composite application of those tools. Several integration approaches have been proposed for easy use of the tools. This paper proposes a new multi agent system to integrate bioinformatics tools in the perspective of workflow since the composite applications of tools can be regarded as workflows. For the easy integration, the proposed system employs wrapper agents for existing tools, uses XML-based messages in the inter-agent communication, and agents are supposed to extract necessary information from the received messages. This allows new tools to be easily added on the integration framework. The proposed method allows various control structures in workflow definition and provides the progress monitoring capability of the on-going workflows. In particular, agents in this system have the rule-based architecture which allows the defined rule set to be a special role agent. This feature provides fast and flexible agent development to aid in managing the complexity of bioinformatics application. This system has been partially implemented and has been proven to be a viable implementation for workflow-based bioinformatics tool integration.

• The Plant Pathology Journal
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• 제20권1호
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• pp.63-66
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• 2004

Ginseng (Panax ginseng) is one of the most widely cultivated medicinal herbs in Korea. However, yield losses reached up to 30-60％ due to various diseases during 3 or 5 years of ginseng cultivation in the country. Therefore, successful production of ginseng roots depends primarily on the control of diseases. The objective of this study was to select potential biocontrol agents from rhizobacteria isolated from various plant internal root tissues for the control of multiple ginseng diseases as an alternative to fungicides. Among 106 Bacillus strains, two promising biocontrol agents, Bacillus pumilus strain B1141 and Paenibacillus lentimobus strain B1146, were selected by screening against root rot of ginseng caused by Cylindrocarpon destructans in a greenhouse. Pre-inoculation of selected isolates to seed or l-year-old root of ginseng resulted in stimulation of shoot and/or root growth of seedlings, and successfully controlled root rot caused by C. destructans (P<0.05). Furthermore, drenching of cell suspension of the selected isolates on seedling-growing pots reduced the incidence of Phytophthora blight after the seedlings were challenged with zoospores of Phytophthora cactorum (P<0.05). P. lentimorbus strain B1146 showed antifungal activity against various soil-borne pathogens in vitro, while B. pumilus strain B1141 did not show any. Results of this study suggest that some rhizobacteria can induce resistance against various plant diseases on ginseng.

• 한국유기농업학회지
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• 제5권1호
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• pp.137-147
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• 1996

For the purpose of acquiring microbial agents that can be utilized to biologically control the major airborne diseases to apple trees, such as canker(Botryosphaeria dothidea), bitter rot(Glomerella cingulata), alternaria leaf spot(Alternaria mali), root rot(rosellinia necatrix), canker(Valsa ceratosperma) and gray mold rot(Botrytis cinerea), the effective microorgaisms were isolated, tested for antagonistic activity to the pathogens causing major diseases to apple trees and identifed. Screening of more than 5,000 species of microorganisms collected in nature for them antagonistic action to the pathogens causing 5 major diseases to apple trees resulted in selection of effective species. Out of the 11 species, one species designated as CAP134 demonstrated outstanding activity. The bacterial strain, CAP134 exerted antagonistic efficiency of 57% on an isolated strain and 40% on a donated strain of Botryosphaeria dothidea., 52% on an isolated strain and 46% on a purchased strain of Alternaria mali, 60% on Valsa ceratosperma 25% on Glomerella cingulata, and 64% Rosellinia necatrix. The CAP134 was identified as a bacterial strain to Bacillus subtilis ATCC 6633 based on morephology, culture conditions, and physio-biochemical characteristics.

• The Plant Pathology Journal
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• 제32권3호
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• pp.251-259
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• 2016

The present study investigated the suppression of the disease development of anthracnose caused by Colletotrichum gloeosporioides and C. acutatum in harvested apples using an antagonistic rhizobacterium Paenibacillus polymyxa APEC128 (APEC128). Out of 30 bacterial isolates from apple rhizosphere screened for antagonistic activity, the most effective strain was APEC128 as inferred from the size of the inhibition zone. This strain showed a greater growth in brain-heart infusion (BHI) broth compared to other growth media. There was a reduction in anthracnose symptoms caused by the two fungal pathogens in harvested apples after their treatment with APEC128 in comparison with non-treated control. This effect is explained by the increased production of protease and amylase by APEC128, which might have inhibited mycelial growth. In apples treated with different APEC128 suspensions, the disease caused by C. gloeosporioides and C. acutatum was greatly suppressed (by 83.6% and 79%, respectively) in treatments with the concentration of $1{\times}10^8$ colony forming units (cfu)/ml compared to other lower dosages, suggesting that the suppression of anthracnose development on harvested apples is dose-dependent. These results indicated that APEC128 is one of the promising agents in the biocontrol of apple anthracnose, which might help to increase the shelf-life of apple fruit during the post-harvest period.

• 식물병연구
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• 제23권2호
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• pp.89-98
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• 2017

Ralstonia solanacearum species complex (RSSC) causes bacterial wilt, and it is one of the most important soil-borne plant pathogenic bacteria. RSSC has a large host range of more than 50 botanical families, which represent more than 200 plant species, including tomato. It is difficult to control bacterial wilt due to following reasons: the bacterial wilt pathogen can grow inside the plant tissue, and it can also survive in soil for a long period; moreover, it has a wide host range and biological diversity. In most previous studies, scientists have focused on developing biological control agents, such as antagonistic microorganisms and botanical materials. However, biocontrol attempts are not successful. Plant-derived metabolites and extracts have been promising candidates to environmentally friendly control bacterial wilt diseases. Therefore, we review the plant extracts, essential oils, and secondary metabolites that show potent in vivo antibacterial activities (in potted plants or in field) against tomato bacterial wilt, which is caused by RSSC.

• Journal of Ginseng Research
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• 제43권3호
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• pp.408-420
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• 2019

Background: Ginseng (Panax ginseng Meyer) is an invaluable medicinal plant containing various bioactive metabolites (e.g., ginsenosides). Owing to its long cultivation period, ginseng is vulnerable to various biotic constraints. Biological control using endophytes is an important alternative to chemical control. Methods: In this study, endophytic Trichoderma citrinoviride PG87, isolated from mountain-cultivated ginseng, was evaluated for biocontrol activity against six major ginseng pathogens. T. citrinoviride exhibited antagonistic activity with mycoparasitism against all ginseng pathogens, with high endo-1,4-${\beta}$-D-glucanase activity. Results: T. citrinoviride inoculation significantly reduced the disease symptoms caused by Botrytis cinerea and Cylindrocarpon destructans and induced ginsenoside biosynthesis in ginseng plants. T. citrinoviride was formulated as dustable powder and granules. The formulated agents also exhibited significant biocontrol activity and induced ginsenosides production in the controlled environment and mountain area. Conclusion: Our results revealed that T. citrinoviride has great potential as a biological control agent and elicitor of ginsenoside production.