• 제목/요약/키워드: Biological agent

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Development of biological agent seeded on fine sand for control of brown patch and Pythium blight disease on golf course grasses.

  • Hur, Jae-Seoun;Lim, Kwang-Mi;Oh, Soon-Ok;Yum, Kyu-Jin;Koh, Young-Jin
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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    • pp.88.1-88
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    • 2003
  • Antogonistic bacteria against Rhizoctonia solani and Pythium spp., causing serious damage to golf course grasses, were isolated from the top soil of several golf courses in Korea. The isolate of Limk0102 was selected as the biological agent by characterization of antifungal activity, large scale preparation, fungicides tolerance and ecological fitness to the targe environment. The isolate was identified as Bacillus subtilis by biochemical and physiological characterization, and 165 rDNA sequence analysis. The bacterial agent was formulated as a granule type by seeding it on fine sand. The formulated agent showed high recovery rate (more than 10$\^$8/ cells/g sand) even after 6 month-storage at room temperature with similar antifungal activity with that of original cells. In vitro, the biological agent successfully exhibited antagonistic performance on bentgrass inoculated with R. solani or Pythium spp. isolated from the diseased grasses on golf courses. Field evaluation on disease control activity and ecological fitness of the agent is now under going on several golf courses.

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알코올중독의 약물치료 (Pharmacological Treatment of Alcoholism)

  • 성상경
    • 생물정신의학
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    • 제6권1호
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    • pp.41-48
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    • 1999
  • This review focused on the pharmacological treatment of alcoholism, especially alcoholism-related mental disorder. The pharmacological agent for alcoholism can be divided into the following categories : anticraving agent, aversive agent, agent to treat acute alcohol withdrawal, agent to diminish drinking by treating associated psychiatric pathology, agent to induce sobriety in intoxicated individuals. Following trends are included in new trends of pharmacological treatment of alcoholism. What are precise conditions amenable to pharmacological intervention? ; How can psychosocial and behavioral intervention be integrated with pharmacotherapy to enhance treatment outcome? ; Is the concept of "matching" specific pharmacotherapy treatment to different aspect of alcoholism more efficacious than a more generalized medicational approach to treatment? One of the most important factors for alcoholics treatment is good and proper therapeutic relationship with patients and setting up individually specialized treatment program is also important.

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Lactobacillus acidophilus가 생산한 항균물질(抗菌物質)에 관한 연구(硏究) (Studies on antimicrobial agent produced by lactobacillus acidophilus)

  • 김동신
    • 대한수의학회지
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    • 제24권2호
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    • pp.149-162
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    • 1984
  • The research was conducted(1) to confirm the agent(s) responsible for the antimicrobial activity contained in the fermented tomato juice with L. acidophilus(2) to extract and purify the antimicrobial agent(s)(3) to find the biological, physical and chemical properties of the agent(s). The following results were obtained and summarized as followings; 1. The agent responsible for the inhibitory activity was confirmed by both well assay method using fermented tomato juice with L. acidophilus and turbidimetric technique using the cell-free filtrate or neutralized filtrate of tomato acidohilus culture and found exerted antimicrobial agent other than lactic acid. 2. The procedures of purification : The isolation and purification of antimicrobial agent from the lyophilized acidophilus tomato culture were carried out by (1) methanol extraction (2) acetone extraction, (3) Sephadex G-50 gel filtration (4) paper chromatography and (5) thin layer chromatography. 3. The biological, physical and chemical properties of antimicrobial agent: The biological, physical, chemical properties of the purified antimicrobial agent were: (1) The antimicrobial activity was strong against test organisms; Bacillus subtilis(ATCC 6633), Escheichia coli(ATCC 25922), Staphylococcus aureus(ATCC 167), Pseudomonas fluorescens(KFCC 32394), Proteus vulgaris and Shigella dysenteriae. (2) The pH value of the agent was 2.0 and the inhibitory activity was lost when it was neutralized at 7.0 of pH and the agent was heat stable at $121^{\circ}C$ for 60 minutes. (3) The ultraviolet light absorption spectra of methanol-acetone extract and TLC fraction exhibited a maximum absorption at 260nm and 224nm respectively. (4) The most purified agent from TLC plate increased about 130-fold in activity. (5) The agent isolated from TLC plate was free from $H_2O_2$ or lactic acid. 4. Bioautographic assy: By means of bioautography of the agent on silica gel of TLC plate a strong inhibitory activity against B. subtilis was demonstrated. 5. Mass spectrometry: The agent obtained from TLC plate was analyzed by mass spectrometry which show the parent peak at m/e 264 suggesting the molecular weight of the compound and molecular group such as [$C_2H{^+}_4$], [CO], [CH=NH], [$C_3{H^}4_7$], [$\begin{array}{rcl}O\\{\parallel}\\CH_3-C\\\end{array}$], [$C_6-H{^+}_{11}$], [$C_5H{^+}_{11}$], [$\begin{array}{rcl}O\\{\parallel}\\C_5H_7-C^+\\\end{array}$] were suggested.

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Biological control of Colletotrichum panacicola on Panax ginseng by Bacillus subtilis HK-CSM-1

  • Ryu, Hojin;Park, Hoon;Suh, Dong-Sang;Jung, Gun Ho;Park, Kyungseok;Lee, Byung Dae
    • Journal of Ginseng Research
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    • 제38권3호
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    • pp.215-219
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    • 2014
  • Background: Biological control of plant pathogens using benign or beneficial microorganisms as antagonistic agents is currently considered to be an important component of integrated pest management in agricultural crops. In this study, we evaluated the potential of Bacillus subtilis strain HK-CSM-1 as a biological control agent against Colletotrichum panacicola. Methods: The potential of B. subtilis HK-CSM-1 as a biological control agent for ginseng anthracnose was assessed. C. panacicola was inoculated to ginseng plants and the incidence and severity of disease was assessed to examine the efficacy of the bacterium as a biological control against C. panacicola. Results: Inoculation of Panax ginseng plants with B. subtilis significantly suppressed the number of disease lesions of C. panacicola and was as effective as the chemical fungicide iminoctadine tris(albesilate). The antifungal activity of B. subtilis against C. panacicola was observed on a co-culture medium. Interestingly, treatment with B. subtilis did not significantly affect the diameter of the lesions, suggesting that the mechanism of protection was through the reduction in the incidence of infection related to the initial events of the infection cycle, including penetration and infection via spore germination and appressorium formation rather than by the inhibition of invasive growth after infection. Conclusion: Our results suggest that B. subtilis HK-CSM-1 can be used as an effective and ecologically friendly biological control agent for anthracnose in P. ginseng.

The Atom of Evolution

  • Bhak, Jonghwa;Bolser, Dan;Park, Daeui;Cho, Yoobok;Yoo, Kiesuk;Lee, Semin;Gong, SungSam;Jang, Insoo;Park, Changbum;Huston, Maryana;Choi, Hwanho
    • Genomics & Informatics
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    • 제2권4호
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    • pp.167-173
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    • 2004
  • The main mechanism of evolution is that biological entities change, are selected, and reproduce. We propose a different concept in terms of the main agent or atom of evolution: in the biological world, not an individual object, but its interactive network is the fundamental unit of evolution. The interaction network is composed of interaction pairs of information objects that have order information. This indicates a paradigm shift from 3D biological objects to an abstract network of information entities as the primary agent of evolution. It forces us to change our views about how organisms evolve and therefore the methods we use to analyze evolution.

분열형 효모인 Schizosaccharomyces pombe 로부터 rqh1 돌연변이의 DNA damaging agent sensitivity를 보상하는 유전자의 특성 연구 (Isolation and Characterization of DNA Damaging Agent Sensitivity of rqh1 mutant from Schizosaccharomyce pombe)

  • 이인혜;최인순
    • 생명과학회지
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    • 제17권1호
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    • pp.39-44
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    • 2007
  • 분열형 효모에서 Rqh1은 Top3과 함께 vegetative growth에 필수적이다. $rqh^-$ 돌연변이는 DNA damaging agent에 민감성을 보이는데 이때, 부적절한 유전자 발현, 세포 신장, 염색체의 불안전성, 비정상적인 다중격막, 발아의 결핍을 포함한 넓은 범위의 표현형을 보인다. rqh1-overexpression cell 역시 rqh1 deletion mutant에서 보이는 DNA damaging agent 민감성을 관찰할 수 있다. 논문은 nmtl promoter를 가지는 PREP vector에 Rqhl이 과발현 할 때 나타나는 DNA damaging agent 민감성를 보상하는 유전자를 찾아 $rqh1^+$의 기능을 알아보는 것이다. 여기서 보상능이 보이는 rqh156, rqh172 두 개의 돌연변이를 골라냈다. rqhl deletion mutant의 DNA damaging agent 민감성은 rqh156, rqh172의 발현에 의해 보상 되어지는 것을 확인하였다.

Characteristics of Microbial Biosurfactant as an Antifungal Agent Against Plant Pathogenic Fungus

  • YOO DAL-SOO;LEE BAEK-SEOK;KIM EUN-KI
    • Journal of Microbiology and Biotechnology
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    • 제15권6호
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    • pp.1164-1169
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    • 2005
  • Characteristics of sophorolipid and rhamnolipid were evaluated as antifungal agents against plant pathogenic fungi. Eight percent of mycelial growth of plant pathogen (Phytophthora sp. and Pythium sp.) was inhibited by 200 mg/l of rhamnolipid or 500 mg/l of sophorolipid, and zoospore motility of Phytophthora sp. decreased by $90\%$ at 50 mg/l of rhamnolipid and $80\%$ at 100 mg/l of sophorolipid. The effective concentrations for zoospore lysis were two times higher than those of zoospore motility inhibition. The highest zoospore lysis was observed with Phytophthora capsici; $80\%$ lysis at 100 mg/I of di-rhamnolipid or lactonic sophorolipid, showing the dependency of structure on the lysis. In the pot test, the damping-off disease incidence ratio decreased to $42\%\;and\;33\%$ of control value at 2,000 mg/l sophorolipid and rhamnolipid, respectively. These results showed the potential of microbial glycolipid biosurfactants as an effective antifungal agent against damping-off plant pathogens.

Enhancing the Biological Control of Rice Seedling Disease by Adding Specific Carbon Sources into the Bacillus cereus D324 Formulation in Water-Seeded Rice

  • Sim, Jung-Bo;Chung, Ill-Min;Ku, Han-Mo;Choi, Hyoi-Won;Lee, Jong-Moon;Chun, Se-Chul
    • The Plant Pathology Journal
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    • 제24권1호
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    • pp.58-62
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    • 2008
  • Utilization of carbon sources by Bacillus cereus D324, a biological control agent, and Pythium species, which causes rice seedling disease, was studied with the objective of increasing the efficacy of biological control by providing the biological control agent with specific beneficial carbon sources. D-galactose, D-sorbitol, and D-mannitol were poor carbon sources for Pythium spp. growth but were good for B. cereus D324 growth. Growth in a growth chamber of rice seeds coated with B. cereus D324 amended with specific carbon sources, such as D-galactose and D-sorbitol, showed significantly enhanced seedling emergence compared to seeds coated only with B. cereus D324. Field trials showed that both seedling emergence and yield increased, when the above specific carbon sources were added to B. cereus D324 in seed coating formulations. This result indicated that amending seed coating formulations with specific carbon sources could significantly increase seedling emergence and yield in the field.

에어로졸 시험장비를 이용한 방호 의복 소재의 여과 효율에 대한 연구 (The Experimental Study of SPM(Selectively Permeable Membrane Materials) by using Aerosol Test Instrument)

  • 권태근;서현관;김진원;강재성;강기태;안강호;최진수;조재호;권용택;박현배
    • 한국입자에어로졸학회지
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    • 제10권3호
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    • pp.109-117
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    • 2014
  • In Korea, permeable protection clothes for chemical agent is being developed and distributed. But permeable protection clothes are vulnerable for biological agent of particle type. Therefore selective permeable membranes are being developed to protect chemical agent and biological agent simultaneously. In this study, aerosol collection efficiency test was performed to validate the protection performance of permeable clothes and selective permeable membranes. Aerosol collection efficiency test was performed by using the aerosol test equipment that could test aerosol particle diameter from $0.005{\mu}m$ to $3.0{\mu}m$. This study shows the test method and performance test results for collection efficiency by using the aerosol test equipment.