• Title/Summary/Keyword: antagonistic effects

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In Vitro Antagonistic Effects of Bacilli Isolates against Four Soilborne Plant Pathogenic Fungi

  • Kim, Wan-Gyu;Weon, Hang-Yeon;Lee, Sang-Yeob
    • The Plant Pathology Journal
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    • v.24 no.1
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    • pp.52-57
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    • 2008
  • Twenty isolates of Bacillus spp. obtained from livestock manure composts and cotton-waste composts were tested for in vitro antagonistic effects against soilborne plant pathogenic fungi, Fusarium oxysporum, Phytophthora capsici, Rhizoctonia solani AG-4, and Sclerotinia sclerotiorum. Seven isolates of Bacillus spp. had antagonistic effects on mycelial growth of all the isolates of F. oxysporum tested. The bacterial isolate RM43 was the most effective to inhibit the mycelial growth of the fungal isolates. Twelve isolates of Bacillus spp. had antagonistic effects on mycelial growth of all the isolates of P. capsici tested. The bacterial isolates M34 and M47 were very effective to inhibit the mycelial growth of the fungal isolates. Thirteen isolates of Bacillus spp. had antagonistic effects on mycelial growth of all the isolates of R. solani AG-4 tested. The bacterial isolates M27 and M75 were very effective to inhibit the mycelial growth of the fungal isolates. Fourteen isolates of Bacillus sp. had antagonistic effects on mycelial growth of all the isolates of S. sclerotiorum tested. The bacterial isolates M49 and M75 were very effective to inhibit the mycelial growth of the fungal isolates. The antagonistic effects of most Bacillus spp. isolates against the isolates of the four fungi differed depending on the fungal species and the isolates of each fungus. The bacterial isolates M27 and M75 were the most effective to inhibit the mycelial growth of all four fungi.

In Vitro Antagonistic Characteristics of Bacilli Isolates against Trichoderma spp. and Three Species of Mushrooms

  • Kim, Wan-Gyu;Weon, Hang-Yeon;Seok, Soon-Ja;Lee, Kang-Hyo
    • Mycobiology
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    • v.36 no.4
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    • pp.266-269
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    • 2008
  • Twenty isolates of Bacillus species obtained from livestock manure composts and cotton-waste composts were tested for their antagonistic effects in vitro against three green mold pathogens of mushrooms (Trichoderma harzianum, T. koningii, and T. viridescens). However, there exists a possibility Bacillus species may have antagonistic effects against mushrooms themselves, and thus the same 20 isolates were tested in vitro against three species of mushrooms (Flammulina velutipes, Lentinus edodes, and Pleurotus ostreatus). Of the 20 Bacillus species isolates tested, two inhibited mycelial growth of T. harzianum, seven that of T. koningii, and eight that of T. viridescens. Importantly, the bacterial isolates M27 and RM29 strongly inhibited mycelial growth of all the Trichoderma spp. isolates tested. The isolate M27 was subsequently identified as the most effective in inhibiting mycelial growth of all the Trichoderma species. Interesting results of the effect Bacillus isolates had upon the mushroom species followed. It was found that most Bacillus isolates except 5T33 at least somewhat inhibited mycelial growth of the three mushroom species or some of the mushrooms. Furhermore, the antagonistic effects of the bacterial isolates against the three species of mushrooms varied depending on the mushroom species, suggesting a role for mushroom type in the mechanism of inhibition. The bacterial isolates M27 and RM29 were identified as having the most antagonistic activity, inhibiting mycelial growth of all the Trichoderma spp. as well as mycelial growth of the three species of mushrooms. These results suggest that the bacterial isolates and their antagonistic effects on green mold pathogens should be further studied for their practical use for biological control of green mold in the growing room of the mushrooms.

Effects of Antagonistic Rhizobacteria on the Biological Control of Gray Mold in Greenhouse Grown Strawberry Plants (길항성 근원 세균이 딸기 시설재배에서 발생하는 잿빛곰팡이병의 생물학적 제어에 미치는 영향)

  • Cho, Jung-Il;Cho, Ja-Yong;Yang, Seung-Yul
    • Korean Journal of Organic Agriculture
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    • v.13 no.2
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    • pp.161-173
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    • 2005
  • This study was carried out to clarify the effects of antifungal bacterial strains isolated from the greenhouse soil grown strawberry plants on the growth inhibition of plant pathogen, gray mold (Botrytis cinerea) infected in strawberry plants in Damyang and Jangheung districts. Antagonistic bacterial strains were isolated and investigated into the antagonistic activity against gray mold. Screened ten bacterial strains which strongly inhibited Botrytis cinerea were isolated from the greenhouse grown strawberry plants, and the best antifungal microorganism designated as SB 143 was finally selected. Antifungal bacterial strain SB 143 was identified to be the genus Bacillus sp. based on the morphological and biochemical characterization. Bacillus sp. SB 143 showed 59.4% of antifungal activity against Botrytis cinerea. By the bacterialization of culture broth and heated filtrates of culture broth, Bacillus sp. SB 143 showed 93.1% and 32.1% of antagonistic activity against Botrytis cinerea.

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Biological Control of Fusarium Wilt by Antagonistic Microorganism in Greenhouse Grown Cucumber Plants (오이의 온실재배에서 발생하는 위조병의 미생물학적 제어)

  • Cho, Jung-Il;Cho, Ja-Yong
    • Korean Journal of Organic Agriculture
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    • v.12 no.1
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    • pp.101-114
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    • 2004
  • This study was carried out to clarify the effects of antagonistic microorganism, Bacillus sp. JC181 isolated from the greenhouse soil grown cucumber plants on the growth inhibition of plant pathogen, fusarium wilt (Fusarium oxysporum) occurred in cucumber plants in greenhouse. Antagonistic bacterial strains were isolated and were investigated into the antifungal activity of the antagonistic microorganism against fusarium wilt. Screened fourteen bacterial strains which strongly inhibited F. oxysporum were isolated from thc greenhouse soil grown cucumber plants, and the best antagonistic bacterial strain designated as JC181, was finally selected. Antagonistic bacterial strain JC181 was identified to be the genus Bacillus sp. based on the morphological and biochemical characterization. Bacillus sp. JC181 showed 58.2% of antifungal activity against the plant pathogen growth of F. oxysporum. By the bacterialization of culture broth and heated filtrates of culture broth, Bacterial strain, Bacillus sp. JC181. showed 91.2% and 260% of antifungal activity against F. oxysporum, respectivrly.

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Output Compliance Effects By Both Redundant Joint Compliances and Antagonistic Torques of A Spherical 3-DOF Mechanism (구형 3 자유도 메카니즘의 잉여관절 콤플라이언스와 상반토크로 인한 출력 콤플라이언스 효과)

  • 이준용;김희국
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.793-798
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    • 1996
  • In this paper, output compliance effects at RCC point by both redundant joint compliances and antagonistic torques generated by internal preloading between joints of a spherical 3 degree-of-freedom mechanism are investigated. For this purpose, kinematic analysis is briefly described. Then, output compliance models at RCC point, which is generated by redundant joint compliances and by internal preloading between joints are derived. Finally, ranges of output compliance modulation due to these redundant joint compliances and antagonistic torques are examined through simulation.

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Antagonistic effects on Respiration and Photosynthesis of Chlorella cells treated with GA and IAA (Chlorella의 호흡 및 광합성에 미치는 IAA와 GA의 길항작용)

  • 채인기;정영숙;이영녹
    • Korean Journal of Microbiology
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    • v.12 no.4
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    • pp.188-193
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    • 1974
  • Effects of GA and IAA on the respiratory and photosynthetic activity of each growth stage during the synchronous culture of Chlorella ellipsodiea, were investigated. 1) GA ($2{\times}10^{-8}M$) affected most insignificantly on the respiratory activity of the stages Dn, Da, $L_1$, $L_2$, $L_3$-cells but only at $L_4$-cells treated with IAA($10^{-3}/M$) were promoted and $L_3$, $L_4$-cells were suppressed. With the treatment of GA-IAA the effects on respiration of eah stage cells were antagonistic. 2) Photosynthetic activity treated with GA during the each stage of Chlorella cells was promoted and IAA treated-cell were suppressed. The effect of GA-IAA upon the process of life cycle was also antagonistic. 3) It was revealed that respiratory and photosynthetic activity of Chlorella cells by the treatment of GA(($2{\times}10^{-8}M$) and IAA($10{\times}^{-3}/M$) had antogonistic effects.

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Antagonistic Effects of Intravenous and Subcutaneous Administration of Yohimbine on Xylazine-Induced Immobilized Dog (Xylazine으로 진정시킨 개에서 Yohimbine의 정맥 및 피하주사의 길항효과)

  • Seo Kang-Moon;Cheong Chang-Kook;Nam Tchi-Chou
    • Journal of Veterinary Clinics
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    • v.5 no.2
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    • pp.61-71
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    • 1988
  • This study was performed to compare the antagonistic effects of intravenous(0.125mg / kg) and subcutaneous(0.25mg /kg) administration of yohimbine on xylazine-induced immobilized(4.5mg/ kg) dog and to investigate the effectiveness of yohimbine compound(0.25mg / kg) in clinical practice. Mean arousal time(MAT), mean walk time(MWT), and time to return to normal electroencephalograms were remarkably decreased in all yohimbine-treated groups compared with the control. In electroencephalograms(A-B$\sub$I/ lead), there were no significant alteration, except RR interval. RR interval was decreased in all yohimbine-treated groups compared with the control. Second-degree heart blocks(41.7%) shown after xylazine administration disappeared within 2 min after yohimbine administration. The frequency of electroencephalograms(RO-RF trace) was recovered faster to normal in yohimbine-treated groups than that of the control. In histopathological changes of ICR mice given yohimbine compound subcutaneously, edema with inflammatory cells of hypodermis was slightly shown on the 1st day, but this findings were not observed on the 5th day. It was considered that no difference in the antagonistic effects of intravenous and subcutaneous administration of yohimbine on xylazine- induced immobilized dog were observed and yohimbine compound was usable in clinical practice for antagonistic agent to the xylazine.

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Diversity and Characterization of Endophytic Bacteria Associated with Tidal Flat Plants and their Antagonistic Effects on Oomycetous Plant Pathogens

  • Bibi, Fehmida;Yasir, Muhammad;Song, Geun-Cheol;Lee, Sang-Yeol;Chung, Young-Ryun
    • The Plant Pathology Journal
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    • v.28 no.1
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    • pp.20-31
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    • 2012
  • Endophytic bacterial communities of tidal flat plants antagonistic to oomycete plant pathogens were studied by the isolation of 256 root colonizing endophytic bacteria from surface-disinfected root tissues of six plants ($Rosa$ $rugosa$, $Suaeda$ $maritima$, $Vitex$ $rotundifolia$, $Carex$ $scabrifolia$, $Glehnia$ $littoralis$ and $Elymus$ $mollis$) growing in a tidal flat area of Namhae Island, Korea. To understand the antagonistic potential, an $in$ $vitro$ antagonistic assay was performed to characterize and identify strains that were antagonistic to the oomycete plant pathogens $Phytophthora$ $capsici$ and $Pythium$ $ultimum$ from the total population. Nine percent of the total number of isolated bacteria exhibited in vitro inhibitory activity against target plant pathogenic oomycetes. Taxonomic and phylogenetic placement of the antagonistic bacteria was investigated by analysis of the 16S rRNA gene sequences. The sequence analysis classified the antagonistic strains into four major classes of the domain bacteria ($Firmicutes$, ${\alpha}-Proteobacteria$, ${\gamma}-Proteobacteria$ and $Actinomycetes$) and 10 different genera. Further production of secondary metabolites, hydrolytic enzymes and plant growth promoting traits were determined for the putative new species of antagonistic endophytic bacteria. These new strains could not be identified as known species of ${\alpha}-Proteobacteria$, and so may represent novel bacterial taxa. The unexpected high antagonistic bacterial diversity associated with the tidal flat plants may be indicative of their importance in tidal flat plants as a promising source of novel antimicrobial compounds and biocontrol agents.

Yield Decrease of Tall Fescue ( Festuca arundinacea Schreb. ) by Pathogenic Fungi and its Control by Antagonistic Bacteria (병원성사상균에 의한 Tall Fescue ( Festuca arundinacea Schreb. ) 의 수량 손실과 길항 미생물에 의한 그 방제)

  • Choi, Ki-Chun;Song, Chae-Eun;Lee, Joung-Kyong;Kim, Jong-Hyun;Rhee, Young-Hwan;Youn, Chang
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.18 no.2
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    • pp.133-142
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    • 1998
  • This study was conducted to investigate the effects of antagonistic bacteria and pathogenic fungi on the growth of tall fescue(Festuca arundinacea Schreb.) in continuous cropping soil(CCS) and non-continuous cropping soil(NCCS). Tall fescue was established by seeding into pots of 11 cm in diameter and 9 cm in depth containing 1 : 1 mixture of soil and vermiculite, and cultivated at pots with antagonistic bacteria and pathogenic fungi in a vinyl house. The bacteria used in this study were Bacillus subtilis and hsants. B. subtilis was isolated and identified kern forage rhizosphere soil and fusants were isolated through cell hsion from B. subtilis and B. thwingiensis. B. subtilis was named as B. subtilis 101 and hsants were named as F-3, F-7 and F-8. In dark culture experiment, tall fescue inoculated with the antagonistic bacteria lived longer than that of control in both CCS and NCCS. However, tall fescue of CCS lived shorter than that of NCCS. Dry weight of tall fescue inoculated with the antagonistic bacteria was higher than that of tall fescue inoculated with pathogenic hngi in both CCS and NCCS(P< 0.05), and the antagonistic bacteria showed positive effects on the growth of tall fescue. However, Dry weight of tall fescue was decreased by the inoculation of the pathogenic b g i in both CCS and NCCS(P< 0.05).

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Flavonoids with Bradykinin Antagonistic Effects from Scutellariae Radix

  • YunChoi, Hye-Sook;Yoo, Kyung-Sook;Chung, Sung-Hyun;Yang, Hyun-Sook;Choi, Jin-Jae;Kim, Young-Joo
    • Korean Journal of Pharmacognosy
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    • v.23 no.4
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    • pp.234-239
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    • 1992
  • Seven flavonoid components were isolated from fr. C of Scutellariae radix which showed antagonistic effects against bradykinin(BK). The results indicated that two oxygen functions (either -OH or $-OCH_3$) at 2'- and 6'-positions and/or an oxygen function at 6-position of flavone seemed to be favored for the BK inhibitory activities. Skullcapflavone-II(IV) which contains $6-OCH_3$, 2'-OH and $6-OCH_3$ in the structure was the most active among the flavones tested.

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