• 제목/요약/키워드: antagonistic activities

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Biocontrol Activity of Volatile-Producing Bacillus megaterium and Pseudomonas protegens Against Aspergillus and Penicillium spp. Predominant in Stored Rice Grains: Study II

  • Mannaa, Mohamed;Kim, Ki Deok
    • Mycobiology
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    • 제46권1호
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    • pp.52-63
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    • 2018
  • In our previous studies, Bacillus megaterium KU143, Microbacterium testaceum KU313, and Pseudomonas protegens AS15 have been shown to be antagonistic to Aspergillus flavus in stored rice grains. In this study, the biocontrol activities of these strains were evaluated against Aspergillus candidus, Aspergillus fumigatus, Penicillium fellutanum, and Penicillium islandicum, which are predominant in stored rice grains. In vitro and in vivo antifungal activities of the bacterial strains were evaluated against the fungi on media and rice grains, respectively. The antifungal activities of the volatiles produced by the strains against fungal development and population were also tested using I-plates. In in vitro tests, the strains produced secondary metabolites capable of reducing conidial germination, germ-tube elongation, and mycelial growth of all the tested fungi. In in vivo tests, the strains significantly inhibited the fungal growth in rice grains. Additionally, in I-plate tests, strains KU143 and AS15 produced volatiles that significantly inhibited not only mycelial growth, sporulation, and conidial germination of the fungi on media but also fungal populations on rice grains. GC-MS analysis of the volatiles by strains KU143 and AS15 identified 12 and 17 compounds, respectively. Among these, the antifungal compound, 5-methyl-2-phenyl-1H-indole, was produced by strain KU143 and the antimicrobial compounds, 2-butyl 1-octanal, dimethyl disulfide, 2-isopropyl-5-methyl-1-heptanol, and 4-trifluoroacetoxyhexadecane, were produced by strain AS15. These results suggest that the tested strains producing extracellular metabolites and/or volatiles may have a broad spectrum of antifungal activities against the grain fungi. In particular, B. megaterium KU143 and P. protegens AS15 may be potential biocontrol agents against Aspergillus and Penicillium spp. during rice grain storage.

한국인삼론(韓國人蔘論) (Current Status of Korean Ginseng Research)

  • 한병훈
    • 생약학회지
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    • 제3권3호
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    • pp.151-160
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    • 1972
  • Recent achievements of scientific research on the pharmacologic activities and the chemical problems of dammalene glycosides, which are considered to be effective principles of Korean ginseng, are reviewed and analyzed in view of structure-activity relationship. 1) S. Shibata and his co-workers detected 12 glycoside spots of dammalene series on the two dimensional T.L.C. of total glycoside fraction from Japanese ginseng, and designated them Ginsenoside Rx(x=a, b, c, g, h, etc.) in the order of increasing Rf-value. The aglycones of those glycosides were characterized to be protopanaxadiol for the Ginsenoside $Rx(x=a,\;b_{1},\;b_{2},\;c,\;d,\;e,\;f)$ and protopanaxatriol for the Ginsenoside $Rx(x=g_{1},\;g_{2},\;g_{3},\;h_{1}\;'h_{2})$. Using Korean ginseng as the material for our study, the author and his coworkers isolated a new dammalene glycoside(Panax Saponin C), which comes under the category of protopanaxadiol glycosides based on the classification of S. Shibata et al., and characterized this saponin to be the glycoside of protopanaxatriol series. Furthermore, Panax Saponin C dissociated into $two\;components(C_{1}\;and\;C_{2}-acetate)$ by acetylation, both of which returned to original Panax Saponin C by deacetylation. Based on this result, more than 13 glycoside components of dammalene series will be expected in the Korean ginseng. 2) The structures of protopanaxadiol and protopanaxatriol, the genuine aglycones of dammalene glycosides, are fully established to be structural analogues by S. Shibata and his co-workers, therefore antagonistic and/or analogical activities will be expected for the pharmacologic activities of these glycoside series of structural analogues. K. Takaki and his co-workers found central nervous system (CNS) stimmulant activity from the glycosides of protopanaxatriol series and CNS-depressant activity from the glycosides of protopanaxadiol series. On the other hand, the author and his co-workers found stimmulating activity on the protein synthesis from both the series of dammalene glycosides with delayed and long-lasting characteristics. This delayed and long-lasting characteristics were also observed in the anti-inflammatory activity of glycosides of protopanaxatriol series on their time course tendency. For the convenience's sake of argument, pluralistic pharmacologic activities of dammalene glycosides, which were observed by many workers at various pharmacologic site, may be classified into two main categories; one is pan-cellular activity and the other is organ specific activity to the certain tissue which is a mass of cells differentiated to a certain direction for their special functions in the body. Based on the data of K. Takaki and those of the authors, following assumption will be probable; Pharmacologic activities of both series of glycosides of protopanaxadiol and protopanaxatriol aglycones may be antagonistic on their tissue-specific activities and analogic on their pan-cellular activities. Therefore, the mixture of these two series of glycosides in an appropriate ratio, as the case of total extract of Korean ginseng, will be probably beneficial to the host by increasing the synthesis of some functional proteins, due to the additive action of pan-cellular activity, and with the disappearance of any significant behavioral symptoms due to the antagonism of tissue specific activity. This fact will probably be the main reason why classical trials of pharmacologists failed in re-discovering the efficacy of Korean ginseng with their behavioral test. 3) The author and his co-workers achieved the synthesis of $C^{14}-labelled\;Panax\;Saponin\;A\;on\;C_{25}-C_{27}\;position\;of\;aglycone$ in the interest of tracer studies in vivo. The method will be applicable to other dammalene glycosides regardless of their chemical structure. 4) The author and his co-workers converted chemically betulafolienetriol, a triterpene component of Betula platyphylla, to the protopanaxadiol, one of genuine aglycone of dammalene glycosides.

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식물역병균 Phytophthora spp.에 특이 길항균인 YNB54 균주의 분류 (Taxonomy of a Soil Bacteria YNB54 Strain Which Shows Specific Antagonistic Activities against Plant Pathogenic Phytophthora spp.)

  • 김삼선;권순우;이선영;김수진;구본성;원항연;김병용;여윤수;임융호;윤상홍
    • 한국미생물·생명공학회지
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    • 제34권2호
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    • pp.101-108
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    • 2006
  • Phytophthora sp.의 균사성장을 특이적으로 저해하는 토양 미생물인 YNB54 균주의 정확한 분류적 위치를 밝히기 위해 Biolog GN2, API 20E와 같은 상업적 생화학 kit, 16S rDNA, DAN-DNA hybridization, GC함량, MIDI 등의 분석을 수행하였다. 다양한 생화학적 kit를 사용한 동정 결과는 이 균주가 다른 어떤 종보다 Enterobacter cloacae와 E. cancerogenus에 보다 더 가까움을 보여주었다. 또한 DAN-DNA hybridization, GC함량, MIDI 분석의 결과들 역시 다른 속 (Citerobacter, Klebsiella, Leclercia)보다 Enterobacter 속에 더 유사함을 암시해 주었다. 그러나 16S rDNA분석에서 이 균주는 Citrobacter freundii(99.4%)와 동일 그룹으로 구분되었지만 Enterobacter, Leclecia, Klebsiella 속 등과도 98%이상의 상동성을 보여주는 polyphyletic 특성을 보였다. 결론적으로 YNB54의 분류 동정을 위한 우리의 조사들은 이 균주가 유전적으로 다양하고 지금까지 아는 것보다 분류학적으로 더 복잡함을 암시해줌에도 불구하고 Enterobacter속임이 가장 유력하다는 것을 보여 주었다.

벼의 생엽절편을 이용한 병원균 억제물질의 대량 스크리닝 방법 개발 (Development of a Method for High throughput Screening of Antagonistic Substances against Rice Pathogens using Rice Leaf Explants)

  • 박샛별;이충환;김태종;강린우;이병무;김정구
    • 한국미생물·생명공학회지
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    • 제40권1호
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    • pp.39-42
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    • 2012
  • 벼흰잎마름병을 억제하는 물질의 활성을 확인하기 위하여 벼 잎 생엽절편을 이용하는 새로운 스크리닝 방법을 개발하였다. 96 well plate에 잔토모나스 오라이자의 배양액을 분주하고 균등한 크기의 벼 잎 생엽절편을 배치한 후 효능을 확인하고자 하는 물질을 처리하였다. 흰잎마름병균을 억제하는 물질의 활성도는 벼 잎 생엽절편 병징의 면적율로 환산되었다. 물질에 의하여 병의 발생이 억제된 벼 잎 생엽절편은 병원균 배양액 내에서 건전한 녹색을 유지하였고 병이발생된 벼 잎 생엽절편은 황갈색 병징을 나타내었다. 이를 통하여 본 실험법이 빠르고 간편하며, 농도 의존적인 활성확인이 가능하고, 소량으로 다수 물질의 활성 여부를 동시에 평가할 수 있음을 확인하였다. 본 스크리닝 법은 벼흰잎마름병 뿐만 아니라 여타의 수인성 작물질병억제 활성을 확인하는 데 응용 가능성이 있을 것으로 생각된다.

Metarhizium anisopliae의 Fusarium oxysporum, Botrytis cinerea, Alternaria solani 등에 대한 항진균활성 (Antifungal Activities of Metarhizium anisopliae against Fusarium oxysporum, Botrytis cinerea, and Alternaria solani)

  • 강선철;박영구;이동규;김용헌
    • 한국균학회지
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    • 제24권1호통권76호
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    • pp.49-55
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    • 1996
  • 살충성진균 Metarhizium anisopliae가 시들음병을 일으키는 Fusarium oxysporum, 잿빛곰팡이 병을 일으키는 Botrytis cinerea, 겹둥근무늬병을 일으키는 Alternaria solani 등에 대하여 항진균활성을 갖는지 알아보았다. 그 결과 Plate상에서 균사생장저해 실험과 inhibition rate실험을 했을 때 항진균활성이 검정되었으며 또한 YPD배지에서 배양된 M. anisopliae로부터 얻은 배양여액을 식물병원균에 30%농도로 첨가했을 때 이들의 포자발아율은 B. cinerea, F. oxysporum에서 각각 21.5%(control: 88.2%), 53.0%(control: 78.6%)로 감소하였으며 발아개시 시간도 8시간 정도 지연되었다. 또한 현미경을 통한 미세구조관찰에서는 10% 배양여액을 첨가했을 때 F. oxysporum의 균사로부터 후막포자가 생성되고 생장저해가 일어나는 것이 확인되었다. 이상의 결과로부터 M. anisopliae의 항진균활성은 fungistatic effect를 나타냄을 알 수 있었다.

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Analysis of the Potent Platelet Glycoprotein IIb-IIIa Antagonist from Natural Sources

  • Kang, In-Cheol;Kim, Doo-Sik
    • BMB Reports
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    • 제31권5호
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    • pp.515-518
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    • 1998
  • Adhesive interaction of the platelet glycoprotien IIb-IIIa (GP IIb-IIIa) with a plasma protein, such as fibrinogen, plays an important role in thrombosis and hemostasis. The specific sequence Arg-Gly-Asp (RGD) is critical for the binding of fibrinogen to platelet. To examine and characterize the GP IIb-IIIa antagonist from natural sources, we have developed a simple enzyme-linked immunosorbant assay (ELISA) system. The GP IIb-IIIa complex was purified to homogeneity from platelet Iysates by the combination of two affinity chromatographic methods using the synthetic RGD peptide (GRGDSPK)-immobilized Sepharose and wheat germ lectin-Sepharose. The synthetic peptide GRGDSP inhibits GP IIb-IIIa binding to immobilized fibrinogen with an $IC_{50}$ of $1.5\;{\mu}M$. Venoms of three different snake species and a Korean scolopendra extract have strong antagonistic activities for the binding of human fibrinogen to the platelet GP IIb-IIIa complex. The $IC_{50}$ values of the snake venom s and scolopendra were in the range of $5.5\;{\mu}g$ to $60\;{\mu}g$. These results provide meaningful information for developing antiplatelet agents.

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Screening of Bacteriocin-producing Bacillus Strains Isolated from Domestic Animal Feces for Antagonistic Activities against Clostridium perfringens

  • Han, Sun-Kyung;Choi, Hyun-Jong;Lee, Sang-Myeong;Shin, Myeong-Su;Lee, Wan-Kyu
    • 한국축산식품학회지
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    • 제31권3호
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    • pp.405-412
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    • 2011
  • The purpose of this study was to isolate and characterize bacteriocin-producing bacteria against Clostridium perfringens from domestic animals to determine their usefulness as probiotics. The feces of cattle and chicken were used as sources to isolate bacteriocin-producing bacteria using the spot-on-lawn method. In total, 900 bacterial stains were isolated from domestic animal feces, and 19 strains were finally selected after determining the inhibitory activity against the pathogenic indicator C. perfringens KCTC 3269. Eighteen strains of Bacillus subtilis and one strain of Brevibacillus parabrevis were identified by 16s rRNA sequencing. Most of the bacterial strains isolated were resistant to 0.5% bile salts and remained viable after 2 h at pH 3.0. Additionally, some B. subtilis strains showed strong inhibitory activity against Listeria monocytogenes. We isolated and screened B. subtilis strains CB 153 and CB 189 from cattle and B. subtilis MSC 156 and B. parabrevis MSC 164 from chickens using probiotic selection criteria such as inhibition activity against C. perfringens and tolerance to acid and bile salts. The isolated bacteriocin-producing bacteria and/or bacteriocin have the potential to be used as probiotics in the livestock industry.

Effect of Enterococcus faecalis strain PL9003 on Adherence and Growth of Helicobacter pylori

  • Nam, Hye-Ran;Ha, Mi-Sun;Lee, En-Jung;Lee, Yeon-Hee
    • Journal of Microbiology and Biotechnology
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    • 제12권5호
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    • pp.746-752
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    • 2002
  • The purpose of the present study was to examine the antagonistic activities of Enterococcus faecalis strain PL9003 (PL9003) on Helicobacter pylori. This strain was isolated from infant feces and found to inhibit both the growth of H. pylori and its in vitro adherence to the human gastric cell line MKN-45. The binding of PL9003 to MKN-45 was observed under a light microscope after Cram staining and under a scanning electron microscope. When detected with an FITC-conjugate antibody, both viable and nonviable PL9003 were found to decrease the number of H. pylori bound to MKN-45. When detected by an enzyme-linked immunoabsorbent assay, about 70% of the H. pylori bound on MKN-45 disappeared with the four-1314 addition of viable or nonviable PL9003. The spent culture supernatant (SCS) of PL9003 also decreased the viability of H pylori even after neutralization and pepsin treatment. The above results suggest that PL9003 has a potential as a new probiotic for the stomach.

Plant-derived Antibacterial Metabolites Suppressing Tomato Bacterial Wilt Caused by Ralstonia solanacearum

  • Vu, Thuy Thu;Choi, Gyung Ja;Kim, Jin-Cheol
    • 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.

Diversity of Fungi from Dokdo Island Soil, Korea and Their Antimicrobial and Hydrolytic Enzyme Activity

  • Lee, Hye Won;Lee, Hyang Burm
    • 한국균학회소식:학술대회논문집
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    • 한국균학회 2014년도 추계학술대회 및 정기총회
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    • pp.47-47
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    • 2014
  • Dokdo island is located in the northeastern part of Ulleungdo, known as volcanic island. In total, 53 fungal isolates were isolated from Dokdo island soil sample, using dilution plate technique. The isolates were identified on the basis of morphological characteristics and rDNA ITS sequence analysis. Out of them, 41 isolates were identified at the level of species. The dominant fungal species and genera included Fusarium spp., Mucor sp., Clonostachys spp., and Trichoderma sp. The % sequence identity (the number of matches/the complete alignment length) values via NCBI BLAST searching of EML-IF9, EML-MF30-1 and EML-DDSF4 represented 97.19% (485/499) with Clonostachys cf. rosea (GenBank accession no. KC313107), 98.33% (472/480) with Metarhizium guizhouense (GenBank accession no. HM055445), and 100% (350/350) with Mortierella oligospora (GenBank accession no. JX976032), respectively. Three species of C. rosea, M. guizhouense and M. oligospora represented new records of fungi from Dokdo island, Korea. The antimicrobial activities of the fungal strains varied with tested. Two isolates (EML-MFS30-1 and EML-IF9) showed antifungal activity against several fungi including Fusarium oxysporum and Rhizotonia solani. Clonostachys rosea (EML-IF9) showed strong hydrolytic enzyme activity. Our results showed that the antagonistic fungi including Clonostachys rosea will be used as potential biocontrol agents for control of fungal diseases.

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