• The Plant Pathology Journal
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• 제38권5호
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• pp.449-460
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• 2022

This study was performed to reveal phenotypic characters and identity of symbiont bacteria of Nasutitermes as well as investigate their potential as antagonist of plant pathogenic fungi. Isolation of the symbiont bacteria was carried out from inside the heads and the bodies of soldier and worker termite which were collected from 3 locations of nests. Identification was performed using phenotypic test and sequence of 16S ribosomal DNA (16S rDNA). Antagonistic capability was investigated in the laboratory against 3 phytopathogenic fungi i.e., Phytophthora capsici, Ganoderma boninense, and Rigidoporus microporus. Totally, 39 bacterial isolates were obtained from inside the heads and the bodies of Nasutitermes. All the isolates showed capability to inhibit growth of P. capsici, however, 34 isolates showed capability to inhibit growth of G. boninense and 32 isolates showed capability to inhibit growth of R. microporus. Two bacterial strains (IK3.1P and 1B1.2P) which showed the highest percentage of inhibition were further identified based on their sequence of 16S rDNA. The result showed that 1K3.1P strain was placed in the group of type strain and reference strains of Lysinibacillus fusiformis meanwhile 1B1.2P strain was grouped within type strain and reference strains Paenibacillus alvei. The result of this study supply valuable information on the role of symbiont bacteria of Nasutitermes, which may support the development of the control method of the three above-mentioned phytopathogenic fungi.

• 한국수산과학회지
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• 제35권6호
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• pp.578-582
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• 2002

양식어류 질병 세균에 대한 31종의 천연물을 $70\%$ ethanol로 추출하여 항균효과를 조사하였다. 그 중에서 망태버섯 ethanol 추출물이 비교적 높은 활성을 나타내었으며, 망태버섯을 극성이 낮은 dichlorornethane, ethyl acetate, n-buthanol, water의 순서로 분획하여 항균효과를 본 결과 ethyl acetate 추출물에서 모든 균주에대한 clear zone을 형성하여 항균효과가 보였다. 또한, 망태버섯로부터의 ethyl acetate 추출물을 Si-chromatography를 이용하여 fraction별 7개로 분획하여 항균효과를 조사한 결과 Fraction 2 (Hx :EtAOc, 3: 1)에서는 L. anguillarum에 대해 가장 항균효과가 뛰어났으며, Fraction 5 (DCM:MeOH, 5: 1)에서 5. iniae가 가장 높았다. 그 중에서 세 균주에 대해서 공통적으로 항균활성이 높은 것은 Fraction 5로 나타났다.

• 한국자원식물학회지
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• 제12권2호
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• pp.152-160
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• 1999

1. 콩잎의 세균밀도는 4.60$\times$$10^2$~ 9.10$\times$$10^{5}$CFU/$\textrm{cm}^2$으로, 생육단계가 진전됨에 따라 세균밀도가 증가하는 경향이었다. 2. 콩나물 부패 세균의 밀도는 콩잎에서 0~5.00$\times$$10^3$CFU/$\textrm{cm}^2$으로, 부패세균의 밀도는 생육단계에 관련이 없었으나 재배지역과는 관련이 있었다. 3. 나물 콩 품종과 콩나물 부패세균의 밀도는 품종과 관련이 적었으며 생육단계와 작물의 부위에 따라 변이가 심하였다. 4. 콩잎에서 분리된 콩나물 부패세균은 Erwinia cypripedii, E. carotovora subsp. carotovora, Xanthomonas campestris pv. glycines, Staphylococcus sp., Micrococcus sp. 이며, E. carotovora subsp. carotovora, X. campestris pv. glycines가 밀도가 높았다.다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2002년도 총회 및 추계학술발표회
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• pp.56.2-57
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• 2002

• Mycobiology
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• 제37권1호
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• pp.48-52
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• 2009

Essential oils are mixtures of volatile, lipophilic compounds originating from plants. Some essential oils have useful biological activities including antimicrobial, spasmolytic, antiplasmodial, and insect-repelling activities. In this study, we tested the antimicrobial activity of essential oil prepared from the aromatic plant, Cymbopogon citrates, against three important plant pathogenic and medical microorganisms, Pectobacterium carotovorum, Colletotrichum gloeosporioides, and Aspergillus niger. It effectively inhibited the growth of the bacterium, Pectobacterium carotovorum, in a dose-dependent fashion, and 0.5% of the oil inhibited the growth of bacteria completely. Similarly, the essential oil inhibited the growth of plant pathogenic fungus, Colletotrichum gloeosporioides, and the addition of 1% of essential oil completely inhibited the growth of fungus even after 5 days of culture. Finally, it effectively inhibited the growth of the medically and industrially important fungal species, Aspergillus spp. These results suggest that the essential oil from Cymbopogon citrates may be an environmentally safe alternative to inhibit antimicrobial agents for various uses.

• Mycobiology
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• 제35권4호
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• pp.210-214
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• 2007

Antibacterial and antifungal activities of liquid culture filtrate, water and ethanol extract (solid culture) of Stereum ostrea were evaluated against 5 bacteria and 3 plant pathogenic fungi. To determine the minimal inhibitory concentration (MIC), we studied $5{\sim}300\;mg/ml$ concentrations against bacteria and fungi separately. The MIC was 10 mg/ml for Bacillus subtilis and 40 mg/ml for Colletotrichum gloeosporioides and Colletotrichum miyabeanus. Liquid culture filtrate was more effective against Gram positive than Gram negative bacteria, and Staphylococcus aureus was the most inhibited (20.3 mm) bacterium. Water and ethanol extracts were effective against both Gram positive and Gram negative bacteria, and water extract was better than ethanol extract. In water and ethanol extract, inhibition zones were 23.6 and 21.0 mm (S. aureus) and 26.3 and 22.3 mm (Pseudomonas aeruginosa), respectively. For plant pathogenic fungi, the highest and lowest percent inhibition of mycelial growth (PIMG) was found 82.8 and 14.4 against C. miyabeanus and Botrytis cinerea in liquid culture filtrate, respectively. In water extract, the PIMG was found to be the highest 85.2 and lowest 41.7 for C. miyabeanus and C. gloeosporioides, respectively. The inhibitory effect of ethanol extract was better against C. miyabeanus than C. gloeosporioides and B. cinerea. Among 3 samples, water extract was the best against tested pathogenic fungi. This study offers that the extracts isolated from S. ostrea contain potential compounds which inhibit the growth of both bacteria and fungi.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.48-55
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• 2004

Six strains of an obligate predatory bdellovibrio isolate that preys on Burkholderia glumae in rice paddy field water and rhizosphere soil, were identified and characterized. The numbers of Bdellovibrio cells varied from $3.2{\times}10^3$ to $9.2{\times}10^3$ plaque-forming unit/g after enrichment in cells of B. glumae. Prey range tests with six Bdellovibrio strains and 17 prey strains of rice-pathogenic, antibiosis-related, or nitrogen-fixing bacteria resulted in unique predation patterns in related prey cells. Strain BG282 had the widest prey range on 7 plant pathogenic bacteria among the 17 prey strains tested. However, no predation occurred with strains of Azospirillum brasilense, Paenibacillus polymyxa, Pseudomonas fluorescens, P. putida, and Serratia marcescens that are associated with antibiosis or nitrogen fixation in the rice ecosystem. Identification was confirmed by the presence of typical bdelloplast in the prey cells of B. glumae and by a PCR assay using B. bacteriovorus-specific primers. Furthermore, 16S rDNA sequencing of the six bdellovibrio strains showed a homology range of 97.2% to 99.2% to the type strain of B. bacteriovorus.

• 한국식물병리학회지
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• 제14권2호
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• pp.125-129
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• 1998

Phytopathogenic bacteria causing soft-rot many vegetables; extracellular enzymes produced by them, pectate lyase(Pel) is important pathogenicity facotrs which cause tissue maceration and cell death. Ten of seventeen plant pathogenic bacteria showed weak Pel activity, four of them showed low Pel activity and Erwinia acrotovora subsp. carotovora, E. chrysanthemi, Pseudomonas marginalis and Xanthomonas campestris pv. campestris showed high Pel activity in the polygalacturonate yeast extract agar (PAY) plate. High Pel activity of the four bacteria species produced the highest Pel activity when pectin or polygalacturonic acid (PGA) was added to minimal salts (MS) medium. Pel activity of the four bacterial species was the highest at 2$0^{\circ}C$ among different temperature conditions. The rate and amount of maceration of potato tuber tissue were highest at 2$0^{\circ}C$ in E. carotovora subsp. carotovora, E. chrysanthemi and P. marginalis, while those were the highest at $25^{\circ}C$ in X. campestris pv. campetris.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 1999년도 정기총회 및 춘계 학술발표회
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• pp.19.2-19
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• 1999

• 농약과학회지
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• 제13권1호
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• pp.45-53
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• 2009

KLF01으로 명명된 세균이 토마토의 뿌리에서 분리 되었고 생화학적, 유전학적 검증을 통해 Lactobacillus sp.로 동종 되었다. In vitro 실험에서 식물성 세균인 Ralstonia solanacearum를 비롯하여, Xanthomonas axonopodis pv. citri, Xanthomonas campestris pv. vesicatoria, Eriwinia pyrifoliae, Eriwinia carotovora subsp. carotovora group에게도 저해 효과를 나타내는 것으로 확인되었다. 고추와 토마토를 이용한 in vivo 실험에서는 특히 R. solanacearum에 대해 대조구와 비교 시들음병의 진행을 저해하는 것으로 관찰되었다.