• 한국미생물·생명공학회지
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• 제23권1호
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• pp.98-103
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• 1995

During the screening of antifungal antibiotics from microbial metabolites, we selected Pseudomonas aeruginosa KGM-100 showing powerful antagonistic activity against various phytopathogenic fungi. Antibiotics KGM-100A and KGM-100B were purified from the culture broth of Pseudomonas aeruginosa KGM-100 by diaion HP-20 column chromatography, ethyl acetate extraction, silica gel column chromatography, preparative TLC and recrystallization. KGM-100A which was recrystallized in MeOH showed antimicrobial activities against a broad spectrum of fungi and bacteria. Physico-chemical properties of KGM-100A were determined and identified to be phenazine-l-carboxylic acid by UV, IR, $^{1}$H-NMR, $^{13}$C-NMR, mass spectrum, and elemental analyses.

• Journal of Applied Biological Chemistry
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• 제49권4호
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• pp.131-134
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• 2006

The in vitro anti-fungal activity of hydroxylated fatty acids obtained from microbial conversion by Psuedomonas aeruginosa PR3 using ricinoleic acid(RA), eicosadienoic acid(EDA) and conjugated linoleic acid(CLA) as substrates, was investigated. Bioconverted hydroxylated fatty acids showed different anti-fungal activities potentials against the range of phytopathogenic fungi such as Botrytis cinerea, Rhizoctonia solani, Fusarium oxysporum, Sclerotonia sclerotiorum, Colletotricum capsici, Fusarium solani and Phytophthora capsici. RA and EDA showed up to 50% fungal mycelial inhibition at the concentration of $5{\mu}l\;ml^{-1}$. RA, EDA and CLA also exhibited anti-fungal activities with minimum inhibitory concentration(MIC), ranging from 500 to $1000{\mu}g\;ml^{-1}$. Screening was also carried out using varied concentrations of bioconverted RA and EDA for determining the anti-fungal effect on the spore germination of different fungi. Bioconverted RA and EDA showed a considerable degree of spore germination inhibition.

• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.349-353
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• 1994

An isolate 90-GT-302, identified as Kitasatosporia kimorexae, was found to produce antibiotics that induce mycelial swelling in Magnaporthe grisea, and Fusarium solani. The strain produced at least 5 antibiotics. Among them, the main active compound designated as kimorexin A was isolated and its physico-chemical properties and biological activities were examined, and as a result was found to be of the thiopeptide antibiotic. A comparison between the properties of kimorexin A and those of the known thiopeptide antibiotics led us to conclude that kimorexin A was a new thiopeptide polythiazolyl antibiotic. Kimorexin A showed a narrow antimicrobial spectrum against very limited genus of phytopathogenic fungi. It prevented host plants from infections of Rhizoctonia solani and absolute parasitic fungi, such as Sphaerotheca fuliginea and Puccinia recondita, almost completely at the treatment concentration of approximately 20 ppm.

• 한국식물병리학회지
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• 제12권2호
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• pp.245-250
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• 1996

식물병원균 Botrytis cinerea와 Fusarium oxysporum에 대한 생물학적 방제의 기초자료를 얻기 위하여 살충성 진균 Beauveria bassiana의 식물병원균에 대한 균사성장저해, 포자발아 억제, 균사와 포자의 형태변화 등의 효과를 살펴보았다. 평판배지 상에서 두 식물병원균의 균사생장이 저해되었으며, 저해효과는 배지종류에 따라 달랐는데 B. cinerea의 경우 PDA배지에서 가장 크게 저해되었으며 F. oxysporum의 경우에는 TSA배지에서 가장 크게 저해되었다. B. bassiana는 $25^{\circ}C$에서 6일간 배양했을 때 F. oxysporum에 대한 항균력이 가장 높았으며 동시에 최대의 균체량을 생산하였다. 또한 B. bassiana의 배양여액을 식물병원균에 30% 농도로 첨가하여 배양했을 때 식물병원균의 포자 발아율은 B. cinerea, F. oxysporum에서 각각 30%(control: 88.2%), 10.0%(control: 78.6%)로 낮아졌으며 발아 개시 시간도 4~8시간 지연되었다. 현미경을 통한 미세구조관찰에서는 10%의 B. bassiana배양여액을 첨가했을 때 F. oxysporum의 포자 크기가 1/2~1/3으로 줄어들었으며 균사와 격막의 형태도 비정상적으로 변하여 균사외막과 격막-격막 사이의 구분이 불명확해졌다.

• 농약과학회지
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• 제10권3호
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• pp.201-209
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• 2006

43종의 식물오일들을 대상으로 잿빛곰팡이병균 (Botrytis cinerea) 외 9종의 식물병원균에 대한 살균 효과로 이들의 생리활성 검증을 실시하였다. 이 중 thyme 오일이 잿빛곰팡이병균(Botrytis cinerea), 잎집무늬 마름병균(Rhizoctonia solani), 고추역병균(Phytophthora capsici), 고추탄저병균(Glomerella cingulate), 사과점무늬 낙엽병균(Alternaria mali)과 벼도열병균(Magnaporthe grisea)에서 광범위하게 살균효과를 나타내었다. Thyme 오일의 주성분을 GC/MS로 분석한 결과 thymol, carvacrol, borneol, linalool과 p-cymene임을 확인하였다. 이 중 thymol과 carvacrol이 높은 살균활성을 나타내었다. 한편, 식물병원균에 대한 살균활성관련 작용기작을 실험한 결과, 잿빛곰팡이병균(Botrytis cinerea), 잎집무늬마름병균(Rhizoctonia solani)과 사과점무늬낙엽병균(Alternaria mali)의 포자발아를 억제하는 것으로 나타났다. Thymol과 carvacrol은 in vivo에서 잿빛곰팡이병균(Botrytis cinerea)과 잎집무늬마름병균(Rhizoctonia solani)에 대하여 높은 예방효과를 나타내었으며, thymol, carvacrol의 유사구조를 갖는 alkylphenol계 화합물들도 살균활성이 있음을 검정하였다.

• 한국균학회지
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• 제39권2호
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• pp.126-130
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• 2011

작물의 생육촉진 및 식물 진균병의 생물방제능을 동시에 나타내는 다기능성 미생물제제를 개발하고자 토양으로부터 분리하여 보관중인 세균 120종의 활성을 검토하였다. 그 중 siderophore를 생성하고 항진균 활성을 보이는 BS11-1, BS11-2, BS11-3를 선발하였다. 이들 균주는 cellulase, protease 같은 lytic enzyme을 생산하였으며 식물성장 촉진 호르몬중의 하나인 IAA를 생성하였다. 이들 선발균들에 의한 식물 생장 촉진을 조사한 결과, BS11-1, BS11-2, BS11-3 균 배양액 관주 시 고추 유묘의 생육을 132%, 122%, 120% 증가 시켰으며, BS11-1, BS11-2 균주의 경우 뿌리의 신장 및 생육이 촉진되었음을 확인 할 수 있었다.

• 생명과학회지
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• 제17권7호통권87호
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• pp.983-989
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• 2007

Auxin, siderophore, 그리고 cellulase를 동시에 생산하는 생물방제균주 B. licheniformis Kll을 식물병원성진균을 대상으로 균사 성장억제능을 확인결과 6종의 식물병원성 진균에서 균사체 성장억제능을 확인하였으며, 그 중에서 토마토 시들음병을 유발하는 F. oxysporum(KACC 40037)에 가장 강력한 억제능을 나타내었다. 그리고 본 균주가 생산하는 항진균성 siderophore이외에 세포벽이 cellulose로 구성된 P. capsici의 cell wall을 분해하는 cellulase를 생산하는 것을 추가적으로 확인하였다. 뿐만아니라 B. licheniformis Kll은 nutrient broth(pH 8.0), $30{\circ}C$에서 96시간 배양시 토마토 시들음병에 대한 항진균 활성이 가장 높았고, 이는 cellulase의 활성과 sideropore의 최대 생산조건과는 상이하였다. 또한 탄소원과 질소원으로 starch와 urea를 각각 첨가시 항진균성 활성이 가장 높았고, 이 역시는 cellulase의 활성과 항진균성 siderophore의 최대 생산조건과 일치하지 않았다. 그리하여 본균주 B. licheniformis Kll은 식물성장촉진 물질은 auxin, 항진균성 siderophore와 cellulase를 생산함과 동시에 또 다른 강력한 항진균성 물질을 생산하는 것을 추가로 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제7권2호
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• pp.107-113
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• 1997

A strain producing a high amount of chitinase was isolated from soil, identified as Pseudomonas sp., and tentatively named Pseudomonas sp. YHS-A2. An extracellular chitinase of Pseudomonas sp. YHS-A2 was purified according to the procedure of ammonium sulfate saturation, affinity adsorption, Sephadex G-100 gel filtration and Phenyl-sepharose CL-4B hydrophobic interaction column chromatography. The molecular weight of the purified enzyme was estimated to be 55 kDa on SDS-PAGE was confirmed by active staining. Optimal pH and temperature of the enzyme are pH 7.0 and $50^{\circ}C$, respectively, and the enzyme is stable between pH 5.0 and 8.0 and below $50^{\circ}C$. The main products of colloidal chitin by the chitinase were N-acetyl-D-glucosamine and N,N'-diacetylchitobiose both of which were detected by HPLC analysis. The enzyme is supposed to be a random-type endochitinase which can degrade any position of ${\beta}$-l,4-linkages of chitin and chitooligosaccharides. The chitinase inhibited the growth of some phytopathogenic fungi, Fusarium oxysporum, Botrytis cineria, and Mucor rouxii and these antifungal effects were thought to be due to the characteristics of endochitinase.

• 한국토양비료학회지
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• 제47권4호
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• pp.299-305
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• 2014

In this paper, fractional factorial screening design (FFSD) and central composition design (CCD) were used to optimize the medium components for producing chitinase and gelatinase by Lysobacter capsici YS1215. Crab shell powder, nutrient broth and gelatin were proved to have significant effects on chitinase and gelatinase activity by FFSD first. An optimal medium was obtained by using a three factor CCD, which consisted of nutrient broth of $2.0gL^{-1}$, crab shell powder of $2.0gL^{-1}$ and gelatin of $1.0gL^{-1}$, respectively with the highest chitinase activity ($3.34UmL^{-1}$) and gelatinase activity ($14.15UmL^{-1}$). This value was 3.76 and 1.11 fold of the chitinase and gelatinase activity, respectively, compared to the lowest productive medium in the design matrix. In investigating potential of these enzymes partially purified from L. capsici YS1215 for biotechnological use, the crude enzymes was found to be inhibition against pathogenic fungal mycelia: Colletotrichum gleosporioides, Phytophthora capsici, and Rhizoctonia solani. In this study, we demonstrated the optimal medium for producing the chitinolytic and gelatinolytic enzymes by the strain YS1215 and the role of their enzymes that may be useful for further development of a biotechnological use and agricultural use for biological control of phytopathogenic fungi.

• The Plant Pathology Journal
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• 제31권3호
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• pp.278-289
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• 2015

Indigenous strains of Trichoderma species isolated from rhizosphere soils of Tea gardens of Assam, north eastern state of India were assessed for in vitro antagonism against two important tea fungal pathogens namely Pestalotia theae and Fusarium solani. A potent antagonist against both tea pathogenic fungi, designated as SDRLIN1, was selected and identified as Trichoderma viride. The strain also showed substantial antifungal activity against five standard phytopathogenic fungi. Culture filtrate collected from stationary growth phase of the antagonist demonstrated a significantly higher degree of inhibitory activity against all the test fungi, demonstrating the presence of an optimal blend of extracellular antifungal metabolites. Moreover, quantitative enzyme assay of exponential and stationary culture filtrates revealed that the activity of cellulase, ${\beta}$-1,3-glucanase, pectinase, and amylase was highest in the exponential phase, whereas the activity of proteases and chitinase was noted highest in the stationary phase. Morphological changes such as hyphal swelling and distortion were also observed in the fungal pathogen grown on potato dextrose agar containing stationary phase culture filtrate. Moreover, the antifungal activity of the filtrate was significantly reduced but not entirely after heat or proteinase K treatment, demonstrating substantial role of certain unknown thermostable antifungal compound(s) in the inhibitory activity.