• Journal of Microbiology and Biotechnology
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• 제24권1호
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• pp.13-18
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• 2014

Bacillus subtilis JW-1 was isolated from rhizosphere soil as a potential biocontrol agent of bacterial wilt caused by Ralstonia solanacearum. Seed treatment followed by a soil drench application with this strain resulted in >80% reduction in bacterial wilt disease compared with that in the untreated control under greenhouse conditions. The antibacterial compound produced by strain JW-1 was purified by bioactivity-guided fractionation. Based on mass spectroscopy and nuclear magnetic resonance spectral data ($^1H$, $^{13}C$, $^1H-^1H$ correlation spectroscopies, rotating frame nuclear Overhauser effect spectroscopy, and heteronuclear multiple-bond correlation spectroscopy), the structure of this compound was elucidated as a cyclic lipopeptide composed of a heptapeptide (Gln-Leu-Leu-Val-Asp-Leu-Leu) bonded to a ${\beta}$-hydroxy-iso-hexadecanoic acid arranged in a lactone ring system.

• 한국균학회지
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• 제24권4호통권79호
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• pp.310-321
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• 1996

토양으로부터 항진균 활성을 나타내는 5종류의 Pseudomonas cepacia 균주 AF027, AF069, AF2001, AF2011, SD02가 분리되었으며 이들은 각각 cyclic lipopeptide계 항진균 물질 CLP027A, CLP069A, Cepacidine A, CLP2011A, CLP02A를 생산하였다. 조사된 P cepacia 균주들은 배지중에 함유된 질소원 및 탄소원의 종류에 따라 항진균 물질 생산성에 현저한 차이가 있었는데, 질소원으로서는 polypeptone-S, 탄소원으로서는 glucose와 fructose가 생산성 증대에 가장 효과적이었다. 항진균물질 $CLP069A_1$과 $CLP069A_2$는 각각 분자량이 1215와 1199이며, 아미노산 조성, UV spectrum, IR spectrum 및 항진균 스펙트럼에 있어서, Xylocandin $A_1,\;A_2$와 일치하였으며, CLP027 $A_1$과 $A_2$ 또한 이러한 물리 화학적 특성이 Cepacidine A와 완전히 일치함으로써 동일 물질로 생각된다. $CLP2011A_1,\;A_2$와 $CLP02A_1,\;A_2$는 아미노산 조성 및 항진균 스펙트럼이 Xylocandin $A_1,\;A_2$와 다르고, Cepacidine $A_1,\;A_2$와는 항진균 스펙트럼에서 현저하게 차이가 났다. CLP2011A, CLP02A가 분자량, 아미노산 조성, UV spectrum, IR spectrum에서 Cepacidine A와 동일하지만 항진균 스펙트럼이 상이한 것은 이들이 다른 물질임을 시사하며, 이는 aliphatic side chain이 Cepacidine A의 그것과 다른 데에서 비롯된 분자구조의 상이함에서 기인된 것으로 추론된다.

• The Plant Pathology Journal
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• 제32권3호
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• pp.273-280
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• 2016

Most biocontrol agents for plant diseases have been isolated from sources such as soils and plants. As an alternative source, we examined the feces of tertiary larvae of the herbivorous rhino beetle, Allomyrina dichotoma for presence of biocontrol-active microbes. The initial screen was performed to detect antifungal activity against two common fungal plant pathogens. The strain with strongest antifungal activity was identified as Bacillus amyloliquefaciens KB3. The inhibitory activity of this strain correlated with lipopeptide productions, including iturin A and surfactin. Production of these surfactants in the KB3 isolate varied with the culture phase and growth medium used. In planta biocontrol activities of cell-free culture filtrates of KB3 were similar to those of the commercial biocontrol agent, B. subtilis QST-713. These results support the presence of microbes with the potential to inhibit fungal growth, such as plant pathogens, in diverse ecological niches.

• 생명과학회지
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• 제25권8호
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• pp.910-916
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• 2015

최근 식물 성장에 있어 곰팡이 독소에 관련된 질병에 효과가 있는 Bacillus mojavensis 균주 사용의 보고가 있다. 우리는 B. mojavensis KJS-3균주의 다양한 온도, 염도, 에탄올, pH에서 성장하는 특징을 확인 하였다. B. mojavensis KJS-3균주는 Polymerase chain reaction 분석에 의해 fengycin을 LC-MS/MS 분석을 통해서는 iturin 및 surfactin 와 같은 cyclic lipopeptides를 생산함을 확인 하였다. B. mojavensis KJS-3균주는 식물 유해 곰팡이 균주인 Botrytis cinerea, Rhizoctonia solani AG-4, Sclerotinia sclerotiorum, Colletotricum goeosporioides에 항곰팡이 효과가 있음을 확인하였고 이 결과를 바탕으로 인삼재배에 있어 B. mojavensis KJS-3를 사용하여 성장을 관찰한 결과 뿌리 내에서 성장하여 plant growth promoting endophyte가 있음을 알 수 있었다. 이러한 특징들에 의해 미생물 농약 및 비료로 사용할 수 있을 것이다.

• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.480-491
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• 2017

Fluorescent pseudomonads have been isolated from halophytes, mesophytes, and xerophytes of Pakistan. Among these, eight isolates, GS-1, GS-3, GS-4, GS-6, GS-7, FS-2 (cactus), ARS-38 (cotton), and RP-4 (para grass), showed antifungal activity and were selected for detailed study. Based on biochemical tests and 16S rRNA gene sequences, these were identified as strains of P. chlororaphis subsp. chlororaphis and aurantiaca. Secondary metabolites of these strains were analyzed by LC-MS. Phenazine-1-carboxylic acid (PCA), 2-hydroxy-phenazine, Cyclic Lipopeptide (white line-inducing principle (WLIP)), and lahorenoic acid A were detected in variable amounts in these strains. P. aurantiaca PB-St2 was used as a reference as it is known for the production of these compounds. The phzO and PCA genes were amplified to assure that production of these compounds is not an artifact. Indole acetic acid production was confirmed and quantified by HPLC. HCN and siderophore production by all strains was observed by plate assays. These strains did not solubilize phosphate, but five strains were positive for zinc solubilization. Wheat seedlings were inoculated with these strains to observe their effect on plant growth. P. aurantiaca strains PB-St2 and GS-6 and P. chlororaphis RP-4 significantly increased both root and shoot dry weights, as compared with uninoculated plants. However, P. aurantiaca strains FS-2 and ARS-38 significantly increased root and shoot dry weights, respectively. All strains except PB-St2 and ARS-38 significantly increased the root length. This is the first report of the isolation of P. aurantiaca from cotton and cactus, P. chlororaphis from para grass, WLIP and lahorenoic acid A production by P. chlororaphis, and zinc solubilization by P. chlororaphis and P. aurantiaca.