Institut für Mikrobiologie, Mikrobielle Phytopathologie, Friedrich-Schiller-Universität Jena, Neugasse 25, D-07743 Jena, Germany.
Appl Environ Microbiol. 2009 Dec;75(24):7710-7. doi: 10.1128/AEM.01244-09. Epub 2009 Oct 9.
The epiphyte Pantoea agglomerans 48b/90, which has been isolated from soybean leaves, belongs to the Enterobacteriaceae, as does the plant pathogen Erwinia amylovora, which causes fire blight on rosaceous plants such as apples and leads to severe economic losses. Since P. agglomerans efficiently antagonizes phytopathogenic bacteria, the P. agglomerans strain C9-1 is used as a biocontrol agent (BlightBan C9-1). Here we describe the bioassay-guided isolation of a peptide antibiotic that is highly active against the plant pathogen E. amylovora and pathovars of Pseudomonas syringae, and we elucidate its structure. Bioassay-guided fractionation using anion-exchange chromatography followed by hydrophobic interaction liquid chromatography yielded the bioactive, highly polar antibiotic. The compound was identified as 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine by using high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance techniques. This peptide was found to be produced by three of the nine P. agglomerans strains analyzed. Notably, the biocontrol strain P. agglomerans C9-1 also produces 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine. Previously, 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine has been characterized only from Serratia plymuthica. 2-Amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine has been shown to inhibit the growth of the human pathogen Candida albicans efficiently, but its involvement in the defense of epiphytes against phytopathogenic bacteria has not been investigated so far.
从大豆叶片中分离得到的植物病原菌革兰氏阴性菌成团泛菌 48b/90 属于肠杆菌科，而导致蔷薇科植物（如苹果）发生火疫病的植物病原菌梨火疫病菌也属于肠杆菌科。由于成团泛菌能够有效拮抗植物病原菌，因此成团泛菌菌株 C9-1 被用作生物防治剂（BlightBan C9-1）。在这里，我们描述了一种具有高度抗植物病原菌梨火疫病菌和丁香假单胞菌变种活性的肽类抗生素的生物测定指导分离，并阐明了其结构。使用阴离子交换色谱和疏水性相互作用液相色谱进行生物测定指导的分级分离，得到了具有生物活性的高极性抗生素。通过使用高分辨率电喷雾电离质谱和核磁共振技术，该化合物被鉴定为 2-氨基-3-（环氧乙烷-2,3-二羧酸酰胺基）-丙酰缬氨酸。研究发现，在所分析的 9 株成团泛菌菌株中有 3 株能够产生这种肽。值得注意的是，生物防治菌株成团泛菌 C9-1 也能产生 2-氨基-3-（环氧乙烷-2,3-二羧酸酰胺基）-丙酰缬氨酸。以前，仅从粘质沙雷氏菌中鉴定出 2-氨基-3-（环氧乙烷-2,3-二羧酸酰胺基）-丙酰缬氨酸。已证明 2-氨基-3-（环氧乙烷-2,3-二羧酸酰胺基）-丙酰缬氨酸能够有效抑制人类病原体白色念珠菌的生长，但迄今为止，其在防御植物病原菌方面的作用尚未得到研究。
