The development of sustainable agriculture and the increasing antibiotic resistance of human pathogens call for novel antimicrobial compounds. Here, we describe the extraction and characterization of a class of cationic circular lipopeptides, for which we propose the name relacidines, from the soil bacterium Brevibacillus laterosporus MG64. Relacidines are composed of a fatty acid side chain (4‐methylhexanoic acid) and 13 amino acid residues. A lactone ring is formed by the last five amino acid residues and three positively charged ornithines are located in the linear fragment. Relacidines selectively combat Gram‐negative pathogens, including phytopathogens and human pathogens. Further investigation of the mode of action revealed that relacidine B binds to the lipopolysaccharides but does not form pores in the cell membrane. We also provide proof to show that relacidine B does not affect the biosynthesis of the cell wall and RNA. Instead, it affects the oxidative phosphorylation process of cells and diminishes the biosynthesis of ATP. Transcription of relacidines is induced by plant pathogens, which strengthens the potential of B. laterosporus MG64 to be used as a biocontrol agent. Thus, we identified a new group of potent antibiotic compounds for combating Gram‐negative pathogens of plants or animals.

中文翻译：

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表征属于一类新型环状脂肽的两种赖氨嘧啶，它们可抵抗革兰氏阴性细菌病原体。

可持续农业的发展以及人类病原体对抗生素的耐药性不断提高，都需要新型的抗菌化合物。在这里，我们描述了从土壤细菌Bratebacillus Laterosporus的一类阳离子环状脂肽的提取和表征，为此，我们提出了名称为relacidines的方法。MG64。甲氨蝶呤由脂肪酸侧链（4-甲基己酸）和13个氨基酸残基组成。内酯环由最后五个氨基酸残基形成，三个带正电荷的鸟嘌呤位于线性片段中。甲氨蝶呤选择性地对抗革兰氏阴性病原体，包括植物病原体和人类病原体。对作用方式的进一步研究表明，雷卡替丁B与脂多糖结合，但未在细胞膜上形成孔。我们还提供证据表明，甲氨蝶呤B不会影响细胞壁和RNA的生物合成。相反，它影响细胞的氧化磷酸化过程并减少ATP的生物合成。植物病原体诱导relacidines的转录，这增强了B.lateosporus的潜力MG64用作生物防治剂。因此，我们确定了一组新的有效的抗生素化合物来对抗动植物的革兰氏阴性病原体。