Grifé-Ruiz Montserrat, Hierrezuelo-León Jesús, de Vicente Antonio, Pérez-García Alejandro, Romero Diego
Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Departamento de Microbiología, Universidad de Málaga, Málaga 29071, Spain.
J Agric Food Chem. 2025 Jan 15;73(2):1403-1416. doi: 10.1021/acs.jafc.4c11372. Epub 2025 Jan 6.
Cyclic lipopeptides (CLPs) are potent secondary metabolites with diverse biological functions. strains primarily produce CLPs of three key families, namely, iturins, fengycins, and surfactins, each comprising structural variants characterized by a cyclic peptide linked to a fatty acid chain. Despite extensive research on CLPs, the individual roles of these analogues and their proportion in driving biological activity have remained largely overlooked. In this study, we purified and chemically characterized CLP variants from UMAF6639 and tested them individually for their antifungal and plant growth-promoting effects. We isolated 5 fractions containing iturin A analogues (from C to C), 5 fengycin fractions (containing C, C, and C fengycin A and C, C, C, and C fengycin B), and 5 surfactin fractions (from C to C). We show how antifungal activity and seed radicle growth promotion relied on the lipopeptide structural variant and concentration based on the physiological ratio calculated for each lipopeptide variant. Notably, we found that the most toxic variants were the least abundant, which likely minimized autotoxicity while preserving bioactivity. This balance is achieved through synergistic interactions with more abundant, less aggressive analogues. Furthermore, certain fengycin and surfactin variants were shown to increase bacterial population density and exopolysaccharide production, crucial strategies for microbial competition with significant ecological impacts. In addition to advancing basic knowledge, our findings will support the development of precision biotechnological innovations, offering targeted solutions to drive sustainable food production and preservation strategies.
环脂肽（CLPs）是具有多种生物学功能的强效次生代谢产物。菌株主要产生三个关键家族的环脂肽，即伊枯草菌素、丰原素和表面活性素，每个家族都包含以与脂肪酸链相连的环肽为特征的结构变体。尽管对环脂肽进行了广泛研究，但这些类似物的个体作用及其在驱动生物活性中的比例在很大程度上仍被忽视。在本研究中，我们从UMAF6639中纯化并对环脂肽变体进行了化学表征，并分别测试了它们的抗真菌和促进植物生长的作用。我们分离出5个含有伊枯草菌素A类似物的组分（从C到C）、5个丰原素组分（含有C、C和C丰原素A以及C、C、C和C丰原素B）和5个表面活性素组分（从C到C）。我们展示了抗真菌活性和促进种子胚根生长如何基于为每个环脂肽变体计算的生理比例依赖于脂肽结构变体和浓度。值得注意的是，我们发现毒性最大的变体含量最少，这可能在保持生物活性的同时将自毒性降至最低。这种平衡是通过与含量更高、攻击性更小的类似物的协同相互作用实现的。此外，某些丰原素和表面活性素变体被证明可增加细菌种群密度和胞外多糖产量，这是微生物竞争的关键策略，具有重大的生态影响。除了推进基础知识外，我们的研究结果将支持精准生物技术创新的发展，提供有针对性的解决方案以推动可持续粮食生产和保鲜策略。
