Bacteria and fungi secrete many natural products that inhibit each other’s growth and development. The dynamic changes in secreted metabolites that occur during interactions between bacteria and fungi are complicated. Pyochelin is a siderophore produced by many Pseudomonas and Burkholderia species that induces systemic resistance in plants and has been identified as an antifungal agent. Through imaging mass spectrometry and metabolomics analysis, we found that Phellinus noxius, a plant pathogen, can modify pyochelin and ent-pyochelin to an esterification product, resulting in reduced iron-chelation and loss of antifungal activity. We also observed that dehydroergosterol peroxide, the fungal metabolite, is only accumulated in the presence of pyochelin produced through bacteria–fungi interactions. For the first time, we show the fungal transformation of pyochelin in the microbial interaction. Our findings highlight the importance of understanding the dynamic changes of metabolites in microbial interactions and their influences on microbial communities.

细菌和真菌会分泌许多抑制彼此生长发育的天然产物。在细菌和真菌相互作用过程中发生的分泌代谢物的动态变化是复杂的。Pyochelin 是一种由许多假单胞菌属和伯克霍尔德菌属物种产生的铁载体，可在植物中诱导系统抗性，并已被确定为抗真菌剂。通过成像质谱和代谢组学分析，我们发现桑黄这种植物病原菌可以修饰绿脓杆菌和耳鼻喉科植物。-pyochelin 为酯化产物，导致铁螯合减少和抗真菌活性丧失。我们还观察到，过氧化氢麦角甾醇（真菌代谢物）仅在细菌-真菌相互作用产生的脓毒杆菌素存在的情况下才会积累。我们首次展示了真菌在微生物相互作用中的转化。我们的研究结果强调了了解代谢物在微生物相互作用中的动态变化及其对微生物群落的影响的重要性。