Competition for limited iron resources is a key driver of microbial community structure in many regions of the surface ocean. The bacterial siderophores ferrioxamine and amphibactin have been identified in marine surface waters, suggesting that they may represent an important bacterial strategy for obtaining iron from a scarcely populated pool. Using proteomics, siderophore isolation, and iron uptake experiments, we observed a dynamic proteome response to iron and ferrioxamine treatments by the amphibactin-producing marine bacterium, Vibrio cyclitrophicus str. 1F-53 (V. cyclitrophicus). Proteomic analyses identified upregulation of the amphibactin NRPS system and a putative amphibactin siderophore transporter in response to low iron concentrations. However, when desferrioxamine was present, amphibactin production decreased and an uncharacterized putative ferrioxamine receptor increased in abundance. This suggests that in low Fe conditions, V. cyclitrophicus senses and takes up exogenous ferrioxamine in lieu of producing its own siderophores. Such cheating phenotypes, which appear widespread among marine amphibactin producers, highlight the strategies that contribute to the fitness of marine bacteria in the face of iron stress. These results provide mechanistic information behind the siderophore producer and cheater phenotypes that likely contribute to the ecological success of these microbes across iron-limited marine ecosystems.

有限的铁资源的竞争是表层海洋许多区域微生物群落结构的关键驱动力。在海洋地表水域中已鉴定出细菌铁载体铁氧嘧啶和两性霉素，表明它们可能代表了从人口稀少的池中获取铁的重要细菌策略。使用蛋白质组学，铁载体分离和铁吸收实验，我们观察到了由产两性霉素的海洋细菌，弧菌弧菌对铁和铁氧胺的动态蛋白质组反应。1F-53（圆环菌）。蛋白质组学分析确定了响应低铁浓度的两性霉素NRPS系统和一个可能的两性激素铁转运蛋白的上调。但是，当存在去铁胺时，两性霉素的产量降低，未表征的推定铁氧胺受体的丰度增加。这表明在低铁条件下，圆弧菌感知并吸收外源性铁氧嘧啶来代替产生自己的铁载体。这种作弊表型在海洋两性霉素生产者中普遍存在，突显了在面对铁胁迫时有助于海洋细菌适应的策略。这些结果提供了铁载体生产者和作弊者表型背后的机制信息，这些信息可能有助于这些微生物在铁有限的海洋生态系统中的生态成功。