State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China.
Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China.
Appl Environ Microbiol. 2018 Dec 13;85(1). doi: 10.1128/AEM.01938-18. Print 2019 Jan 1.
Many bacteria secrete siderophores to enhance iron uptake under iron-restricted conditions. In this study, we found that JMP134, a well-known aromatic pollutant-degrading bacterium, produces an unknown carboxylate-type siderophore named cupriabactin to overcome iron limitation. Using genome mining, targeted mutagenesis, and biochemical analysis, we discovered an operon containing six open reading frames () in the JMP134 genome that encodes proteins required for the biosynthesis and uptake of cupriabactin. As the dominant siderophore of JMP134, cupriabactin promotes the growth of JMP134 under iron-limited conditions via enhanced ferric iron uptake. Furthermore, we demonstrated that the iron concentration-dependent expression of the operon is mediated by the ferric uptake regulator (Fur). Physiological analyses revealed that the cupriabactin-mediated iron acquisition system influences swimming motility, biofilm formation, and resistance to oxidative and aromatic compound stress in JMP134. In conclusion, we identified a carboxylate-type siderophore named cupriabactin, which plays important roles in iron scavenging, bacterial motility, biofilm formation, and stress resistance. Since siderophores have been widely exploited for agricultural, environmental, and medical applications, the identification and characterization of new siderophores from different habitats and organisms will have great beneficial applications. Here, we identified a novel siderophore-producing gene cluster in JMP134. This gene cluster produces a previously unknown carboxylate siderophore, cupriabactin. Physiological analyses revealed that the cupriabactin-mediated iron acquisition system influences swimming motility, biofilm formation, and oxidative stress resistance. Most notably, this system also plays important roles in increasing the resistance of JMP134 to stress caused by aromatic compounds, which provide a promising strategy to engineer more efficient approaches to degrade aromatic pollutants.
许多细菌会分泌铁载体以在缺铁条件下增强铁的摄取。在这项研究中，我们发现，JMP134，一种众所周知的芳香族污染物降解细菌，会产生一种未知的羧酸盐型铁载体，命名为 Cupriabactin，以克服铁限制。通过基因组挖掘、靶向诱变和生化分析，我们在 JMP134 基因组中发现了一个包含六个开放阅读框（ORFs）的操纵子，该操纵子编码 Cupriabactin 生物合成和摄取所需的蛋白。作为 JMP134 的主要铁载体，Cupriabactin 通过增强三价铁的摄取促进 JMP134 在缺铁条件下的生长。此外，我们证明，该操纵子的铁浓度依赖性表达是由铁摄取调节剂（Fur）介导的。生理分析表明，Cupriabactin 介导的铁获取系统影响 JMP134 的游泳运动性、生物膜形成以及对氧化和芳香族化合物应激的抗性。总之，我们鉴定了一种名为 Cupriabactin 的羧酸盐型铁载体，它在铁获取、细菌运动性、生物膜形成和应激抗性中发挥重要作用。由于铁载体已广泛应用于农业、环境和医学领域，因此从不同生境和生物体中鉴定和表征新的铁载体将具有重要的应用价值。在这里，我们在 JMP134 中鉴定了一个新的铁载体产生基因簇。该基因簇产生了一种以前未知的羧酸盐铁载体 Cupriabactin。生理分析表明，Cupriabactin 介导的铁获取系统影响游泳运动性、生物膜形成和氧化应激抗性。值得注意的是，该系统在增加 JMP134 对芳香族化合物应激的抗性方面也起着重要作用，这为设计更有效的方法来降解芳香族污染物提供了一种有前景的策略。
