The role of the ionophore calcimycin in the fight for iron

离子载体钙霉素在争夺铁中的作用

• 批准号: 323951376
• 负责人: Professorin Dr. Julia Bandow
• 金额: --
• 依托单位: Lehrstuhl für Angewandte Mikrobiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/323951376?language=en
• 关键词: role; ionophore; calcimycin; fight; iron

Calcimycin produced by the soil bacterium Streptomyces chartreusis is a carrier ionophore that transports bivalent metal cations. It can only cross membranes as a calcimycin-cation complex, so that overall transport is electroneutral. We could show that in soil-dwelling Bacillus subtilis, calcimycin disturbs the metal homeostasis, causing depletion of cellular iron and manganese while calcium accumulates. Antibacterial activity of the ionophore increases under low-iron and low-manganese conditions. B. subtilis responds to calcimycin by upregulating siderophore synthesis and the oxidative stress response.Since iron is a highly contested micronutrient in soil, we seek a better understanding of the role of calcimycin in the fight for iron. Does calcimycin primarily serve to eliminate competitors? Is calcimycin a sophisticated tool for stealing iron from other soil-dwellers? Does it prompt xenosiderophore production for exploitation of additional iron sources? To address these questions we will investigate the contributions of calcium influx and iron/manganese efflux to the antibacterial effects of calcimycin. We will quantify calcimycin and siderophore levels in mixed cultures of S. chartreusis and B. subtilis and study the iron flux in mixed cultures employing wild-type strains as well as calcimycin-deficient S. chartreusis and siderophore-deficient B. subtilis strains.

由土壤细菌Streptomyces chartreusis产生的钙霉素是一种转运二价金属离子的载体离子载体。它只能以钙霉素-阳离子复合物的形式穿过细胞膜，因此整个转运是电中性的。我们可以证明，在土壤中的枯草芽孢杆菌，卡西霉素扰乱金属稳态，导致细胞铁和锰的消耗，而钙积累。离子载体的抗菌活性在低铁和低锰条件下增加。B。枯草杆菌通过上调铁载体合成和氧化应激反应来响应卡西霉素。由于铁是土壤中高度竞争的微量营养素，我们寻求更好地了解卡西霉素在争夺铁中的作用。卡西霉素是否主要用于消除竞争对手？卡西霉素是一种从其他土壤居民那里窃取铁的复杂工具吗？它是否会促进异铁载体的生产，以开发额外的铁源？为了解决这些问题，我们将研究钙内流和铁/锰外流对卡西霉素抗菌作用的贡献。我们将定量卡昔霉素和铁载体水平在混合培养的S。chartreusis和B.枯草杆菌和研究铁通量的混合培养物采用野生型菌株以及钙霉素缺陷的S。chartreusis和铁载体缺陷型B。枯草杆菌菌株