SGER: Development of a Reporter System Regulated by the Biological Availability of Fe in Saltwater

铁（Fe）作为海洋系统中生物生产力的限制因子的作用已被广泛研究。已知海洋原核生物响应于铁限制性生长条件而保持产生铁载体（或至少铁载体样化合物）的能力。 虽然研究分析技术可以量化总铁在令人难以置信的小浓度，并提供信息的铁形态，我们仍然没有指标的生物可用性，这铁的自然社区。 为了了解铁在全球海洋生产力中的作用，需要量化真正生物可利用铁的工具/技术。 由于水生系统中的生物可以确定自己的铁状态，基于海洋生物的铁传感系统的工具将是最好的。 研究人员开发了一种具有发光报告基因的基因工程微生物（GEM），该报告基因使用海洋细菌的天然铁吸收调节因子（Fur）蛋白直接响应Fe的生物利用度。 研究人员现在将尝试将报告基因整合到其他10种海洋细菌中。 实验室实验将建立铁的生物利用度和光的产生之间的关系。 将在马尾藻海、伊利湖和秘鲁上升流区域的机会巡航中对作为Fe生物利用度报告者的GEM进行实地测试。

The role of iron (Fe) as a limiting agent of biological productivity in marine systems has been studied extensively. Marine prokaryotic organisms are known to maintain the ability to produce siderophore (or at least siderophore-like compounds) in response to Fe-limiting growth conditions. While research analytical techniques can quantify total Fe at incredibly small concentrations and provide information on Fe speciation, we remain without indicators of the biological availability of this Fe to natural communities. To understand the role that Fe plays in global marine productivity, tools/techniques for quantifying truly bioavailable iron are needed. Since organisms in aquatic systems can determine their own Fe status, a tool based on the Fe sensing system of a marine organism would be the best. The investigators have developed a genetically engineered microorganism (GEM) with a luminescent reporter that directly responds to Fe bioavailability using the native ferric-uptake-regulator (Fur) protein of a marine bacterium. The researchers will now attempt integration of the reporter into ten other strains of marine bacteria. Laboratory experiments will establish the relationship between Fe bioavailability and light production. Field testing of the GEMs as Fe bioavailability reporters will be conducted on cruises of opportunity in the Sargasso Sea, Lake Erie, and the Peru upwelling region.