Studies on Cyanobacterial Cyderophores

蓝藻是原核浮游植物，是水环境中具有代表性的初级生产者。它们利用各种含铁的催化作用进行光合作用，其中许多物种还可以通过富铁酶固氮。然而，目前对蓝藻获取铁的分子机制知之甚少。在本报告中，我报道了第一个真正的蓝藻铁载体从淡水蓝藻固氮能力。不同淡水蓝藻铁载体生产活性的筛选为了进行大规模筛选，从NIES、PCC、UTEX和IAM四个培养物收集地选择了41株淡水蓝藻纯菌株。在该筛选中，所有铜绿微囊藻菌株均未显示铁载体生产活性。另一个值得注意的结果是，大多数异囊重氮营养物种产生铁载体。这个结果给了我一个 ...更多信息 异囊藻种具有产生铁载体以维持固氮酶（一种富含铁的蛋白质）固氮的能力。Anachelin-2和Anachelin是从Anabaena cylindrica NIES-19中分离得到的两种蓝藻铁载体。经HRFAB-MS分析确定其分子式为C35 H49 O 13 N6。这些化合物的结构均通过COSY、HMQC、1H-13 C HMBC和1H-15 N HMBC等2D NMR分析确定. Schizokinen是变异鱼腥藻M-204和NIES-23产生的铁载体。variabilis（M-204，NIES-23）在Csaky试验中也呈阳性，表明该化合物是异羟肟酸盐型铁载体，即铁基宁。通过核磁共振谱分析确定了其结构.细颤藻（Oscillatoria tenuis）UTEX 1566产生的一种新型铁载体--颤杆菌素（Oscillabactin）。Oscillabactin是第一个含有羟基吡啶酮结构作为铁结合基团的铁载体。少

Cyanobacteria are the prokaryotic phytoplankton and the representative primary producer in aquatic environment. They perform oxygenic photosynthesis using various iron-containing catalysis, and many species of them can also fix nitrogen by the iron-rich enzyme, nitrogenase. However little is known about the molecular mechanism to acquire the iron of cyanobacteria. In this report, I reported the first genuine Cyanobacterial siderophores from the freshwater cyanobacteria with nitrogen fixation ability.1. Screening for siderophore productive activity of various freshwater Cyanobacterial speciesFor large-scale screening, 41 axenic strains of freshwater cyanobacteria were selected and obtained from four culture collections, NIES, PCC, UTEX and IAM. In this screening, all strains of Microcystis aeruginosa did not show siderophore productive activity. The other noticeable result in this screening was that most of heterocystous diazotrophic species produced siderophores. This result gave me a … More hypothesis that heterocystous species had the faculty of producing siderophores to maintain their nitrogenase, an iron-rich protein, for nitrogen fixation.2. Anachelins, novel siderophores produced by Anabaena cylindrica NIES-19Novel Cyanobacterial siderophores, Anachelin-2 and Anachelin were isolated from Anabaena cylindrica NIES-19. The molecular formula of these compounds were determined to be C35H49013N6 from HRFAB-MS analysis. These structures were decided 2D NMR analyses including COSY, HMQC, 1H-13C HMBC, and 1H-15N HMBC experiments.3. Schizokinen, a siderophore produced by two strains of Anabaena variabilis M-204 and NIES-23Isolated siderophores from A. variabilis(M-204, NIES-23) were also positive in the Csaky test, indicating that this compound was a hydroxamate-type siderophore, schizokinen. The structure of schizokinen was confirmed by NMR analysis.4. Oscillabactin, a novel siderophore produced by Oscillatoria tenuis UTEX1566We isolated a novel Cyanobacterial siderophore, oscillabactin from Oscillatoria tenuis UTEX 1566. Oscillabactin is the first siderophore containing the hydroxypyridinone structure as the iron-binding group. Less