The alkaliphilic cyanobacterium Limnospira fusiformis is an integral part in food webs of tropical soda lakes. Recently, sudden breakdowns of Limnospira sp. blooms in their natural environment have been linked to cyanophage infections. We studied ultrastructural details and prophage components in the laboratory by means of confocal laser scanning microscopy (CLSM) and transmission electron microscopy (TEM). For a comparison at the subcellular level, we included transmission electron microscopy (TEM) material of infected cells collected during a field survey. Compared to TEM, CLSM has the advantage to rapidly providing results for whole, intact cells. Moreover, many cells can be studied at once. We chemically induced lysogenic cyanophages by means of mitomycin C (MMC) treatments and studied the ultrastructural alterations of host cells. In parallel, the number of cyanophages was obtained by flow cytometry. After treatment of the culture with MMC, flow cytometry showed a strong increase in viral counts, i.e., prophage induction. CLSM reflected the re-organization of L. fusiformis with remarkable alterations of thylakoid arrangements after prophage induction. Our study provides a first step towards 3D visualization of ultrastructure of cyanobacteria and showed the high potential of CLSM to investigate viral-mediated modifications in these groups.

嗜碱蓝藻Limnospira fusiformis是热带苏打湖食物网中不可或缺的一部分。最近，Limnospira突然崩溃sp。自然环境中的水华与噬藻体感染有关。我们在实验室通过共聚焦激光扫描显微镜 (CLSM) 和透射电子显微镜 (TEM) 研究了超微结构细节和前噬菌体成分。为了在亚细胞水平上进行比较，我们包括在实地调查期间收集的感染细胞的透射电子显微镜 (TEM) 材料。与 TEM 相比，CLSM 具有快速提供完整细胞结果的优势。此外，可以同时研究许多细胞。我们通过丝裂霉素 C (MMC) 处理化学诱导溶原性噬藻体，并研究了宿主细胞的超微结构变化。同时，通过流式细胞术获得噬藻体的数量。用 MMC 处理培养物后，流式细胞术显示病毒计数强烈增加，即，原噬菌体诱导。CLSM反映了重组L. fusiformis在前噬菌体诱导后类囊体排列发生显着变化。我们的研究为蓝藻超微结构的 3D 可视化迈出了第一步，并显示了 CLSM 在研究这些群体中病毒介导的修饰方面的巨大潜力。