Original paper

Structural and ultrastructural characterization of several culture strains assigned to Oscillatoria and Lyngbya (Cyanophyta/Cyanoprokaryota/Cyanobacteria)

Porta, David; Hernández-Mariné, Mariona


Several cyanobacterial strains from different environments and maintained in culture, which were assigned to the genera Oscillatoria (strains PCC 7515, PCC 8704, PCC 8903, PCC 9014) and Lyngbya (strains PCC 7419, PCC 8937, PCC 8992), were characterized at the structural and ultrastructural levels using both a confocal laser scanning microscope and a transmission electron microscope. The strains consisted of ensheathed filaments without ramifications, whose cells were disk-shaped and had two rows of junctional pores surrounding the cross walls. Mainly peripheral waved thylakoids were present, being arranged nearly radial in most of them. Several cell inclusions of irregular occurrence were characteristic of each strain. A compacted nucleoid divided simultaneously with cell division, which was demonstrated to be continuous in strains PCC 7515 and PCC 8937. Trichome reproduction was mainly mediated by necridia. A detailed comparison among the morphological features of the studied strains found no clear differences among them included either to Oscillatoria or Lyngbya, and suggested that the different inclusions shown are not taxonomically significant. Notwithstanding, the strains PCC 7515 and PCC 8937 are different from the other ones, and might be considered as in a group apart.


confocal microscopynucleoidsytox greentransmission electron microscopyultrastructure