Characteristics of cyanobacterium Pseudanabaena galeata CCNP1313 from the Baltic Sea

Abstract Cyanobacteria of the genus Pseudanabaena are ubiquitous organisms present in diverse ecosystems worldwide. So far, mainly the taxonomy, toxicity and pigment content in members of the genus have been studied. In the current work, we present a detailed characterization of the Baltic Pseudanabaena strain CCNP1313. The results of ultrastructural studies and genetic analyses (16S-ITS-23S rDNA, rbcLX and mcyE) allowed for a definitive classification of the strain as Pseudanabaena galeata. The metabolite profile of CCNP1313, including peptide and pigment contents, was determined. In this cyanobacterium, twenty-six unknown peptides were detected. The similarities in their mass fragmentation spectra indicate that they probably are structural variants of the same class of the compounds. Aside from chlorophyll-a and β-carotene, CCNP1313 produces zeaxanthin, echinenone, phycocyanin and phycoerythrin. Culture experiments conducted under different light regimes confirmed the role of the pigments in light-harvesting and photoprotection of the strain. The detailed description of CCNP1313 presented in this work can be useful in further studies on Pseudanabaena diversity and taxonomy when more information on genetic and phenotypic features of other Pseudanabana strains is available.