Polyphasic approach and typification of selected Phormidium strains (Cyanobacteria)

Area of Science:

• Microbiology
• Phycology
• Ecology

Background:

• Cyanobacteria are widespread, ecologically vital microorganisms performing oxygenic photosynthesis.
• Taxonomic identification is challenging due to their prokaryotic nature, cryptic species, and varied nomenclature.
• Missing original reference strains (holotypes) complicate cyanobacteria characterization.

Purpose of the Study:

• To characterize a filamentous cyanobacterium (strain ETS-02) from the Euganean Thermal District using a comprehensive polyphasic approach.
• To address the difficulties in cyanobacteria taxonomy, including the lack of holotypes.
• To contribute to the accurate identification and classification of cyanobacterial species.

Main Methods:

• Polyphasic characterization of strain ETS-02.
• Morphological and ultrastructural analyses.
• Biochemical analysis (pigment and fatty acid content).
• Physiological analysis (nitrogen fixation).
• Genetic analyses (16S rRNA, 16S-23S ITS, cpcB-IGS-cpcA, rpoC1, gyrB, rbcL, nifD loci).
• Utilized epitypification of Phormidium irriguum CCALA 759.

Main Results:

• Strain ETS-02 was thoroughly analyzed using integrated morphological, biochemical, physiological, and genetic data.
• The study leveraged the epitype description of Phormidium irriguum CCALA 759 for comparative analysis.
• The findings provide a detailed characterization of the isolated cyanobacterium.

Conclusions:

• The polyphasic approach, including genetic and epitypification methods, is effective for cyanobacteria identification.
• This study contributes to resolving taxonomic ambiguities in filamentous cyanobacteria.
• Accurate cyanobacteria classification is crucial for ecological and biotechnological applications.