Morphological and molecular characterization of a thermophilic cyanobacterium (Oscillatoriales) from Euganean Thermal Springs (Padua, Italy)

The Euganean thermal mud is mostly colonized by cyanobacteria and microal- eschweizerbartxxx ingenta gae which seem to be the responsible of the therapeutic properties on rheumatic diseases of mud therapy. The most abundant and widespread taxon among the cyanobacteria belongs to the Oscillatoriales. Morphological investigations carried out by means of light and transmission electron microscopes and of molecular analysis inferred by 16S rDNA suggest that this cyanobacterium is a species belonging to the Phormidium genus and it seems to be different from similar Phormidium species from other biotopes as well as from types already reported in other hot springs. The similarity of morphology, ultra- structure and phylogenetic position to other Phormidium types found here, support the view that the genus Phormidium represents a separate and well delimited cyanobacterial cluster containing several morpho- and ecotypes.