Phylogenetic and morphological evaluation of Wollea saccata (Nostocales, Cyanobacteria) isolated from the Yenissei River basin (Eastern Siberia, Russia)

Abstract

For the first time the genus Wollea Bornet et Flahault was recorded in Eastern Siberia (Yenissei River, Karskoe See Basin) and isolated to monoclonal axenic strain ACCS 045. The strain was characterized by a combination of morphological and molecular approaches. It shares the diacritical features of the type-species W. saccata (Wolle) Bornet et Flahault and W. bharadwajae R.N. Singh such as macroscopic gelatinous colonies, tube-like, trichomes more or less straight or slightly curved, sheaths around trichomes are absent, heterocytes intercalary, and paraheterocytic akinete development at both sides of heteocytes in short series. A morphological comparison shows that it differs from W. saccata in the form of colonies being saccule, the form of vegetative cells and the heterocytes being barrel-shaped, the form of terminal cells being conical-rounded, and from W. bharadwajae in the form of akinetes being cylindrical or ellipsoid. The first available 16S rRNA gene sequence of Wollea appeared poorly related to other cyanobacterial sequences. According to the traditional classification systems based on morphological and ecological observations genus Wollea appears closest to Anabaena and Nostoc. However, the phylogenetic placement of Wollea based on 16S rRNA gene sequence was distant from Nostoc and the most closely related to taxa in benthic Anabaena, Sphaerospermopsis, Cylindrospermopsis, and Raphidiopsis. © Czech Phycological Society (2011).