Geminocystis urbisnovae sp. nov. (Chroococcales, Cyanobacteria): polyphasic description complemented with a survey of the family Geminocystaceae

Progress in phylogenomic analysis has led to a considerable re-evaluation of former cyanobacterial system, with many new taxa being established at different nomenclatural levels. The family <i>Geminocystaceae</i> is among recently described on the basis polyphasic approach. Within this family, there are six genera: <i>Geminocystis</i>, <i>Cyanobacterium</i>, <i>Geminobacterium</i>, <i>Annamia</i>, <i>Picocyanobacterium</i>, and <i>Microcrocis</i>. genus <i>Geminocystis</i> previously encompassed two species: <i>G. herdmanii </i>and papuanica</i>. Herein, species urbisnovae</i> was proposed under provision International Code Nomenclature for algae, fungi, plants (ICN). Polyphasic performed five strains from CALU culture collection (St. Petersburg State University, Russian Federation), they were assigned Geminocystis accordance high 16S rRNA gene similarity existing species, as well because proximity these phylogenetic trees reconstructed RaxML Bayes methods. Plausibility their assignment separate substantiated smaller cell size; stenohaline freshwater ecotype; capability complementary chromatic adaptation second type (CA2); distinct clustering; sequences folding D1−D1′ B box domains 16S−23S internal transcribed spacer region. objective pursued by communication provide survey <i>Geminocystaceae</i>. overall assessment that, despite attention researchers, been understudied and, especially case crucially important Cyanobacterium, taxonomically problematic.