The morphological characteristic strain KPABG LID-610023 of Chroococcus s.l. group (Cyanoprokaryota)

The Chroococcus-like strain was collected from anthropogenic meadow on the Barents Sea coast (Murmansk Region, Russia). It was studied by light microscope, the nucleotide sequences of 16S rRNA and ITS were obtained. Based on 16S rRNA phylogenetic analysis, the strain KPABG LID-610023 was placed in the clade of Inacoccus in spite of morphological and molecular differences from one already established species: Inacoccus carmineus. Morphologically the tested strain did not show colored hyaline envelopes, and nanocytes were absent. The nucleotide sequences of 16S rRNA gene clearly demonstrated a genetic difference, separating it from Inacoccus carmineus. In addition, we compared ITS sequences of KPABG LID-610023 strain and Inacoccus carmineus and found that nucleotide composition, length, and secondary structures of D1–D1' and Box-B were different. These results suggest that the strain KPABG LID-610023 appear to be a new species of the genus Inacoccus. Possibly this new species is a cryptic taxon due to its morphological similarity with Chroococcus pallidus Näg.