Expanding the occurrence of Euryhalinema (Leptolyngbyaceae, Cyanobacteria) to the Atlantic Ocean and description of E. epiphyticum sp. nov. on the Brazilian coast

Two Leptolyngbya-like cyanobacterial strains were isolated from two marine benthic environments on the Brazilian coast. These strains were cultured and characterized based on their morphology, molecular, and ultrastructural data. The two taxa were identified mainly by 16S rRNA gene phylogeny and 16S-23S ITS secondary structures since their morphology is similar to members of Leptolyngbya senso lato. The phylogenetic analysis indicated that our strains belong to Euryhalinema genus (Leptolyngbyaceae), with one strain close to type species E. mangrovii AP9F (MK402979), and the other described as a new species, E. epiphyticum sp. nov. Morphologically, both strains form green mats, had trichomes without sheath, and their thylakoid disposition is the same as described for Leptolyngbyaceae. The secondary structures Box B and D1-D1' of the internal transcribed spacer (16S-23S ITS) also corroborated our proposal of the new species E. epiphyticum. These findings constitute the first description of a new-to-science species for this genus outside Indian marine environments. Also, it expands the knowledge on Euryhalinema systematic.