Alkalinema pantanalense and Roholtiella edaphica (Cyanobacteria): Two New Species Records for Egypt

Our current knowledge of the cyanobacterial diversity in Egypt is still underestimated During our routine study on Egyptian cyanobacteria, two interesting and morphologically cryptic strains were isolated from streams of Bahr Yussef and Qarun Lake, one of the oldest lakes in the world, located at the Faiyum depression, Egypt. We applied the polyphasic approaches, combining the state-of-the-art morphotaxonomy, 16S rRNA gene phylogenies, and ecological preferences to precisely unravel the taxonomic positions of these two cyanobacterial strains. Based on a combination of their morphotaxonomic traits and 16S rRNA phylogenetic assessment, we identified them as Alkalinema pantanalense (Leptolyngbyaceae, Leptolyngbyales) and Roholtiella edaphica (Nostocaceae, Nostocales). Both species are considered new cyanobacterial records for Egypt and the African continent based on the available literature. From an ecological standpoint, both species are eutraphentic, where they could tolerate relatively elevated concentrations of NO3−, NH4+ (in particular for R. edaphica), and silicates, reflecting eutrophication signs in the ecosystems they colonize. This study adds to the limited molecular information available on the Egyptian cyanobacteria, and also highlights the need for re-investigation of Egyptian cyanobacteria, using polyphasic approaches, to better understand their taxonomy and ecology.