A new species of the previously monotypic genus <i>Iningainema</i> (Cyanobacteria, Scytonemataceae) from the Western Ghats, India

A novel cyanobacterial species from the genus <i>Iningainema</i> is described according to the International Code of Nomenclature for Algae, Fungi, and Plants. The new species, <i>Iningainema sahyadrensis</i> sp. nov., is recorded from the Western Ghats (Sahyadri mountain range), India. The description is based on morphological features and the phylogenetic analysis of partial 16S rDNA gene. Phylogenetic analysis places <i>I. sahyadrensis</i> in the <i>Iningainema</i> clade, within the family Scytonemataceae. The novel strain formed a strongly supported monophyletic lineage with strains of the type species of <i>Iningainema, I. pulvinus</i>. Laboratory-grown culture and the naturally occurring samples of <i>I. sahyadrensis</i> differed from the type species of the genus (<i>I. pulvinus</i>) by the size of vegetative cells, thickness of sheath, presence of vacuole-like structures in cells and habitat type. Comparison of predicted secondary structures of the partial 16S rRNA molecule of <i>I. sahyadrensis</i> and three clones of <i>I. pulvinus</i> showed a number of evolutionary events in Domain 1 (H8-H10, H17), Domain 2 (H21, H22) and Domain 3 (H33, H34). Amplification of a fragment of the <i>ndaF</i> gene involved in nodularin biosynthesis from <i>I. sahyadrensis</i> did not confirm that it has this genetic determinant, in contrast with <i>I. pulvinus</i>. The recognition and description of this novel species suggests that the cyanobacterial flora of mountain habitats of India has yet to be fully documented.