Westiellopsis tiwarii sp. nov., a New Cyanobacterium from North-East India Soils

Abstract

In modern times, cyanobacterial identification, characterization, and classification have adopted a pragmatic polyphasic approach assigning equal weight to the ecological, morphological, physiological, and molecular parameters. The paucity of data on cyanobacterial diversity across unexplored regions resulted in poor taxonomic characterization of cyanobacteria. Hence, the poorly explored North-Eastern lower Himalayan region of India was targeted and a true-branched soil inhabiting cyanobacterial strain KFS2 was isolated. Along with habitat analysis, morphological and 16S-rRNA gene-based molecular characterization of the isolated strain have been performed. The complex cellular morphology, uni-seriate to multi-seriate main filaments and branches, along with the 16S rRNA gene sequence-based phylogeny indicated affiliation of this strain with the genus Westiellopsis. Furthermore, the strain KFS2 showed unique morphological features such as the multi-seriate base of lateral branches, the presence of both intercalary and terminal heterocytes in the main filaments along with the intercalary position of heterocytes in the lateral branches, and was found to form a separate node with the Westiellopsis clade having strong bootstrap support in the 16S-rRNA gene-based phylogeny. Moreover, comparative analysis of folded secondary structures of D1-D1' and box-B in the 16S-23S ITS region of the strain also exhibited striking differences with other members of the genus. Considering all the unique morphological and molecular characteristics of the strain KFS2, it was suggested to represent a new species of the genus Westiellopsis, with the name Westiellopsis tiwarii being proposed in accordance with the International Code of Nomenclature of algae, fungi, and plants.