Polyphasic analysis for elucidating the taxonomic position of selected unicellular marine cyanobacteria from Indian and Hong Kong coast

Abstract

Cyanobacteria, the primordial oxygenic photosynthetic prokaryotes encompass a wide spectrum of morphologies and ecologies. The diversity of twelve marine unicellular cyanobacteria isolated from different marine habitats was analyzed morphologically. The evolutionary relationship among the investigated strains was examined by phylogenetic analysis of nearly complete 16S rRNA gene and 16-23S internal transcribed spacer region. Phylogenetic analysis of both 16S rRNA genes and internal spacer regions exhibited coherent clustering patterns. The genetic relatedness of the investigated strains was largely congruent with morphology-based taxonomic groupings. All the investigated strains possess both the types of tRNA (tRNAIle and tRNAAla) in their 16-23S internal spacer regions and significantly varied GC contents and spacer sequence lengths. Further, ultrastructural studies provide a more valuable insight into the cyanobacterial taxa studied. Our study helps to apply the polyphasic approach (use of morphology, ultra-structure, ecology, and molecular analysis of complete 16S rRNA genes and 16-23S internal spacer regions) to resolve taxonomic ambiguities and provide a fairly robust cyanobacterial classification system among the unicellular forms studied.

Introducing Petrachlorosaceae fam. nov., Petrachloros gen. nov. and Petrachloros mirabilis sp. nov. (Synechococcales, Cyanobacteria) Isolated from a Portuguese UNESCO monument

“…BDU 130052 (Bhuvaneshwari et al. 2017). However, to the best of our knowledge, none of latter strains were formally described.…”

“…S1) also showed that Petrachloros forms a cluster with environmental sequences isolated during the studies of Couradeau et al (2011), and Sahl et al (2010 and a GenBank 16S rRNA gene sequence identified as Aphanocapsa sp. BDU 130052 (Bhuvaneshwari et al 2017). However, to the best of our knowledge, none of latter strains were formally described.…”

“…Petrachloros is morphologically similar to the strain Aphanocapsa sp. BDU 130052 isolated and characterized by Bhuvaneshwari et al (2017). These authors morphologically characterized 12 marine unicellular cyanobacteria and investigated their phylogenetic positions.…”