Issues in cyanobacterial taxonomy: comprehensive case study of unbranched, false branched and true branched heterocytous cyanobacteria

Abstract

The order Nostocales is represented by morphologically diverse forms with respect to the branching patterns and polarity of the filaments. With growing understanding of taxonomy and systematics, members of the order Nostocales have also undergone multiple taxonomic revisions. The last decade has seen a surge in the description of new genera and families within the order Nostocales. In this study, we discuss the taxonomic status of all the newly described and reclassified taxa of some of the prominent morphological forms within the order Nostocales by constructing comprehensive phylogenetic trees. Further, we propose certain strategies that would contribute to resolving the taxonomic complexities arising due to inadequate taxon sampling.

Insights into the phylogenetic inconsistencies of the genus Amazonocrinis and description of epilithic Amazonocrinis malviyae sp. nov. (Cyanobacteria, Nostocales) from Jammu and Kashmir, India

“…Here we would like to mention that, even though the phylogenomic analysis would provide much higher resolution in delineating the closely related taxa as evident in different bacterial groups, in cases of cyanobacterial taxonomy due to the limited number of available genomes, especially in the order Nostocales, it is still very important to first reconstruct a comprehensive phylogenetic analysis using the 16S rRNA gene. The problems associated with low taxon sampling were discussed in detail by Mishra et al [44].…”

Identification of Bacterial Communities Involved in Bioweathering Crusts on Limestone Sculptures of the Longmen Grottoes

“…However, there were still 20%-30% of the communities that were unclassified. This might be attributed to the incomplete taxonomy of bacteria, especially for Cyanobacteria [17].…”

“…However, there were still 20%-30% of the communities that were unclassified. This might be attributed to the incomplete taxonomy of bacteria, especially for Cyanobacteria [17]. Early in 1991, studies have demenstrated that the biofilm of Cyanobacteria and algae grows on stones, spontaneously detaches, and gives rise to the removal of grains from the stone surface, thus causing mechanical deterioration on the colonized materials [18].…”

Late Ediacaran cavity-dwelling filamentous microorganisms accommodated in a valve-like organism from the uppermost Dengying Formation in eastern Yunnan of South China

“…Considering the branching pattern, complex filaments of modern cyanobacteria may develop some false branching, e.g., Scytonematopsis (Mishra et al, 2021). These pseudo-branches typically result from artefacts of filaments that are immediately adjacent to others, which lack cellular organic connection among themselves.…”