Abstract:
To advance the development of a monophyletic toxonomy system for modern cyanobacteria, two strains of filamentous cyanobacteria, CHAB7530 and CHAB7535, were isolated and purified from soil crust samples in Shapotou Nature Ecological Reserve, Ningxia Hui Autonomous Region, China. These strains exhibited morphologically similarities to the
Coleofasciculus-like and
Microcoleus-like species. Analysis based on 16S rRNA gene sequences identified CHAB7530 and CHAB7535 as belonging to
Crustifilum hispaliculae Moreira-Fernandes, Giraldo-Silva, D. oush & Garcia-Pichel 2021, with 99.7%—99.9% similarity in their sequences. Phylogenetic analyses showed that they clustered within
Crustifilum and formed a well-supported evolutionary clade. Additionally, supplementary ITS secondary structure data for this species were provided. The integration of molecular, morphological, and ecological data using a polyphasic approach indicates that CHAB7530 and CHAB7535 were
C.
hispaliculae, which were represent new records for China. The article also discusses taxonomic revisions and proposals for certain genera previously separated from the
Microcoleus steenstrupii complex (e.g.
Parifilum) based on the results of phylogenetic analyses.