Fottea X:X | DOI: 10.5507/fot.2025.010

Pushkarnema curajae gen. et sp. nov. (Nodosilineales), a novel filamentous cyanobacterium isolated from a freshwater reservoir of northwest India

Sonam Sonam1, Anuj K. Tomer2, Dale A. Casamatta3, Pawan K. Dadheech1
1 Department of Microbiology, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Ajmer 305817, Rajasthan, India
2 Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
3 Department of Biology, University of North Florida, Jacksonville, Florida 32250, USA

During the exploration of cyanobacterial diversity of the semi-arid region of northwest India, a non-heterocytous cyanobacterium was isolated from an aquatic habitat and characterized using a polyphasic approach based on morphology, ecology and sequencing of the 16S rRNA gene. Two strains (AT2016/6; SN2021/02) were isolated and characterized by cells longer than wide, the presence of a thick sheath, and the formation of nodules. 16S rRNA gene sequences revealed that the strains formed a highly supported, distinct clade within the Nodosilineales, ranging from 89.52% to 92.76% similarity to other strains. Secondary structures (the D1-D1´, BoxB, and V3 helices) of the 16S-23 rRNA Internal Transcribed Spacer (ITS) regions of both novel strains exhibited unique sequential differences from phylogenetically related taxa. Based on the combination of morphological characters and well-supported phylogenetic data, we describe a new genus and species: Pushkarnema curajae gen. et sp. nov. in accordance with the International Code of Nomenclature for Algae, Fungi, and Plants (ICN).

Keywords: Cyanobacteria; Phylogeny; Polyphasic approach; Pushkarnema curajae; 16S-23S rRNA ITS; 16S rRNA gene

Received: January 27, 2025; Revised: July 24, 2025; Accepted: July 28, 2025; Prepublished online: March 31, 2026 

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