Brasilonema lichenoides sp. nov. and Chroococcidiopsis lichenoides sp. nov. (Cyanobacteria): two novel cyanobacterial constituents isolated from a tripartite lichen of headstones

Abstract

Cyanolichens are an assemblage of fungi and cyanobacteria from diverse, cosmopolitan habitats. Typically composed of a single species of cyanobacterium, with or without another eukaryotic alga, here we present two novel cyanobionts isolated from an undescribed tripartite lichen. This endolithic lichen was isolated from a granite cemetery tombstone from Jacksonville, FL, and contains two potentially nitrogen-fixing cyanobionts. Employing a total evidence approach, we characterized the cyanobionts using molecular (the 16S rDNA and ITS gene region), morphological, and ecological data. Phylogenetic analyses revealed two novel taxa: Brasilonema lichenoides and Chroococcidiopsis lichenoides, both of which fell within well-supported clades. To our knowledge, this represents the first instance of a tripartite lichen with two cyanobacterial and no eukaryotic members. These types of lichens may well represent an unexplored reservoir of cyanobacterial diversity. The specific epithets are proposed under the provisions of the International Code of Nomenclature for algae, fungi, and plants.

Lichen algae: the photosynthetic partners in lichen symbioses

“…Brasilonema Fiore et al -This cyanobacterial genus, forming a distinct clade in molecular analyses (Fiore et al 2007), has aggregated filaments morphologically similar to Scytonema but only rarely showing false branching. A recent paper reported new species of both Brasilonema and Chroococcidiopsis as co-occurring photobionts of an unidentified lichen growing on gravestones in a northern Florida cemetery (Villanueva et al 2018). However, as no description or evidence of this association has yet been published, the status of Brasilonema as lichen photobiont awaits corroboration.…”

Discovery of Unusual Cyanobacterial Tryptophan-Containing Anabaenopeptins by MS/MS-Based Molecular Networking

“…Strains belonging to the genus Brasilonema are a good source of diverse secondary metabolites [26]. The genus Brasilonema, belonging to the family Scytonemataceae, are terrestrial filamentous, heterocytous false-branching cyanobacteria previously isolated from subtropical and tropical climate zones [27][28][29]. To the best of our knowledge, the only tryptophan-containing APTs were detected in 2015 from the genus Brasilonema sp.…”

Discovery of Unusual Cyanobacterial Tryptophan-containing Anabaenopeptins by MS/MS Based Molecular Networking

“…Strains belonging to the genus Brasilonema is a good source for diverse secondary metabolites [26]. Genus Brasilonema, belonging to the family Scytonemataceae, are terrestrial filamentous, heterocytous false-branching cyanobacteria, that have been previously isolated from subtropical and tropical climate zones [27][28][29]. To the best of our knowledge, the only tryptophan-containing APTs were detected in 2015 from the genus Brasilonema sp.…”