RUI: Polyphasic Characterization and Phylogenetic Classification of the Problematic Form-Genus Leptolyngbya (Cyanobacteria)

John Carroll University, Cleveland OH

Investigators

Abstract

A grant has been awarded to Dr. Jeffrey R. Johansen of John Carroll University to study a problematic genus of blue-green algae (cyanobacteria) called Leptolyngbya. This genus is difficult to understand because it has very few morphological characters, but occurs in a wide variety of habitat types. Morphologically similar forms have been found to be actually very different in terms of their 16S rRNA gene sequence. Dr. Johansen will use a polyphasic approach to characterize over 60 strains of this microbe from collections all over the world, including an extensive collection of desert soil forms isolated as part of a past NSF-supported project. Polyphasic characterization means that morphological, genetic, ecological, and physiological data will be collected on these strains, so that the genus can be revised. Preliminary evidence indicates that there are many new species in the genus, and probably even groups of species that merit creation of new genera. Unlike all other cyanobacterial taxonomic studies and most bacteriological systematic studies, this project will test the applicability of three modern species concepts for asexual species. Further precedents will be set in designating a suite of new kinds of type materials for new taxa. Phylogenetic analyses, which determine evolutionary relationships of taxa, will be run in ways unique to bacteria and uncommon in other groups. This work will help us to characterize biodiversity in the world. It may serve as an example for others wishing to use modern systematic approaches to describe new cyanobacterial species. Excellent systematics and taxonomy are necessary for development of the cyanobacteria for biotechnological, pharmacological, and reclamation purposes.