<i>Gloeobacter</i> and the implications of a freshwater origin of Cyanobacteria

The earliest branching cyanobacterium, Gloeobacter, exhibits a number of ancestral traits including the lack thylakoids. It occurs epilithically in microbial mats, both subaerially and submerged low-salinity habitats. These habitats absence thylakoids are associated with occurrence membrane-associated photosynthetic processes plasma membrane, possibly limiting rate assembly reassembly oxygen-evolving complex, as well vitro growth rate. factors interact Gloeobacter mats to constrain productivity nature. Traits found living probable time origin oxygenic photosynthesis diversification cyanobacteria, can be related possible role primary organic carbon burial on land during early Earth environments around global oxidation event.