Gloeobacter

Gloeobacter
Scientific classification
Domain:	Bacteria
Phylum:	Cyanobacteria
Class:	Cyanophyceae
Order:	Gloeobacterales Cavalier-Smith
Family:	Gloeobacteraceae Komárek et Anagnostidis
Genus:	Gloeobacter Rippka, Waterbury, & Cohen-Bazire, 1974[1]
Species
Gloeobacter violaceus Rippka, Waterbury & Cohen-Bazire, 1974 Gloeobacter kilaueensis Saw et al., 2013

Gloeobacter is a genus of cyanobacteria. It is the sister group to all other cyanobacteria.^[2] Gloeobacter is unique among cyanobacteria in not having thylakoids, which are characteristic for all other cyanobacteria and chloroplasts. Instead, the light-harvesting complexes (also called phycobilisomes), that consist of different proteins, sit on the inside of the plasma membrane among the (cytoplasm). Subsequently, the proton gradient in Gloeobacter is created over the plasma membrane, where it forms over the thylakoid membrane in cyanobacteria and chloroplasts.^[2]

The whole genome of G. violaceus (strain PCC 7421) and of G. kilaueensis have been sequenced. Many genes for photosystem I and II were found missing, likely related to the fact that photosynthesis in these bacteria does not take place in the thylakoid membrane as in other cyanobacteria, but in the plasma membrane.^[3][4]