title: The green non-sulfur bacteria:  a deep branching in the eubacterial line of descent.
abstract: Ribosomal RNA sequence comparisons define a phylogenetic grouping, the green non-sulfur bacteria and relatives (GNS), known to contain the genera Chloroflexus, Herpetosiphon and Thermomicrobium--organisms that have little phenotypic similarity.  The unit is phylogenetically deep, but entirely distinct from any other eubacterial division (phylum).  It is also relatively ancient--branching from the common eubacterial stem earlier than any other group of eubacteria reported thus far.  The group phenotype is predominantly thermophilic, and its thermophilic members, especially Thermomicrobium, are more slowly evolving than Herpetosiphon, a mesophile.  The GNS unit appears significantly older than either the green sulfur bacteria or the cyanobacteria--making it likely that organisms such as Chloroflexus, not the cyanobacteria, generated the oldest stromatolites, which formed over three billion years ago.
authors.affiliation: Department of Genetics and Development, University of Illinois, Urbana 61801, USA.
authors.forename: H
authors.initials: H
authors.lastname: Oyaizu
authors.forename: B
authors.initials: B
authors.lastname: Debrunner-Vossbrinck
authors.forename: L
authors.initials: L
authors.lastname: Mandelco
authors.forename: J A
authors.initials: JA
authors.lastname: Studier
authors.forename: C R
authors.initials: CR
authors.lastname: Woese
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics; D018407:Bacterial Physiological Phenomena; D001483:Base Sequence; D005075:Biological Evolution; D019414:Chlorobi / Q000145:classification* / Q000235:genetics / Q000502:physiology; D004926:Escherichia coli; D006358:Hot Temperature; D008969:Molecular Sequence Data; D010641:Phenotype; D010802:Phylogeny; D012329:RNA, Bacterial / Q000145:classification / Q000235:genetics*; D012336:RNA, Ribosomal, 16S / Q000145:classification / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D016999:Sulfur-Reducing Bacteria / Q000145:classification / Q000235:genetics / Q000502:physiology
chemical_list: D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S