Chapter 2 - Biodiversity and taxonomy

Abstract

Chlorophototrophic bacteria have traditionally been classified based on morphologic, cultural, and physiologic properties and referred to by corresponding common names, i.e., purple nonsulfur bacteria, purple sulfur bacteria, green sulfur bacteria, chloroflexus, and cyanobacteria. Late to these, anoxygenic aerobic phototrophic bacteria and heliobacteria have been discovered and taxonomically described. Genome-wide approaches to bacterial systematics and metagenomics are accelerating taxonomic rearrangement and descriptions of new taxa of the phototrophic bacteria including those as yet cultured. The phototrophic bacteria are now known in the following eight phyla: Pseudomonadota, Chlorobiota, Chloroflexota, Bacillota, Acidobacteriota, Gemmatimondota, Cyanobateriota, and “Candidatus Eremiobacterota.” This chapter overviews the history and the current status of the taxonomy and phylogeny of anoxygenic phototrophic bacteria.