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The Chloroflexi or Chlorobacteria are a phylum of bacteria containing isolates with a diversity of phenotypes including members that are aerobic thermophiles, which use oxygen and grow well in high temperatures, anoxygenic phototrophs, which use light for photosynthesis, and anaerobic halorespirers, which uses halogenated organics (such as the toxic chlorinated ethenes and polychlorinated biphenyls) as energy sources. Whereas most Bacteria, in terms of diversity, are diderms and stain Gram negative with the exception of the ''Firmicutes'' (low CG Gram positives), ''Actinobacteria'' (high CG gram positives) and the Deinococcus-Thermus group (Gram positive, but diderms with thick peptidoglycan), the members of the phylum Chloroflexi are monoderms, but stain mostly Gram negative. ==History== In 1987, Carl Woese, regarded as the forerunner of the molecular phylogeny revolution, divided Eubacteria into 11 divisions based on 16S ribosomal RNA (SSU) sequences and grouped the genera ''Chloroflexus'', ''Herpetosiphon'' and ''Thermomicrobium'' into the "Green non-sulfur bacteria and relatives", which was temporarily renamed as "Chloroflexi" in Volume One of Bergey's Manual of Systematic Bacteriology.〔 Being a deep branching phylum (cf. Bacterial phyla) its classification was analysed in Volume One of Bergey's Manual of Systematic Bacteriology and included a single class with the same name, the class ''Chloroflexi''.〔〕 Since 2001 however, new classes have been created thanks to newly discovered species, therefore currently the phylum ''Chloroflexi'' is divided into: * Chloroflexi Gupta et al. 2012 * Thermomicrobia Hugenholtz & Stackebrandt, 2004 * "Dehalococcoidetes" Hugenholtz & Stackebrandt, 2004 * Anaerolineae Yamada et al., 2006 * Caldilineae Yamada et al., 2006 * Ktedonobacteria Cavaletti et al., 2007 emend. Yabe et al., 2010 Regarding the class "Dehalococcoidetes", the placeholder name was given by Hugenholtz & Stackebrandt, 2004, after "Dehalococcoides ethenogenes" a partially described species in 1997, whereas the first species fully described was ''Dehalogenimonas lykanthroporepellens'' by Moe et al. 2009, but in the description of that species the class was not made official nor were families or orders laid out as the two species share only 90% 16S identity, meaning that they could fall in different families or even orders.〔 Recent phylogenetic analysis of the Chloroflexi has found very weak support for the grouping together of the different classes currently part of the phylum. The six classes that make up the phylum did not consistently form a well-supported monophyletic clade in phylogenetic trees based on concatenated sequences for large datasets of proteins and no conserved signature indels were identified that were uniquely shared by the entire phylum.〔 However, the classes “Chloroflexi” and Thermomicrobia were found to group together consistently by both the usual phylogenetic means and the identification of shared conserved signature indels in the 50S ribosomal protein L19 and the enzyme UDP-glucose 4-epimerase.〔 It has been suggested that the phylum Chloroflexi “''sensu stricto''” should comprise only the classes Chloroflexi and Thermomicrobia, and the other four classes (“Dehalococcoidetes,” Anaerolineae, Caldilineae and Ktedonobacteria) may represent one or more independent phyla branching in the neighborhood of the Chloroflexi.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Chloroflexi (phylum)」の詳細全文を読む スポンサード リンク
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