The FCB is a proposed superphylum of bacteria named after the main member phyla Fibrobacterota, Chlorobiota, and Bacteroidota. The members are considered to form a clade due to a number of conserved signature indels.
Cavalier-Smith calls the equivalent grouping a phylum by the name of Sphingobacteria. It contains the classes Chlorobiota, Fibrobacterota, Bacteroidota, and Flavobacteria. However, this megaclassification is not followed by the larger scientific community.
FCB groupEmiley A Eloe-Fadrosh et al. 2017, Global metagenomic survey reveals a new bacterial candidate phylum in geothermal springs. Nature Communications 7 · January 2016 DOI: 10.1038/ncomms1047 16S rRNA based LTP_07_2026 120 marker proteins based GTDB 11-RS232
An analogous situation is seen with the PVC group/Planctobacteria.
See also List of bacterial orders List of bacteria genera
References