, Caedibacter , Caenibacterium , Caldalkalibacillus , Caldanaerobacter , Caldicellulosiruptor , Caldilinea , Caldilineaceae , Caldilineae , Caldilineales , Caldimonas , Caldithrix , Caloramator , Caloranaerobacter , Caminibacter , Caminicella , Campylobacter , Campylobacteraceae , Campylobacterales , Capnocytophaga , Carbophilus , Carboxydocella , Carboxydothermus , Cardinium , Cardiobacteriaceae , Cardiobacteriales , Cardiobacterium , Carnimonas , Carnobacteriaceae , Carnobacterium , Caryophanaceae , Caryophanon , Castellaniella , Catellatospora , Catellibacterium , Catellicoccus , Catenibacterium , Catenococcus , Catenulispora , Catenulisporaceae , Catenuloplanes , Catonella , Caulobacter , Caulobacteraceae , Caulobacterales
, Cedecea , Cellulomonadaceae , Cellulomonas , Cellulophaga , Cellulosimicrobium , Cellvibrio , Centipeda , Cerasibacillus , Cetobacterium
, Chelatobacter
Bacteria → Proteobacteria → Alphaproteobacteria → Rhizobiales → Beijerinckiaceae , Chimaereicella , Chitinibacter , Chitinimonas , Chitinophaga , Chlamydia , Chlamydiaceae , Chlamydiae , Chlamydiae , Chlamydiales , Chlamydophila , Chlorobaculum , Chlorobi , Chlorobia , Chlorobiaceae , Chlorobiales , Chlorobium , Chloroflexaceae , Chloroflexales , Chloroflexi , Chloroflexi , Chloroflexus , Chloroherpeton , Chloronema , Chondromyces , Chromatiaceae , Chromatiales , Chromatium , Chromobacterium , Chromohalobacter , Chryseobacterium , Chryseomonas , Chrysiogenaceae , Chrysiogenales , Chrysiogenes , Chrysiogenetes , Chrysiogenetes
, Citreicella , Citricoccus , Citrobacter
, Clavibacter , Clevelandina , Cloacibacterium , Clostridia , Clostridiaceae , Clostridiales , Clostridium
, Cobetia , Coenonia , Cohnella , Collimonas , Collinsella , Colwellia , Colwelliaceae , Comamonadaceae , Comamonas , Conchiformibius , Conexibacter , Conglomeromonas , Coprobacillus , Coprococcus , Coprothermobacter , Corallococcus , Coriobacteriaceae , Coriobacteriales , Coriobacterium , Corynebacteriaceae , Corynebacterium , Costertonia , Couchioplanes , Coxiella , Coxiellaceae
, Crabtreella , Craurococcus , Crenothrix , Crenotrichaceae , Cristispira , Croceibacter , Crocinitomix , Crossiella , Cryobacterium , Cryomorpha , Cryomorphaceae , Cryptanaerobacter , Cryptobacterium , Cryptosporangium
, Cupriavidus , Curtobacterium , Curvibacter
Bacteria → Cyanobacteria → Chroococcales → Synechococcaceae
Bacteria → Cyanobacteria → Cyanophyceae → Synechococcales → Synechococcaceae
Bacteria → Cyanobacteria → Cyanophyceae → Stigonematales → Stigonemataceae
Bacteria → Cyanobacteria → Cyanophyceae → Synechococcales → Synechococcaceae , Cycloclasticus , Cystobacter , Cystobacteraceae , Cytophaga