Bergey’s Classification of Bacteria

1. Gram-negative Bacteria of medical and commercial importance: (1984)
   Spirochetes, spiral and curved, aerobic and facultatively aerobic rods, obligate anaerobes, aerobic and anaerobic cocci, sulfate and sulfur-reducing, rickettsias, clamydias, mycoplasmas

   Gram-positive Bacteria of medical and commercial importance: (1986)

   Cocci, endospore-forming and nonsporing rods, mycobacteria, nonfilamentous actinomycetes

Kingdom Procaryotae

Divisions

1. Gracilicutes
   Procaryotes with thin cell walls, implying a gram-negative type cell wall

   Firmicutes

   Procaryotes with thick and strong skin, indicating a gram-positive type cell wall

   Tenericutes

   Procaryotes of a pliable and soft nature, indicating the lack of a rigid cell wall

   Mendosicutes

   Procaryotes that lack conventional peptidoglycan (archaeobacteria)

Spirochetes
Spirochaetales
Spirochaetaceae
Borrelia
Cristispira
Spirochaeta
Treponema
Leptospiraceae
Leptospira
Other: Hindgut Spirochetes of Termites and Cryptocercus punctulatus (wood-eating cockroach)

Aerobic/Microaerophilic, Motile, Helical/Vibrioid Gram-Negative Bacteria
Alteromonas
Aquaspirillum
Azospirillum
Bdellovibrio
Campylobacter
Cellvibrio
Halovibrio
Helicobacter
Herbaspirillum
Marinomonas
Micavibrio
Oceanospirillum
Spirillum
Sporospirillum
Vampirovibrio

Nonmotile (or rarely), Gram-Negative Curved Bacteria
Spirosomaceae
Flectobacillus
Runella
Spirosoma

Other Genera

Ancyclobacter
Brachyarcus
Cyclobacterium
Meniscus
Microcyclus
Pelosigma

Gram-Negative Aerobic Rods and Cocci
Pseudomonadaceae
Frateuria
Pseudomonas
Xanthomonas
Zooglea

Azotobacteriaceae

Azomonas
Azotobacter

Rhizobiaceae

Agrobacterium
Bradyrhizobium
Phyllobacterium
Rhizobium

Methylococcaceae

Methylococcus
Methylomonas

Acetobacteraceae

Acetobacter
Gluconobacter

Halobacteriaceae

Halobacterium
Halococcus

Legionellaceae

Legionella

Neisseriaceae

Acinetobacter Kingella
Moraxella
Neisseria

Other Genera

Acidiphilium
Acidomonas
Acidothermus
Afipia
Agromonas
Alcaligenes
Alteromonas
Aminobacter
Aquaspirillum
Azorhizobium
Beijerinckia
Bordetella
Brucella
Chromohalobacter
Chryseomonas
Comoamonas
Cupriavidas
Deleya
Derxia
Ensifer
Erythrobacter
Flavimonas
Flavobacterium
Francisella
Halomonas
Hydrogenophaga
Janthinobacterium
Lampropedia
Marinobacter
Marinomonas
Mesophilobacter
Methylobacillus
Methylobacterium
Methylophaga
Methylophilus
Methylovorus
Morococcus
Oceanospirillum
Oligella
Paracoccus
Phenylobacterium
Psychrobacter
Rhizobacter
Roseobacter
Rugamonas
Serpens
Sinorhizobium
Sphingobacterium
Thermoleophilum
Thermomicrobium
Thermus
Variovorax
Volcaniella
Weeksella
Xanthobacter
Xylella
Xylophilus
Zoogloea

Facultatively Anaerobic Gram-Negative Rods
Enterobacteriaceae
Arsenophonus
Budvicia
Buttiauxella
Cedecea
Citrobacter
Edwardsiella
Enterobacter
Erwinia
Escherichia
Ewingella
Hafnia
Klebsiella
Kluyvera
Leclercia
Leminorella
Moellerella
Morganella
Obesumbacterium
Pantoea
Pragia
Proteus
Providencia
Rahnella
Salmonella
Serratia
Shigella
Tatumella
Xenorhabdus
Yersinia
Yokenella

Vibrionaceae

Aeromonas
Enhydrobacter
Photobacterium
Plesiomonas
Vibrio

Pasturellaceae

Actinobacillus
Haemophilus
Pasteurella

Other Genera

Calymmatobacterium
Cardiobacterium
Cedecea
Eikenella
Gardnerella (has thin, gram-positive walls but stains as negative)
Kluyvera
Obesumbacterium
Rahnella
Streptobacillus
Tatumella
XenorhabdusChromobacterium
Zymomonas

Gram-Negative Anaerobic, Straight, Curved, and Helical Rods
Bacteroidaceae
Acetivibrio
Acetoanaerobium
Acetofilamentum
Acetogenium
Acetomicrobium
Acetothermus
Acidaminobacter
Anaerobiospirillum
Anaerorhabdus
Anaerovibrio
Bacteroides
Butyrivibrio (has thin, gram-positive walls but stains as negative)
Centipeda
Fervidobacterium
Fibrobacter
Fusobacterium
Haloanaerobium
Halobacteroides
Ilyobacter
Lachnospira (has thin, gram-positive walls but stains as negative)
Leptotrichia
Malonomonas
Megamonas
Mitsuokella
Oxalobacter
Pectinatus
Pelobacter
Porphyromonas
Prevotella
Propionigenium
Propionispira
Rikenella
Roseburia
Ruminobacter
Sebaldella
Selenomonas
Sporomusa
Succinimonas
Succinivibrio
Syntrophobacter
Syntrophosmonas
Thermobacteroides
Thermospipho
Thermotoga
Tissierella
Wolinella
Zymophilus

Dissimulatory Sulfate- or Sulfur-Reducing Bacteria

Desulfobacter
Desulfobacterium
Desulfobulbus
Desulfococcus
Desulfomicrobium
Desulfomonas
Desulfomonile
Desulfonema
Desulfosarcina
Desulfotomaculum (also endospore-forming)
Desulfovibrio
Desulfurella
Desulfuromonas
Thermodesulfobacterium

Anaerobic Gram-Negaitve Cocci

Veillonellaceae
Acidaminococcus
Megasphaera
Syntrophococcus
Veillonella

Rickettsias and Chlamydias
Rickettsiales
Rickettsiaceae
Cowdria
Coxiella
Ehrlichia
Neorickettsia
Rickettsia
Rickettsiella
Rochalimaea
Wolbachia

Bartonellaceae

Bartonella
Grahamella

Anaplasmataceae

Aegyptianella
Anaplasma
Eperythrozoon
Haemobartonella

Chlamydiales

Chlamydiaceae
Chlamydia

Mycoplasmas
Mycoplasmataceae
Mycoplasma
Ureaplasma

Acholeplasmataceae

Acholeplasma

Spiroplasmataceae

Spiroplasma

Other Genera

Anaeroplasma
Asteroleplasma
Thermoplasma

Endosymbionts
Endosymbionts of Protozoa
Caedibacter
Holospora
Lyticum
Pseudocaedibacter
Tectibacter

Endosymbionts of Insects (blood sucking, plant sap-sucking, cellulose and stored grain feeders, and insects feeding on complex diets)

Blattabacterium

Endosymbionts of Fungi and Invertebrates other than Arthropods (Fungi, Sponges, Coelenterates, Helminthes, Annelids, Marine worms and mollusks)
Endosymbionts of Protozoa, ciliates, flagellates, and amoebas

Caedibacter
Holospora
Lyticum
Pseudocaedibacter
Tectibacter

Gram-Positive Cocci
Aerobic, Catalase-Positive Genera
Deinobacter
Deinococcus
Marinococcus
Micrococcus
Planococcus
Saccharococcus
Staphylococcus
Stomatococcus

Aerotolerant, Catalase-Negative Genera

Aerococcus Enterococcus
Gemella
Lactococcus
Leuconostoc
Melissococcus
Pediococcus
Streptococcus (Pyogenic Hemolytic Streptococci, Oral Streptococci, Enterococci, Lactic Acid Streptococci, Anaerobic Streptococci)
Trichococcus
Vagococcus

Anaerobic, Catalase-Negative Genera

Coprococcus
Peptococcus
Peptostreptococcus
Ruminococcus
Sarcina

Endospore-Forming Gram-Positive Rods and Cocci
Amphibacillus
Bacillus
Clostridium
Desulfotomaculum (also dissimilatory sulfate reducer)
Oscillospira
Sporolactobacillus
Sporosarcina
Sulfidobacillus
Syntrophospora

Regular, Nonsporing Gram-Positive Rods
Brochothrix
Carnobacterium
Caryophanon
Erysipelothrix
Kurthia
Lactobacillus
Listeria
Renibacterium

Irregular, Nonsporing Gram-Positive Rods
Acetobacterium
Acetogenium
Actinomyces
Aeromicrobium
Agromyces
Arachnia
Arcanobacterium
Arthrobacter
Aureobacterium
Bifidobacterium
Brachybacterium
Brevibacterium
Butyrivibrio (has thin, gram-positive walls, but stains as negative)
Caseobacter
Cellulomonas
Clavibacter
Coriobacterium
Corynebacterium
Curtobacterium
Dermabacter
Eubacterium
Exigouibacterium
Falcivibrio
Gardnerella (has thin, gram-positive walls but stains as negative)
Jonesia
Lachnospira (has thin, gram-positive walls but stains as negative)
Microbacterium
Mobiluncus
Pimelobacter
Propionibacterium
Rarobacter
Rothia
Rubrobacter
Sphaerobacter
Terrabacter
Thermoanaerobacter

Mycobacteria
Mycobacteriaceae
Mycobacterium

Nocardioforms
Intrasporangium
Micropolyspora
Nocardia
Nocardioides
Oerskovia
Promicromonospora
Pseudonocardia
Rhodococcus
Saccharopolyspora

Anoxygenic Phototrophic Bacteria
Purple Sulfur Bacteria: Internal Sulfur Granules
Chromatiaceae
Amoebobacter
Chromatium
Lamprobacter
Lamprocystis
Thiocapsa
Thiocystis
Thiodictyon
Thiopedia
Thiospirillum
Purple Sulfur Bacteria: External Sulfur Granules
Ectothiorhodospiraceae
Ectothiorhodopsin
Ectothiorhodospira
Purple Nonsulfur Bacteria
Rhodobacter
Rhodyclus
Rhodomicrobium
Rhodopila
Rhodopseudomonas
Rhodospirillum
Green Nonsulfur Bacteria
Heliobacillus
Heliobacterium
Green Sulfur Bacteria
Anacalochloris
Chlorobium
Chloroherpeton
Pelodictyon
Prosthecochloris
Multicellular Filamentous Green Bacteria
Chloroflexus
Chloronema
Heliothrix
Oscillochloris
Anaerobic Chemotrophic Bacteria
Erythrobacter

Oxygenic Phototrophic Bacteria
Cyanobacteria
Chroococcales
Chamaespiphon
Cyanothece
Gloeobacter
Gloeocapsa
Gloethece
Microcystis
Myxobaktron
Synechococcus
Synechocystis

Pleurocapsales

Chroococcidiopsis
Dermocarpa
Dermocarpella
Myxosarcina
Pleurocapsa
Xenococcus

Oscillatoriales

Arthrospira
Crinalium
Lyngbya
Microcoleus
Oscillatoria
Pseudanabaena
Spirulina
Starria
Trichodesmium

Nostocales

Nostocaceae
Anabaena
Aphanizomenon
Cylindrospermum
Nodularia
Nostoc

Scytonemataceae

Scytonema

Rivulariaceae

Calothrix

Stigonematales

Chlorogloeopsis
Fischerella
Geitleria
Stigonema

Prochlorales

Prochloraceae
Prochloron Prochlorothrix

Aerobic Chemolithotrophic Bacteria and Associated Organisms
Nitrifying Bacteria
Nitrobacteraceae
Nitrate-oxidizing bacteria
Nitrobacter
Nitrococcus
Nitrospina
Nitrospira

Ammonia-oxidizing bacteria

Nitrosococcus
Nitrosolobus
Nitrosomonas
Nitrosospira
Nitrosovibrio

Colorless sulfur-oxidizing bacteria

Acidiphilium
Macromonas
Thermothrix
Thiobacillus
Thiobacterium
Thiodendron
Thiomicrospira
Thiosphaera
Thiospira
Thiovulum

Obligate Chemolithotrophic Hydrogen Bacteria

Hydrogenobacter

Iron- and Manganese-oxidizing and/or -Depositing Bacteria

Siderocapsaceae
Aquaspirillum
Bilophococcus
Gallionella (both iron-oxidizing and appendaged)
Leptospirillum
Metallogenium
Naumaniella
Ochrobium
Siderocapsa
Siderococcus
Sulfobacillus

Budding (indicated by *) and/or Appendaged Bacteria
Prosthecate Bacteria
Ancalomicrobium *
Asticcacaulus
Caulobacter
Dichotomicrobium
Filomicrobium
Hirschia
Hyphomicrobium *
Hyphomonas *
Labrys *
Pedomicrobium *
Prosthecobacter
Prosthecomicrobium *
Stella *
Verrucomicrobium

Planctomycetales

Gemmata
Pirelulla

Nonprosthecate Budding Bacteria

Angulomicrobium
Blastobacter
Ensifer
Gemmiger
Isosphaera
Planctomyces

Nonbudding Bacteria
Asticcacaulis
Caulobacter
Gallionella
Nevskia
Prosthecobacter

Morphologically Unusual Budding Bacteria (involved in iron and manganese deposition)
Caulococcus
Kuznezovia
Metallogenium
Seliberia
Thiodendron

Sheathed Bacteria
Clonothrix
Crenothrix
Haliscominobacter
Leptothrix
Lieskeela
Phragmidiothrix
Sphaerotilus

Nonphotosynthetic, Nonfruiting Gliding Bacteria
Single-celled, Rod-shaped Gliding Bacteria
Cytophagales
Cytophagaceae
Capnocytophaga
Chitinophaga
Cytophaga
Flexibacter
Flexithrix
Microscilla
Sporocytophaga
Thermonema

Lysobacterales

Lysobacteriaceae
Lysobacter

Flattened, Filamentous Gliding Bacteria

Simonsiellaceae
Alysiella
Simonsiella

Sulfur-Oxidizing Gliding Bacteria

Beggiatoales
Beggiatoaceae
Achromatium
Beggiatoa
Thioploca
Thiospirillopsis
Thiothrix

The Pelonemas

Pelonemataceae
Achroonema Desmanthus
Pelonema
Peloploca

Other Genera

Agitococcus
Desulfonema
Herpetosiphon
Isosphaera
Leucothrix
Saprospira
Toxothrix
Vitreoscilla

Gliding, Fruiting Bacteria
Archangiaceae
Archangium

Cystobacteraceae

Cystobacter
Melittangium
Stigmatella

Myxococcales

Myxococcaceae
Myxococcus

Polyangiaceae

Chondromyces
Nannocystis
Polyangium

Other Genera

Angiococcus
Corallococcus
Haploangium
Sorangium

Archaeobacteria (an older term for the Archaea)

The Methanogens
Cell Walls With Pseudomurein
Methanobacteriales
Methanobacteriaceae
Methanobacterium
Methanobrevibacter

Methanothermaceae

Methanothermus

Cell Walls Without Pseudomurein

Methanococcales
Methanococcaceae
Methanococcus

Methanosarcinaceae

Methanolacinia
Methanococcoides
Methanolobus
Methanothrix

Methanomicrobiales

Methanomicrobiaceae
Methanomicrobium
Methanogenium
Methanospirillum

Methanoplanaceae

Methanoplanus

Other Genera

Methanocorpusculum
Methanoculleus
Methanohalobium
Methanohalophilus
Methanosarcina
Methanosphaera

Archaeal Sulfate Reducers
Archaeoglobales
Archaeoglobaceae
Archaeoglobus

Extremely Halophilic, Aerobic Archaeobacteria
Halobacteriales
Halobacteriaceae
Haloarcula
Halobacterium
Halococcus
Haloferax
Natronobacterium
Natronococcus

Cell Wall-Less Archaeobacteria
Thermoplasma

Extremely Thermophilic and Hyperthermophilic So – Metabolizers
Cocci, Optimum Growth Below pH4
Desulfurolobus Metallosphaera

Sulfolobales

Sulfolobaceae
Acidianus
Sulfolobus

Rods That Use H2 as Energy Source

Pyrobaculum

Thermoproteales

Thermoproteaceae
Thermofilum
Thermoproteus

Cocci or Disc-Shaped That Oxidize H2S

Hyperthermus
Staphylothermus
Thermodiscus
Desulfurococcaceae
Desulfurococcus
Pyrodictium

Thermococcales

Thermococcaceae
Thermococcus
Pyrococcus

Actinomycetes

Nocardioform Actinomycetes
Actinobispora
Actinokineospora
Actinopolyspora
Amycolata
Amycolatopsis
Faenia (Micropolyspora)
Gordona
Intrasporangium
Jonesia
Kibdelosporangium
Nocardia
Nocardioides
Oerskovia
Promicromonospora
Pseudoamycolata
Pseudonocardia
Rhodococcus
Saccharomonospora
Saccharopolyspora
Terrabacter
Tsukamurella

Actinomycetes With Multilocar Sporangia
Dermatophilus
Frankia
Geodermatophilus

Actinoplanetes
Actinoplanes
Ampullariella
Catelbatospora
Dactylosporangium
Micromonospora
Pilimelia

Streptomyces and Related Genera
Intrasporangium
Kineosporia
Sporichthya
Streptomyces
Streptoverticillium

Maduromycetes
Actinomadura
Microbispora
Microtetraspora
Planobispora
Planomonospora
Spirillospora
Streptosporangium

Thermomonospora and Related Genera
Actinosynnema
Nocardiopsis
Streptoalloteichus
Thermomonospora

Thermoactinomycetes
Thermoactinomyces

Other Actinomycete Genera
Glycomyces
Kibdelosporangium
Kitasatosporia
Saccarothrix