symbionts, etc.) are also present in this class with a large
number of taxa in close interaction with host animals or
plants. Among the best-known representatives, there are
Sinorhizobium meliloti, the dinitrogen fixing root symbiont
in alfalfa; Agrobacterium tumefaciens, the pathogen that
transforms its host plant by injecting it with its own DNA;
Rickettsia conorii, the agent of Q fever; and Nitrobacter
hamburgensis, nitrifying soil bacteria.
In Rhodospirillales, an order consisting of two families
(Rhodospirillaceae and Acetobacteraceae), the purple bacterium Rhodospirillum and other relatives (Rhodovibrio,
Rhodospira, etc.) coexists with Acetobacter, Gluconobacter
(bacteria oxidizing ethanol to acetic acid), and various other
bacteria isolated from soil and aquatic continental or marine
environments (Azospirillum, Magnetospirillum).
The Rhodobacterales with a single family (Rhodobacteraceae) contain many purple nonsulfur bacteria
(Rhodobacter, Rhodovulum, etc.) and marine aerobic or
denitrifying bacteria (Amaricoccus, Antarctobacter,
Paracoccus, etc.) or containing bacteriochlorophyll a
(Roseobacter, Roseovivax, etc.).
The Rhizobiales with 10 families contain some purple
phototrophic bacteria in Rhodobiaceae (Rhodobium) or in
Bradyrhizobiaceae (Rhodopseudomonas). Other families of
this order include many soil bacteria, fixing dinitrogen. It is
the case of Rhizobiaceae (Rhizobium), of Phyllobacteriaceae
(Phyllobacterium,
Mesorhizobium),
of
Beijerinckiaceae (Beijerinckia), and of Bradyrhizobiaceae
(Bradyrhizobium) which also contain nitrifying bacteria
(Nitrobacter). Other families concern methylotrophic bacteria as Methylocystaceae, Methylobacteriaceae (Methylobacterium). The Hyphomicrobiaceae (Hyphomicrobium,
Aquabacter, and Blastochloris) isolated from soil or aquatic
environments, Brucellaceae (Brucella) responsible for brucellosis, and Bartonellaceae (Bartonella) are also part of
Rhizobiales.
The three other orders of this class are the Rickettsiales
with three bacteria family symbionts or parasites,
Rickettsiaceae (Rickettsia, Wolbachia) which are intracellular parasites or symbionts, the Ehrlichiaceae (Ehrlichia),
and the Holosporaceae. The Sphingomonadales with family
Sphingomonadaceae (Sphingomonas) and Caulobacterales
with family Caulobacteraceae (Caulobacter) are the last
two orders of this class which includes as a whole many
bacteria which are diverse in their metabolism
(phototrophic, chemolithotrophic, chemoorganotrophic)
and multiply by budding or form stalks, enabling them to
live
on
fixed
supports
(Hyphomicrobium,
Rhodopseudomonas,
Rhodomicrobium,
Blastochloris,
Caulobacter, Ancalomicrobium, and Prosthecomicrobium).
The Class Betaproteobacteria
It includes some phototrophic purple nonsulfur bacteria but
also chemolithotrophic or chemoorganotrophic bacteria that
live in varied ecological niches with a predominance of
contaminated sites. It consists of six orders with two that
contain some purple bacteria. These are Burkholderiales
with family Comamonadaceae (Rubrivivax, Rhodoferax)
which also contains many non-photosynthetic bacteria and
Rhodocyclales with family Rhodocyclaceae (Rhodocyclus)
which also includes the chemoorganotrophic genera
Propionibacter or Zooglea.
The order Burkholderiales includes five families especially
chemoorganotrophic using metals (Ralstoniaceae with
Ralstonia metallidurans) or isolated from polluted soils
(Burkholderiaceae with Burkholderia, Alcaligenaceae with
Alcaligenes) capable of biodegrading hydrocarbons or
xenobiotics (pesticides). The family Comamonadaceae
includes many chemoorganotrophic bacteria (Comamonas,
Aquabacterium) isolated from aquatic environments, or polluted environments including wastewaters (filamentous bacteria: Leptothrix, Sphaerotilus) and chemolithotrophic bacteria
ä
Fig. 6.14 (continued) Michael Madigan, University of Illinois,
Michigan, USA); (d) Rhodopseudomonas palustris (Photograph: Pierre
Caumette); (e) Allochromatium vinosum (Photograph: Pierre
Caumette); (f) Allochromatium sp. containing polyhydroxybutyrate
globules, electron microscopy (Photograph: courtesy of Michael
Madigan, University of Illinois, Michigan, USA); (g) Rhodospirillum
sp. (Photograph: Pierre Caumette); (h) Desulfovibrio halophilus (Photograph: Pierre Caumette); (i) Desulfobacterium vacuolatum (Photograph: courtesy of Friedrich Widdel, MP Institute of Microbiology,
Bremen, Germany); (j) Desulfonema ishimotoi (Photograph: courtesy
of Friedrich Widdel, MP Institute of Microbiology, Bremen,
Germany); (k) Ectothiorhodospira sp. (Photograph: courtesy of Remy
Guyoneaud, IPREM, University of Pau, France); (l) Desulfobulbus
propionicus (Photograph: courtesy of Friedrich Widdel, MP Institute
of Microbiology, Bremen, Germany); (m) Desulfovibrio sp.
(Photograph: courtesy of Friedrich Widdel, MP Institute of Microbiology, Bremen, Germany); (n) Chromatium sp. interference contrast
(Photograph: courtesy of Heribert Cypionka, University of Oldenburg,
Germany); (o) Desulfovibrio desulfuricans (Photograph: courtesy of
Friedrich Widdel, MP Institute of Microbiology, Bremen, Germany;
(p) Desulfobacterium autotrophicum (Photograph: courtesy of
Friedrich Widdel, MP Institute of Microbiology, Bremen, Germany);
(q) Thiodictyon sp., iron-oxidizing bacteria purple (Photograph: courtesy of Armin Ehrenreich, MP Institute of Microbiology, Bremen,
Germany); (r) Desulfobacter latus (Photograph: courtesy of Friedrich
Widdel, MP Institute of Microbiology, Bremen, Germany). The bars
represent 10 mm except for figures c and f where they are 1 mm. With
the exception of figures c, f, and n, all photographs correspond to phase
contrast microscopy
6 Taxonomy and Phylogeny of Prokaryotes
181
number of taxa in close interaction with host animals or
plants. Among the best-known representatives, there are
Sinorhizobium meliloti, the dinitrogen fixing root symbiont
in alfalfa; Agrobacterium tumefaciens, the pathogen that
transforms its host plant by injecting it with its own DNA;
Rickettsia conorii, the agent of Q fever; and Nitrobacter
hamburgensis, nitrifying soil bacteria.
In Rhodospirillales, an order consisting of two families
(Rhodospirillaceae and Acetobacteraceae), the purple bacterium Rhodospirillum and other relatives (Rhodovibrio,
Rhodospira, etc.) coexists with Acetobacter, Gluconobacter
(bacteria oxidizing ethanol to acetic acid), and various other
bacteria isolated from soil and aquatic continental or marine
environments (Azospirillum, Magnetospirillum).
The Rhodobacterales with a single family (Rhodobacteraceae) contain many purple nonsulfur bacteria
(Rhodobacter, Rhodovulum, etc.) and marine aerobic or
denitrifying bacteria (Amaricoccus, Antarctobacter,
Paracoccus, etc.) or containing bacteriochlorophyll a
(Roseobacter, Roseovivax, etc.).
The Rhizobiales with 10 families contain some purple
phototrophic bacteria in Rhodobiaceae (Rhodobium) or in
Bradyrhizobiaceae (Rhodopseudomonas). Other families of
this order include many soil bacteria, fixing dinitrogen. It is
the case of Rhizobiaceae (Rhizobium), of Phyllobacteriaceae
(Phyllobacterium,
Mesorhizobium),
of
Beijerinckiaceae (Beijerinckia), and of Bradyrhizobiaceae
(Bradyrhizobium) which also contain nitrifying bacteria
(Nitrobacter). Other families concern methylotrophic bacteria as Methylocystaceae, Methylobacteriaceae (Methylobacterium). The Hyphomicrobiaceae (Hyphomicrobium,
Aquabacter, and Blastochloris) isolated from soil or aquatic
environments, Brucellaceae (Brucella) responsible for brucellosis, and Bartonellaceae (Bartonella) are also part of
Rhizobiales.
The three other orders of this class are the Rickettsiales
with three bacteria family symbionts or parasites,
Rickettsiaceae (Rickettsia, Wolbachia) which are intracellular parasites or symbionts, the Ehrlichiaceae (Ehrlichia),
and the Holosporaceae. The Sphingomonadales with family
Sphingomonadaceae (Sphingomonas) and Caulobacterales
with family Caulobacteraceae (Caulobacter) are the last
two orders of this class which includes as a whole many
bacteria which are diverse in their metabolism
(phototrophic, chemolithotrophic, chemoorganotrophic)
and multiply by budding or form stalks, enabling them to
live
on
fixed
supports
(Hyphomicrobium,
Rhodopseudomonas,
Rhodomicrobium,
Blastochloris,
Caulobacter, Ancalomicrobium, and Prosthecomicrobium).
The Class Betaproteobacteria
It includes some phototrophic purple nonsulfur bacteria but
also chemolithotrophic or chemoorganotrophic bacteria that
live in varied ecological niches with a predominance of
contaminated sites. It consists of six orders with two that
contain some purple bacteria. These are Burkholderiales
with family Comamonadaceae (Rubrivivax, Rhodoferax)
which also contains many non-photosynthetic bacteria and
Rhodocyclales with family Rhodocyclaceae (Rhodocyclus)
which also includes the chemoorganotrophic genera
Propionibacter or Zooglea.
The order Burkholderiales includes five families especially
chemoorganotrophic using metals (Ralstoniaceae with
Ralstonia metallidurans) or isolated from polluted soils
(Burkholderiaceae with Burkholderia, Alcaligenaceae with
Alcaligenes) capable of biodegrading hydrocarbons or
xenobiotics (pesticides). The family Comamonadaceae
includes many chemoorganotrophic bacteria (Comamonas,
Aquabacterium) isolated from aquatic environments, or polluted environments including wastewaters (filamentous bacteria: Leptothrix, Sphaerotilus) and chemolithotrophic bacteria
ä
Fig. 6.14 (continued) Michael Madigan, University of Illinois,
Michigan, USA); (d) Rhodopseudomonas palustris (Photograph: Pierre
Caumette); (e) Allochromatium vinosum (Photograph: Pierre
Caumette); (f) Allochromatium sp. containing polyhydroxybutyrate
globules, electron microscopy (Photograph: courtesy of Michael
Madigan, University of Illinois, Michigan, USA); (g) Rhodospirillum
sp. (Photograph: Pierre Caumette); (h) Desulfovibrio halophilus (Photograph: Pierre Caumette); (i) Desulfobacterium vacuolatum (Photograph: courtesy of Friedrich Widdel, MP Institute of Microbiology,
Bremen, Germany); (j) Desulfonema ishimotoi (Photograph: courtesy
of Friedrich Widdel, MP Institute of Microbiology, Bremen,
Germany); (k) Ectothiorhodospira sp. (Photograph: courtesy of Remy
Guyoneaud, IPREM, University of Pau, France); (l) Desulfobulbus
propionicus (Photograph: courtesy of Friedrich Widdel, MP Institute
of Microbiology, Bremen, Germany); (m) Desulfovibrio sp.
(Photograph: courtesy of Friedrich Widdel, MP Institute of Microbiology, Bremen, Germany); (n) Chromatium sp. interference contrast
(Photograph: courtesy of Heribert Cypionka, University of Oldenburg,
Germany); (o) Desulfovibrio desulfuricans (Photograph: courtesy of
Friedrich Widdel, MP Institute of Microbiology, Bremen, Germany;
(p) Desulfobacterium autotrophicum (Photograph: courtesy of
Friedrich Widdel, MP Institute of Microbiology, Bremen, Germany);
(q) Thiodictyon sp., iron-oxidizing bacteria purple (Photograph: courtesy of Armin Ehrenreich, MP Institute of Microbiology, Bremen,
Germany); (r) Desulfobacter latus (Photograph: courtesy of Friedrich
Widdel, MP Institute of Microbiology, Bremen, Germany). The bars
represent 10 mm except for figures c and f where they are 1 mm. With
the exception of figures c, f, and n, all photographs correspond to phase
contrast microscopy
6 Taxonomy and Phylogeny of Prokaryotes
181