or responsible for poisoning (staphylococcal enteropathogenic Staphylococcus aureus). Families Caryophanaceae
(Caryophanon), Paenibacillaceae (Paenibacillus), Alicyclobacillaceae (Alicyclobacillus, Pasteuria), Thermoactinomycetaceae (Thermoactinomyces), and Sporolactobacillaceae
(Sporolactobacillus) group aerobic or fermentative bacteria
isolated from soil and water sometimes thermophiles. The
family Listeriaceae (Listeria) contains bacteria common in
soil and water with a species (Listeria monocytogenes) which
can be pathogenic and is responsible for food poisoning
especially in dairy products.
The order Lactobacillales consisting of six family
includes lactic acid bacteria and many cocci. The family
Lactobacillaceae (Lactobacillus, Pediococcus) corresponds
to chemoorganotrophic aerotolerant and fermentative lactic
acid bacteria such as Lactobacillus acidophilus and Lactobacillus bulgaricus used in the manufacture of yogurt. The
families Aerococcaceae (Aerococcus), Carnobacteriaceae
(Carnobacterium), and Enterococcaceae (Enterococcus)
include a majority of aerobic or anaerobic fermentative
cocci, isolated from soil and water; some may reduce
nitrates, iron, or manganese. The family Leuconostocaceae
concerns aerotolerant fermentative or aerobic cocci used in
the food industry of lactic fermentation such as Leuconostoc
and Oenococcus, this latter being used in malolactic fermentation of grapes juice (winemaking) or cabbage (sauerkraut).
The family Streptococcaceae corresponds to the genera
Streptococcus with certain pathogens such as hemolytic
streptococci (Streptococcus pyogenes) and Lactococcus, lactic acid fermentation bacteria.
The Phylum Tenericutes
This phylum, formerly grouped with Firmicutes was elevated
to the rank of phylum in the second edition of Bergey’s Manual
of Systematic Bacteriology. It contains mycoplasma bacteria
that are devoid of peptidoglycan but derive from Grampositive bacteria while reacting negatively to this test. They
are grouped into a single class, the class Mollicutes, including
Mycoplasma genitalium, pathogen of animals and man, and
Spiroplasma citri, citrus trees pathogen. This class Mollicutes
is structured in five orders. The order Mycoplasmatales with
the family Mycoplasmataceae (Mycoplasma), the order
Entomoplasmatales with the families Entomoplasmataceae
(Entomoplasma) and Spiroplasmataceae (Spiroplasma), the
order Acholeplasmatales with the family Acholeplasmataceae
(Acholeplasma), the order Anaeroplasmatales with the family
Anaeroplasmataceae (Anaeroplasma), this family concerning
anaerobic mycoplasma, and the order Haloplasmatales with
the
genus
Haloplasma
(halophilic
mycoplasma).
Mycoplasmas are obligate parasites of plants or animals
and thus often pathogens in many infections (pulmonary or
urogenital animals and man, leaf necrosis and degeneration in
plants). A genus Incertae sedis* in the family Erysipelotrichaceae the Erysipelothrix genus is also present in this
class Mollicutes, whereas it has a wall normal for Grampositive bacteria. It is a bacterial pathogen of humans and
animals (agent of swine erysipelas, zoonosis transmitted to
man). This group has, in addition to unusual morphology (no
wall), a high mutation rate (Dybvig and Voelker 1996).
The Phylum Actinobacteria
It concerns Gram-positive bacteria with high G + C% (% by
GC in the DNA > usually 50 %) (Fig. 6.3). This group of
microorganisms has as most striking character varied
morphologies ranging from unicellular organisms to irregular shapes consisting of mycelial branched hyphae. This
character, also found in Fungi, has been a source of confusion for years when taxonomy was not based on molecular
sequences. It is now recognized unequivocally that this is an
instance of convergent evolution with Fungi.
Actinobacteria, especially the most famous of them, Streptomyces coelicolor, and related genera (Actinomyces,
Nocardia) producing structures called conidiophores useful
for dissemination. Actinobacteria are dominant in the soil
where their dissemination structures (conidiophores and
hyphal cells) give them a competitive advantage. They also
have the ability to synthesize antibiotic compounds, some of
which are used as important drugs in therapy of infectious
diseases, and they also confer a competitive advantage vis-a `vis other soil bacteria (cf. Sect. 9.5.1). This phylum contains
a class (Actinobacteria) which is composed of five
subclasses (the Acidimicrobidae, the Rubrobacteridae, the
Coriobacteridae, the Sphaerobacteridae, and the
Actinobacteridae).
The first four subclasses contain very few species, often
with only one representative and only one family. The
Acidimicrobidae with the order Acidimicrobiales and the family Acidimicrobiaceae (Acidimicrobium), the Rubrobacteridae
with the order Rubrobacterales and the family Rubrobacteraceae (Rubrobacter), the Coriobacteridae with the order
Coriobacteriales which contains a single family and several
Coriobacteriaceae genera (Coriobacterium, Atopobium,
Cryptobacterium), and with the Sphaerobacteridae with the
order Sphaerobacterales containing a family Sphaerobacteraceae (Sphaerobacter) correspond to aerobic Gram-positive
facultative anaerobic or aerobic, with stick-shaped, more or
less regular, isolated from soils or aquatic sediments, and
which perform aerobic or nitrate respiration or fermentation.
The fifth subclass (Actinobacteridae) contains most of the
bacteria of the phylum and is divided into two orders
(Actinomycetales and Bifidobacteriales) containing numerous suborders and many families.
The order Actinomycetales comprises 10 suborders under
which are grouped most of the bacteria of the phylum
Actinobacteria. The suborder Actinomycinae with family
Actinomycetaceae (Actinomyces, Actinobaculum) contains
filamentous, branched bacteria, which are aerobic,
chemoorganotrophic, producing antibiotics, colonizing the
6 Taxonomy and Phylogeny of Prokaryotes
187
(Caryophanon), Paenibacillaceae (Paenibacillus), Alicyclobacillaceae (Alicyclobacillus, Pasteuria), Thermoactinomycetaceae (Thermoactinomyces), and Sporolactobacillaceae
(Sporolactobacillus) group aerobic or fermentative bacteria
isolated from soil and water sometimes thermophiles. The
family Listeriaceae (Listeria) contains bacteria common in
soil and water with a species (Listeria monocytogenes) which
can be pathogenic and is responsible for food poisoning
especially in dairy products.
The order Lactobacillales consisting of six family
includes lactic acid bacteria and many cocci. The family
Lactobacillaceae (Lactobacillus, Pediococcus) corresponds
to chemoorganotrophic aerotolerant and fermentative lactic
acid bacteria such as Lactobacillus acidophilus and Lactobacillus bulgaricus used in the manufacture of yogurt. The
families Aerococcaceae (Aerococcus), Carnobacteriaceae
(Carnobacterium), and Enterococcaceae (Enterococcus)
include a majority of aerobic or anaerobic fermentative
cocci, isolated from soil and water; some may reduce
nitrates, iron, or manganese. The family Leuconostocaceae
concerns aerotolerant fermentative or aerobic cocci used in
the food industry of lactic fermentation such as Leuconostoc
and Oenococcus, this latter being used in malolactic fermentation of grapes juice (winemaking) or cabbage (sauerkraut).
The family Streptococcaceae corresponds to the genera
Streptococcus with certain pathogens such as hemolytic
streptococci (Streptococcus pyogenes) and Lactococcus, lactic acid fermentation bacteria.
The Phylum Tenericutes
This phylum, formerly grouped with Firmicutes was elevated
to the rank of phylum in the second edition of Bergey’s Manual
of Systematic Bacteriology. It contains mycoplasma bacteria
that are devoid of peptidoglycan but derive from Grampositive bacteria while reacting negatively to this test. They
are grouped into a single class, the class Mollicutes, including
Mycoplasma genitalium, pathogen of animals and man, and
Spiroplasma citri, citrus trees pathogen. This class Mollicutes
is structured in five orders. The order Mycoplasmatales with
the family Mycoplasmataceae (Mycoplasma), the order
Entomoplasmatales with the families Entomoplasmataceae
(Entomoplasma) and Spiroplasmataceae (Spiroplasma), the
order Acholeplasmatales with the family Acholeplasmataceae
(Acholeplasma), the order Anaeroplasmatales with the family
Anaeroplasmataceae (Anaeroplasma), this family concerning
anaerobic mycoplasma, and the order Haloplasmatales with
the
genus
Haloplasma
(halophilic
mycoplasma).
Mycoplasmas are obligate parasites of plants or animals
and thus often pathogens in many infections (pulmonary or
urogenital animals and man, leaf necrosis and degeneration in
plants). A genus Incertae sedis* in the family Erysipelotrichaceae the Erysipelothrix genus is also present in this
class Mollicutes, whereas it has a wall normal for Grampositive bacteria. It is a bacterial pathogen of humans and
animals (agent of swine erysipelas, zoonosis transmitted to
man). This group has, in addition to unusual morphology (no
wall), a high mutation rate (Dybvig and Voelker 1996).
The Phylum Actinobacteria
It concerns Gram-positive bacteria with high G + C% (% by
GC in the DNA > usually 50 %) (Fig. 6.3). This group of
microorganisms has as most striking character varied
morphologies ranging from unicellular organisms to irregular shapes consisting of mycelial branched hyphae. This
character, also found in Fungi, has been a source of confusion for years when taxonomy was not based on molecular
sequences. It is now recognized unequivocally that this is an
instance of convergent evolution with Fungi.
Actinobacteria, especially the most famous of them, Streptomyces coelicolor, and related genera (Actinomyces,
Nocardia) producing structures called conidiophores useful
for dissemination. Actinobacteria are dominant in the soil
where their dissemination structures (conidiophores and
hyphal cells) give them a competitive advantage. They also
have the ability to synthesize antibiotic compounds, some of
which are used as important drugs in therapy of infectious
diseases, and they also confer a competitive advantage vis-a `vis other soil bacteria (cf. Sect. 9.5.1). This phylum contains
a class (Actinobacteria) which is composed of five
subclasses (the Acidimicrobidae, the Rubrobacteridae, the
Coriobacteridae, the Sphaerobacteridae, and the
Actinobacteridae).
The first four subclasses contain very few species, often
with only one representative and only one family. The
Acidimicrobidae with the order Acidimicrobiales and the family Acidimicrobiaceae (Acidimicrobium), the Rubrobacteridae
with the order Rubrobacterales and the family Rubrobacteraceae (Rubrobacter), the Coriobacteridae with the order
Coriobacteriales which contains a single family and several
Coriobacteriaceae genera (Coriobacterium, Atopobium,
Cryptobacterium), and with the Sphaerobacteridae with the
order Sphaerobacterales containing a family Sphaerobacteraceae (Sphaerobacter) correspond to aerobic Gram-positive
facultative anaerobic or aerobic, with stick-shaped, more or
less regular, isolated from soils or aquatic sediments, and
which perform aerobic or nitrate respiration or fermentation.
The fifth subclass (Actinobacteridae) contains most of the
bacteria of the phylum and is divided into two orders
(Actinomycetales and Bifidobacteriales) containing numerous suborders and many families.
The order Actinomycetales comprises 10 suborders under
which are grouped most of the bacteria of the phylum
Actinobacteria. The suborder Actinomycinae with family
Actinomycetaceae (Actinomyces, Actinobaculum) contains
filamentous, branched bacteria, which are aerobic,
chemoorganotrophic, producing antibiotics, colonizing the
6 Taxonomy and Phylogeny of Prokaryotes
187