bluuebunny/crossref_metadata_2025 huggingface dataset:
Anaerobranca
Authors: Wiegel Juergen
Published: August 2015

An.ae.ro.bran'ca. Gr. pref.
an
not; Gr. n.
aer
air; N.L. fem. n.
branca
claw, paw, the root of the En. word branch, an arm‐like part diverging from a main axis; N.L. n.
Anaerobranca
referring to the branched cell shape of the obligately anaerobic bacterium.

Firmicutes / “Clostridia” / Clostridiales / incertae Sedis ‐ Family IV / Anaerobranca

Gram‐positive type cell‐wall ultrastructure
but, depending on the species, cells stain
Gram‐positive or ‐negative
. The cell wall is either thick (
Anaerobranca horikoshii
) or thin. To date, the genus contains only
thermophilic
species growing in the range 30–67°C (no growth at 70°C) and pH 10.3 at 60°C. As indicated by the genus name, all three species exhibit the occurrence of truly branched cells with no septa; up to 10% of the cells in a culture are branched, depending on strain, growth stage, and conditions. General physiology is
organoheterotrophic
(proteolytic and glucolytic), but all species also can reduce Fe(III) to Fe(II) with magnetite formation, selenite to elemental selenium (red precipitate) and selenide (Se
2−
), elemental sulfur to sulfide, and thiosulfate to sulfide. Some of the species can reduce (dissimilatory) fumarate to succinate. Proteinaceous compounds are the preferred substrates. The presence of thiosulfate stimulates the slow utilization of selected carbohydrates by functioning as an efficient electron acceptor. Spore formation not observed, but sporulation genes are present.

DNA G
+
C content
(
mol
%): 30–34.

Type species
:
Anaerobranca horikoshii
Engle, Li, Woese and Wiegel 1995, 459
VP
.
Halanaerobacter
Authors: Mesbah Noha M.
Published: August 2015

Hal.an.ae.ro.bac'ter. Gr. n.
hals
salt; Gr. pref.
an
not; Gr. n.
aer
air; N.L. masc. n.
bacter
rod; N.L. masc n.
Halanaerobacter
salt rod which grows in the absence of air.

Firmicutes / “Clostridia” / Halanaerobiales / Halobacteroidaceae / Halanaerobacter

Cells are rod‐shaped or slightly curved
,
motile by means of peritrichous flagella
. Gram‐stain‐negative.
Strictly anaerobic
.
Chemo‐organotrophic
with fermentative metabolism; some strains can
utilize amino acids
in Stickland reactions or with H
2
as electron donor. Carbohydrates are fermented with production of acetate, H
2
, and CO
2
. In some species, ethanol, propionate, formate, and isobutyrate are also formed. Elemental sulfur can be used as an electron acceptor in a certain species.
Halophilic
; optimal growth occurs at NaCl concentrations around 2.0–3.0 M. Cells require a minimum of 0.5–1.6 M NaCl for growth. Neutral to slightly alkaline pH values required for optimal growth (6.5–7.8). Mesophilic to slightly thermotolerant, and optimal growth occurs between 35 and 45 °C. Endospores have not been observed; short degenerate cells and sphaeroplasts occur in stationary phase.
Catalase‐ and oxidase‐negative
.
Found in anoxic sediments in hypersaline environments
.

DNA G
+
C content
(
mol
%): 32–35.

Type species
:
Halanaerobacter chitinivorans
corrig. Liaw and Mah 1996, 362
VP
(Effective publication: Liaw and Mah 1992, 265.).
Halonatronum
Authors: Zhilina Tatjana N. , Zavarzin George A. , Oren Aharon
Published: August 2015

Ha.lo.na.tro'num. Gr. n.
hals, halos
salt; Ar. n.
natron
soda; N.L. neut. n.
Halonatronum
an organism growing with salt and soda.

Firmicutes / “Clostridia” / Halanaerobiales / Halobacteroidaceae / Halonatronum

Cells are rod‐shaped
,
flexible
,
and motile by peritrichous flagella
.
The cell wall has a Gram‐stain‐negative structure
.
Strictly anaerobic
. Chemo‐organotrophic with fermentative metabolism. Carbohydrates, including soluble polysaccharides, are fermented to acetate, ethanol, formate, H
2
, and CO
2
.
Halophilic and alkaliphilic
.
Endospores produced
.

DNA G
+
C content
(
mol
%): 34.4 (
T
m
).

Type species
:
Halonatronum saccharophilum
Zhilina, Garnova, Tourova, Kostrikina and Zavarzin 2001a, 263
VP
(Effective publication: Zhilina, Garnova, Tourova, Kostrikina and Zavarzin 2001b, 71.).
Orenia
Authors: Rainey Fred A.
Published: August 2015

O.re'ni.a. N.L. fem. n.
Orenia
named after Aharon Oren, an Israeli microbiologist.

Firmicutes / “Clostridia” / Halanaerobiales / Halobacteroidaceae / Orenia

Gram negative
. Rods, 2.5–13 µm in length with round ends. Motile by peritrichous flagella.
Spores
are round, terminal or subterminal. Gas vacuoles detected in some species. Forms sphaeroplasts.
Strictly anaerobic
. Catalase‐ and oxidase‐negative.
Halophilic
; optimum NaCl concentration for growth ranges 3–12%; no growth below 2% or above 25%. Mesophilic to slightly thermophilic. Optimum temperature range for growth 36–45 °C, maximum below 52 °C, minimum 25 °C.
Chemoorganotrophic
. End products of glucose fermentation include H
2
, CO
2
, formate, lactate, acetate, butyrate, and ethanol.

DNA G
+
C content
(
mol
%): 28.6–33.7.

Type species
:
Orenia marismortui
(Oren, Pohla and Stackebrandt 1987) Rainey, Zhilina, Boulygina, Stackebrandt, Tourova and Zavarzin 1995b, 880
VP
(Effective publication: Rainey, Zhilina, Boulygina, Stackebrandt, Tourova and Zavarzin 1995a, 197.) (
Sporohalobacter marismortui
Oren, Pohla and Stackebrandt 1987, 245).
Caldanaerobacter
Authors: Fardeau Marie‐Laure , Ollivier Bernard , Cayol Jean‐luc
Published: August 2015

Cald.an.ae.ro.bac'ter. L. adj.
caldus
hot; Gr. pref.
an
not; Gr. n.
aer
air; N.L. masc. n.
bacter
equivalent of Gr. neut. dim. n.
bakterion
rod, staff; N.L. masc. n.
Caldanaerobacter
a rod that grows in the absence of air at high temperatures.

Firmicutes / “Clostridia” / Thermoanaerobacterales / Thermoanaerobacteraceae / Caldanaerobacter

Cells are
straight rods
that stain
Gram‐positive or negative
. Endospores may be observed.
Strictly anaerobic heterotrophs
. Acetate and

l

‐
alanine
are major end products of glucose fermentation, with approximately 1 mol of
L
‐alanine being produced per mol of glucose.
Thermophilic
member of the family
Thermoanaerobacteraceae
.

DNA G
+
C content
(
mol
%): 33–41.

Type species
:
Caldanaerobacter subterraneus
(Fardeau, Magot, Patel, Thomas, Garcia and Ollivier 2000) Fardeau, Bonilla‐Salinas, L'Haridon, Jeanthon, Verhé, Cayol, Patel and Garcia 2004, 471
VP
(
Thermoanaerobacter subterraneus
Fardeau, Magot, Patel, Thomas, Garcia and Ollivier 2000, 2145).
Thermacetogenium
Authors: Kamagata Yoichi
Published: August 2015

Therm.a.ce.to.ge'ni.um. Gr. adj.
thermos
hot; L. n.
acetum
vinegar; Gr. v. suff.
genium
producing; N.L. neut. n.
Thermacetogenium
thermophilic vinegar producer.

Firmicutes / “Clostridia” / Thermoanaerobacterales / Thermoanaerobacteraceae / Thermacetogenium

Cells are rod‐shaped
.
Strictly anaerobic and thermophilic
.
Chemoautotrophic and chemo‐organotrophic
. Gram reaction is negative, but has a Gram‐stain‐positive cell‐wall structure. Round terminal endospores are sometimes formed. Colonies are disk‐shaped.
Able to oxidize acetate in co‐culture with hydrogenotrophic micro‐organisms
. Acetate can also be utilized by sulfate reduction in pure culture. Possesses
menaquinone‐7
.
Grows acetogenically on several alcohols
,
methoxylated aromatics
,
organic acids
,
amino acids
,

and H
2

/

CO
2

. Sugars are not utilized. Additional supplements are not required.

DNA G
+
C content
(
mol
%): 53.5.

Type species
:
Thermacetogenium phaeum
Hattori, Kamagata, Hanada and Shoun 2000, 1608
VP
.
Coprothermobacter
Authors: Ollivier Bernard , Garcia Jean‐Louis
Published: August 2015

Co.pro.ther'mo.bac'ter. Gr. fem. n.koprosmanure; Gr. adj.thermoswarm; Gr. masc. dim. n.bakterionrod; N.L. masc. n.Coprothermobactera thermophilic rod from manure.

Firmicutes / “Clostridia” / Thermoanaerobacterales / Thermodesulfobiaceae / Coprothermobacter

Rod‐shaped cells,0.5×1.0–6.0μm; occur singly or in pairs in young cultures; pleomorphic in old cultures. Colonies are white, circular (diameter 1–2 mm), convex, smooth with entire edges. Gram‐stain‐negative. Nonsporeforming.Nonmotile.Strictly anaerobic.Thermophilic. Optimum temperature, 55–70 °C. Neutrophilic. Chemo‐organotrophic. Proteolytic using gelatin and peptones. Sugars are used poorly unless yeast extract or rumen fluid is added. Trypticase peptone stimulates glucose utilization. The principal fermentation end products from sugar or protein fermentation are acetic acid, H2, and CO2. Thiosulfate, but not sulfate, is used as electron acceptor for growth. Isolated from thermophilic digestors. The type species,Coprothermobacter proteolyticus, represents a deeply branched taxon of the domainBacteria.

DNA G+C content(mol%): 43.

Type species:Coprothermobacter proteolyticus(Ollivier, Mah, Ferguson, Boone, Garcia and Robinson 1985) Rainey and Stackebrandt 1993a, 857VP(Thermobacteroides proteolyticusOllivier, Mah, Ferguson, Boone, Garcia and Robinson 1985, 427).
Mahella
Authors: Bonilla‐Salinas Monica , Ollivier Bernard , Patel Bharat K.C. , Cayol Jean‐Luc
Published: August 2015

Mah.el'la. L. dim. ending ‐
ella
; N.L. fem. n.
Mahella
named in honor of the American microbiologist Robert A. Mah for his important contribution to the taxonomy of anaerobes.

Firmicutes / “Clostridia” / Thermoanaerobacterales / incertae Sedis ‐ Family IV / Mahella

Cells are
straight rods
, about 3–20 µm × 0.5 µm, occurring singly or in pairs. The rods are motile by
peritrichous flagella
and stain
Gram‐positive. Spores
are formed.
Obligately anaerobic
. Moderately
thermophilic
; the optimum growth temperature is 50 °C.
Halotolerant
and grows in the presence of up to 4% NaCl with an optimum of 0.1%. The pH optimum is 7.5.
Heterotroph
. Glucose is fermented to lactate, formate, H
2
, and CO
2
. Yeast extract is not required for growth. Elemental sulfur, sulfate, thiosulfate, sulfite, nitrate, and nitrite are not used as electron acceptors.

DNA G
+
C content
(
mol
%): 55.5.

Type species
:
Mahella australensis
Bonilla‐Salinas, Fardeau, Thomas, Cayol, Patel and Ollivier 2004, 2172
VP
.
Catenibacterium
Authors: Rainey Fred A.
Published: August 2015

Ca.te.ni.bac.te'ri.um. L. fem. n.
catena
chain; Gr. dim. n.
bakterion
a small rod; N.L. neut. n.
Catenibacterium
chain rodlet.

Firmicutes / Erysipelotrichia / Erysipelotrichales / Erysipelotrichaceae / Catenibacterium

Cells occur in tangled chains. Gram‐stain‐positive and obligately anaerobic. Spores are absent. Fermentation products of glucose are acetic, lactic, butyric and isobutyric acids. Cell wall contains an A1c‐type peptidoglycan with an (
L
‐Ala)–
D
‐Glu–
m
‐Dpm peptide subunit. The genus
Catenibacterium
is a member of the
Clostridium
subphylum of the Gram‐positive bacteria and exhibits a close phylogenetic association with
Lactobacillus catenaformis
and
Lactobacillus vitulinus
.

DNA G
+
C content
(
mol
%): 36–39 (HPLC).

Type species
:
Catenibacterium mitsuokai
Kageyama and Benno 2000e, 1598
VP
.
Coprobacillus
Authors:   The Editorial Board
Published: August 2015

Co.pro.ba.cil'lus. L. n.
copro
feces; L. dim. n.
bacillus
a small rod; N.L. n.
Coprobacillus
rodlet isolated from feces.

Firmicutes / Erysipelotrichia / Erysipelotrichales / Erysipelotrichaceae / Coprobacillus

Gram‐positive short rods that occur in chains
. Spores are not formed. Nonmotile.
Obligate anaerobe
that produces acetate and lactate from glucose.

DNA G
+
C content
(
mol
%): 32–34 (HPLC).

Type species
:
Coprobacillus cateniformis
corrig. Kageyama and Benno 2000d, 949
VP
(Effective publication:
Coprobacillus catenaformis
[sic] Kageyama and Benno 2000c, 28.).
Holdemania
Authors: Willems Anne
Published: August 2015

Hold.eman'ia. L. n. named in honor of Lillian V. Holdeman Moore, a contemporary American microbiologist, for her outstanding contribution to anaerobic bacteriology.

Firmicutes / Erysipelotrichia / Erysipelotrichales / Erysipelotrichaceae / Holdemania

Gram‐stain‐positive, strictly anaerobic, nonsporeforming rods
. Cells occur in pairs and short chains. Catalase‐negative.
Fermentative metabolism
. Growth in broth media is enhanced by the addition of Tween 80.
Major end products from glucose fermentation are acetic and lactic acid. Succinic acid is also produced but in smaller quantities. The cell‐wall peptidoglycan is of type B1
with an
L
‐Asp–
L
‐Lys interpeptide bridge.
Major cellular fatty acids are nonhydroxylated, monounsaturated or saturated
. The only known representatives are three strains that were isolated from human feces.

DNA G
+
C content
(
mol
%): 38.

Type species
:
Holdemania filiformis
Willems, Moore, Weiss and Collins 1997, 1203
VP
.
Cetobacterium
Authors: Edwards Kirstin J. , Logan Julie M. J. , Gharbia Saheer E.
Published: August 2015

Ce.to.bac.te'ri.um. Gr. n.
kêtos
whale; L. neut. n.
bacterium
a rod; N.L. neut. n.
Cetobacterium
a bacterium found in association with whales.

Fusobacteria / Fusobacteriia / Fusobacteriales / Fusobacteriaceae / Cetobacterium

Short pleomorphic, nonsporeforming, rod‐shaped cells
. Central swelling and filaments may be present. Gram‐stain‐negative. Nonmotile. Microaerotolerant. Catalase negative.
Fermentative. Acetic acid is the major end product from peptones or carbohydrates
; butyric, propionic, lactic, and succinic acids may or may not be formed in small amounts. Indole produced and ONPG hydrolyzed. Alkaline phosphatase, and acid phosphatase positive. Produces small to moderate amounts of phosphohydrolase. May or may not produce α‐ or β‐galactosidase and α‐glucosidase. Urease may or may not be produced. Lecithinase and lipase negative. Gelatin is not hydrolyzed. Nitrate may or may not be reduced to nitrite. Resistant to 20% bile. Resistant to vancomycin. Sensitive to kanamycin and colistin sulfate discs. Susceptible to cefoxitin, clindamycin, imipenem, and metronidazole. Isolated from mammalian intestinal tract and oral cavity.

DNA G
+
C content
(
mol
%): 29–31.

Type species
:
Cetobacterium ceti
Foster, Ross, Naylor, Collins, Ramos, Fernández‐Garayzábal and Reid 1996, 362
VP
(Effective publication: Foster, Ross, Naylor, Collins, Ramos, Fernández‐Garayzábal and Reid 1995, 206.).
Fusobacterium
Authors: Gharbia Saheer E. , Shah Haroun N. , Edwards Kirstin J.
Published: August 2015

Fu.so.bac.te'ri.um. L. n.
fusus
a spindle; L. neut. n.
bacterium
a small rod; N.L. neut. n.
Fusobacterium
a small spindle‐shaped rod.

Fusobacteria / Fusobacteriia / Fusobacteriales / Fusobacteriaceae / Fusobacterium

Nonsporeforming rods
that are
Gram‐stain‐negative
and
obligately anaerobic
. Metabolize peptone or carbohydrates in PY‐glucose to
produce butyrate
, often with acetate and lower levels of lactate, propionate, succinate, and formate.

DNA G
+
C content
(
mol
%): 26–34.

Type species
:
Fusobacterium nucleatum
Knorr 1922, 17
AL
[
Bacillus fusiformis
Veillon and Zuber 1898, 540 and other combinations using “
Fusiformis
” except the organism described as
Fusobacterium fusiforme
by Hoffman in the 7th edition of the
Manual
; Group I, Spaulding and Rettger 1937, 535; Group III (and probably
Fusobacterium polymorphum
) Baird‐Parker 1960, 458;
not Fusobacterium plauti‐vincentii
Knorr 1922, 5.].
Ilyobacter
Authors: Schink Bernhard , Janssen Peter H. , Brune Andreas
Published: August 2015

I.ly.o.bac'ter. Gr. fem. n.
ilys
mud; N.L. masc. n.
bacter
rod; N.L. masc. n.
Ilyobacter
a mud‐inhabiting rod.

Fusobacteria / Fusobacteriia / Fusobacteriales / Fusobacteriaceae / Ilyobacter

Strictly anaerobic chemoorganotrophic bacteria with fermentative metabolism, nonphotosynthetic, inorganic electron acceptors not used. Nonsporeforming
.

DNA G
+
C content
(
mol
%): 31.7–36.7.

Type species
:
Ilyobacter polytropus
Stieb and Schink 1 9 8 5, 375
VP
(Effective publication: Stieb and Schink 1 9 8 4, 145.).
Propionigenium
Authors: Schink Bernhard , Janssen Peter H.
Published: August 2015

Pro.pi.o.ni.ge'ni.um. N.L. n.
acidum propionicum
propionic acid; L. v.
genere
to make, produce; N.L. neut. n.
Propionigenium
propionic acid maker.

Fusobacteria / Fusobacteriia / Fusobacteriales / Fusobacteriaceae / Propionigenium

Strictly anaerobic chemoorganotrophic bacteria with fermentative metabolism, nonphotosynthetic, inorganic electron acceptors not used. Nonsporeforming
.

DNA G
+
C content
(
mol
%): 32.9–41.

Type species
:
Propionigenium modestum
Schink and Pfennig 1983, 896
VP
(Effective publication: Schink and Pfennig 1982, 215.).
Sebaldella
Authors: Gharbia Saheer E. , Edwards Kirstin J.
Published: August 2015

Se.bal.del'la. N.L. dim. ending ‐
ella
; N.L. fem. dim. n.
Sebaldella
named after the French microbiologist Madeleine Sebald, who first described the organism.

Fusobacteria / Fusobacteriia / Fusobacteriales / Leptotrichiaceae / Sebaldella

Rods. Nonsporeforming. Nonmotile. Gram‐stain‐negative. Anaerobic. Acid produced from glucose
and some other sugars. The
major end products of glucose fermentation are acetic and lactic acids
; formic acid may also be produced. Hexose monophosphate shunt enzymes, glucose‐6‐phosphate dehydrogenase, and 6‐phosphogluconate dehydrogenase are absent. Glutamate dehydrogenase and malate dehydrogenase are absent. Nonhydroxylated and 3‐hydroxylated long‐chain fatty acids are present. The fatty acids are primarily of the straight‐chain saturated and monounsaturated types. Menaquinones are absent.

DNA G
+
C content
(
mol
%): 32–36.

Type species
:
Sebaldella termitidis
(Sebald 1962) Collins and Shah 1986, 349
VP
(
Sphaerphorus siccus
var.
termitidis
Sebald 1962, 124;
Bacteroides termitidis
Holdeman and Moore 1970, 33).
Streptobacillus
Authors: Gharbia Saheer E. , Edwards Kirstin J.
Published: August 2015

Strep.to.ba.cil'lus. Gr.adj.streptostwisted, curved; L. masc. n.bacillusa small rod; N.L. masc. n.Streptobacillusa twisted or curved small rod.

Fusobacteria / Fusobacteriia / Fusobacteriales / Leptotrichiaceae / Streptobacillus

Rods with rounded or pointed ends. Occur singly or form long, wavy chains. Nonsporeforming. Nonmotile. Gram‐stain‐negative. Conversion toL‐phase or transitional‐phase variant may occur spontaneously during cultivation.Capable of growth anaerobically or aerobically. Ferments glucose to produce acid but not gas. Optimum temperature 35–37°C. Catalase and oxidase negative. Indole not produced. Nitrate not reduced to nitrite. Require serum, ascitic fluid, or blood for growth.Isolated from the throat and nasopharynx of wild and laboratory rats. Causes rat‐bite fever in man.

DNA G+C content(mol%): 24–26.

Type species:Streptobacillus moniliformisLevaditi, Nicolau and Poincloux 1925, 1188AL.
Nitrospira
Authors: Spieck Eva , Bock Eberhard
Published: August 2015

Ni.tro.spi' ra
. L. n.
nitrum
nitrate; Gr. n.
spira
a coil, spiral; M.L. fem. n.
Nitrospira
nitrate spiral.

Nitrospirae / “Nitrospira” / “Nitrospirales” / “Nitrospiraceae” / Nitrospira

Vibrio‐like to spiral‐shaped rods
,
0
.
2–0
.
4
×
0
.
9–2
.
2
μ
m
. Cells reproduce by binary fission.
Intracytoplasmic membranes are lacking
. Gram negative. Usually
nonmotile
.
Aerobic
. The major source of energy and reducing power is from the
oxidation of nitrite to nitrate
.
Lithoautotrophs
, but cells can also grow mixotrophically. Cells were isolated from ocean environments and heating systems. Also occurs in soil samples, freshwater, and activated sludge.

The mol
%
G
+
C of the DNA is
: 50.0–56.9.

Type species
:
Nitrospira marina
Watson, Bock, Valois, Waterbury and Schlosser 1986b, 489 (Effective publication: Watson, Bock, Valois, Waterbury and Schlosser 1986a, 6).
Blastopirellula
Authors: Schlesner Heinz
Published: August 2015

Blas.to.pi.rel'lu.la. Gr. masc. n.
blastos
bud, shoot; N.L. fem. n.
Pirellula
name of a bacterial genus; N.L. fem. n.
Blastopirellula
a budding
Pirellula
.

Planctomycetes / Planctomycetia / Planctomycetales / Planctomycetaceae / Blastopirellula

Cells are ovoid
,
ellipsoidal or pear‐shaped
,
occurring singly or in rosettes by attachment at the smaller cell pole
.
Cells divide by budding
. Buds are produced directly from the broader cell pole of the mother cell;
they may appear bean‐shaped
.
Crateriform structures and fimbriae are found in the upper cell region
.
Cells have an intracytoplasmic membranous structure
(
pirellulosome
). Gram‐stain‐variable. Buds may have a single flagellum inserted subpolarly at the proximal pole. Adult cells are immobile. Strictly aerobic.
Colonies are grayish to brownish white
. Mesophilic. Requires sea water for growth. Nonsporeforming. PHB is not stored. Chemoheterotrophic. Carbon and energy sources are mainly carbohydrates. C1‐compounds are not used.
N
‐Acetylglucosamine serves as carbon and nitrogen source. Catalase‐ and cytochrome oxidase‐positive.
The proteinaceous cell wall lacks peptidoglycan
. The major polyamine is
sym
‐homospermidine.
The major menaquinone is MK‐6
. The major phospholipid is phosphatidylglycerol. The major fatty acids present are C
15:0
, C
16:0
iso, C
16:1
ω7, C
16:0
, C
17:1
ω8, C
17:0
, C
18:1
ω9, C
18:1
ω7, C
18:0
, C
19:1
ω8, and C
20:1
ω9.

DNA G
+
C content
(
mol
%): 54–57 (HPLC).

Type species
:
Blastopirellula marina
(Schlesner 1986) Schlesner, Rensmann, Tindall, Gade, Rabus, Pfeiffer and Hirsch 2004, 1578 (
Pirella marina
Schlesner 1986, 180;
Pirellula marina
Schlesner and Hirsch 1987, 441).
Bartonella
Authors: Welch David F.
Published: August 2015

Bar.to.nel' la. M.L. dim. ending ‐ella; M.L. fem. dim. n.Bartonellanamed after Alberto L. Barton, who described these organisms in 1909, after studying the agent of Carrion's disease.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Bartonellaceae / Bartonella

Morphology is small (0.5–0.6 × 1.0 µm),slightly curved bacillus. Not acid‐fast.Faintly stains Gram negative(stains poorly or not at all with many aniline dyes) but satisfactorily with Romanowsky's or Giemsa's stain. Warthin‐Starry silver staining of fixed tissue sections reveals bacilli in clusters. May be seen in stained blood films appearing as rounded or ellipsoidal forms or as slender, straight, curved, or bent rods, occurring singly or in groups. They characteristically occur in chains of seve ral segmenting organisms, sometimes swollen at one or both ends and frequently beaded. In the tissues, they are situatedwithin the cytoplasm of endothelial cellsas isolated elements or are grouped in rounded masses.Intraerythrocytic forms occurin the blood of felines, small rodents, birds, fish, and other animals. In cultures, the cells may be veryautoadherent. Some species possess unipolar flagella.The presence of piliis associated with the marked adherence and may mediate specific interaction with host endothelial cells and erythrocytes leading to intracellular localization.

Type species:Bartonella bacilliformis(Strong, Tyzzer, Brues, Sellards and Gastiaburu 1913) Strong, Tyzzer and Sellards 1915, 808 (Bartonia bacilliformisStrong, Tyzzer, Brues, Sellards and Gastiaburu 1913, 1715.)
Bradyrhizobium
Authors: Kuykendall L. David
Published: August 2015

Bra.dy.rhi.zo' bi.um. Gr. adj.bradusslow; M.L. neut. n.Rhizobiuma bacterial generic name; M.L. neut. n.Bradyrhizobiumthe slow (growing) rhizobium.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Bradyrhizobiaceae / Bradyrhizobium

Rods 0.5–0.9 × 1.2–3.0 µm.Commonly pleomorphic under adverse growth conditions. Usually contain granules of poly‐β‐hydroxybutyrate that are refractile by phase‐contrast microscopy.Nonsporeforming.Gram negative.Motile by one polar or subpolar flagellum. Fimbriae have not been described.Aerobic,possessing a respiratory type of metabolism with oxygen as the terminal electron acceptor.Optimal temperature 25–30°C. Optimal pH, 6–7, although lower optima may be exhibited by strains from acid soils. Colonies are circular, opaque, rarely translucent, white, and convex, and tend to be granular in texture; they do not exceed 1.0 mm in diameter in less than 5–6 days incubation on A1EG medium.Turbidity develops only after 3–4 days in agitated broth.Generation times are 9–18 h. Chemoorganotrophic, utilizing a range of carbohydrates and salts of organic acids as carbon sources, without gas formation; arabinose and other pentoses are preferred carbon sources. Cellulose and starch are not utilized. Produce an alkaline reaction in mineral salts medium containing mannitol and/or many other carbohydrates.Growth on carbohydrate media is usually accompanied by extracellular polysaccharide slime production particularly with glycerol,gluconate,or mannitol. Some strains can grow chemolithotrophically in the presence of H2, CO2, and low levels of O2. Ammonium salts, usually nitrates, and some amino acids, can serve as nitrogen sources. Peptone is poorly utilized (except for strains isolated fromLotononis). Casein and agar are not hydrolyzed. There is usually no requirement for vitamins with the rare exception of biotin, which also may be inhibitory to some strains. 3‐Ketoglycosides are not produced (Bernaerts and De Ley, 1963).The organisms are characteristically able to enter the root hairs of tropical‐zone and some temperate‐zone leguminous plants(family Leguminosae)and incite the production of root nodules,in which the bacteria occur as intracellular nitrogen‐fixing symbionts. Some strains, especiallyB.elkanii, fix nitrogen in the free‐living state when examined under special conditions.

The mol%G+C of the DNA is: 61–65.

Type species:Bradyrhizobium japonicum(Kirchner 1896) Jordan 1982, 137 (“Rhizobacterium japonicum” Kirchner 1896, 221;Rhizobium japonicum(Kirchner 1896) Buchanan 1926, 90.)
Filomicrobium
Authors: Schlesner Heinz
Published: August 2015

Fi.lo.mi.cro' bi.um
. L. masc. n.
filum
thread; Gr. adj.
micros
small; Gr. n.
bios
life; M.L. neut. n.
Filomicrobium
threadlike microbe.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Hyphomicrobiaceae / Filomicrobium

Fusiform cells, 0.5–0.7 × 1.5–4.0 µm, with two or three polar prosthecae, which are about 0.2 µm in diameter and have a length of up to 40 µm or more. Buds are formed at the tips of the prosthecae (Fig. BXII.α.208).
Nonmotile
.
Gram negative
.
Aerobic and chemoorganotrophic
. Utilize some organic acids.

C
1
‐compounds are not used as carbon sources

. The ubiquinone system is a
Q‐9
system. Hydroxy fatty acids are of the
3‐OH
type.

The mol
%
G
+
C of the DNA is
: 62.

Type species
:
Filomicrobium fusiforme
Schlesner 1988, 220 (Effective publication: Schlesner 1987, 65.)
Rhodomicrobium
Authors: Imhoff Johannes F.
Published: August 2015

Rho.do.mi.cro' bi.um
. Gr. n.
rhodon
the rose; Gr. adj.
micros
small; Gr. n.
bios
life; M.L. neut. n.
Rhodomicroibum
red microbe.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Hyphomicrobiaceae / Rhodomicrobium

Ovoid to elongate‐ovoid bacteria showing polar growth and performing a characteristic vegetative growth cycle
. This cycle includes the formation of peritrichously flagellated swarmer cells and nonmotile “mother cells”, which form prosthecae from one to several times the length of the mother cell. Daughter cells originate as spherical buds at the end of the prosthecae and may undergo differentiation in various ways.
Gram negative
,
belonging to the

Alphaproteobacteria

.
Internal photosynthetic membranes are of the lamellar type
.
Photosynthetic pigments are bacteriochlorophyll

a

and carotenoids of the spirilloxanthin series
. The
predominant cellular fatty acid is C

18
:
1

, which comprises more than 80% of the membrane‐bound fatty acids.
Ubiquinone and rhodoquinone with 10 isoprene units
are present, and the lipopolysaccharides are characterized by a glucosamine‐containing, phosphate‐free lipid A with amide‐bound C
16:0 3OH
.

The mol
%
G
+
C of the DNA is
: 61.8–63.8.

Type species
:
Rhodomicrobium vannielii
Duchow and Douglas 1949, 415.
Methylosinus
Authors: Bowman John P.
Published: August 2015

Me.thyl.o.si' nus. Fr.methylethe methyl radical;sinusbend; M.L. n.Methylosinusmethyl bender.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Methylocystaceae / Methylosinus

Cells arepyriform or vibrioidin shape, 0.5–1.5 × 1.5–3.0 µm, usually arranged in rosettes of 4–6 cells. Reproduce bybinary and budding division. In budding division, the bud contains aheat and desiccation‐resistant exospore, which germinates into a vegetative daughter cell; thisdaughter cell is motile, propelled by a tuft of 3–10 polar and/or subpolar flagella. Cells containtype II intracytoplasmic membranesthat are arranged as multiple layers along the periphery of the cell wall. Strongly accumulate inclusions of poly‐β‐hydroxybutyrate. Aerobic, possessing astrictly respiratory type of metabolism with oxygen as the terminal electron acceptor.Obligately methanotrophic, utilizing only methane and methanol as sole carbon and energy sources. C2+and other C1compounds are not utilized. Fix formaldehyde for cell carbon via the serine pathway. Enzymes for the Benson–Calvin cycle pathway are absent. The tricarboxylic acid pathway is complete.Fix atmospheric nitrogen by means of an oxygen‐sensitive nitrogenase. Mesophilic. Nonhalophilic. Optimal temperature, 25–30°C; optimal pH, 6.5–7.0. Major habitats include soil, freshwater sediments and groundwater.Primary fatty acids are C18:1ω8cand C18:1ω7c.Primary quinone is ubiquinone‐8(Q‐8). Member of the FamilyMethylocystaceaefound in theAlphaproteobacteria.

The mol%G+C of the DNA is: 62–67 (Tm).

Type species:Methylosinus trichosporium(ex Romanovskaya, Malashenko and Bogachenko 1978) Bowman, Sly, Nichols and Hayward 1993c, 751.
Ensifer
Authors: Balkwill David L.
Published: August 2015

En' si.fer
. L. adj.
ensifer
sword‐bearing; M.L. masc.
Ensifer
sword bearer.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Rhizobiaceae / Ensifer

Rods 0.7–1.1 × 1.0–1.9 µm, occurring singly or in pairs.
Reproduction by budding at one pole of the cell
, with the bud then elongating to produce
asymmetric polar growth
.
Attaches endwise to various living Gram‐positive and Gram‐negative host bacteria and may cause lysis of the host cells
.
Host cells are not required for growth
. Gram negative, but may stain poorly.
Motile by a tuft of three to five subpolar flagella
. Aerobic; does not grow anaerobically in the presence of light. Optimal growth occurs at 27°C; good growth occurs at 20°C and 37°C. Not heat resistant. Weakly catalase positive. Nitrate and nitrite are reduced. Nitrification is negative for nitrite and ammonia. The
metabolism of glucose and galactose is oxidative
. Growth is inhibited by 4% NaCl but not by 2.5% NaCl. Grows well on most media. Definite but slow growth on soil extract agar and on 1.5% Noble agar in distilled water. Agar is not hydrolyzed. Utilizes a variety of organic carbon sources. A segment of the
Ensifer
16S rDNA sequence (TACGGAGACGTTT, corresponding to positions 1009 through 1021 in the
Escherichia coli
16S rDNA sequence; Brosius et al., 1978) might represent a signature sequence for this genus, as it did not match any other bacterial sequences available in public databases as of June, 2003.

The mol
%
G
+
C of the DNA is
: 67 (

T
m

) and 63 (Bd).

Type species
:
Ensifer adhaerens
Casida 1982, 343.
Rhodobium
Authors: Imhoff Johannes F. , Hiraishi Akira
Published: August 2015

Rho.do' bi.um
. Gr. n.
rhodon
the rose; Gr. n.
bios
life; M.L. n.
Rhodobium
red life.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Rhodobiaceae / Rhodobium

Cells are ovoid to rod shaped
, motile by means of polar, subpolar or randomly distributed flagella; and cells multiply by budding and asymmetric cell division. Rosette formation is rare.
Gram negative and belong to the

Alphaproteobacteria

. Phototrophically grown cells contain
internal photosynthetic membranes as lamellar stacks parallel to the cytoplasmic membrane
. Photosynthetic pigments are bacteriochlorophyll
a
and carotenoids of the spirilloxanthin series.
Straight‐chain saturated and monounsaturated C

18
:
1

and C

18:
0

are the major components of cellular fatty acids,
with the former being predominant
.
Ubiquinones and menaquinones with 10 isoprene units
(
Q‐10 and MK‐10
)
are present as major quinones
.

The mol
%
G
+
C of the DNA is
: 61.5–65.7.

Type species
:
Rhodobium orientis
Hiraishi, Urata and Satoh 1995d, 230.
Gemmobacter
Authors: Hirsch Peter , Schlesner Heinz
Published: August 2015

Gem.mo.bac' ter
. L. n.
gemma
a bud; M.L. masc. n.
bacter
equivalent; Gr. neut. n.
bactrum
a rod; M.L. masc. n.
Gemmobacter
a budding rod.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Gemmobacter

Rod‐shaped cells with rounded poles or ovoid, 1.0–1.2 × 1.25–2.7 µm. New cell formation by budding from one cell pole or laterally (Figure 1). Daughter cells may stay connected with the mother cell resulting in formation of short chains. Not acid‐fast, do not form spores or cysts; without prosthecae or other appendages. Nonmotile.
Gram negative
. Colonies colorless, round with entire margins. Temperature range 17–39°C, optimal temperature for growth 31°C.

The mol
%
G
+
C of the DNA is
: 63.4.

Type species
:
Gemmobacter aquatilis
Rothe, Fischer, Hirsch, Sittig and Stackebrandt 1988, 328 (Effective publication: Rothe, Fischer, Hirsch, Sittig and Stackebrandt 1987, 98.)
Ketogulonicigenium
Authors:   The Editorial Board
Published: August 2015

Ke.to.gu.lo.ni.ci.ge' ni.um
. N.L. n.
acidum ketogulonicum
ketogulonic acid; N.L. neut. suff.
genium
genium that which produces; L. neut. n.
Ketogulonicigenium
that which produces ketogulonic acid.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Ketogulonicigenium

Gram‐negative chemoorganotrophic facultative anaerobes
. Cells ovoid or rod‐shaped (0.5–0.7 × 0.8–1.3 µm). Oxidase and catalase positive.
Convert L‐sorbose to 2‐keto
‐

l

‐
gulonic acid
.
Major fatty acids C

16
:
0

,
and C

18
:
1
ω
7c
/ω
9t
/ω
12t

. Temperature optimal 27–31°C; pH optimal 7.2–8.5. Grow best on arabinose, glycerol, inositol, lactose, mannitol, and sorbitol.

The mol
%
G
+
C of the DNA is
: 52.1–54.

Type species
:
Ketogulonicigenium vulgare
Urbance, Bratina, Stoddard and Schmidt 2001, 1069 (
Ketogulonigenium vulgare
(sic) Urbance, Bratina, Stoddard and Schmidt 2001, 1069.)
Rubrimonas
Authors: Rathgeber Christopher , Yurkov Vladimir V.
Published: August 2015

Ru.bri.mo' nas
. L. adj.
ruber
reddish; Gr. n.
monas
unit; M.L. fem. n.
Rubrimonas
reddish monad.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Rubrimonas

Rubrimonas
cells are Gram‐negative

,
short to ovoid rods
,
1
.
0–1
.
5
×
1
.
2–2
.
0
μ
m
.
Motile by polar flagella
.
Division occurs by binary fission
. Forms pink circular colonies when grown on agar media.
Pink coloration is due to the presence of carotenoid pigments
.
Cells grow heterotrophically under aerobic conditions and produce bacteriochlorophyll
(
Bchl
)

a

.
No growth occurs under anaerobic conditions even in the light
. Habitat is saline lakes.

The mol
%
G
+
C of the DNA is
: 70.4–74.8.

Type species
:
Rubrimonas cliftonensis
Suzuki, Muroga, Takahama, Shiba and Nishimura 1999b, 204.
Sulfitobacter
Authors: Sorokin Dimitry Y. , Rainey Fred A. , Webb Richard I. , Fuerst John A.
Published: August 2015

Sul
.
fi
.
to
.
bac
'
ter
. M.L. n.
sulfitum
sulfite; M.L. masc. form
bacter
Gr. neut. n.
bactrum
rod; M.L. masc. n.
Sulfitobacter
sulfite rod.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Sulfitobacter

Rod‐shaped cells 0
.
5–1
.
0
×
1
.
0–3
.
0 µm
. Often dumbbell shaped, with a tendency for polar growth.
Motile by means of 1–5 subpolar flagella
. Gram negative. Inside the cells, the nucleoid and polar region are often in separate compartments.
Obligately aerobic
,
having a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor
.
Obligately chemoorganotrophic
,
but can use energy from the oxidation of thiosulfate and sulfite during growth in the presence of an organic carbon source
.
Cells cannot grow autotrophically with sulfur compounds or hydrogen as electron donors
,
but are able to oxidize thiosulfate
,
sulfur
,
and sulfite to sulfate
. Can grow in presence of at least 10 mM sulfite; some strains can grow with up to 60 mM sulfite.
NaCl is required for growth
. Mesophilic. Neutrophilic.

The mol
%
G
+
C of the DNA is
: 59–62.

Type species
:
Sulfitobacter pontiacus
Sorokin 1996, 362 (Effective publication: Sorokin 1995, 304.)
Incertae Sedis
XXVI
. Rhodothalassium
Authors: Imhoff Johannes F.
Published: August 2015

Rho' do.tha.las' si.um
. Gr. n.
rhodon
the rose; Gr. adj.
thalassios
belonging to the sea; M.L. neut. n.
Rhodothalassium
the rose belonging to the sea.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / incertae Sedis XXVI. Rhodothalassium

Cells are vibrioid to spiral‐shaped
, motile by means of polar flagella and multiply by binary fission.

Gram‐negative members of the
Alphaproteobacteria

. Internal photosynthetic membranes are present as lamellar stacks lying parallel to the cytoplasmic membrane. Photosynthetic pigments are

bacteriochlorophyll
a

(esterified with phytol) and
carotenoids of the spirilloxanthin series
.
Ubiquinones and menaquinones with 10 isoprene units
(
Q‐10 and MK‐10
)
are present
.
Major cellular fatty acids are C

18
:
1

,
C

18
:
0

,
and
C
16:0
, with C
18:1
as dominant component (~60% of total fatty acids).
Cells grow preferably photoheterotrophically
under anoxic conditions in the light.
Chemotrophic growth is possible under oxic conditions in the dark
. Amino acids may be required as growth factors.
Obligately halophilic bacteria that require NaCl or sea salt for growth
, have salt optima above seawater salinity and an extended salt tolerance. Habitat: anoxic zones of hypersaline environments such as salterns and salt lakes that are exposed to the light.

The mol
%
G
+
C of the DNA is
: 64.0.

Type species
:
Rhodothalassium salexigens
(Drews 1982) Imhoff, Petri and Süling 1998, 797 (
Rhodospirillum salexigens
Drews 1982, 384.)
Stella
Authors: Vasilyeva Leana V.
Published: August 2015

Stel' la. M.L. fem. n.Stellastar, to denote star‐shaped morphology of cells.

Proteobacteria / Alphaproteobacteria / Rhodospirillales / Acetobacteraceae / Stella

Cells are flat,six‐pronged stars,radially symmetrical, and 0.7–3.0 µm. Occur singly or in pairs. Some strains possessgas vesicles. Spores are not formed.Gram negative. Aerobic. Reproduction is bysymmetrical cell division.

The mol%G+C of the DNA is: 69.3–73.5 (Tm).

Type species:Stella humosaVasilyeva 1985, 520.
Zavarzinia
Authors:   The Editorial Board
Published: August 2015

Za.var.zi' ni.a.
M.L. n.
Zavarzinia
named for Georgi Alexandrovich Zavarzin, the Russian microbiologist who with his co‐workers made the first thorough investigation of mesophilic, Gram‐negative carboxidotrophic strains.

Proteobacteria / Alphaproteobacteria / Rhodospirillales / Acetobacteraceae / Zavarzinia

The genus description is the same as the description for
Zavarzinia compransoris
.

The mol
%
G
+
C of the DNA is
: 66.1.

Type species
:
Zavarzinia compransoris
(ex Nozhevnikova and Zavarzin 1974) Meyer, Stackebrandt and Auling 1994, 182 (Effective publication: Meyer, Stackebrandt and Auling 1993, 393.)
Phaeospirillum
Authors: Imhoff Johannes F.
Published: August 2015

Phae.o.spi.ril' lum
. Gr. adj.
phaeos
brown; M.L. neut. n.
Spirillum
a bacterial genus; M.L. neut. n.
Phaeospirillum
brown
Spirillum
.

Proteobacteria / Alphaproteobacteria / Rhodospirillales / Rhodospirillaceae / Phaeospirillum

Cells are vibrioid to spiral shaped
, motile by means of polar flagella and multiply by binary fission.
Gram negative and belong to the

Alphaproteobacteria

. Internal photosynthetic membranes are lamellar stacks forming a sharp angle with the cytoplasmic membrane. Photosynthetic pigments are
bacteriochlorophyll

a

(esterified with phytol) and
carotenoids of the spirilloxanthin series
, with spirilloxanthin itself lacking.
Ubiquinones and menaquinones with nine isoprene units
(
Q‐9 and MK‐9
) are present.
Major cellular fatty acids are C
18:1
,
C
16:1
,
and C
16:0
, with C
18:1
as dominant component (44–55% of total fatty acids).

The mol
%
G
+
C of the DNA is
: 60.5–65.3.

Type species
:
Phaeospirillum fulvum
(van Niel 1944) Imhoff, Petri, and Süling 1998, 797 (
Rhodospirillum fulvum
van Niel 1944, 108.)
Rhodospira
Authors: Imhoff Johannes F.
Published: August 2015

Rho' do.spi' ra
. Gr. n.
rhodon
the rose; Gr. n.
spira
the spiral; M.L. fem. n.
Rhodospira
the rose spiral.

Proteobacteria / Alphaproteobacteria / Rhodospirillales / Rhodospirillaceae / Rhodospira

Cells are vibrioid to spirilloid in shape
, motile by means of flagella and multiply by binary fission.
Gram negative
.
Belong to the

Alphaproteobacteria

. Internal photosynthetic membranes are of the vesicular type. Photosynthetic pigments are
bacteriochlorophyll

b

and
carotenoids
.
Menaquinones and ubiquinones with seven isoprene units
(
MK‐7 and Q‐7
) are present.
Major cellular fatty acids are C

18
:
1

and C

16:
0

, with C
18:1
as dominant component (~60% of total fatty acids).

The mol
%
G
+
C of the DNA is
: 65.7.

Type species
:
Rhodospira trueperi
Pfennig, Lünsdorf, Süling and Imhoff 1998, 328 (Effective publication: Pfennig, Lünsdorf, Süling and Imhoff 1997, 44.)
Skermanella
Authors:   The Editorial Board
Published: August 2015

Sker.ma.nel' la
. M.L. dim. ‐
ella
ending; M.L. fem. dim. n.
Skermanella
named after V.B.D. Skerman, who first isolated this bacterium, and in honor of his contribution to bacterial systematics.

Proteobacteria / Alphaproteobacteria / Rhodospirillales / Rhodospirillaceae / Skermanella

Gram negative, with unicellular and multicellular growth phases. Does not form spores. Unicellular phase cells are rod shaped, with rounded or tapered ends and a straight or curved axis. Motile with single polar flagellum and one or more lateral flagella of different wavelengths.
Multicellular phase conglomerates
arise from cells that lose motility, become optically refractile, and
reproduce by multiplanar septation
. No filamentous structures or buds are formed. Obligately chemoorganotrophic and
facultatively anaerobic
, having fermentative metabolism. Belongs to the
Alphaproteobacteria
.

The mol
%
G
+
C of the DNA is
: 67.2 ± 0.8.

Type species
:
Skermanella parooensis
(Skerman, Sly and Williamson 1983) Sly and Stackebrandt 1999, 543 (
Conglomeromonas largomobilis
subsp.
parooensis
Skerman, Sly and Williamson 1983, 307.)
Neorickettsia
Authors: Rikihisa Yasuko , Stephen Dumler J. , Dasch Gregory A.
Published: August 2015

Ne.o.rick.ett' si.a. Gr. pref.neo‐ new; M.L. fem. n.Rickettsiatype genus of the family,Rickettisaceae; M.L. fem. n.Neorickettsiathe newRickettsia

Proteobacteria / Alphaproteobacteria / Rickettsiales / Anaplasmataceae / Neorickettsia

Coccoid or pleomorphic cells that reside in cytoplasmic vacuoles within monocytes and macrophages of dogs,horses,bats,and humans. Small (0.2–0.4 µm) electron dense forms and relatively large (0.8–1.5 µm) lighter forms may occur. Tissues of adulttrematode(fluke)vectorsand all other fluke stages—eggs, miracidia, rediae, sporocysts, cercariae, and metacercariae—produce infection when injected into susceptible hosts, indicating transovarial transmission in the vector. Transstadial transmission also occurs. Gram negative. Nonmotile. Most species are cultivable in peripheral blood monocytes, myelomonocytic cell lines, or promyelocytic cell lines. Some species are pathogenic to laboratory mice.Etiologic agents of diseases of dogs and other canids,horses,and humans. Where studied, these bacteria possess an antigenically cross‐reactive group‐specific protein gene with a high degree of sequence identity. Sensitive to tetracycline antibiotics. The estimated genome size is 860–900 kb.

The mol%G+C of the DNA is: 42.

Type species:Neorickettsia helminthoecaPhilip, Hadlow and Hughes 1953, 257.
Incertae Sedis VI. Pseudocaedibacter
Authors: Görtz Hans‐Dieter , Schmidt Helmut J.
Published: August 2015

Pseu.do.cae'di.bac.ter
. Gr. adj.
pseudo
false; M.L. n.
Caedibacter
genus of endosymbionts that include organisms commonly known as kappa; M.L. masc. n.
Pseudocaedibacter
false kappa particles.

Proteobacteria / Alphaproteobacteria / Rickettsiales / Holosporaceae / incertae Sedis VI. Pseudocaedibacter

Rods 0.25–0.7 × 0.5–4 μm. Gram negative. Nonmotile.
Do not produce R‐body‐containing cells.
May or may not confer a killer trait upon their host paramecia. Occurs in
Paramecium primaurelia
,
P. biaurelia
,
P. pentaurelia
, and
P. octaurelia
. Whether lacking the ability to produce R bodies justifies separation of the genus
Pseudocaedibacter
from the genus
Caedibacter
may be questioned because the newly found endosymbiont from
Acanthamoeba polyphaga
,
Candidatus
Caedibacter acanthamoebae, does not establish R bodies but showed 93% sequence similarity (16S rRNA) to
Caedibacter caryophilus
and was therefore included in the genus
Caedibacter
(Horn et al., 1999).

The mol% G
+
C of the DNA is:
35–39.

Type species
:
Pseudocaedibacter conjugatus
(ex Preer, Preer and Jurand 1974) Quackenbush 1982, 267 (Effective publication: Quackenbush 1978, 187) (
Caedibacter conjugatus
Preer, Preer and Jurand 1974, 157.)
Incertae Sedis VII.“Pseudolyticum”
Authors: Görtz Hans‐Dieter , Schmidt Helmut J.
Published: August 2015

pseu' do.ly.ti.cum
. Gr. adj.
pseudo
false; L. adj.
lyticus
dissolving; M.L. neut. n.
Lyticum
genus of endosymbionts producing labile toxins which kill sensitive strains of paramecia very quickly by lysis; M.L. n.
Pseudolyticum
false
Lyticum
.

Proteobacteria / Alphaproteobacteria / Rickettsiales / Holosporaceae / incertae Sedis VII. “Pseudolyticum”

Straight rods, 2.0 × 3.5–14.0 µm. Bacteria are not infective and do not confer a killer trait on their host. Gram negative. Non‐motile in spite of numerous flagella. Occur in
Paramecium caudatum
.

The mol
%
G
+
C of the DNA is
: not determined.

Type species
: “
Pseudolyticum multiflagellatum
” Boss, Borchsenius and Ossipov 1987, 98.
Rickettsia
Authors: Yu Xue‐jie , Walker David H.
Published: August 2015

Rick.ett' si.a. M.L. fem. n.Rickettsianamed after Howard Taylor Ricketts, who first associated organisms of this description with spotted fever and typhus and who died of typhus contracted in the course of his studies.

Proteobacteria / Alphaproteobacteria / Rickettsiales / Rickettsiaceae / Rickettsia

Short,often paired rods,0.3–0.5×0.8–2.0μm. The rickettsial envelope has a typical Gram‐negative structure with a bilayer inner membrane, a peptidoglycan layer, and a bilayer outer membrane. The cells are often surrounded by a protein microcapsular layer and slime layer. Rickettsiae retain basic fuchsin when stained by the method of Giménez (1964). The organisms areobligately intracellular and reside free in the cytoplasm of the eucaryotic host cell, where they divide bybinary fission. Rickettsiae of the spotted fever group (SFG) may also reside in the nucleus of the eucaryotic host cells.Rickettsiae are closely associated with arthropods(ticks, mites, fleas, lice, and other insects)for their maintenance in nature. Their natural cycle usually involves both a vertebrate and an invertebrate host. For some, the arthropod host is both a reservoir and a vector.Transovarian transmissionof the agent from the infected female to the next generation is the essential mechanism for the maintenance of many species (Burgdorfer, 1988). Rickettsial cells are usually unstable when separated from host components, except for highly stable forms found in the feces of arthropod hosts; stability can be enhanced by certain proteins, sucrose, and reagents that tend to maintain the integrity of outer membranes, osmolarity, and ATP level. Rickettsiae are best preserved by rapid freezing and storage below −50°C. The cells are rapidly inactivated at 56°C. Rickettsiae derive energy from the metabolism of glutamate via the citric acid cycle, but do not utilize glucose. They transport and metabolize phosphorylated compounds but do not synthesize or degrade nucleoside monophosphates.Rickettsiae are etiological agents of typhus and spotted fevers in humans. There are 21 recognized species.

The mol%G+C of the DNA is: 29–33.

Type species:Rickettsia prowazekiida Rocha‐Lima 1916, 567 (Nom. Cons. Opin. 19, Jud. Comm. 1958, 158.)
Erythrobacter
Authors: Shiba Tsuneo , Imhoff Johannes F.
Published: August 2015

E.ryth' ro.bac.ter. Gr. adj.erythrosred; M.L. masc. n.bacterrod; M.L. masc. n.Erythrobacterred rod.

Proteobacteria / Alphaproteobacteria / Sphingomonadales / Sphingomonadaceae / Erythrobacter

Cells are ovoid to rod‐shaped, 0.2–0.4 × 1.0–5.0 µm, multiply by binary fission, and are motile by means of polar or subpolar flagella. Gram negative and belong to theAlphaproteobacteria. Cell suspensions and colonies are orange or pink.Bacteriochlorophyllais present.The major respiratory quinone is ubiquinone‐10. The main cellular fatty acid is C18:1.

The mol%G+C of the DNA is: 57–67.

Type species:Erythrobacter IongusShiba and Simidu 1982, 216.