bluuebunny/crossref_metadata_2025 huggingface dataset:
Blastobacter
Authors: Sly Lindsay I. , Hugenholtz Philip
Published: August 2015

Blas.to.bac' ter
. Gr. n.
blastos
bud, shoot; M.L. n.
bacter
equivalent of Gr. masc. n.
bactrum
rod; M.L. masc. n.
Blastobacter
a budding rod.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Bradyrhizobiaceae / Blastobacter

Cells
ovoid rods
,
wedge or club shaped
, or pleomorphic,
often slightly curved and occasionally branched
. Cell poles are rounded or slightly tapering on one pole. Cell size range is 0.5–1.0 × 1.0–4.5 µm. Cells
may form rosettes
.
Gram negative
. New
cell formation and multiplication occur by budding
on the free cell pole, subpolarly or laterally. Young
buds initially rod shaped
,
ovoid
,
or spherical to oblong
. Buds may be released or remain attached.
Motile
,
flagellated swarmer cells may occur
in some species. Do not form spores or cysts. Some strains produce large amounts of exopolymer. Grow in liquids as turbidity, pellicle, or precipitate. Colony pigmentation may be yellow, or colorless, becoming brown in older cultures.

The mol
%
G
+
C of the DNA is
: 59–69.

Type species
:
Blastobacter henricii
Zavarzin 1961, 962.
Nitrobacter
Authors: Spieck Eva , Bock Eberhard
Published: August 2015

Ni.tro.bac' ter
. L. n.
nitrum
nitrate; M.L. n.
bacter
the masc. form of Gr. neut. n.
bactrum
a rod; M.L. masc. n.
Nitrobacter
nitrate rod.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Bradyrhizobiaceae / Nitrobacter

Pleomorphic rod‐ or pear‐shaped cells 0
.
5–0
.
9
×
1
.
0–2
.
0
μ
m
. Cells reproduce by budding or binary fission.
Intracytoplasmic membranes occur as a polar cap of flattened vesicles
in the cell periphery. Gram negative. Cells may be motile by means of a single polar to subpolar flagellum.
Grows lithoautotrophically and chemoorganotrophically
.
Under oxic conditions
a
nitrite is the preferred energy source and carbon dioxide is the main source of carbon
.
Aerobic
,
but also capable of anaerobic respiration with nitrate
. Under anoxic conditions nitrate is reduced to nitrite, nitric oxide, and nitrous oxide. Occurs in aerobic and microaerophilic habitats where organic matter is mineralized.

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

Type species
:
Nitrobacter winogradskyi
Winslow, Broadhurst, Buchanan, Krumwiede, Rogers and Smith 1917, 552 emended mut. char. Watson 1971, 264.
Rhodopseudomonas
Authors: Imhoff Johannes F.
Published: August 2015

Rho
.
do
.
pseu
.
do
.
mo
'
nas
. Gr. n.
rhodon
the rose; M.L. fem. n.
Pseudomonas
a bacterial genus; M.L. fem. n.
Rhodopseudomonas
the red
Pseudomonas
.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Bradyrhizobiaceae / Rhodopseudomonas

Cells are rod‐shaped
,
motile by means of polar or subpolar flagella
;
show polar growth
,
budding and asymmetric cell division
.

Gram‐negative and belong to the
Alphaproteobacteria

. Internal photosynthetic membranes appear as lamellae underlying and parallel to the cytoplasmic membrane. Photosynthetic pigments are

bacteriochlorophyll
a
and carotenoids of the spirilloxanthin series

.
Straight‐chain monounsaturated C

18
:
1

is the major component of cellular fatty acids.
Contains ubiquinones with 10 isoprene units
(
Q‐10
).

The mol
%
G
+
C of the DNA is
: 64.8–66.3.

Type species
:
Rhodopseudomonas palustris
(Molisch 1907) van Niel 1944, 89 (“
Rhodobacillus palustris
” Molisch 1907, 14.)
Brucella
Authors: Corbel Michael J. , Banai Menachem
Published: August 2015

Bru. cel' la. L. dim. ending ‐ella; M.L. fem. n.Brucellanamed after Sir David Bruce, who first recognized the organism causing undulant (Malta) fever.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Brucellaceae / Brucella

Cocci,coccobacilli,or short rods, 0.5–0.7 × 0.6–1.5 µm. Arranged singly and, less frequently, in pairs, short chains, or small groups. True capsules are not produced. Do not usually show true bipolar staining. Resting stages are not known. Gram negative.Nonmotile; do not produce flagella.Aerobic, possessing a respiratory type of metabolism and having acytochrome‐based electron transport systemwith oxygen or nitrate as the terminal electron acceptor. Nitrate reductase is produced.Many strains require supplementary CO2for growth, especially on primary isolation. Colonies on serum‐dextrose agar or other clear media are transparent, raised, convex, with an entire edge and a smooth, shiny surface. They appear apale honey colorby transmitted light. Smooth strains produce perosamine synthetase and a distinctive lipopolysaccharide (LPS). Nonsmooth variants of the smooth species occur, but there are also stable nonsmooth nomenspecies with a distinctive host range. Optimal temperature for growth 37°C. Growth occurs between 20 and 40°C. Optimal pH for growth 6.6–7.4.Catalase positive. Usually oxidase positive, but negative strains occur. Chemoorganotrophic. Most strains require complex media containing several amino acids, thiamin, nicotinamide, iron, and magnesium ions; some strains may be induced to grow on minimal media containing an ammonium salt as the sole nitrogen source.Growth is improved by serum or blood,but hemin(X‐factor)and nicotinamide adenine dinucleotide(NAD:V‐factor)are not essential.Acid production does not occur from carbohydrates in conventional media, except forB.neotomae. Do not produce indole.Do not liquefy gelatinor inspissated serum. Do not lyse erythrocytes. Do not produceacetyl methyl carbinol(Voges–Proskauer test.)The methyl red test is negative. Intracellular parasites, transmissible to a wide range of animal species including man. The genome typically comprises two circular chromosomes, but a single large chromosome is present inB.suisbiovar 3.

The mol%G+C of the DNA is: 57.9–59.

Type species:Brucella melitensis(Hughes 1893) Meyer and Shaw 1920, 179 (Streptococcus melitensisHughes 1893, 235.)
Mycoplana
Authors: Urakami Teizi , Segers Paul
Published: August 2015

My
.
co
.
pla
'
na
. Gr.
mykes
fungus; Gr.
plane
a wandering; M.L. fem. n.
Mycoplana
fungus wanderer.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Brucellaceae / Mycoplana

Cells are
curved or irregular rods
with rounded ends, 0.5–0.8 × 2.0–3.0 µm. Occur singly or rarely in pairs. The cells form
branching filaments
prior to fragmentation into irregular rods. Gram negative and nonsporeforming.
Motile by means of peritrichous flagella
.

The mol
%
G
+
C of the DNA is
: 63–65.

Type species
:
Mycoplana dimorpha
Gray and Thornton 1928, 82 emend. Urakami, Oyanagi, Araki, Suzuki and Komagata 1990d, 440.
Ochrobactrum
Authors: Holmes Barry
Published: August 2015

O.chro.bac' trum
. Gr. adj.
ochros
pale, colorless; Gr. neut. n.
baktron
a staff or stick; M.L. neut. n.
Ochrobactrum
a colorless rod.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Brucellaceae / Ochrobactrum

Rods with parallel sides and rounded ends
,
typically 1
.
0
×
1
.
5–2
.
0 µm
; shorter oval forms, 1.0–1.5 µm in length, may occur. Cells usually occur singly.
Gram negative
.
Motile
by means of peritrichous flagella.
Obligately aerobic
, having a strictly
respiratory
type of metabolism. Optimal growth temperature in the range 20–37°C. Colonies on nutrient agar are smooth, low convex, and translucent (opaque and mucoid, quickly becoming confluent in
O
.
tritici
). Chemoorganotrophic, using a variety of amino acids, organic acids, and carbohydrates as carbon sources. Acid is produced from glucose, arabinose, ethanol, fructose, rhamnose, and xylose.
Oxidase positive
.
Catalase positive
. Indole is not formed.
Nitrates usually reduced
. Growth occurs on MacConkey agar. Urease usually positive. Ornithine decarboxylase (ODC) negative. Occur in human clinical specimens, also in soil samples and wheat roots. Parameters of DNA–rRNA hybrids indicate that
Ochrobactrum
belongs to the
Brucella
branch within rRNA superfamily IV. 16S rRNA gene sequence analysis places
Ochrobactrum
in the group of bacteria known as the α‐2 subclass of the
Proteobacteria
. At the suprageneric level,
Ochrobactrum
is related to
Brucella
,
Phyllobacterium
,
Rhizobium
, and
Agrobacterium
.

The mol
%
G
+
C of the DNA is
: 56–59.

Type species
:
Ochrobactrum anthropi
Holmes, Popoff, Kiredjian and Kersters 1988, 412.
Aquabacter
Authors: Staley James T.
Published: August 2015

Aq
'
ua
.
bac
.
ter
. L. n.
aqua
water; Gr. neut. n.
bacter
masc. form of Gr. neut. n.
bacterion
a rod; N.L. masc. n.
Aquabacter
aquatic rod.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Hyphomicrobiaceae / Aquabacter

Rod‐shaped cells, 0.5–1.0 × 1.5–3.0 µm.
Unicellular
. Encapsulated.
Motile by flagella
,
but only under certain conditions
. No resting stages known.
Gram negative
.

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

Type species
:
Aquabacter spiritensis
Irgens, Kersters, Segers, Gillis and Staley 1993, 864 (Effective publication: Irgens, Kersters, Segers, Gillis and Staley 1991, 141.)
Azorhizobium
Authors: Kuykendall L. David
Published: August 2015

A
.
zo
.
rhi
.
zo
'
bi
.
um
. Fr. n.
azote
nitrogen; M.L. neut. n.
Rhizobium
a bacterial generic name; M.L. neut. n.
Azorhizobium
a nitrogen (using) rhizobium.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Hyphomicrobiaceae / Azorhizobium

Rods 0
.
5–0
.
6
×
1
.
5–2
.
5
μ
m
. Motile by one polar or subpolar flagellum.
Nonsporeforming
.
Gram negative
.
Peritrichous flagella are formed on solid media
,
and a single lateral flagellum is formed in broth
. Growth temperature, 12–43°C. Broad optimum pH, 5.5–7.8. Colonies are circular and creamy. Urease negative.
Oxidase and catalase positive
.
Do not denitrify
.
Of sugars
,
only glucose is oxidized
. The organic acids lactic acid and succinic acid are preferred substrates for growth, both under and not under nitrogen‐fixing conditions. Growth on malonate and
DL
‐proline. Starch is not hydrolyzed. Nitrogen‐fixing root‐ and stem‐nodulating microsymbiont of
Sesbania rostrata
. Readily

fixes nitrogen
ex planta
under microaerobic conditions and with nicotinic acid provided

. Can grow on nitrogen‐free medium, unlike all other legume microsymbionts, of the genera
Bradyrhizobium
,
Rhizobium
, and
Mesorhizobium
, which lie in distinct families.

The mol
%
G
+
C of the DNA is
: 66–68.

Type species
:
Azorhizobium caulinodans
Dreyfus, Garcia, and Gillis 1988, 89.
Blastochloris
Authors: Imhoff Johannes F.
Published: August 2015

Blas
.
to
.
chlo
'
ris
. Gr. n.
blastos
bud shoot; Gr. adj.
chloros
green; M.L. fem. n.
Blastochloris
green bud shoot.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Hyphomicrobiaceae / Blastochloris

Cells are rod shaped to ovoid
and motile by means of subpolar flagella. They exhibit polar growth, budding, and asymmetric cell division and form rosette‐like cell aggregates. They are
Gram negative and belong to the

Alphaproteobacteria

. Internal photosynthetic membranes are present as lamellae underlying and parallel to the cytoplasmic membrane. Photosynthetic pigments are
bacteriochlorophyll

b

and carotenoids
.
Straight‐chainmonounsaturated C

18
:
1

is the predominant component of cellular fatty acids.
Ubiquinones and menaquinones are present
, and the lipopolysaccharides are characterized by a 2,3‐diamino‐2,3‐deoxy‐
D
‐glucose (DAG)‐containing, phosphate‐free lipid A with amidebound C
14:0 3OH
.

The mol
%
G
+
C of the DNA is
: 66.3–71.4.

Type species
:
Blastochloris viridis
(Drews and Giesbrecht 1966) Hiraishi 1997, 218 (
Rhodopseudomonas viridis
Drews and Giesbrecht 1966, 261.)
Devosia
Authors: Nakagawa Yasuyoshi , Sakane Takeshi , Yokota Akira
Published: August 2015

De.vos' i.a
. M.L. dim. ending ‐
ia
M.L. fem. n.
Devosia
honoring Paul De Vos, a Belgian microbiologist, for his contributions to the taxonomy of pseudomonads.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Hyphomicrobiaceae / Devosia

Rods
, 0.4–0.8 × 2.0–8.0 µm.
Motile by means of several polar flagella
. Endospores are not formed. Gram negative.
Aerobic
.
Oxidase and catalase positive
.
The major respiratory quinone is ubiquinone‐10
.
The major cellular hydroxy fatty acids are 3‐hydroxytetracosenoic acid and 3‐hydroxyhexacosenoic acid
.
3‐Hydroxy fatty acids that are shorter than 3‐hydroxyoctadecanoic acid are absent
. Phylogenetically related to members of the
Alphaproteobacteria
.

The mol
%
G
+
C of the DNA is
: 61.4.

Type species
:
Devosia riboflavina
Nakagawa, Sakane and Yokota 1996, 20.
Hyphomicrobium
Authors: Gliesche Christian , Fesefeldt Andreas , Hirsch Peter
Published: August 2015

Hy.pho.mi.cro' bi.um
. Gr.
hyphe
thread; Gr. adj.
micros
small; Gr. masc. n.
bios
life; M.L. neut. n.
Hyphomicrobium
thread‐producing microbe.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Hyphomicrobiaceae / Hyphomicrobium

Cells
0.3–1.2 × 1–3 µm; rod‐shaped with pointed ends, or
oval, egg‐, or bean‐shaped
; produce
monopolar or bipolar filamentous outgrowths
(hyphae or prosthecae) of varying length and 0.2–0.3 µm in diameter. Hyphae are not septate, but hyphal cytoplasmic membranes show conspicuous constrictions.
Hyphae may be truly branched
; secondary branches are rare. Cells stain with carbol fuchsin, but stain weakly with aqueous aniline dyes. Gram negative and non‐acid‐fast. Do not form spores.

The mol
%
G
+
C of the DNA is
: 59–65 (

T
m

).

Type species
:
Hyphomicrobium vulgare
Stutzer and Hartleb 1898, 76.
Labrys
Authors: Vasilyeva Leana V.
Published: August 2015

Lab' rys
. Gr. n.
Labrys
double‐headed ax, an organism resembling a Minoan ax, by the shape of the cell.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Hyphomicrobiaceae / Labrys

Unicellular flat bacterium
; cells possess
triangular radial symmetry
. Dimensions are 1.1–1.3 × 1.3–1.5 µm.
Two to three tapering
,
short prosthecae
(<0.6 µm) protrude from two corners of the triangle; the third remains free and is associated with multiplication.

The mol
%
G
+
C of the DNA is
: 67.9.

Type species
:
Labrys monachus
Vasilyeva and Semenov 1985, 375 (Effective publication: Vasilyeva and Semenov 1984, 92.)
Pedomicrobium
Authors: Hirsch Peter
Published: August 2015

Pe.do.mi.cro' bi.um
. Gr. n.
pedon
soil; Gr. adj.
micros
small; Gr. masc. n.
bios
life; M.L. neut. n.
Pedomicrobium
soil microbe.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Hyphomicrobiaceae / Pedomicrobium

Cells oval
,
spherical
,
or rod‐shaped
, 0.4–2.0 × 0.4–2.5 µm.
Up to 5 hyphae
(i.e., cellular outgrowths or prosthecae of constant diameter with reproductive function) are formed per cell body. Hyphae are 0.15–0.2 µm in diameter.
At least one hypha originates laterally
; others may appear at the cell poles. Multiplication is by
budding at the hyphal tips
,
with the long axis of the bud arranged perpendicular to the hyphal axis
(Figures 1 and 2). Mature buds either separate from the hyphae as uniflagellated swarmers or remain attached. Extracellular polymers can be stained with ruthenium red and sometimes are visible in India ink mounts as thick capsules around mother cells.
Oxidized iron or manganese compounds are deposited on mother cells and later on hyphae
. Resting stages are not known.
Gram negative
, older cells variable. Swarmer cells are motile by a single subpolar or polar flagellum (Figure 3). Other stages of the cell cycle (Figure 4) are nonmotile. Colonies are yellowish or reddish brown to dark brown, due to accumulated iron or manganese oxides. Aerobic. Catalase positive (test is in absence of MnO
2
and at neutral pH).
Chemoorganotrophic
. Acetate is utilized as a carbon source; most strains also grow on caproate or pyruvate. Protein digests, such as yeast extract, peptone, Casamino acids, and soytone, serve as carbon and/or nitrogen sources. Organic nitrogen sources utilized by most strains are glutamate, aspartate, glycine, serine, threonine, and valine. Inorganic nitrogen compounds allow only poor growth of some isolates; nitrate is reduced by most strains.
Slow and poor growth occurs on agar media with 0
.
1–1
%
fulvic acid iron sesquioxide complexes as sole carbon and nitrogen sources
. Vitamin mixtures stimulate growth; lack of vitamins results in pleomorphic cells, which produce large granules of poly‐β‐hydroxybutyric acid. Growth is inhibited by polymyxin B and neomycin.

The mol
%
G
+
C of the DNA is
: 63–66.8.

Type species
:
Pedomicrobium ferrugineum
Aristovskaya 1961, 957, emend. Gebers and Beese 1988, 308.
Prosthecomicrobium
Authors: Jenkins Cheryl , Rainey Fred A. , Ward Naomi L. , Staley James T.
Published: August 2015

Pros.the' co.mi.cro.bi.um
. Gr. fem. n.
prosthece
appendage; Gr. adj.
micros
small; Gr. masc. n.
bios
life; M.L. neut. n.
Prosthecomicrobium
appendage (‐bearing) microbe.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Hyphomicrobiaceae / Prosthecomicrobium

Unicellular
bacterium with coccobacillary to rod‐shaped cells ranging in diameter from 0.8 to 1.2 µm and containing
numerous prosthecae
extending from all locations on the cell surface. Prosthecae, which may number from 10 to more than 30/cell, are typically short (i.e., <1.0 µm in length); some species, however, also produce longer prosthecae (>2.0 µm).
Cells divide by budding
. Buds are produced directly from the mother cell, never from tips of prosthecae.
Gram negative
. Motile and nonmotile species exist. Motile organisms produce single polar to subpolar flagella; one species forms gas vacuoles but not flagella.
Obligately aerobic
,
nonfermentative
,
heterotrophic
. A variety of sugars and organic acids are used as energy sources for growth. All strains tested require one or more B vitamins for growth. Oxidase and catalase positive. Found in soils and fresh and marine waters.

The mol
%
G
+
C of the DNA is
: 64–70.

Type species
:
Prosthecomicrobium pneumaticum
Staley 1968, 1940.
Seliberia
Authors: Schmidt Jean M. , Kelly Suzanne V.
Published: August 2015

Se
.
li
.
be
'
ri
.
a
. M.L. fem. n.
Seliberia
of Seliber, named for the Russian microbiologist, Professor G.L. Seliber.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Hyphomicrobiaceae / Seliberia

Rods
, 0.5–0.8 µm in diameter and 1–12 µm in length, with a
helically sculptured
or
furrowed
topography. The ends of the cell may be either blunt or rounded.
Stellate aggregates
(
rosettes
) of
sessile rods
joined at one pole, and individual, shorter
motile rods
(
swarmers
) occur in the same culture. An adhesive
holdfast
, secreted at one pole, mediates attachment into rosettes. Growth on appropriate soil extract media may permit formation of round to ovoid “
generative cells
”. Capsules are not produced, although a thin glycocalyx is produced later in the growth cycle. Resting stages are not known. Gram negative. Following
unidirectional polar cell growth
, a shorter motile cell (a
swarmer
) and a longer sessile cell are produced by
asymmetric transverse fission
. A single
subpolar ensheathed flagellum
is characteristically present on the swarmer;
several lateral flagella
,
not ensheathed
, may also be present.
Strictly aerobic
. Optimal temperature, 25–30°C; maximum ca. 37°C, minimum 15–20°C. Chemoorganotrophic, having an
oxidative type of metabolism
. Catalase and oxidase positive. These organisms live in soil and fresh water environments as autochthonous microflora, often where oligotrophic conditions prevail.

The mol
%
G
+
C of the DNA is
: 63–66.

Type species
:
Seliberia stellata
Aristovskaya and Parinkina 1963, 55.
Starkeya
Authors: Kelly Donovan P. , Wood Ann P.
Published: August 2015

Star
.
ke
'
ya
. M.L. n.
Starkeya
of Starkey; named after Robert L. Starkey, who made important contributions to the study of soil microbiology and sulfur biochemistry.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Hyphomicrobiaceae / Starkeya

Short rods, coccoidal or ellipsoidal cells 0.4–0.8 × 0.8–2.0 µm, occurring singly and, occasionally, in pairs. Nonmotile. Colonies grown on thiosulfate agar (with biotin) are small, smooth, circular, round, and opalescent, becoming white with sulfur. Thiosulfate liquid medium (lacking biotin) becomes turbid and sulfur precipitates during static incubation; thiosulfate is incompletely used, and the pH falls from 7.8 to 5.8. This poor development is due to the requirement for biotin exhibited by the type strain. The organism is
facultatively chemolithoautotrophic
, but optimal autotrophic development requires biotin, and optimal heterotrophic growth requires yeast extract, biotin, or other additions, such as pantothenate, depending on the organic substrate. Autotrophic growth is also observed with formate when high levels of ribulose 1,5‐bisphosphate carboxylase are expressed. Some strains may degrade methylated sulfides. This organism is
strictly aerobic
,
both autotrophically and heterotrophically
, and is incapable of denitrification.
Oxidizes and grows on thiosulfate and tetrathionate but not on sulfur or thiocyanate
. Ammonium salts, nitrates, urea, and glutamate are used as nitrogen sources. Optimal temperature 25–30°C; growth range 10–37°C (no growth at 5°C or 42°C). Optimal pH 7.0; growth range pH 5.7–9.0. Contains ubiquinone Q‐10. Major cellular fatty acids are octadecenoic acid and cyclopropane acid of C
19
; lacks a major hydroxy fatty acid. The lipopolysaccharide lacks heptoses and has only 2,3‐diamino‐2,3‐dideoxyglucose as the backbone sugar. Member of the
Alphaproteobacteria
. Isolated from soil. Presumably widely distributed.

The mol
%
G
+
C of the DNA is
: 67.3–68.4.

Type species
:
Starkeya novella
(Starkey 1934) Kelly, McDonald and Wood 2000, 1800 (
Thiobacillus novellus
Starkey 1934, 365.)
Methylobacterium
Authors: Green Peter N.
Published: August 2015

Meth
.
yl
.
o
.
bac
.
te
'
ri
.
um
. M.L. n.
methyl
the methyl radical; Gr. n.
bacterion
a small rod; M.L. neut. n.
Methylobacterium
methyl bacterium.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Methylobacteriaceae / Methylobacterium

Rods 0
.
8–1
.
2
×
1
.
0–8
.
0 µm that occasionally branch and
/
or exhibit polar growth
.
Form pink to orange‐red colonies on methanol salts agar
. Stain Gram negative to Gram variable; Gram‐negative cell wall type. Motile by means of a single polar, subpolar, or lateral flagellum.
Aerobic
, having a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor.
Mesophilic
.
Chemoorganotrophic and facultatively methylotrophic
, able to grow with formaldehyde (often at micromolar concentrations), formate, and methanol; some strains grow on methylated amines. Widely distributed in nature.

The mol
%
G
+
C of the DNA is
: 68.0–72.4.

Type species
:
Methylobacterium organophilum
Patt, Cole and Hanson 1976, 228.
Albibacter
Authors: Doronina Nina V. , Trotsenko Yuri A.
Published: August 2015

Al
.
bi
.
bac
'
ter
. L. adj.
albus
white; M.L. masc. n.
bacter
equivalent of Gr. neut. n.
baktron
a small rod; M.L. masc. n.
Albibacter
small, white rod.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Methylocystaceae / Albibacter

Rods 0
.
9–1
.
0
×
1
.
2–1
.
8
μ
m
, singly, in pairs, or in clusters.
Nonmotile
. Gram negative. Multiplication is by binary fission. Endospores and prosthecae are not formed. Colonies are white. Obligately
aerobic
, having a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor. Nitrate is reduced to nitrite. Growth occurs on nutrient agar and peptone–yeast extract–glucose (PYG) agar.
Facultatively methylotrophic and chemolithotrophic
.

Assimilate C
1
compounds via the ribulose bisphosphate pathway

. Able to grow on a wide spectrum of polycarbon substrates. Sugars are utilized aerobically but not fermented. Ammonium salts, nitrate, urea, peptone, some amino acids, and methylated amines are utilized as nitrogen sources. Growth factors are not required. Methyl red and Voges–Proskauer negative. Catalase and urease positive.
Oxidase activity is very low
. Indole is formed from
L
‐tryptophan in the mineral medium with methanol as a sole carbon and energy source and with KNO
3
as the nitrogen source. The major ubiquinone is Q‐10. The predominant cellular fatty acids are
cis
‐vaccenic (C
18:1 ω7
) and palmitic (C
16:0
). The dominant phospholipids are phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, and phosphoserine. Belongs to the
Alphaproteobacteria
.

The mol
%
G
+
C of the DNA is
: 66.7.

Type species
:
Albibacter methylovorans
Doronina, Trotsenko, Tourova, Kuznetsov and Leisinger 2001, 1056.
Incertae Sedis
IV
. Methylopila
Authors: Doronina Nina V. , Trotsenko Yuri A.
Published: August 2015

Me.thy.lo.pi' la
. Fr.
méthyle
the methyl radical; Gr. adj.
pila
ball or sphere; M.L.
Methylopila
methyl‐using sphere.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Methylocystaceae / incertae Sedis IV. Methylopila

Rods
,
0
.
5–0
.
7
×
1
.
0–1
.
3
μ
m
, occurring singly or in pairs.
Motile or nonmotile
. If motile, the cells have a single lateral flagellum. Gram negative.
Poly
‐β‐
hydroxybutyrate granules are formed
. Prosthecae are not formed. Colonies are white. Do not produce pyocyanine and fluorescein. Methyl red and Voges–Proskauer negative.
Oxidase and urease positive
. Indole is formed from
L
‐tryptophan on the mineral medium with methanol as the sole carbon and energy source and KNO
3
as the sole nitrogen source. Produce acid from sugars oxidatively.
Aerobic
, having a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor. Chemoorganotrophic.
Facultatively methylotrophic
.

Assimilate C
1
compounds by the serine pathway

(
isocitrate lyase
−
variant
). Growth factors are not required. Optimal pH 6.5–7.5; no growth above pH 9 or below pH 5. Optimal temperature, 28–35°C; no growth at 42°C. No growth with 7% NaCl. NaCl is not required for growth. Cellular fatty acid profile is characterized by the presence of 45–70%
cis
‐vaccenic acid (C
18:1 ω7
); main quinone is Q‐10. Dominant cell phospholipids are phosphatidylethanolamine and phosphatidylcholine. The genus belongs to the order
Rhizobiales
in the class
Alphaproteobacteria
.

The mol
%
G
+
C of the DNA is
: 66–70.

Type species
:
Methylopila capsulata
Doronina, Trotsenko, Krausova, Boulygina and Tourova 1998a, 1320.
Aquamicrobium
Authors:   The Editorial Board
Published: August 2015

A.qua.mi.cro' bi.um
. L. n.
aqua
water; L. n.
microbium
a microbe;
Aquamicrobium
a bacterium living in water/wastewater.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Phyllobacteriaceae / Aquamicrobium

Gram negative, pleomorphic or regularly formed short
rods
. Motile or nonmotile. Respiratory metabolism using either O
2
or nitrate under anoxic conditions.

Nitrate reduced to nitrite or N
2

. Mesophilic. Optimal pH 6–9. Salt tolerant, up to 3% NaCl. Utilize sugars, fatty acids, and heterocyclic aromatic compounds as carbon sources. Utilize nitrate or O
2
as electron acceptors.

The mol
%
G
+
C of the DNA is
: 59–65.

Type species
:
Aquamicrobium defluvii
Bambauer, Rainey, Stackebrandt and Winter 1998b, 631 (Effective publication: Bambauer, Rainey, Stackebrandt and Winter 1998a, 300.)
Liberibacter
Authors: Garnier Monique
Published: August 2015

Li.be.ri' bac.ter
. L. n.
liber
phloem; Gr. n.
bakterion
a small rod; N.L. masc. n.
Liberibacter
rod in the phloem. Copyright © 2015 John Wiley & Sons, Ltd.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Phyllobacteriaceae / Liberibacter

Filamentous bacteria occurring in the phloem sieve tubes of plants
(Fig. 146). Round forms are also observed but have been shown to correspond to degenerating bacteria. The bacteria are also present in the hemolymph and salivary glands of insect vectors (Psyllidae) responsible for the transmission. Like most phloem‐restricted bacteria,
Candidatus
Liberibacter spp. have resisted
in vitro
cultivation (Garnier and Bové, 1993). The characterized species originated from sweet orange (
Citrus sinensis
). The original description is based on bacteria present in the phloem sieve tubes of sweet orange trees affected by huanglongbing (ex. greening disease) in Poona (India) and Nelspruit (South Africa).

Type species
:
Candidatus
Liberibacter asiaticus Jagoueix, Bové and Garnier 1994, 385 (
Candidatus
Liberobacter asiaticum (sic) Jagoueix, Bové and Garnier 1994, 385.)
Pseudaminobacter
Authors: Kämpfer Peter
Published: August 2015

Pseud.ami.no.bac' ter
. Gr. adj.
pseudos
false; M.L.
aminobacter
generic name of a bacterium;
Pseudaminobacter
false aminobacters.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Phyllobacteriaceae / Pseudaminobacter

Rods 0.5–0.8 × 1.0–2.0 μm
, with rounded ends.
Motile
. Gram negative.
Aerobic
, having a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor.
Oxidase and catalase positive
. Colonies on nutrient agar at 25°C are circular, entire, slightly convex and smooth, glistening, and pale beige. Contains ubiquinone Q‐10. Major polyamines are spermidine,
sym
‐homospermidine, and putrescine. Polar lipid pattern characterized by nearly equal amounts of phosphatidylcholine, phosphatidylglycerol, phosphatidyldimethylethanolamne, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, and diphosphatidylglycerol. The major cellular fatty acid is C
18:1
. The hydroxy acids include the hydroxylated fatty acid C
15:0 iso 3OH
. Isolated from wastewater and river water.

The mol
%
G
+
C of the DNA is
: 62.9–63.9.

Type species
:
Pseudaminobacter salicylatoxidans
Kämpfer, Müller, Mau, Neef, Auling, Busse, Osborn and Stolz 1999, 894.
Allorhizobium
Authors: Kuykendall L. David , Dazzo Frank B.
Published: August 2015

Al.lo.rhi.zo' bi.um
. Gr. adj.
allos
other; M.L. neut. n.
Rhizobium
a bacterial generic name; M.L. neut. n.
Allorhizobium
the other
Rhizobium
, to refer to the fact that it is phylogenetically separate from other
Rhizobium
species.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Rhizobiaceae / Allorhizobium

Rods 0.5–0.7 × 2.0–4.0 µm. Nonsporeforming. Gram negative. Aerobic, having a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor.
Relatively fast growing
; colonies 0.5–3.0 mm develop in 1–2 days on yeast–mannitol–mineral salts agar, and pronounced turbidity develops after 1–2 days in agitated broth media. Chemoorganotrophic.
A wide range of carbohydrates
,
organic acids
,
and amino acids are used as sole carbon sources for growth
.
Ketolactose is not produced from lactose
.
Growth on carbohydrate media is usually accompanied by extracellular polysaccharide production
. At the molecular level, the genus can be distinguished from related species in other genera by SDS‐PAGE whole cell protein analysis, ITS PCR‐RFLP, and 16S rRNA gene sequencing.
Initiates the production of root nodules
,
in which the bacteria occur as nitrogen‐fixing intracellular symbionts
. Exhibits specificity to certain temperate‐zone and tropical‐zone leguminous plants (family Leguminoseae).

The mol
%
G
+
C of the DNA is
: 60.1.

Type species
:
Allorhizobium undicola
De Lajudie, Laurent‐Fu‐lele, Willems, Torck, Coopman, Collins, Kersters, Dreyfus and Gillis 1998a, 1288.
Carbophilus
Authors: Meyer Ortwin O.
Published: August 2015

car.bo.phi' lus
. L. masc.
carbo
carbon; M.L. part.
philus
loving, loving carbohydrates and other carbonaceous substrates.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Rhizobiaceae / Carbophilus

Rod‐shaped cells
with slightly tapered ends, 0.7–0.9 × 0.9–1.7 µm. Motility variable; when present, it is by means of up to five peritrichous flagella. Flagellation is maximal in the late exponential growth phase, when more than 80% of the cells are flagellated. Formation of aggregates is rare.
Gram negative
. Colonies are white to cream colored. Organic growth factors are not required.
Aerobic
, having a strictly respiratory type of metabolism, with oxygen as the terminal electron acceptor. Neither denitrification nor reduction of nitrate to nitrite has yet been observed.
Facultatively chemolithoautotrophic
. CO is utilized as a substrate under aerobic chemolithoautrophic conditions. Chemoorganoheterotrophic substrates encompass a wide variety of the salts of organic acids (except citrate), amino acids, sugars, and sugar alcohols (see Table 1 of Meyer et al., 1993). Suitable nitrogen sources are ammonia, hydroxylamine, nitrate, and urea (Frunzke and Meyer, 1990). Dinitrogen is not fixed. Not phototrophic. Not methanogenic. Isolated from soil at the city of Moscow (Russia).

The mol
%
G
+
C of the DNA is
: 62.8 (

T
m

).

Type species
:
Carbophilus carboxidus
(ex Nozhevnikova and Zavarzin 1974) Meyer, Stackebrandt and Auling 1994, 182 (Effective publication: Meyer, Stackebrandt and Auling 1993, 393.)
Chelatobacter
Authors: Egli Thomas W. , Auling Georg
Published: August 2015

Che.la' to.bac.ter
. Gr. n.
chele
claw; M.L. v.
chelato
to form claw‐like complexes with divalent cations, i.e., to chelate; M.L. masc. n.
bacter
equivalent of Gr. neut. n.
bakterion
rod or staff; M.L. masc. n.
Chelatobacter
chelating rod.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Rhizobiaceae / Chelatobacter

Rods 0
.
7–0
.
9
×
1–2
μ
m
,
often pleomorphic and budding
.
L
‐,
Y
‐,
and X‐shaped forms occur
. Gram negative.
Motile
,
usually by two or three subpolar flagella
.
Obligately aerobic
. Optimal growth temperature, 28–30°C; no growth at 41°C and 4°C. Slow growers with all substrates tested so far (μ
max
<0.25 h
−1
). Poly‐β‐hydroxybutyrate is accumulated. All strains are sensitive to β‐lactam antibiotics but resistant to nalidixic acid.
The metal‐chelating aminopolycarboxylic acid nitrilotriacetic acid
(
NTA
)
can be utilized as a sole source of carbon
/
energy and nitrogen
. A great variety of sugars, acids, alcohols, and methylated amines are utilized. Vitamins are not required. Ubiquinone Q‐10 is present. The main polyamine present is
sym
‐homospermidine; putrescine and spermidine occur as major polyamines and spermine as a minor polyamine.

The mol
%
G
+
C of the DNA is
: 62–63.

Type species
:
Chelatobacter heintzii
Auling, Busse, Egli, El‐Banna and Stackebrandt 1993b, 624 (Effective publication: Auling, Busse, Egli, El‐Banna and Stackebrandt 1993a, 110.)
Rhizobium
Authors: Kuykendall L. David , Young John M. , Martínez‐Romero Esperanza , Kerr Allen , Sawada Hiroyuki
Published: August 2015

Rhi.zo' bi.um. Gr. n.rhizaa root; Gr. n.bioslife; M.L. neut. n.Rhizobiumthat which lives in a root.

Proteobacteria / Alphaproteobacteria / Rhizobiales / Rhizobiaceae / Rhizobium

Rods 0.5–1.0×1.2–3.0 µm. Nonsporeforming. Gram negative.Motile by 1–6 peritrichous flagella. Fimbriae have been described on some strains.Aerobic, possessing a respiratory type of metabolism with oxygen as the terminal electron acceptor. Optimal temperature for growth, 25–30°C; some species can grow at temperatures >40°C. Optimal pH for growth, 6–7; range pH 4–10. Generation times ofRhizobiumstrains are 1.5–5.0 h.Coloniesare usually white or beige, circular, convex, semi‐translucent or opaque, raised and mucilaginous,usually 2–4 mm in diameter within 3–5 days on yeast‐mannitol‐mineral salts agar(YMA).Growth on carbohydrate media is usually accompanied by copious amounts of extracellular polysaccharide. Pronounced turbidity develops after 2 or 3 days in aerated or agitated broth. Chemoorganotrophic, utilizing a wide range of carbohydrates and salts of organic acids as sole carbon sources, without gas formation. Cellulose and starch are not utilized.Produce an acidic reaction in mineral‐salts medium containing mannitol or other carbohydrates. Ammonium salts, nitrate, nitrite, and most amino acids can serve as nitrogen sources. Strains of some species will grow in a simple mineral salts medium with vitamin‐free casein hydrolysate as the sole source of both carbon and nitrogen, but strains of many species require one or more growth factors such as biotin, pantothenate, or nicotinic acid. Peptone is poorly utilized. Casein, starch, chitin, and agar are not hydrolyzed.All knownRhizobiumspecies include strains which induce hypertrophisms in plants as root nodules with or without symbiotic nitrogen fixation. Some cells of symbiotic bacterial species enter root hair cells of leguminous plants (Family Leguminosae) via invagination or by wounds (“crack entry”) and elicit the production of root nodules wherein the bacteria engage as intracellular symbionts, usually fixing nitrogen. Many well‐defined nodulation (nod) and nitrogen fixation (nif) genes are clustered on large plasmids or megaplasmids (pSyms). Plasmid transfer between species results in the expression and stable inheritance of the particular plant‐interactive properties of the plasmid‐donor species. Plant host specificity is usually for a few legume genera but may, in some strains, include a wide variety of legume genera and is to some extent determined by the chemical structure of the lipochito‐oligosaccharideNodfactors produced. These chitin‐like molecules induce nodule organogenesis in the absence of bacteria.In root nodules the bacteria occur as endophytes that exhibit pleomorphic forms,termed“bacteroids”,which reduce or fix gaseous atmospheric nitrogen into a combined form utilizable by the host plant.

The mol%G+C of the DNA is: 57–66.

Type species:Rhizobium leguminosarum(Frank 1879) Frank 1889, 338 (Schinzia leguminosarumFrank 1879, 397.)
Ahrensia
Authors: Krieg Noel R.
Published: August 2015

Ahrens.i.a
. M.L. dim ending ‐
ia
; M.L. fem. n.
Ahrensia
named after R. Ahrens, a German microbiologist, who contributed to the taxonomy of marine species of
Agrobacterium
.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Ahrensia

Rods
,
0
.
6–1
.
0
×
2
.
0–4
.
0 µm
.
Motile
. Do not form spores. Gram negative.
Aerobic
, having a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor.
Na
+
is required for growth
. Optimal growth occurs between 20 and 30°C; growth occurs at 5°C but not at 37°C.
Catalase and oxidase positive
. Nitrate is not reduced to nitrite or to gas. Gelatin, starch, chitin, and alginate are not hydrolyzed. Indole is not produced. The major fatty acid is C
18:1
. The 3‐hydroxy fatty acid is C
12:0 3OH
. 2‐Hydroxy fatty acids are absent. The major quinone is ubiquinone 10. The genus belongs to the class
Alphaproteobacteria
. Isolated from seawater.

The mol
%
G
+
C of the DNA is
: 48.

Type species
:
Ahrensia kieliensis
(ex Ahrens 1968) Uchino, Hirata, Yokota and Sugiyama 1999, 1 (Effective publication: Uchino, Hirata, Yokota and Sugiyama 1998, 208) (
Agrobacterium kieliense
Ahrens 1968, 156.)
Amaricoccus
Authors: Maszenan Abdul M. , Seviour Robert J. , Patel Bharat K.C.
Published: August 2015

A.ma' ri.coc.cus
. Gr. n.
amara
sewage duct; Gr. n.
coccus
grain; L. n.
Amaricoccus
spherical cells from sewage ducts.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Amaricoccus

Cocci, 1.3–1.8 µm in diameter, usually arranged in tetrads. Gram negative. Nonmotile. Do not form spores or store polyphosphate granules. Oxidase positive. Aerobic, having a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor. Growth occurs at 20–37°C and at pH 5.5–9.0. Chemoheterotrophic. A variety of organic compounds can be used as carbon sources, including
D
‐fructose, glucose, mannitol,
L
‐glutamic acid,
D
‐mannose,
D
‐sorbitol, sucrose,
L
‐rhamnose,
L
‐arabinose,
L
‐leucine, and
L
‐histidine. Isolated from activated sludge and sewage.

The mol
%
G
+
C of the DNA is
: 51–63.

Type species
:
Amaricoccus kaplicensis
Maszenan, Seviour, Patel, Rees and McDougall 1997, 733.
Antarctobacter
Authors: Labrenz Matthias , Hirsch Peter
Published: August 2015

Ant.arc' to.bac.ter
. M.L.
Antarctica
name of the South Pole continent; derived from Gr. pref.
anti
against (on the other side); Gr. adj.
arcticos
northern; M.L. masc. n.
bacter
Gr. n.
baktron
a rod or staff;
Antarctobacter
a rod‐shaped bacterium from Antarctica.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Antarctobacter

Rods
,
one or both cell poles narrower
,
sizes vary due to age and growth conditions
:
0
.
8–1
.
2
×
2
.
0–33
.
6 µm
. Rosettes are formed. Gram negative.
Daughter cells may be motile
. No resting stages are known.
Aerobic
, with a strictly respiratory type of metabolism.
Intracellular granules of poly‐β‐hydroxybutyrate are present
. Cells have an absolute requirement for Na
+
. Temperature range <3–43.5°C, salinity range <1.0 to <10.0% NaCl and <10 to >150‰ of artificial seawater (ASW), pH range 5.3 to >9.
Oxidase and catalase positive
. Do not grow photoautotrophically with H
2
/CO
2
(80:20) or photoorganotrophically with acetate or glutamate. Do not contain bacteriochlorophyll
a
(bchl
a
). Occur in marine habitats.

The mol
%
G
+
C of the DNA is
: 62–63.

Type species
:
Antarctobacter heliothermus
Labrenz, Collins, Lawson, Tindall, Braker and Hirsch 1998, 1371.
Hyphomonas
Authors: Weiner Ronald M.
Published: August 2015

Hy.pho.mo' nas
. Gr. n.
hyphos
filament; Gr. n.
monas
a unit, monad; M.L. fem. n.
Hyphomonas
hyphabearing unit.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Hyphomonas

Rod‐shaped to oval mature cells measure 0.5–1.0 × 1.0–3.0 µm and may become larger and rounder just prior to bud formation. Unicellular. Cell division occurs by budding.
Buds are produced at tips of single polar prosthecae
, which are 0.2–0.3 µm in diameter and 1–5 times the length of the cell body. Prosthecae are nonseptate and rarely branch under normal growth conditions. Pleomorphic.
Hyphomonas
spp. have a
biphasic life cycle
and normally generate only a single polar prostheca (hypha). Young daughter cells (i.e., newly formed buds) are oval to pear shaped, lack prosthecae, and are smaller than the mother cell. Motile by means of a
single polar to lateral flagellum located on developing buds
or young daughter cells.
Gram negative
. Not acid‐fast. Aerobic. Nonsporeforming. Chemooganotrophic.
Hyphomonas
spp.
catabolize amino acids or tricarboxylic acid cycle intermediates
for energy and growth. All strains investigated thus far are catalase positive, oxidase positive, nonproteolytic, nonsaccharolytic, and nonpathogenic. Gelatin and starch not hydrolyzed; no indole from tryptophan; no DNase, ornithine decarboxylase, lysine decarboxylase, or coagulase activity. With one exception, all species denitrify. Amino acids are required for heterotrophic growth. Optimal temperature for growth ranges from 22 to 37°C at one atmosphere of pressure. Prefer slightly alkaline conditions for growth.
All strains were isolated from marine sources
.

The mol
%
G
+
C of the DNA is
: 57–64.

Type species
:
Hyphomonas polymorpha
(ex Pongratz 1957) Moore, Weiner and Gebers 1984, 71.
Maricaulis
Authors: Poindexter Jeanne S.
Published: August 2015

Ma' ri.cau' lis.
L. neut. n.
mare
the sea; L. masc. n.
caulis
stalk; M.L. masc. n.
Maricaulis
stalk from the sea.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Maricaulis

Cells single, unbranched, with poles gently rounded or slightly tapered; long axis typically straight and cell shape
bacteroid
, but may be slightly curved in some cells and some isolates and cell shape
subvibrioid
; 0.4–0.6 × 1–2 µm during growth in most media. The younger pole of the dividing cell bears a
single flagellum
, and the older pole bears a prostheca (the
stalk
) developed by outgrowth of the cell envelope. Stalk diameter is constant along its length, varying from 0.11 to 0.18 µm among isolates. Binary
fission is asymmetric
: prior to fission, one pole bears a stalk and the other a single flagellum, and fission results in the separation of a non‐motile stalked cell and a motile, monoflagellate swarmer cell. At the base of the flagellum and at the outer tip of the stalk is a small mass of adhesive material, the
holdfast
, which confers adhesiveness on each of the progeny.

The mol
%
G
+
C of the DNA is
: 62.5–64.0.

Type species
:
Maricaulis maris
(Poindexter 1964) Abraham, Strömpl, Meyer, Lindholst, Moore, Christ, Vancanneyt, Tindall, Bennasar, Smit and Tesar 1999, 1071 (
Caulobacter maris
Poindexter 1964, 289.)
Methylarcula
Authors: Doronina Nina V. , Trotsenko Yuri A.
Published: August 2015

Me.thyl.ar.cu' la.
Fr.
méthyle
the methyl radical; L. fem. n.
arcula
small box; M.L. fem. n.
Methylarcula
methyl‐using small box.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Methylarcula

Rods 0
.
5–0
.
8
×
0
.
8–2
.
0
μ
m
.
Nonmotile
. Gram negative.
Poly
‐β‐
hydroxybutyrate granules are formed
. Endospores and prosthecae are not formed. Colonies are white or pale pink. Do not produce pyocyanin and fluorescein.
Aerobic
, having a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor.
Moderately halophilic
; NaCl is required for growth. Ectoine is accumulated intracellularly as the main osmoprotectant. Growth does not occur on peptone/yeast extract medium, with or without NaCl. Nitrate is not reduced to nitrite. Chemoorganotrophic.
Facultatively methylotrophic
.

Assimilate C
1
compounds via the isocitrate lyase‐negative

(
icI
−
)
serine pathway
.
Methylamine
,
sugars
,
and some organic acids are used as carbon and energy sources
. Ammonium salts, some amino acids, and methylamine are used as nitrogen sources. Growth factors are not required.
Oxidase positive
. Acids are produced from sugars oxidatively. Acetoin, hydrogen sulfide, and ammonium are not formed. Indole is formed from
l
‐tryptophan. The major ubiquinone is Q‐10. The dominant phospholipids are phosphatidylethanolamine and phosphatidylcholine. The predominant cellular fatty acids are straight‐chain unsaturated (C
18:1
), saturated (C
18:0
), and cyclopropane (C
19:0
) acids. Belongs to the
Alphaproteobacteria
.

The mol
%
G
+
C of the DNA is
: 57–60.

Type species
:
Methylarcula marina
Doronina, Trotsenko and Tourova 2000a, 1858.
Paracoccus
Authors: van Spanning Rob J.M. , Stouthamer Adriaan H. , Baker Simon C. , van Verseveld Henk W.
Published: August 2015

Pa.ra.coc' cus
. Gr. prep.
para
like, alongside of; Gr. n.
coccus
a grain, berry; M.L. masc. n.
Paracoccus
like a coccus.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Paracoccus

Spherical cells
0.5–0.9 µm in diameter
or very short rod‐shaped cells
1.1–1.3 µm in diameter.
Occur singly
,
in pairs
,
or in small clusters
. Usually not encapsulated.
Gram negative
. Nonspore‐forming and nonmotile.
Aerobic with a strictly respiratory metabolism
.

N

‐
oxides
such as nitrate, nitrite, and nitrous oxide
can be used as terminal electron acceptors
for respiration under anaerobic conditions.

Nitrate is reduced to N
2

via nitrite, nitric oxide, and nitrous oxide (denitrification). Oxidase and catalase positive.
Chemoorganotrophic growth
occurs with a wide variety of organic compounds as carbon source.
Chemolithoautotrophic growth
occurs with CO
2
as carbon source, and H
2
, methanol, methylamine, or thiosulfate as the electron‐donating free‐energy source.
Occur in water
,
soil
,
sewage
,
and sludge
.

The mol
%
G
+
C of the DNA is
: 64–67.

Type species
:
Paracoccus denitrificans
(Beijerinck and Minkman 1910) Davis 1969, 384 emend. Rainey, Kelly, Stackebrandt, Burghardt, Hiraishi, Kaayama and Wood 1999, 650 (
Micrococcus denitrificans
Beijerinck and Minkman 1910, 53.)
Rhodovulum
Authors: Imhoff Johannes F.
Published: August 2015

Rho.do' vu.lum
. Gr. n.
rhodon
rose; L. dim. n.
ovulum
small egg; M.L. neut. n.
Rhodovulum
small red egg.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Rhodovulum

Cells are ovoid to rod shaped
, are motile by means of flagella or nonmotile, and divide by binary fission.
Gram negative
;

belong to the
Alphaproteobacteria

. Phototrophically grown cells
form vesicular internal photosynthetic membranes
.

Photosynthetic pigments are bacteriochlorophyll
a

(
esterified with phytol
)
and carotenoids of the spheroidene series
. The color of phototrophic cultures is yellow‐green to yellow‐brown, while aerobic cultures are pink to red.
Ubiquinone 10 is the major quinone
.
Major fatty acids are C

18
:
1

(
predominant
),
C

18
:
0

,
and C

16
:
0

.

The mol
%
G
+
C of the DNA is
: 62.1–73.2.

Type species
:
Rhodovulum sulfidophilum
(Hansen and Veldkamp 1973) Hiraishi and Ueda 1994a, 21 (
Rhodopseudomonas sulfidophila
Hansen and Veldkamp 1973, 55;
Rhodobacter sulfidophilus
Imhoff, Trüper, and Pfennig 1984, 342.)
Roseibium
Authors:   The Editorial Board
Published: August 2015

Ro.sei' bi.um
. M.L. adj.
roseus
rose/pink; Gr. n.
bios
life; M.L. neut. n.
Roseibium
pink life.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Roseibium

Gram‐negative aerobic chemoheterotrophic motile rods
(0.5–0.8 × 1.0–4.0 µm for most strains). Peritrichous flagella.

Produce bacteriochlorophyll
a
aerobically

.
Do not grow as anaerobic phototrophs
. Catalase and oxidase positive. Produce phosphatase and nitrate reductase. Major cellular fatty acid C
18:1
.

The mol
%
G
+
C of the DNA is
: 57.6–63.4 (HPLC).

Type species
:
Roseibium denhamense
Suzuki, Muroga, Takahama and Nishimura 2000, 2155.