bluuebunny/crossref_metadata_2025 huggingface dataset:
Krokinobacter
Authors:   The Editorial Board
Published: July 2015

Kro.ki'no.bac.ter. Gr. adj.
krokinos
yellow; N.L. masc. n.
bacter
from Gr. n.
bakterion
rod; N.L. masc. n.
Krokinobacter
a yellow, rod‐like bacterium.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Krokinobacter

Rods
,
0
.
5–0
.
7
×
2
.
5–4
.
0
μ
m
. Gram‐stain‐negative.
Aerobic
.
Lemon‐yellow
carotenoid‐type pigments are present.
Flexirubin‐negative
. Catalase‐ and oxidase‐positive.
Gelatin
,
casein
,
and DNA are hydrolyzed
,
but not agar
,
carrageenan
,
cellulose
,
chitin
,
starch
,
or urea
. Very weak growth, or no growth, occurs at temperatures below 10°C and above 30°C.
No growth occurs in the presence of 0 or 10
%
NaCl
. No acid is produced from glucose.
Nitrate is not reduced
. Denitrification does not occur. The following substrates are utilized: aspartic acid, dextrin, cellobiose,
D
‐fructose, gentiobiose, α‐
D
‐glucose, glutamic acid, glycine, glycyl‐
L
‐aspartic acid, lactose, lactulose, maltose, methyl‐β‐
D
‐glucoside, ornithine, raffinose, sucrose, trehalose, turanose, proline, threonine, and uridine. Do not utilize the following substrates: aconitic acid, adonitol, alaninamide, alanine, aminobutyric acid, aminoethanol, arabitol, asparagine, bromosuccinic acid, butanediol, carnitine, citric acid, erythritol, formic acid, fucose, galactonic acid lactone, galactose, galacturonic acid, gluconic acid, glucosaminic acid, glucose phosphate, glucuronamide, glucuronic acid, glycerol, glycerol phosphate, glycyl‐
L
‐glutamic acid, histidine, α‐, β‐ and γ‐hydroxybutyric acids,
p
‐hydroxyphenylacetic acid, inosine, inositol, itaconic acid, α‐ketobutyric acid, α‐ketoglutaric acid, α‐ketovaleric acid, leucine, malonic acid, mannose, melibiose, phenylalanine, phenylethylamine, propionic acid, psicose, putrescine, pyroglutamic acid, pyruvate, quinic acid, rhamnose, saccharic acid, sebacic acid, serine, sorbitol, succinamic acid, succinic acid, succinate, thymidine, urocanic acid, and xylitol. The major cellular fatty acids are C
15:0
iso, C
15:1
iso, C
17:0
iso 3‐OH, and summed feature A (C
16:1
ω7
c
and/or C
15:0
iso 12‐OH; fatty acids that could not be separated by GC). Isolated from marine sediment samples.

DNA G
+
C content
(
mol
%): 33–39.

Type species
:
Krokinobacter genikus
Khan, Nakagawa and Harayama 2006a, 326
VP
.
Leeuwenhoekiella
Authors: Nedashkovskaya Olga I. , Vancanneyt Marc , Mikhailov Valery V.
Published: July 2015

Leeu.wen.hoe.ki.el'la. N.L. fem. dim. n.
Leeuwenhoekiella
named in honor of the famous Dutchman Antonie van Leeuwenhoek (1632–1723), discoverer of micro‐organisms.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Leeuwenhoekiella

Thin rods
usually measuring 0.4–0.7 × 1.5–4.0 µm.
Motile by gliding
. Produce non‐diffusible yellow pigments. No flexirubin‐type pigments are formed.
Chemo‐organotrophs
.
Strictly aerobic
. Positive for oxidase, catalase, alkaline phosphatase, and β‐galactosidase.
Halotolerant
. Agar, DNA, urea, cellulose (CM‐cellulose and filter paper), and chitin are not attacked. Casein, gelatin, starch, and Tweens 20, 40, and 80 are hydrolyzed. Nitrate is not reduced. H
2
S, indole, and acetoin are not produced.
Marine
, from coastal habitats. Can grow without seawater or Na
+
.
The major respiratory quinone is MK‐6
.

DNA G
+
C content
(
mol
%): 35–43 (
T
m
).

Type species
:
Leeuwenhoekiella marinoflava
(Reichenbach 1989c) Nedashkovskaya, Vancanneyt, Dawyndt, Engelbeen, Vandemeulebroecke, Cleenwerck, Hoste, Mergaert, Tan, Frolova, Mikhailov and Swings 2005i, 1035
VP
.
Lutibacter
Authors:   The Editorial Board
Published: July 2015

Lu.ti.bac'ter. L. n.
lutum
mud; N.L. masc. n.
bacter
rod; N.L. masc. n.
Lutibacter
rod from mud.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Lutibacter

Rod‐shaped cells
.
Nonmotile
. Gram‐stain‐negative. Heterotrophic. Aerobic.
Catalase‐positive
.
Oxidase‐negative
. The predominant menaquinone is MK‐6. Dominant fatty acids are C
15:0
iso 3‐OH, C
15:0
iso, C
15:0
anteiso, and C
16:0
iso 3‐OH. Cells contain carotenoids, but
no flexirubin‐type pigments
. The genus is a member of the family
Flavobacteriaceae
.

DNA G
+
C content
(
mol
%): 33.9 (HPLC).

Type species
:
Lutibacter litoralis
Choi and Cho 2006, 775
VP
.
Mariniflexile
Authors:   The Editorial Board
Published: July 2015

Ma.ri.ni.fle'xi.le. L. adj.
marinus ‐a ‐um
marine; L. part. adj.
flexilis ‐e
pliant, pliable, flexible; N.L. neut. n.
Mariniflexile
a flexible marine bacterium.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Mariniflexile

Rods
,
0
.
4–0
.
5
×
2–3
μ
m
.
Motile by gliding
. Nonsporeforming. Gram‐stain‐negative.
Colonies are orange
. Chemo‐organotrophic.
Do not require Na
+
ions for growth
, but grow best with 1–2% NaCl.
Oxidase‐ and catalase‐positive
. Alkaline phosphatase‐positive.

d

‐
Glucose is fermented in the O‐F test
.
Agar and starch are not hydrolyzed
. The predominant cellular fatty acids are straight‐chain saturated, branched‐chain saturated and unsaturated fatty acids, C
15:0
iso, C
15:0
anteiso, C
15:1
iso, C
15:0
, C
17:0
iso 3‐OH, and summed feature 3 (comprising C
16:1
ω7 and/or C
15:0
iso 2‐OH). The main menaquinone is MK‐6. Isolated from the sea urchin
Strongylocentrotus intermedius
.

DNA G
+
C content
(
mol
%): 35.7 (
T
m
).

Type species
:
Mariniflexile gromovii
Nedashkovskaya, Kim, Kwak, Mikhailov and Bae 2006a, 1636
VP
.
Myroides
Authors:   The Editorial Board
Published: July 2015

My.roi'des. Gr. n.
myron
perfume; L. suff. ‐
oides
(from Gr. suff. ‐
eides
, from Gr. n.
eidos
that which is seen, form, shape, figure), resembling, similar; N.L. masc. n.
Myroides
resembling perfume.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Myroides

Rods
, 0.5 × 1–2 µm. Longer rods and long chains (containing 4–10 cells) may occur in broth medium. Nonmotile.
No gliding motility
or swarming occurs. Gram‐stain‐negative.
Yellow or yellow to orange colonies are usually produced
. A characteristic fruity odor is produced by most strains.
Aerobic
, having a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor. Good growth occurs on nutrient agar and MacConkey agar. No hemolysis occurs on blood agar. Growth occurs at 18–22 and 37°C, but not at 5 or 42°C. NaCl is not required, but growth occurs in the presence of at least 5% NaCl. Positive for oxidase and gelatinase; catalase‐positive or (in one species) weakly positive. Indole‐negative. Nitrate is not reduced. Negative for arginine dihydrolase and β‐galactosidase. Esculin is not hydrolyzed.
Nonsaccharolytic
. The major isoprenoid quinone is menaquinone‐6. The dominant polyamine component is homospermidine. The dominant fatty acids are C
15:0
iso, C
15:0
iso 3‐OH, C
16:0
3‐OH, C
17:0
iso 3‐OH, and C
17:1
iso ω9
c
. Two species are sources of nosocomial infections in humans; a third has been isolated from seawater.

DNA G
+
C content
(
mol
%): 30–38.

Type species
:
Myroides odoratus
(Stutzer and Kwaschnina 1929) Vancanneyt, Segers, Torck, Hoste, Bernardet, Vandamme and Kersters 1996, 931
VP
(
Flavobacterium odoratum
Stutzer
in
Stutzer and Kwaschnina 1929, 221).
Nonlabens
Authors:   The Editorial Board
Published: July 2015

Non.la'bens. L. adv.
non
not; L. part. adj.
labens
gliding; N.L. fem. n. (N.L. part. adj. used as a substantive)
Nonlabens
non‐gliding.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Nonlabens

Short rods. Nonmotile. Nonsporeforming. Gram‐stain‐negative. Strictly aerobic. MK‐6 is the only respiratory quinone.
Colonies are orange
.
NaCl
(2.0–4.0%)
is required for growth
. Flexirubin‐type pigments are not produced. Catalase‐ and oxidase‐positive.
Acetoin is produced
.
Gelatin is hydrolyzed
.
No
α‐
and
β‐
glucosidase and
β‐
galactosidase activities are present
. Isolated from a microbial mat in a subtropical estuary.

DNA G
+
C content
(
mol
%): 33.6 (HPLC).

Type species
:
Nonlabens tegetincola
Lau, Tsoi, Li, Plakhotnikova, Dobretsov, Wong, Pawlik and Qian 2005b, 2281
VP
emend. Lau, Tsoi, Li, Plakhotnikova, Dobretsov, Wu, Wong, Pawlik and Qian 2006, 184.
Polaribacter
Authors: Staley James T.
Published: July 2015

Po.lar.i.bac'ter. N.L. adj.
polaris
pertaining to the geographic poles; N.L. masc. n.
bacter
from Gr. n.
baktron
rod or staff; N.L. masc. n.
Polaribacter
rod‐shaped bacteria from polar habitats.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Polaribacter

Rods
,
curved rods
,
or filaments
. Cell size varies between 0.8 and 48 µm in length and 0.25 and 1.6 µm in diameter depending on species, growth medium, temperature, and physiological state of the culture. Nonmotile; some cells may have flagella, but motility has not been observed. Coccoid bodies often seen in ageing cultures.
Gas vesicles are produced by some species
. Gram‐stain‐negative. Heterotrophic.
Aerobic
.
Psychrophilic or mesophilic
. Organisms grow well in marine media or media that have been supplemented with NaCl. Organisms produce acid from a variety of carbohydrates. Starch is hydrolyzed. Cells can grow on yeast extract. Colonies produce yellow, orange, salmon, or pink non‐diffusible pigments that are not flexirubins.
Some strains produce rhodopsin pigments
that stimulate growth in presence of light. Some strains have been isolated from polar marine and sea ice environments and grow at temperatures of 10°C or lower.
All strains have been isolated from marine habitats
.

DNA G
+
C content
(
mol
%): 30–33.

Type species
:
Polaribacter filamentus
Gosink, Woese and Staley 1998, 232
VP
.
Psychroflexus
Authors: Bowman John P.
Published: July 2015

Psy.chro.flex'us. Gr. adj.
psychros
cold; L. masc. n.
flexus
bend, curve; N.L. masc. n.
Psychroflexus
cold bend.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Psychroflexus

Cells are straight or slightly curved
rods
, 0.4–1.5 × 0.5–3 µm. One species forms partially coiled filaments up to 50 µm in length in liquid media, whereas on solid surfaces the filaments formed are of indeterminant length. Coccoid‐like cells are formed in old cultures. Cells occur singly or in pairs. Spores and resting cells are not present. Gas vesicles and helical or ring‐shaped cells are not formed. Nonmotile or motile by gliding.
Gram‐stain‐negative
.
Strictly aerobic
,
having an oxidative type of metabolism
. Catalase‐positive. Oxidase‐positive.
Chemoheterotrophic
.
Non‐agarolytic
.
Colonies are bright orange
due to production of carotenoids, including β‐carotene.
Flexirubin pigments are not produced
. Produce alkaline phosphatase, α‐glucosidase, β‐glucosidase, and α‐amylase. Strains
usually require Na
+
for growth. Strains are
stenohaline or halotolerant
. Stenohaline species grow over a narrow range of seawater salinity.
Moderate halophiles
grow best with elevated NaCl concentrations (optimal levels 5–10%). Yeast extract may be required for growth by some strains. Species range from psychrophilic to mesophilic in terms of the response of their growth rates to temperature.
Neutrophilic
, with optimal growth occurring at pH 7.0–7.5. The major fatty acids are C
15:1
ω10
c
anteiso, C
15:0
anteiso, C
16:0
iso, C
16:0
3‐OH iso, and C
17:0
3‐OH iso/anteiso. One species produces
polyunsaturated fatty acids
. The major respiratory quinone is menaquinone‐6. The major polyamine is homospermidine.
Habitats
,
depending on the species
,
include polar sea‐ice algal assemblages or hypersaline lakes
.

DNA G
+
C content
(
mol
%): 33–36.

Type species
:
Psychroflexus torquis
Bowman, McCammon, Lewis, Skerratt, Brown, Nichols and McMeekin 1999, 1
VP
(Effective publication: Bowman, McCammon, Lewis, Skerratt, Brown, Nichols and McMeekin 1998, 1607.).
Robiginitalea
Authors: Cho Jang‐Cheon , Giovannoni Stephen J.
Published: July 2015

Ro.bi.gi.ni.tal'e.a. L. gen. n.
robiginis
rust; L. fem. n.
talea
a rod; N.L. fem. n.
Robiginitalea
a rust‐colored rod.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Robiginitalea

Cell shape varies from straight rods in exponential phase to coccoid cells in stationary phase
. Gram‐stain‐negative.
Non‐motile and no gliding motility
. Nonsporeforming. Poly‐β‐hydroxybutyrate granules are not formed. Obligately aerobic and chemoheterotrophic.
Produce carotenoid pigments
,
but not flexirubin pigments
. Require NaCl for growth. Oxidase‐ and catalase‐positive.
Degrade starch and esculin
. Utilize a variety of carbon compounds as sole carbon sources. The major fatty acid types are branched acids and hydroxy acids.

DNA G
+
C content
(
mol
%): 55–56.

Type species
:
Robiginitalea biformata
Cho and Giovannoni 2004, 1105
VP
.
Salegentibacter
Authors: Bowman John P.
Published: July 2015

Sal.e.gent'i.bac.ter. L. n.
salis
salt; L. part. adj.
egentis
needy; Gr. n.
bakterion
rod; L. masc. n.
Salegentibacter
salt‐needy rod.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Salegentibacter

Cells are
rod‐shaped
, 0.5–0.8 × 1.2–11.5 µm. Cells may occur singly, in pairs, or in short chains. Spores and resting cells are not present. Gas vesicles and helical or ring‐shaped cells are not formed.
Nonmotile or motile by gliding
. Gram‐stain‐negative.
Strictly aerobic
,
having an oxidative type of metabolism
. Catalase‐positive. Most species are oxidase‐positive.
Chemoheterotrophic
.
Colonies are bright‐yellow‐pigmented
due to production of carotenoids.
Flexirubin pigments are not produced
. Most strains form alkaline phosphatase, amylase, Tween esterases (Tweens 20, 40, and 80), gelatinase, elastinase, and alginase, and produce H
2
S from
L
‐cysteine. Strains do not form cellulases, chitinases, produce indole from
L
‐tryptophan, or form acetoin (Voges–Proskauer test).
Some species require Na
+
ions for growth
.
Halotolerant
. Tolerates 8% or more NaCl. The major fatty acids are C
15:0
, C
15:1
iso, C
15:0
iso, C
15:0
anteiso, summed feature 3 (C
16:1
ω7
c
/C
15:0
2‐OH iso), C
16:0
3‐OH iso, C
17:0
3‐OH iso, and C
17:0
2‐OH. The major respiratory quinone is
menaquinone‐6
. The major polyamine is homospermidine. Habitats include the surfaces of marine fauna including holothurians, sea urchins and sponges, hypersaline lake surface waters, and marine sediment.

DNA G
+
C content
(
mol
%): 37–44 (
T
m
, HPLC).

Type species
:
Salegentibacter salegens
(Dobson, Colwell, McMeekin and Franzmann 1993) McCammon and Bowman 2000, 1062
VP
(
Flavobacterium salegens
Dobson, Colwell, McMeekin and Franzmann 1993, 81).
Sandarakinotalea
Authors:   The Editorial Board
Published: July 2015

San.da.ra.ki.no.ta'le.a. Gr. adj.
sandarakinos ‐e ‐on
of orange color; L. fem. n.
talea
a slender staff, a rod; N.L. fem. n.
Sandarakinotalea
an orange‐colored rod.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Sandarakinotalea

Rods
,
0
.
5–0
.
7
×
3–5
μ
m
.
Nonmotile
.
Gliding motility is not present
. Gram‐stain‐negative.
Aerobic
.
Colonies are light orange
due to a carotenoid pigment. Flexirubin‐type pigments are not formed. Catalase‐ and oxidase‐positive. Growth occurs at 10–40°C; optimum, 15–20°C; no growth occurs at 4°C.
Growth requires NaCl and either a potassium or magnesium salt
.
Sea salts are required for growth
.
Starch
,
DNA
,
and gelatin are hydrolyzed
.
Nitrate is not reduced
. The predominant fatty acids are C
15:0
iso, C
15:0
anteiso, C
16:0
iso, and C
17:0
iso 3‐OH.
Pentadecenoic acid
(
C

15
:
1

)
is absent
. The only respiratory quinone present is MK‐6. Isolated from marine sediment.

DNA G
+
C content
(
mol
%): 35–37.

Type species
:
Sandarakinotalea sediminis
Khan, Nakagawa and Harayama 2006c, 962
VP
.
Sediminicola
Authors:   The Editorial Board
Published: July 2015

Se.di.mi.ni.co'la. L. n.
sedimen ‐inis
sediment; L. masc. suff. ‐
cola
(from L. n.
incola
) an inhabitant; N.L. masc. n.
Sediminicola
an inhabitant of sediment, referring to the source of the strains.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Sediminicola

Rods
,
0
.
5–0
.
7
×
3–5
μ
m
.
Nonmotile
. Gram‐stain‐negative. Colonies are golden‐yellow. Flexirubin‐type pigments are not produced.
Aerobic
. Catalase‐positive. Weakly positive for oxidase. Growth occurs at 10–30°C; optimum, 20°C.
Growth occurs in 10–100
%
strength artificial seawater
;
NaCl alone is not sufficient to support growth
.
Nitrate is reduced
.
Gelatin
,
casein
,
and starch are hydrolyzed
. Predominant cellular fatty acids are C
15:0
iso, C
15:0
anteiso, C
15:1
iso, C
17:1
iso ω9
c
, C
17:0
iso 3‐OH, and summed feature 3 (C
16:1
iso ω7
c
/i‐C
15:0
2‐OH).
Pentadecanoic acid
(
C

15
:
0

)
is absent
. Isolated from sediments collected on the shores of the Pacific Ocean and the Sea of Japan.

DNA G
+
C content
(
mol
%): 38–40.

Type species
:
Sediminicola luteus
Khan, Nakagawa and Harayama 2006b, 843
VP
.
Subsaxibacter
Authors: Bowman John P.
Published: July 2015

Sub.sa.xi.bac'ter. L. pref.
sub
below; L. neut. n.
saxum
stone; N.L. masc. n.
bacter
rod; N.L. masc. n.
Subsaxibacter
bacterial rod living below stone.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Subsaxibacter

Small coccibacilli
, 0.4–1.0 × 0.3–0.5 µm.
Gram‐stain‐negative
. Cells occur singly or in pairs. Spores and resting cells are not present. Gas vesicles and helical or ring‐shaped cells are not formed.
Gliding motility is present
.
Strictly aerobic
.
Oxidative metabolism
.
Catalase‐positive
.
Oxidase weakly positive
.
Chemoheterotrophic
.
Colonies are orange
due to production of carotenoids.
Flexirubin pigments are not produced
.
Sodium ions
are required for growth. Best growth occurs in organic media containing seawater salts.
Psychrophilic
. Grows between −2 and 20°C, with temperature optima at 10–15°C in seawater or NaCl‐containing media. Neutrophilic, with optimal growth occurring at about pH 7.5–8.0. The major fatty acids include C
15:1
iso ω10
c
, C
15:1
anteiso ω10
c
, C
15:0
iso, C
15:0
anteiso, C
16:1
ω7
c
, C
17:1
, and C
16:0
3‐OH iso. The major isoprenoid quinone is
menaquinone‐6
. Habitat: Antarctic quartz stone sublithic cyanobacterial biofilms.

DNA G
+
C content
(
mol
%): 35.

Type species
:
Subsaxibacter broadyi
Bowman and Nichols 2005, 1481
VP
.
Form‐Stigonema
Authors: Hoffmann Lucien , Castenholz Richard W.
Published: July 2015

Sti.go.ne' ma
. Gr. n.
stigeus
one who marks; Gr. n.
nema
thread; M.L. fem. n.
Stigonema
segmented filament.

Cyanobacteria / Subsection V / Incertae Sedis / Form‐Stigonema

Many species of this genus are extreme examples of multicellular complexity in the cyanobacteria. Main axes with numerous branches may reach thicknesses of 1 mm (Fig. B10.96). Extra‐cellular sheaths are present. Pore channels (synapses of microplasmodesmata) occur between all cells derived by division (Fig. B10.93). Branches, although initially simpler than the main axis, eventually become as complex. Tips of branches may be uniseriate for a considerable distance.
Natrinema
Authors: McGenity Terry J. , Grant William D. , Kamekura Masahiro
Published: July 2015

Na.tri.ne' ma
. M.L. n.
natrium
sodium; Gr. n.
nema
a thread; M.L. neut. n.
Natrinema
sodium (‐requiring) thread.

Euryarchaeota / Halobacteria / Natrialbales / Natrialbaceae / Natrinema

Cells rod shaped, 1–5 × 0.6–1.0 µm, but pleomorphic under unfavorable conditions. Colonies light orange‐red or pale orange, 1–2 mm in diameter, smooth, circular, convex. Cells stain Gram‐negative. Strict aerobes. Chemoorganotrophs. Nitrogen sources: Casamino acids. Carbon sources, Casamino acids and certain sugars. Optimum growth concentration 3.4–4.3 M NaCl. Optimum pH 7.0–7.6. Gelatin liquefied, starch not hydrolyzed, sulfide and indole not produced. Possess menaquinones MK‐8 and MK‐8(H
2
) and both C
20
C
20
and C
20
C
25
diether core lipids. Possess several unidentified but characteristic glycolipids. Phylogenetically tightly clustered genus (99.1% 16S rRNA sequence similarity between the two species), with two signature sequences (Table A2.25).

The mol
%
G
+
C of the DNA is
: 69.9 (major component) and 60.0 (minor component) but has been identified only for the type species.

Type species
:
Natrinema pellirubrum
McGenity, Gemmell and Grant 1998, 1194.
Natronobacterium
Authors: Tindall Brian J.
Published: July 2015

Na.tro.no.bac.te' ri.um
. arbitrarily derived from the Arabic n.
natrun
soda, salt; Gr. n.
bakterion
a small rod; M.L. neut. n.
Natronobacterium
soda rod.

Euryarchaeota / Halobacteria / Natrialbales / Natrialbaceae / Natronobacterium

Rods
in liquid culture in the exponential phase of growth, usually
0
.
5–1
.
0
×
2–15
μ
m
.
Cells become shorter
in older liquid cultures, while cells are
short rods
to
coccobacilli
or
coccoid
on agar plates (Figure 1). Resting stages are not known.
Gram‐negative
.
Cells lyse rapidly in distilled water
.
Nonmotile
.
Aerobic
.
Growth stimulated by carbohydrates
. Nitrate and nitrite are not reduced. Gelatin hydrolyzed. Starch is not hydrolyzed. Sulfide produced from thiosulfate.
Alkaliphilic
, requiring a pH of at least 8.5 for growth, with an
optimum at pH 9
.
5–10
.
0
. Grows at 2.0– 5.2 M NaCl, with an optimum at 3 M.
Requires only low concentrations of magnesium
(<10 mM), elevated concentrations becoming toxic. Temperature range for growth 25–40°C, with an optimum at 37°C.

Type species
:
Natronobacterium gregoryi
Tindall, Ross and Grant 1984b, 355 (Effective publication: Tindall, Ross and Grant 1984a, 41.)
Natronococcus
Authors: Tindall Brian J.
Published: July 2015

Na.tro.no.coc' cus
. arbitrarily derived from the Arabic n.
natrun
soda, salt; Gr. n.
kokkos
a berry, small rod; M.L. masc. n.
Natronococcus
soda berry.

Euryarchaeota / Halobacteria / Natrialbales / Natrialbaceae / Natronococcus

Cocci
in liquid culture and on plates usually 1.0 × 2.0 µm.
Cells occur in irregular clusters
,
although they may also occur in pairs or singly
. Resting stages are not known.
Gram variable
.
Cells do not lyse rapidly in distilled water
. Nonmotile. Aerobic. Colonies on plates smooth, entire, and
pale brown to red‐orange
.
Growth may be stimulated by carbohydrates
. Nitrate may be reduced, although there is no evidence that this is coupled to growth. Gelatin and starch may be hydrolyzed. Sulfide may be produced from thiosulfate.
Alkaliphilic
, requiring a pH of at least 8.5 for growth, with an
optimum at pH 9
.
5–10
.
0
. Grows at 1.4–5.2 M NaCl, with the optimum in the range 2.5–3 M.
Requires only low concentrations of magnesium
(<10 mM), elevated concentrations becoming toxic. Temperature range for growth 22–50°C, with an optimum in the range 35–45°C.

Type species
:
Natronococcus occultus
Tindall, Ross and Grant 1 9 8 4b, 355 (Effective publication: Tindall, Ross and Grant 1 8 8 4a, 41.)
Methanobrevibacter
Authors: Miller Terry L.
Published: July 2015

Me.tha.no.bre.vi.bac' ter. M.L. neut. n.methanummethane; L. masc. adj.brevisshort; M.L. masc. n.bacterequivalent of Gr. neut. n.bakterionrod, staff; M.L. masc. n.Methanobrevibactershort methane (‐producing) rod.

Euryarchaeota / Methanobacteria / Methanobacteriales / Methanobacteriaceae / Methanobrevibacter

Oval rods or cocci to short rods, usually occurring in pairs or chains; about 0.5–0.7 µm in width and 0.8–1.4 µm in length. Rarely, filaments are formed. Nonsporing, Gram‐positive.Cell walls are composed of pseudomurein. Nonmotile. Strict anaerobes. Optimum temperature, 37–40°C; maximum, ~45°C; minimum, ~30°C.

The mol%G+C of the DNA is: 27.5–31.6.

Type species:Methanobrevibacter ruminantium(Smith and Hungate 1958) Balch and Wolfe 1981, 216 (Effective publication: Balch and WolfeinBalch, Fox, Magrum, Woese and Wolfe, 1979, 284) (Methanobacterium ruminantiumSmith and Hungate 1958, 717).
Methanosphaera
Authors: Miller Terry L.
Published: July 2015

Me.tha.no.sphae' ra
. M.L. neut. n.
methanum
methane; L. fem. n.
sphaera
a sphere; M.L. fem. n.
Methanosphaera
methane‐producing sphere.

Euryarchaeota / Methanobacteria / Methanobacteriales / Methanobacteriaceae / Methanosphaera

Round cells
, usually occurring in pairs, tetrads, and clusters, about 1.0 µm in diameter. Resting cells, such as spores, are not known. Gram positive. Nonmotile. Very strict anaerobe.
Cell walls are composed of pseudomurein
. Optimum temperature: near 37°C. Optimum pH: 6.5–6.9.
Chemoorganotrophic
.

The mol
%
G
+
C of the DNA is
: 23–26.

Type species
:
Methanosphaera stadtmanae
Miller and Wolin 1985b, 535 (Effective publication: Miller and Wolin 1985a, 121.)
Methanothermobacter
Authors: Boone David R.
Published: July 2015

Me.tha.no.ther.mo.bac' ter
. M.L. neut. n.
methanum
methane; Gr. adj.
thermos
hot; M.L. masc. n.
bacter
equivalent of Gr. neut. n.
bakterion
rod, staff; M.L. masc. n.
Methanothermobacter
thermophilic methane rod.

Euryarchaeota / Methanobacteria / Methanobacteriales / Methanobacteriaceae / Methanothermobacter

Curved or crooked slender rods
, moderately long to filamentous, 0.3–0.5 µm wide. Endospores not formed.
Cells stain Gram‐positive
, and ultrastructure appears typically Gram‐positive, but cell walls are composed of pseudomurein.

Nonmotile. Cells produce fimbriae. Strictly anaerobic. Fastest growth between 55°C and 65°C. Energy metabolism by reduction of CO
2
to CH
4
, with H
2
as electron donor

; some cells can also use formate as an electron donor. Sulfur is reduced to sulfide, but this reaction does not yield energy for growth. Ammonia is the sole nitrogen source, and sulfide may serve as sulfur source.

The mol
%
G
+
C of the DNA is
: 32–61.

Type species
:
Methanothermobacter thermautotrophicus
(Zeikus and Wolfe 1972) Wasserfallen, Nölling, Pfister, Reeve and Conway de Macario 2000, 51 (
Methanobacterium thermoautotrophicus
Zeikus and Wolfe 1972, 713).
Methanocaldococcus gen
.
nov
.
Authors: Whitman William B.
Published: July 2015

Me.tha.no.cal.do.coc' cus.
M.L. neut. n.
methanum
methane; L. adj.
caldus
hot; Gr. n.
kokkos
a spherical cell; M.L. masc. n.
Methanocaldococcus
a coccus producing methane at hyperthermophilic growth temperatures.

Euryarchaeota / Methanococcales / Methanococcales / Methanocaldococcaceae / Methanocaldococcus

Regular to irregular coccus, 1–3 µm in diameter. Cells stain Gram‐negative and lyse rapidly in dilute solutions of sodium dodecyl‐sulfate.
Motile
,
by means of polar tufts of flagella
.
Obligately anaerobic
.
Hyperthermophilic
(temperature optima: 80–85°C). pH optimum between 5.2 and 7.6. NaCl required for growth, optimal concentration 2–4% (w/v).
Obligately methanogenic
;

H
2
serves as the electron donor

.
Formate
,
acetate
,
methanol
,
and methylamines are not substrates for methanogenesis
. Grows autotrophically in mineral medium; complex carbon sources are sometimes stimulatory. Nitrogen sources include ammonium, nitrate, and N
2
gas. Sulfur sources include sulfide and S
0
. Isolated from deep‐sea hydrothermal vents and surrounding sediments.

The mol
%
G
+
C of the DNA is
: 31–33.

Type species
:
Methanocaldococcus jannaschii
comb. nov. (
Methanococcus jannaschii
Jones, Leigh, Mayer, Woese and Wolfe 1983a, 260).
Methanotorris gen. nov.
Authors: Whitman William B.
Published: July 2015

Me.tha.no.tor' ris
. M.L. neut. n.
methanum
methane; L. masc. n.
torris
fire; M.L. masc. n.
Methanotorris
the methane‐producer at fiery temperatures.

Euryarchaeota / Methanococcales / Methanococcales / Methanocaldococcaceae / Methanotorris

Regular to irregular coccus, 1.3–1.8 µm in diameter.
Nonmotile. Obligate anaerobic. Hyperthermophilic
(temperature optimum: 88°C). pH optimum 5.7. NaCl required for growth, optimal concentration 1.8% (w/v).

Obligate methanogen; H
2
serves as the electron donor. Formate, acetate, methanol, and methylamines are not substrates for methanogenesis

. Grows autotrophically in mineral medium. Complex carbon sources are not stimulatory. Nitrogen sources include ammonium. Sulfur sources include sulfide and elemental sulfur. Isolated from deep‐sea and shallow marine hydrothermal systems.

The mol
%
G
+
C of the DNA is
: 31.

Type species
:
Methanotorris igneus
comb. nov. (
Methanococcus igneus
Burggraf, Fricke, Neuner, Kristjansson, Rouvière, Mandelco, Woese and Stetter 1990a, 268).
Methanocorpusculum
Authors: Chong Song C. , Boone David R.
Published: July 2015

Me.tha.no.cor.pus' cu.lum
. M.L. neut. n.
methanum
relating to methane; L. neut. n.
corpusculum
a particle; M.L. neut. n.
Methanocorpusculum
a methane‐producing particle.

Euryarchaeota / Methanomicrobiales / Methanomicrobiales / Methanocorpusculaceae / Methanocorpusculum

Small, irregular cocci
, <2 µm in diameter. Endospores not formed. Stain Gram‐negative. Lysed by detergent or hypotonic shock.
Nonmotile or very weakly motile. Strictly anaerobic. Fastest growth at 30–40°C, neutral pH, and NaCl concentration of 0.1–0.25 M
. Energy production by reduction of CO
2
to CH
4
, with H
2
, formate, and sometimes secondary alcohols as electron donors; acetate or methylamines are not catabolized.
Acetate and either yeast extract, peptones, or rumen fluid are required
as carbon and nitrogen sources. Sulfide serves as a sulfur source. May be found in anaerobic digestors or anoxic lake sediments.

Type species
:
Methanocorpusculum parvum
Zellner, Alten, Stackebrandt, Conway de Macario and Winter 1988, 136 (Effective publication: Zellner, Alten, Stackebrandt, Conway de Macario and Winter 1987, 18).
Methanoculleus
Authors: Chong Song C. , Boone David R.
Published: July 2015

Me.tha.no.cul' le.us
. M.L. neut. n.
methanum
methane; L. n.
culleus
bag; M.L. masc. n.
Methanoculleus
methane producing.

Euryarchaeota / Methanomicrobiales / Methanomicrobiales / Methanomicrobiaceae / Methanoculleus

Cells are irregular coccoids, 0.5–2.0 μm in diameter, occurring singly or pairs
. Stain Gram‐negative.
Does not form spores
. Cell wall is protein (S‐layer of glycoprotein subunits), sensitive to lysis by detergents.
Thermophilic or mesophilic
. Rapid growth at NaCl concentration of 0.1–0.2

M. Chemolithotrophic, strictly anaerobic, utilizing H
2
/CO
2

. All species but
Methanoculleus olentangyi
grow on formate, and some grow on secondary alcohols/CO
2
, with
methane as a catabolic product
. Nonmotile, but flagella and fimbriae may occur. Most rapid growth between 20 and 45°C and between pH 6.2 and 8.0. Habitat is anaerobic digestors, anoxic lake sediments, or sea sediments.

The mol
%
G
+
C of the DNA is
: 49–61.

Type species
:
Methanoculleus bourgensis
corrig. (Ollivier, Mah, Garcia and Boone 1986) Maestrojuán, Boone, Xun, Mah and Zhang 1990, 121
VP
(
Methanogenium bourgense
Ollivier, Mah, Garcia and Boone 1 9 8 6, 300).
Methanofollis
Authors: Zellner Gerhard , Boone David R.
Published: July 2015

Me.tha.no.fol' lis
. M.L. masc. n.
methanum
methane; L. masc. n.
follis
bag; M.L. masc. n.
Methanofollis
methane‐producing bag.

Euryarchaeota / Methanomicrobiales / Methanomicrobiales / Methanomicrobiaceae / Methanofollis

Irregular cocci, occurring singly, 1.5–3.0 μm in diameter
. Cells lysed by the addition of 1% SDS (w/v) because of its proteinaceous S‐layer composed of hexagonally arranged glycoprotein subunits with an apparent molecular mass of 118–120 kDa. Gram‐negative.
Some strains are motile
. Capsules are not formed. Endospores are not produced. Obligately anaerobic, no microaerophilic or aerobic growth. Mesophilic (range 20–44°C, optimal temperature 37–40°C). Optimum pH for growth is about 7.0 (pH range 6.3–8.8). Chemolithotrophic; substrates for growth and methane production are H
2
/CO
2
or formate; some species may use 2‐propanol/CO
2
, 2‐butanol/CO
2
, and cyclopentanol/CO
2
. Sulfate is not reduced. Acetate is a required organic carbon source. Species may have no other complex nutrient requirements or may have several (usually fulfilled by yeast extract). NaCl may be required by strains or may be stimulatory for growth. Growth of cells is usually promoted by supplementation of medium with 1 to 2 μM tungstate.

The mol
%
G
+
C of the DNA is
: 54–60 (

T
m

).

Type species
:
Methanofollis tationis
(Zabel, König and Winter 1 9 8 4) Zellner, Boone, Keswani, Whitman, Woese, Hagelstein, Tindall and Stackebrandt 1 9 9 9, 253 (
Methanogenium tatii
Zabel, König and Winter 1 9 8 4, 313).
Methanolacinia
Authors: Chong Song C. , Boone David R.
Published: July 2015

Me.tha.no.la.ci' ni.a
. M.L. neut. n.
Methanum
methane; L. fem. n.
lacinia
a lobe, to indicate the irregular lobed shape of the organism.

Euryarchaeota / Methanomicrobiales / Methanomicrobiales / Methanomicrobiaceae / Methanolacinia

Small,
irregular rods
, 0.6 × 1.5–2.5 µm, occurring singly. Colonies are translucent and off‐white.
Endospores not formed
. Stain Gram‐negative.
Susceptible to lysis by detergent
. Nonmotile, although flagella are present.
Strictly anaerobic
. The cells grow fastest at a sodium ion concentration of 0.15 M (growth range 0–0.8 M). Growth is fastest at pH 7.0 (range 6.6–7.3) and mesophilic temperature (40°C).

Energy metabolism is by reduction of CO
2
to CH
4
with H
2

(
or secondary alcohols
)
as electron donor
. Acetate, formate, methylamines, methanol, and methanol/H
2
are not catabolized. Ammonia can serve as the sole nitrogen source, and sulfide can serve as a sulfur source; acetate is required as a carbon source.

The mol
%
G
+
C of the DNA is
: 38–44.9.

Type species
:
Methanolacinia paynteri
(Rivard, Henson, Thomas and Smith 1983) Zellner, Messner, Kneifel, Tindall, Winter and Stackebrandt 1990b, 470 (Effective publication: Zellner, Messner, Kneifel, Tindall, Winter and Stackebrandt 1989b, 199) (
Methanomicrobium paynteri
Rivard, Henson, Thomas and Smith 1983, 486).
Methanomicrobium
Authors: Zellner Gerhard
Published: July 2015

Me.tha.no.mi.cro' bi.um
. M.L. neut. n.
methanum
methane; Gr. adj.
micros
small; Gr. n.
bios
life; M.L. neut. n.
Methanomicrobium
methane (‐producing) small life (‐form).

Euryarchaeota / Methanomicrobiales / Methanomicrobiales / Methanomicrobiaceae / Methanomicrobium

Short, straight to slightly curved, irregular rods
, 0.6–0.7 µm wide and 1.5–2.5 µm long, with rounded ends. Morphology may be influenced by substrate availability, becoming coccoid (0.5–1.0 µm in diameter) under starvation conditions.
Cells occur singly and in pairs but not in chains
. Capsules are not formed. Endospores are not produced. Gram negative. Species may be motile, with monotrichous polar flagellation, or nonmotile. Strictly anaerobic. Growth between 25 and 45°C with an optimum at 40°C. Growth and methanogenesis occur from pH 5.9 to 7.7 with an optimum between 6.1 and 7.0.

H
2
/CO
2
and formate serve as substrates for methanogenesis and growth

. Acetate is a required nutrient. Species may have no other requirements for organic nutrients or may have several. A heat‐stable cofactor present in clarified rumen fluid and in cell extracts of
Methanothermobacter thermautotrophicus
is required for growth. This requirement could be satisfied by addition of 7‐mercaptoheptanoylthreonine phosphate.

The mol
%
G
+
C of the DNA is
: 48.8.

Type species
:
Methanomicrobium mobile
(Paynter and Hungate 1968) Balch and Wolfe 1981, 216 (Effective publication: Balch and Wolfe
in
Balch, Fox, Magrum, Woese and Wolfe 1979, 286) (
Methanobacterium mobilis
Paynter and Hungate 1968, 1943).
Methanoplanus
Authors: Huber Harald , Huber Gertrud , Stetter Karl O.
Published: July 2015

Me.tha.no.pla' nus
. M.L. neut. n.
methanum
methane; L. masc. adj.
planus
flat; M.L. masc. n.
Methanoplanus
the methane (‐producing) plate.

Euryarchaeota / Methanomicrobiales / Methanomicrobiales / Methanomicrobiaceae / Methanoplanus

Cells are angular, crystal‐like plates or disc shaped
. They are 1–3.5 µm long, 1–2 µm wide, and only 0.07–0.3 µm thick (Figures 1 and 2).
They occur singly or in pairs and are sometimes branched
, without septa. Stain Gram‐negative. Flagella or pilus‐like structures are found.

Strictly anaerobic. Chemolithotrophic growth on H
2
and CO
2
or formate

. One species can use CO
2
and 2‐propanol as an energy source for growth and
methane formation
. No growth on methanol or methylamines. On molecular hydrogen in the presence of S
0
, H
2
S is formed in addition to methane. The organisms are
mesophilic
with optimum growth temperatures between 32 and 40°C at neutral pH. Based on 16S rRNA sequence data,
Methanoplanus
belongs to the family
Methanomicrobiaceae
.

The mol
%
G
+
C of the DNA is
: 39–50.

Type species
:
Methanoplanus limicola
Wildgruber, Thomm and Stetter 1984, 270 (Effective publication: Wildgruber, Thomm and Stetter
in
Wildgruber, Thomm, König, Ober, Ricciuto and Stetter 1982, 36).
Methanospirillum
Authors: Ferry James G. , Boone David R.
Published: July 2015

Me.tha.no.spi.ril' lum. M.L. neut. n.methanummethane; Gr. n.speiraa spiral; M.L. neut. n.Methanospirillummethane (‐producing) spiral.

Euryarchaeota / Methanomicrobiales / Methanomicrobiales / Methanospirillaceae / Methanospirillum

Symmetrically curved rods0.4–0.5 × 7.4–10 µm that often form wavy filaments from 15 to several hundred µm in length. Stain Gram‐negative. Progressivelymotileby means of polar, tufted flagella.Strictly anaerobic. Fastest growth at 30–37°C. Fixes N2. Energy metabolism by reduction of CO2to CH4with formate or H2as electron donors. Capable of autotrophic growth, but exogenous organic compounds may be used when present.

The mol%G+C of the DNA is: 45–49.5.

Type species:Methanospirillum hungateiiFerry, Smith and Wolfe 1974, 469 (Methanospirillum hungatii[sic] Ferry, Smith and Wolfe 1974, 469).
Methanococcoides
Authors: Sowers Kevin R.
Published: July 2015

Me
.
tha
.
no
.
coc
.
co
'
i
.
des
. Gr. adj. suff. ‐
oides
similar to; M.L. neut. n.
Methanococcoides
organism similar to
Methanococcus
.

Euryarchaeota / Methanosarcinales / Methanosarcinales / Methanosarcinaceae / Methanococcoides

Irregular cocci
, 0.8–1.8 µm in diameter; occurring singly or in pairs. If motility is observed, it is by a monotrichous flagellum.
Strictly anaerobic
. Temperature range: 1.7–35°C; optimum: 23–35°C.
Slightly halophilic
, with optimal growth near 0.2 M NaCl. Mg
2+
is required for growth, as MgSO
4
or MgCl
2
at concentrations greater than 0.01 M.
Trimethylamine
,
dimethylamine
,
methylamine
,
and methanol are substrates for growth
and methanogenesis;
acetate
,
dimethylsulfide
,
formate
,

and H
2

/

CO
2
are not

.

The mol
%
G
+
C of the DNA is
: 40–42.

Type species
:
Methanococcoides methylutens
Sowers and Ferry 1985b, 223 (Effective publication: Sowers and Ferry 1983, 688).
Methanohalophilus
Authors: Boone David R.
Published: July 2015

Me.tha.no.ha.lo' phi.lus
. M.L. neut. n.
methanum
methane; Gr. masc. n.
hals, halos
salt; Gr. adj.
philos
loving; M.L. masc. n.
Methanohalophilus
salt‐loving methanogen.

Euryarchaeota / Methanosarcinales / Methanosarcinales / Methanosarcinaceae / Methanohalophilus

Irregular cocci
, ~1 µm in diameter, occurring singly or in small clumps. Nonmotile. Does not form endospores. Stain Gram‐negative.
Lysed by detergents or hypotonic shock
. Surface colonies are cream to pale yellow, circular, with entire edges.

Type species
:
Methanohalophilus mahii
Paterek and Smith 1988, 122.
Methanosalsum gen. nov
.
Authors: Boone David R. , Baker Chad C.
Published: July 2015

Me.tha.no.sal' sum
. M.L. neut. n.
methanum
methane; L. neut. part. adj.
salsum
salted, salty; M.L. neut. n.
Methanosalsum
the salty methane (bacterium).

Euryarchaeota / Methanosarcinales / Methanosarcinales / Methanosarcinaceae / Methanosalsum

The generic description is based on that of the type species,
Methanosalsum zhilinae
(
Methanohalophilus zhilinae
Mathrani, Boone, Mah, Fox and Lau, 1988, 141). Additional material supplied by Kevbrin et al. (1997).

The mol
%
G
+
C of the DNA is
: 38–39.5.

Type species
:
Methanosalsum zhilinae
comb. nov. (
Methanohalophilus zhilinae
Mathrani, Boone, Mah, Fox and Lau 1988, 141).
Methanosarcina
Authors: Boone David R. , Mah Robert A.
Published: July 2015

Me.tha.no.sar' ci.na. M.L. neut. n.methanummethane; L. fem. n.sarcinaa package, bundle; M.L. fem. n.Methanosarcinamethane sarcina.

Euryarchaeota / Methanosarcinales / Methanosarcinales / Methanosarcinaceae / Methanosarcina

Irregularspheroid bodies(1–3 µm in diameter), occurring alone or typically inaggregates of cells(aggregates up to 1000 µm in diameter). Sometimes occur aslarge cystswith a common outer wall surrounding individual coccoid cells. Refer to Figures 1, 2, and 3 for typical morphologies. Endospores not formed. Gram stain results are variable.Nonmotile. May contain gas vesicles (Figure 4).Strictly anaerobic. Optimum growth temperatures are 30–40°C for mesophilic species and 50–55°C for thermophiles. Energy metabolism via formation ofmethane from acetate, methanol, monomethylamine, dimethylamine, trimethylamine, H2/CO2, and CO. Some strains do not use H2/CO2as the sole energy substrate. May grow very slowly on pyruvate. N2may be fixed.

The mol%G+C of the DNA is: 36–43.

Type species:Methanosarcina barkeriSchnellen 1947, 73 (Nom. Cons., Opinion 63 of the Jud. Comm. 1986b, 492).
Methanopyrus
Authors: Huber Robert , Stetter Karl O.
Published: July 2015

Me.tha.no.py' rus
. M.L. neut. n.
methanum
methane; Gr. neut. n.
pyr
fire; M.L. masc. n.
Methanopyrus
the “methane fire” (the hyperthermophilic methanogen).

Euryarchaeota / Methanopyri / Methanopyrales / Methanopyraceae / Methanopyrus

Rod‐shaped
cells, usually occurring singly and in chains, about 2–14 µm long and 0.5 µm in diameter (Figures 1, 2). Non‐sporulating.
Cell division by septum formation
. Double‐layered surface coat. Cell wall composed of pseudomurein.
AB
′
B
″
C subunit pattern of the DNA‐dependent RNA polymerase
.
2
,
3‐di
‐

O

‐
phytanyl
‐

sn

‐
glycerol and 2
,
3‐di
‐

O

‐
geranylgeranyl
‐

sn

‐
glycerol present in the lipids
. Gram positive. Motile.
Obligately anaerobic
.
Hyperthermophilic
, optimum growth temperature, 98°C; maximum, 110°C; minimum, 84°C. No growth at 80°C or below. Growth between 0.2 and 4% NaCl; optimum, 2% NaCl. Growth between pH 5.5 and 7; optimum, pH 6.5. Chemolithoautotrophic.

Energy for growth is obtained by reduction of CO
2
to CH
4
by using H
2
as the electron donor

.
Formate
,
acetate
,
methanol
,
methylamine
,
propanol
,

l

(+)‐
lactate
,

and glycerol are not used as electron donors for CH
4
formation

. Epifluorescence at 420 nm. Cyclic 2,3‐diphosphoglycerate present in high concentrations. Sulfur reduced to H
2
S, causing cell lysis. Based on 16S rDNA analysis, a separate and very deeply branching lineage within the euryarchaeal side of the archaeal tree.

The mol
%
G
+
C of the DNA is
: 59–60.

Type species
:
Methanopyrus kandleri
Kurr, Huber, König, Jannasch, Fricke, Trincone, Kristjansson and Stetter 1992, 327 (Effective publication: Kurr, Huber, König, Jannasch, Fricke, Trincone, Kristjansson and Stetter 1991, 245.)
Thermococcus
Authors: Kobayashi Tetsuo
Published: July 2015

Ther.mo.coc' cus
. Gr. fem. n.
therme
heat; Gr. masc. n.
kokkos
berry; M.L. masc. n.
Thermococcus
berry existing in hot environment.

Euryarchaeota / Thermococci / Thermococcales / Thermococcaceae / Thermococcus

Regular to irregular cocci occurring singly and in pairs
, 0.7–2.5 µm in diameter (Figure 1).
Cell division by constriction
. Non‐motile or
motile with polar tufts of flagella. Strictly anaerobic. Extremely thermophilic with optimal temperatures for growth between 75 and 88°C
; maximum 103°C; minimum 50°C. Optimum pH: 6–8; maximum 9; minimum 3.
NaCl is required for growth, with optimal concentrations between 2 and 4
%; maximum 8; minimum 0.8.
Obligately heterotrophic growth on peptides
. Some species also utilize carbohydrates.

Elemental sulfur significantly stimulates growth rates with production of H
2
S

. Some species require elemental sulfur for growth.

The mol% G + C of the DNA is 46.5–58 (Bd,

T
m

, and HPLC).

Type species
:
Thermococcus celer
Zillig 1983, 673 (Effective publication: Zillig
in
Zillig, Holz, Janekovic, Schäfer and Reiter 1983b, 93.)
Picrophilus
Authors: Reysenbach Anna‐Louise , Zillig Wolfram
Published: July 2015

Pi.cro.phi' lus
. Gr. adj.
pikros
acidic; Gr. adj.
philos
loving; M.L. masc. n.
picrophilus
acid‐loving organism.

Euryarchaeota / Thermoplasmata / Thermoplasmatales / Picrophilaceae / Picrophilus

Thermophilic
,
hyperacidophilic
,
obligately aerobic irregular
cocci about 1 µm in diameter.
Nonmotile
. Divides by constriction. Filigreed tetragonal S‐layer present. Grows heterotrophically in the presence of 0.1–0.5% yeast extract. No growth occurs on organic substrates in the absence of yeast extract.
Growth occurs between 47 and 60
°
C and between pH 0 and 3
.
5
.

The mol
%
G
+
C of the DNA is
: 36.

Type species
:
Picrophilus oshimae
Schleper, Zillig and Pülher
in
Schleper, Pülher, Klenk and Zillig 1996, 815.
Alkalibacillus
Authors: Vos Paul De
Published: July 2015

Al.ka.li.ba.cil'lus. N.L. n.
alkali
alkali; L. n.
bacillus
rod; N.L. masc. n.
Alkalibacillus
bacillus living under alkaline conditions.

Firmicutes / “Bacilli” / Bacillales / Bacillaceae / Alkalibacillus

Rod‐shaped, Gram‐positive (may be Gram‐variable in older cultures) bacterium. Mostly long cells, 0.8–1.6 µm in diameter and 2.0–7.0 µm in length. Endospores are spherical and located terminally in swollen sporangia. Cell‐wall peptidoglycan is of the A1γ type and
meso
‐diaminopimelic acid is the diamino acid. Obligately aerobic. Cells are motile by peritrochous or polar flagella. MK‐7 is always present as the major isoprenoid quinone; in one species, DeMK‐6 is also found. The predominant fatty acids are C
15:0 iso
, C
15:0 ante
, and C
17:0 ante
. Phylogenetically, the genus belongs to the family
Bacillaceae
.

DNA G
+
C content
(
mol
%): 37–41.

Type species
:
Alkalibacillus haloalkaliphilus
(Fritze 1996a) Jeon, Lim, Lee, Xu, Jiang and Kim 2005b, 1894
VP
(
Bacillus haloalkaliphilus
Fritze 1996a, 100).
Amphibacillus
Authors: Niimura Youichi , Suzuki Ken‐ichiro
Published: July 2015

Am.phi.ba.cil'lus. Gr. pref.
amphi
both sides or double; L. dim. n.
bacillus
a small rod; N.L. masc. n.
Amphibacillus
rod capable of both aerobic and anaerobic growth.

Firmicutes / “Bacilli” / Bacillales / Bacillaceae / Amphibacillus

Cells are rods, occurring singly, in pairs or, sometimes, in short chains. Gram‐positive, or Gram‐positive in the very early stages of growth and loosely Gram‐positive in the stationary growth phase. Cells are motile by means of flagella or nonmotile. Heat‐resistant. Oval endospores are formed in terminal or center position, but sometimes sporangia are rapidly lysed and the spores are liberated. Growth is good in both well‐aerated and strictly anaerobic liquid media, and also on aerobic agar plates and anaerobic plates. Cell yields and growth rates are almost the same under all these conditions. Growth does not occur in the absence of glucose under either aerobic or anaerobic conditions. Chemo‐organotrophic. Main products from glucose are ethanol, acetic acid, and formic acid under anaerobic conditions and acetic acid under aerobic conditions. Lactic acid is sometimes produced under aerobic and anaerobic conditions. Alkaliphilic, sometimes halophilic or halotolerant. Respiratory quinones, cytochromes, and catalase are absent. Located within the phylogenetic group composed of halophilic/halotolerant/alkaliphilic and/or alkalitolerant genera in
Bacillus
rRNA group 1.

DNA G
+
C content
(
mol
%): 36–41.5 (
T
m
).

Type species
:
Amphibacillus xylanus
Niimura, Koh, Yanagida, Suzuki, Komagata and Kozaki 1990, 300
VP
.
Anoxybacillus
Authors: Pikuta Elena V.
Published: July 2015

An.o.xy.ba.cil'lus. Gr. pref.anwithout; Gr. adj.oxysacid or sour and in combined words indicating oxygen; L. masc. n.bacillussmall rod; N.L. masc. n.Anoxybacillussmall rod living without oxygen

Firmicutes / “Bacilli” / Bacillales / Bacillaceae / Anoxybacillus

Cells are rod‐shaped and straight or slightly curved, sometimes with angular division and Y‐shaped cells, 0.4–1.5 × 2.5–9.0 µm in size, often in pairs or short chains, with rounded ends. Gram‐positive. Motile or nonmotile. Endospores are round, oval or cylindrical and resistant to heating and freezing. Spores are located at the end of the cells. There is not more than one spore per cell. Aerobes, facultative aerobes or facultative anaerobes; catalase‐variable. Alkaliphilic, alkalitolerant or neutrophilic, moderately thermophilic. Chemoorganotrophic, with a fermentative or oxygen respiration metabolism.

DNA G+C content(mol%): 42–57.

Type species:Anoxybacillus pushchinoensiscorrig. Pikuta Lysenko, Chuvilskaya, Mendrock, Hippe, Suzina, Nikitin, Osipov and Laurinavichius 2000a, 2116VPemend. Pikuta, Cleland and Tang 2003a, 1561.