bluuebunny/crossref_metadata_2025 huggingface dataset:
Olleya
Authors:   The Editorial Board
Published: August 2015

Ol.ley'a. N.L. fem. n.
Olleya
named in honor of June Olley, who has made significant contributions to the area of predictive microbiology.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Olleya

Rods
,
approximately 0
.
3–0
.
5
×
2
.
0–2
.
5
μ
m
.
Motile by gliding
. Endospores are not formed. Gram‐stain‐negative. Cell mass is orange/yellow. Flexirubin pigments are absent. Growth occurs at 4–30°C, but not at 37°C. Strictly aerobic. Chemoheterotrophic. Catalase‐positive.
Oxidase‐positive
.
NaCl or sea salts are required for growth
.
Acid is produced from carbohydrates
. β‐Galactosidase activity is not present.
Agar and starch are not hydrolyzed
. The major fatty acids include C
15:1
iso ω10
c
, C
15:0
iso, C
15:0
iso β‐OH, C
15:1
anteiso ω10
c
, C
15:0
, and C
15:0
iso α‐OH.

DNA G
+
C content
(
mol
%): 49 (
T
m
).

Type species
:
Olleya marilimosa
Mancuso Nichols, Bowman and Guezennec 2005, 1560
VP
.
Ornithobacterium
Authors: Hafez Hafez M. , Vandamme Peter
Published: August 2015

Or.ni.tho.bac.te'ri.um. Gr. n.
ornis ‐ithos
bird; L. neut. n.
bacterium
rod; N.L. neut. n.
Ornithobacterium
bird bacterium, because it was first isolated from birds.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Ornithobacterium

Cells are pleomorphic rods, 0.2–0.4 × 1.3 µm. Gram‐stain‐negative.
Nonsporeforming. Nonmotile
. Metabolism is
chemoorganotrophic
and
mesophilic
. Growth occurs at 30–42°C.
Ornithobacterium
strains grow in various atmospheric conditions, but preferentially
microaerobically
.
Ornithobacterium
strains exhibit various levels of capnophilic metabolism. Colonies are not pigmented on common growth media.
Oxidase‐positive. Catalase‐negative
. β‐
Galactosidase
(
ONPG
)‐
positive
. Most strains are urease‐positive.
Indole‐negative. Nitrate is not reduced to nitrite
. This genus has been referred to as
Pasteurella
‐like,
Kingella
‐like, or pleomorphic Gram‐stain‐negative rod (PGNR); the name TAXON 28 has also been used.
Ornithobacterium
strains cause respiratory disease in avian species worldwide.

DNA G
+
C content
(
mol
%): 37–39.

Type species
:
Ornithobacterium rhinotracheale
Vandamme, Segers, Vancanneyt, Van Hove, Mutters, Hommez, Dewhirst, Paster, Kersters, Falsen, Devriese, Bisgaard, Hinz and Mannheim 1994b, 35
VP
.
Ulvibacter
Authors: Nedashkovskaya Olga I. , Kim Seung Bum
Published: August 2015

Ul.vi.bac'ter. N.L. fem. n.
Ulva
generic name of the green alga
Ulva fenestrata
; N.L. masc. n.
bacter
from Gr. n.
bakterion
rod; N.L. masc. n.
Ulvibacter
rod isolated from
Ulva fenestrata
.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Ulvibacter

Thin rods
, usually measuring 0.4–0.5 × 2.5–7.3 µm.
No gliding motility occurs
. Produce non‐diffusible yellow–orange pigments.
Flexirubin pigments are produced
.
Chemo‐organotrophs
.
Strictly aerobic
. Positive for oxidase, catalase, and alkaline phosphatase. Gelatin, Tweens 20 and 40, and DNA are hydrolyzed, but agar, alginate, casein, starch, chitin, and cellulose (carboxymethylcellulose and filter paper) are not hydrolyzed. Carbohydrates are not oxidized or utilized. Growth does not occur without seawater or Na
+
.
The major respiratory quinone is MK‐6
.
Marine
, isolated from coastal seaweeds.

DNA G
+
C content
(
mol
%): 36–38.

Type species
:
Ulvibacter litoralis
Nedashkovskaya, Kim, Han, Rhee, Lysenko, Falsen, Frolova, Mikhailov and Bae 2004c, 121
VP
.
Vitellibacter
Authors: Nedashkovskaya Olga I. , Suzuki Makoto , Mikhailov Valery V.
Published: August 2015

Vi.tel.li.bac'ter. L. n.
vitellus
egg yolk; N.L. masc. n.
bacter
rod; N.L. masc. n.
Vitellibacter
egg‐yolk‐colored rod.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Vitellibacter

Thin rods
, usually measuring 0.3–0.5 × 3–10 µm.
No gliding motility
. Produce nondiffusible, bright orange pigments. Flexirubin‐type pigments are formed.
Chemo‐organotrophs
.
Strictly aerobic
. Positive for oxidase, catalase, and alkaline phosphatase. Gelatin, casein, DNA, and Tweens 20 and 40 are hydrolyzed, but agar, alginate, starch, urea, chitin, and cellulose (carboxymethylcellulose and filter paper) are not attacked.
Marine
, from coastal habitats. Growth does not occur without seawater or Na
+
.
The major respiratory quinone is MK‐6
.
The main cellular fatty acids
are branched‐chain saturated fatty acids C
15:0
iso and C
15:0
anteiso.

DNA G
+
C content
(
mol
%): 41–42.

Type species
:
Vitellibacter vladivostokensis
Nedashkovskaya, Suzuki, Vysotskii and Mikhailov 2003c, 1285
VP
.
Weeksella
Authors:   The Editorial Board
Published: August 2015

Weeks.el'la. N.L. dim. ending ‐
ella
; N.L. fem. n.
Weeksella
named after Owen B. Weeks for his contributions to the taxonomy of the genus
Flavobacterium
.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Weeksella

Rods
with parallel sides and rounded ends, typically 0.6 µm wide and 2–3 µm long. Intracellular granules of poly‐β‐hydroxybutyrate are absent. Endospores are not formed. Gram‐stain‐negative.
Nonmotile
. Do not glide or spread.
Aerobic
, having a strictly respiratory type of metabolism.
Grow at temperatures from 18 to 42
°
C
.
Growth on solid media is not pigmented
.
Catalase‐ and oxidase‐positive
.
Urease‐negative
.
Growth occurs on MacConkey agar and
β‐
hydroxybutyrate agar
. Casein is digested. Agar is not digested. Chemo‐organotrophic.
Nonsaccharolytic
.
Indole is produced
. Not found in the general environment, but seem to be parasites, saprophytes, or commensals of the internal surfaces of man and other warm‐blooded animals.

DNA G
+
C content
(
mol
%): 35–38 (
T
m
).

Type species
:
Weeksella virosa
Holmes, Steigerwalt, Weaver and Brenner 1987, 179
VP
(Effective publication: Holmes, Steigerwalt, Weaver and Brenner 1986b, 185.).
Yeosuana
Authors:   The Editorial Board
Published: August 2015

Yeo.su.a'na. N.L. fem. n.
Yeosuana
named after Yeosu City, where the type strain of the type species was isolated.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Yeosuana

Rods
,
0
.
2–0
.
3
×
0
.
7–1
.
7
μ
m
. Nonmotile.
No gliding motility
. Gram‐stain‐negative. Colonies are yellowish‐brown due to carotenoid pigments. Flexirubin type pigments are not produced. Temperature range for growth, 23–39°C; optimum, 33–46°C.
Requires 0
.
5–4
.
0
%
NaCl
;
optimum
,
2
.
0
%.

Growth does not occur without supplementation with either CaCl
2
or MgCl
2

,
even in the presence of NaCl
. Yeast extract is not required for growth.
Aerobic
.
Oxidase‐negative
. Catalase is weakly positive.
Nitrate is not reduced
.

Indole and H
2
S are not produced

.
Gelatin is hydrolyzed
,
but not urea
,
agar
,
casein
,
or starch
.
Acid is not produced from carbohydrates
. Major cellular fatty acids are straight‐chain and branched‐chain unsaturated fatty acids. Major respiratory quinones are MK‐5 and MK‐6.

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

Type species
:
Yeosuana aromativorans
Kwon, Lee, Jung, Kang and Kim 2006a, 731
VP
.
Zobellia
Authors: Nedashkovskaya Olga I. , Suzuki Makoto
Published: August 2015

Zo.bel'li.a. N.L. fem. n.
Zobellia
named after C.E.
ZoBell
, who isolated and characterized numerous marine bacteria, notably [
Cytophaga
]
uliginosa
in 1944, and for his general contribution to the taxonomy of marine bacteria.

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Zobellia

Rod‐shaped cells
with rounded ends,
0
.
3–0
.
5
×
1
.
2–8
.
0
μ
m
.
Motile by gliding
. Produce non‐diffusible yellow–orange carotenoid pigments. Flexirubin‐type pigments are produced.
Chemoorganotrophs
.
Strictly aerobic
.
The major respiratory quinone is MK‐6
.
The main polar lipid is phosphatidylethanolamine
. Positive for oxidase, catalase, β‐galactosidase, and alkaline phosphatase. Arginine dihydrolase, lysine decarboxylase, ornithine decarboxylase, and urease are not produced. H
2
S, indole, and acetoin are not produced. Agar and gelatin are hydrolyzed; hydrolysis of casein, gelatin, starch, alginate, chitin, DNA, and Tweens varies among species.
Marine
, isolated from coastal habitats. Require seawater or Na
+
for growth.

DNA G
+
C content
(
mol
%): 36–44 (
T
m
).

Type species
:
Zobellia galactanivorans
(Barbeyron, Gerard, Potin, Henrissat and Kloareg 1998) corrig. Barbeyron, L'Haridon, Corre, Kloareg and Potin 2001, 994
VP
(
Cytophaga drobachiensis
Barbeyron, Gerard, Potin, Henrissat and Kloareg 1998, 528).
Saprospira
Authors: Lewin Ralph A.
Published: August 2015

Sap.ro.spi'ra. Gr. adj.
sapros
rotten, putrid; L. fem. n.
spira
a spiral; N.L. fem. n.
Saprospira
spiral associated with decaying matter.

Bacteroidetes / Sphingobacteriia / Sphingobacteriales / Saprospiraceae / Saprospira

The following generic description is modified from Reichenbach (1 9 8 9).
Helical filaments 10–500
μ
m long and 0
.
5–3
μ
m wide, multicellular
, unbranched, without sheaths.
Cells 1
.
5–3
.
5
μ
m in length
. Gram‐stain‐negative. Non‐flagellate.
Move by gliding
in either longitudinal direction at speeds up to 180 µm/min, simultaneously rotating around their long axes. Resting stages not known.
Colonies on agar surfaces are spreading; they may exhibit a regular pattern of stripes. Strictly aerobic organotrophs
requiring amino acids. Pigmentation is by carotenoids – pink, yellow, orange, or red. Aquatic, marine, or freshwater, on surfaces or in bottom sediments.

DNA G
+
C content
(
mol
%): 33–48 (Bd,
T
m
).

Type species
:
Saprospira grandis
Gross 1 9 1 1, 202
AL
.
Criblamydia
Authors: Horn Matthias
Published: August 2015

Crib.la.my'di.a. N.L. fem. n.
Cribia
arbitrary name derived from the abbreviation CRIB (Center for Research on Intracellular Bacteria); N.L. fem. n.
Chlamydia
taxonomic name of a bacterial genus; N.L. fem. n.
Criblamydia
arbitrary name intended to mean a
Chlamydia
named after
CRIB
.

Chlamydiae / Chlamydiia / Chlamydiales / Criblamydiaceae / Criblamydia

Coccoid to pleomorphic, nonmotile, obligately intracellular bacteria, 0.5–1 μm in diameter
. Cells show a
developmental cycle
with morphologically distinct stages and
grow within host‐derived vacuoles
. Organisms are differentiated from all other chlamydiae by the
star‐shaped elementary body
seen with transmission electron microscopy (Figure 1). The genus
Criblamydia
contains a single species,
Criblamydia sequanensis
(Figure 2), which has been recovered from a water sample from the river Seine (France) by co‐cultivation with
Acanthamoeba castellanii
ATCC 30010 (Thomas et al., 2006).

Type species
:
Criblamydia sequanensis
Thomas, Casson and Greub 2006, 2131.
“
Candidatus Fritschea
”
Authors: Horn Matthias
Published: August 2015

Fri'tsche.a. N.L. fem. n.
Fritschea
named after Thomas R. Fritsche, an American physician and parasitologist, in honor of his contributions to our current knowledge on chlamydial diversity.

Chlamydiae / Chlamydiia / Chlamydiales / Simkaniaceae / “Candidatus Fritschea”

Coccoid to rod‐shaped, nonmotile, obligately intracellular bacteria, up to 2.5 μm in length
. Cells show a
developmental cycle
with morphologically distinct stages similar to those of the
Chlamydiaceae
. Organisms were found in whitefly and scale insects, but have not yet been obtained in cell culture. The genus is based on the description of “
Candidatus
Fritschea bemisiae” and “
Candidatus
Fritschea eriococci” (Everett et al., 2005; Thao et al., 2003) (Figure 1).

Type species
: “

Candidatus
Fritschea bemisiae

” Everett, Thao, Horn, Dyszynski and Baumann 2005, 1585.
Green Sulfur Bacteria
Authors: Overmann Jörg
Published: August 2015

Introduction
. The green sulfur bacteria are predominately aquatic bacteria that grow photosynthetically under anoxic conditions. Similar to
Chromatiaceae
(purple sulfur bacteria) and purple nonsulfur bacteria (
Proteobacteria
), the photosynthetic metabolism of green sulfur bacteria differs from that of
Cyanobacteria
, algae, and green plants in that water cannot serve as an electron‐donating substrate and molecular oxygen is not generated. The external electron donors for photosynthetic CO
2
assimilation have low redox potentials and comprise reduced sulfur compounds and molecular hydrogen. Green sulfur bacteria can be distinguished from the
Chromatiaceae
by their distinct bacteriochlorophylls (BChls), the presence of special light‐harvesting structures, and their exclusively photolithotrophic metabolism.

Chlorobi / “Chlorobia” / Subclass I “Chlorobiales” / Green Sulfur Bacteria / Green Sulfur Bacteria

The mol
%
G
+
C of the DNA is
: 47.8–58.1 (Bd).

Type genus
:
Chlorobium
Nadson 1906, 190.
Pyrodictium
Authors: Stetter Karl O.
Published: August 2015

Pyr.o.dic' ti.um
. Gr. neut. n.
pyr
fire; Gr. neut. n.
diktyon
network; M.L. neut. n.
Pyrodictium
fire‐loving network.

Crenarchaeota / Thermoprotei / Desulfurococcales / Pyrodictiaceae / Pyrodictium

Cells disk‐ to dish‐shaped
, highly variable in diameter, ranging from 0.3 to 2.5 µm, frequently with ultraflat areas, about 0.1–0.2 µm thick (Figure 1).
Produce tubule‐shaped structures
(“
cannulae
”), 0.025 µm thick,
which form networks connecting the cells
(Figure 2). Strictly and facultatively
chemolithotrophic
. H
2
S is formed from molecular sulfur and hydrogen. No mobility observed. Cell envelope composed of protein subunits (Figure 3) in hexagonal array. Isopranoid di‐ and tetraether lipids present (Langworthy and Pond, 1986a). Elongation factor 2 is ADP‐ribosylated by diphtheria toxin (F. Klink, personal communication).
Strictly anaerobic. Optimum temperature
:
97–105°C; maximum
:
110°C
; minimum: 80–82°C. Growth occurs at pH 5–7; optimum pH: ~5.5. Optimum NaCl concentration: ~1.5%. Vigorous shaking prevents cell growth.

The mol
%
G
+
C of the DNA is
: 60–62.

Type species
:
Pyrodictium occultum
Stetter, König and Stackebrandt 1984, 270, emend. Pley and Stetter
in
Pley, Schipka, Gambacorta, Jannasch, Fricke, Rachel and Stetter 1991, 251 (Effective publication: Stetter, König and Stackebrandt 1983, 549).
Acidianus
Authors: Huber Harald , Stetter Karl O.
Published: August 2015

A
.
cid
.
i
.
a
'
nus
. L. masc. adj.
acidus
acid; L. masc. n.
lanus
a mythical Roman figure with two faces looking in opposite directions; M.L. masc. n.
Acidianus
acidic bifaced (bacterium).

Crenarchaeota / Thermoprotei / Sulfolobales / Sulfolobaceae / Acidianus

Cells coccoid
,
highly irregular
, about 0.5–2 µm in diameter,
occurring singly almost exclusively
. Gram negative. Neither motility nor flagella was detected. Cell envelope composed of protein subunits with p3 symmetry. Isopranyl ether lipids, calditol, caldariellaquinone and sulfolobusquinone present. Elongation factor EF‐G is ADP‐ribosylated by diphtheria toxin.
Facultatively anaerobic
.

Lithotrophic growth aerobically via S
0
oxidation

to sulfuric acid or by H
2
oxidation (“Knallgas” reaction).

Under anaerobic conditions reduction of S
0
with H
2
to H
2
S

.
Thermoacidophilic
,
growth above 45
°
C at pH 1–6
. Optimal NaCl concentration for growth in culture media around 0.2%, maximum around 4%.

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

Type species
:
Acidianus infernus
Segerer, Neuner, Kristjansson and Stetter 1986, 562.
Metallosphaera
Authors: Huber Harald , Stetter Karl O.
Published: August 2015

Me
.
tal
.
lo
.
sphae
'
ra
. L. neut. n.
metallum
ore; L. fem. n.
sphaera
sphere; M.L. fem. n.
Metallosphaera
the metal‐mobilizing sphere.

Crenarchaeota / Thermoprotei / Sulfolobales / Sulfolobaceae / Metallosphaera

Cells regular to irregular cocci
with a diameter of 0.6–1.5 µm (Figure 1). Gram negative. Motile by possession of one or more flagella.
Obligate aerobic
.
Facultatively chemolithoautotrophic
.
Lithotrophic growth on sulfidic ores
like pyrite, sphalerite, and chalcopyrite, and

on S
0

resulting in the production of sulfuric acid. Aerobic hydrogen oxidation.
Organotrophic growth on beef extract
,
peptone
,
and yeast extract
. No growth by anaerobic sulfur reduction.
Optimal growth temperature around 75
°
C between pH 1 and 4
.
5
. Based on 16S rRNA sequence data, the
Metallosphaera
species are members of the family
Sulfolobaceae
and form a cluster with the representatives of the genus
Acidianus
(Fuchs et al., 1996a).

The mol
%
G
+
C of the DNA is
: 45.

Type species
:
Metallosphaera sedula
Huber, Spinnler, Gambacorta and Stetter 1989b, 496 (Effective publication: Huber, Spinnler, Gambacorta and Stetter 1989a, 46).
Sulfolobus
Authors: Huber Harald , Stetter Karl O.
Published: August 2015

Sul.fo.lo' bus
. L. neut. n.
sulfur
sulfur; Gr. masc. n.
lobos
lobe; M.L. masc. n.
Sulfolobus
lobed sulfur‐oxidizing organism.

Crenarchaeota / Thermoprotei / Sulfolobales / Sulfolobaceae / Sulfolobus

Cells coccoid
,
highly irregular
with a diameter from about 0.7 to 2 µm,
usually occurring singly
. Gram negative. Immotile or motile by possession of one or more flagella.
Obligate aerobe
.
Facultatively chemolithoautotrophic
.
Lithotrophic growth via oxidation of sulfidic ores
,
sulfide
,

S
0

,
or tetrathionate
resulting in the production of sulfuric acid. No growth by anaerobic sulfur reduction. Aerobic hydrogen oxidation by some species.
Organotrophic growth on complex organic material
(e.g., beef extract, peptone, or yeast extract), sugars, or amino acids.
Optimal growth temperatures between 65 and 85
°
C
.
Growth between pH 1 and 5
.
5
(Brock et al., 1972; Brock, 1978). Based on 16S rRNA sequence data, the
Sulfolobus
species are distributed over several branches within the
Sulfolobales
(
Sulfolobaceae
), indicating that they do not represent one cluster (genus) within this order (family) (Fuchs et al., 1996a).

Type species
:
Sulfolobus acidocaldarius
Brock, Brock, Belly and Weiss 1972, 66.
Subsection
I
Authors: Herdman Michael , Castenholz Richard W. , Iteman Isabelle , Waterbury John B. , Rippka Rosmarie
Published: August 2015

Analysis of 16S rRNA gene sequence data (see Turner, 1997; Wilmotte and Herdman, this volume) shows that the unicellular cyanobacteria included in this Subsection do not form a coherent phylogenetic clade but are widely dispersed among strains of other Subsections. Furthermore, with the exception of
Cyanobium
and
Microcystis
, all of the genera for which multiple sequence data are available are polyphyletic. Further examples of polyphyly may arise when more sequences are available for genera that are currently represented by only a single sequence. It is presently impossible to classify the “chroococcalean” cyanobacteria on a phylogenetic basis. However, the data emerging from phylogenetic studies support many taxonomic proposals and will help in the subdivision of some of the form‐genera discussed here.

Cyanobacteria / Subsection I / Incertae Sedis / Subsection I
Form‐Chamaesiphon
Authors: Herdman Michael , Castenholz Richard W. , Waterbury John B. , Rippka Rosmarie
Published: August 2015

Cha.mae.si' phon
. Gr. adv.
chamai
dwarf; Gr. masc. n.
siphon
tube; M.L. masc. n.
Chamaesiphon
microbial tube.

Cyanobacteria / Subsection I / Incertae Sedis / Form‐Chamaesiphon

Unicellular cyanobacteria that reproduce exclusively by successive unequal binary fission (budding) at the apical pole of ovoid, club‐shaped, or pyriform cells. The small spherical buds are produced in succession at one pole of the mother cell. This mode of reproduction confers an intrinsic heteropolarity on the cell.

The mol
%
G
+
C of the DNA is
: 47.
Form‐ Dactylococcopsis
Authors: Rippka Rosmarie , Castenholz Richard W. , Herdman Michael
Published: August 2015

Dac.ty.lo.coc.cop' sis
. Gr. n.
dactylos
finger; Gr. n.
kokkos
grain or kernel; Gr. fem. n.
opsis
appearance; M.L. fem. n.
Dactylococcopsis
appearing as finger‐shaped grain.

Cyanobacteria / Subsection I / Incertae Sedis / Form‐ Dactylococcopsis

Unicellular cyanobacteria that are fusiform in shape. The cells are 4–8 × 35–80 µm. Dividing or paired cells may be up to 135 µm long. A well‐defined sheath is absent; gas vacuoles present along cell margins, but are most abundant at the mature (pointed) ends of the cell. The only axenic isolate (PCC 8305) is halophilic and halotolerant.
Form‐ Gloeobacter
Authors: Herdman Michael , Castenholz Richard W. , Rippka Rosmarie
Published: August 2015

Gloe.o.bac' ter
. Gr. adj.
gloios
sticky; Gr. n.
bakterion
(dim. of
baktron
) small rod; M.L. n.
Gloeobacter
sticky bacterium.

Cyanobacteria / Subsection I / Incertae Sedis / Form‐ Gloeobacter

Unicellular cyanobacteria that possess oval‐ to rod‐shaped cells that divide by transverse binary fission in a single plane. Cells occur in irregular aggregates held together by sheath material. Intracellular photosynthetic thylakoids are lacking; the light‐harvesting and photosynthetic apparatus is associated with the cytoplasmic membrane.

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

Type species
:
Gloeobacter violaceus
Rippka, Waterbury and Cohen‐Bazire 1974.
Form‐ Gloeothece
Authors: Rippka Rosmarie , Castenholz Richard W. , Waterbury John B. , Herdman Michael
Published: August 2015

Gloe.o.the' ce
. Gr. adj.
gloios
sticky; Gr. fem. n.
theke
case, envelope; M.L. fem. n.
Gloeothece
gelatinous sheath.

Cyanobacteria / Subsection I / Incertae Sedis / Form‐ Gloeothece

Unicellular rod‐shaped cyanobacteria that divide by transverse binary fission in a single plane, the cells being united into aggregates by well defined, often laminated, sheath layers.

The mol
%
G
+
C of the DNA is
: 40–43.
Form‐ Prochloron
Authors: Herdman Michael , Castenholz Richard W. , Rippka Rosmarie
Published: August 2015

Pro
.
chlo
'
ron
. Gr. prefix
pro
primitive; Gr. adj.
chloros
green; M.L. neut. n.
Prochloron
primitive green (cell).

Cyanobacteria / Subsection I / Incertae Sedis / Form‐ Prochloron

Unicellular, spherical, without evident mucilaginous sheath. Reproduction by binary fission. Almost exclusively extracellular symbionts of colonial ascidians (chiefly didemnids) on subtropical marine shores. Form chlorophylls
a
and
b
and lack phycobiliproteins.
Form‐ Synechocystis
Authors: Herdman Michael , Castenholz Richard W. , Iteman Isabelle , Rippka Rosmarie
Published: August 2015

Syn
.
e
.
cho
.
cys
'
tis
. Gr. n.
synechia
continuity; Gr. n.
kystis
bladder or bag; M.L. fem. n.
Synechocystis
contiguous bladder‐like cells.

Cyanobacteria / Subsection I / Incertae Sedis / Form‐Synechocystis

Cyanobacteria of this provisional form‐genus are unicellular strains that possess spherical cells 2–6 µm in diameter and reproduce by binary fission in two or three successive planes at right angles. Cells typically occur singly or in pairs in culture; but in nature (and rarely in culture) may occur in aggregates held together by amorphous slime material; well‐defined sheath layers are never produced. Gas vacuoles are absent.

The mol
%
G
+
C of the DNA is
: 35–48.
Subsection
II
Authors: Rippka Rosmarie , Waterbury John B. , Herdman Michael , Castenholz Richard W.
Published: August 2015

Cyanobacteria / Subsection II / Incertae Sedis / Subsection II

Cyanobacteria assigned to this Subsection reproduce either exclusively, or at some stages of their life cycle, by the formation of small, spherical cells (baeocytes). These reproductive cells arise from multiple fissions of a parental cell (“vegetative” cell) and are released after rupture of its fibrous outer wall layer. The number of baeocytes released from a parental cell ranges from 4 to over 1000. Enlargement of vegetative cells is accompanied by progressive thickening of the fibrous outer wall layer. Members of some genera divide exclusively by multiple fission. In others, the baeocytes give rise to cell aggregates or pseudofilaments which reproduce by binary fission (“vegetative division”). Subsequently, some or all of the cells composing the aggregates undergo multiple fission and release new baeocytes.
Form‐ Cyanocystis
Authors: Rippka Rosmarie , Waterbury John B. , Herdman Michael , Castenholz Richard W.
Published: August 2015

Cy.a.no.cyst' is
. Gr. f. n.
cyanos
blue‐green color; Gr. n.
cystis
bladder, bag; M.L. fem. n. blue‐green bladder.

Cyanobacteria / Subsection II / Genera Reproducing by Multiple Fissions Only, or in Combination with Limited (1–3) Binary Fissions / Form‐ Cyanocystis

Unicellular cyanobacteria that have apical‐basal polarity (i.e., ovoid to pyriform in shape), and that reproduce only by multiple fission (i.e., do not exhibit binary fission). Baeocytes are immotile, possessing an outer fibrous wall layer at the time of release from the parental cell.
Form‐ Myxosarcina
Authors: Rippka Rosmarie , Iteman Isabelle , Waterbury John B. , Herdman Michael , Castenholz Richard W.
Published: August 2015

Myx.o.sar' ci.na
. Gr. fem. n.
myxa
slime, mucus; L. n.
sarcina
bundle or package; M.L. fem. n.
Myxosarcina
slime bundle or packet of cells in slime.

Cyanobacteria / Subsection II / Genera in Which Extensive Vegetative Binary Fission Precedes Multiple Fission / Form‐ Myxosarcina

Cyanobacteria that undergo repeated binary fission in three planes to form more or less cubical aggregates of cells. Multiple fission occurs simultaneously in most vegetative cells, resulting in the liberation of a restricted number (about four per vegetative cell) of baeocytes that lack an outer fibrous wall layer and are often capable of gliding motility. The baeocytes enlarge symmetrically into spherical vegetative cells that, just prior to the onset of binary fission, attain a size that is characteristic and constant for any given strain.
Pleurocapsa‐group
Authors: Rippka Rosmarie , Waterbury John B. , Herdman Michael , Castenholz Richard W.
Published: August 2015

Pleu.ro.cap' sa
. Gr. n.
pleyra
rib or side; L. n.
capsa
box; M.L. fem. n.
Pleurocapsa
box with ribs.

Cyanobacteria / Subsection II / Genera in Which Extensive Vegetative Binary Fission Precedes Multiple Fission / Pleurocapsa‐group

The
Pleurocapsa
‐group is a provisional assemblage which can loosely be defined as cyanobacteria that undergo repeated binary fissions in many different planes to produce cell aggregates that are diverse in size and form. They range from smaller or larger cell aggregates of variable compactness to very complex structures, all of which exhibit at the periphery pseudofilamentous appendages of varying length. Multiple fission occurs in some cells of the aggregates, resulting in baeocytes which may be motile because they lack a fibrous wall layer at the time of release.
Subsection III
Authors: Castenholz Richard W. , Rippka Rosmarie , Herdman Michael , Wilmotte Annick
Published: August 2015

Cyanobacteria / Subsection III / Incertae Sedis / Subsection III

It is now apparent from multiple 16S rDNA sequence analyses that this subsection is not phylogenetically coherent. Some of the genera of this former order and even named species of the genus
Oscillatoria
, for example, are polyphyletic (see Turner, 1997; Phylogenetic relationships amongst the
Cyanobacteria
, p. 487). It is premature to reclassify this “oscillatorian” group of morphotypes on the basis of the still incompletely determined genetic relationships. The present treatment, therefore, will follow the older, artificial grouping of Subsection III, although the degree of genetic similarities of some genera (on the basis of nucleotide and other sequence similarities) are mentioned in the text description of each genus and also in the discussion in the chapter on phylogeny.
Form‐ Borzia
Authors: Castenholz Richard W. , Rippka Rosmarie , Herdman Michael
Published: August 2015

Bor' zi.a
. M.L. fem. n.
Borzi
named after A. Borzi, Italian cyanobacteriologist.

Cyanobacteria / Subsection III / Incertae Sedis / Form‐ Borzia

This genus is characterized by
very short trichomes of 2–8 (16) cells
, with conspicuous constrictions at crosswalls, of various diameters; motility slight or lacking;
cells usually shorter than broad
. This last characteristic seems to be the main feature separating this genus from
Pseudanabaena
(as represented in this volume), since many strains of
Pseudanabaena
consistently exhibit comparably short trichomes. Brevitrichomy may also occur in other filamentous cyanobacteria (Pinevich et al., 1997), and mutants with short trichomes have been isolated from heterocystous forms such as
Anabaena
(Bauer et al., 1995). Thus this property may be trivial, which could be demonstrated by genetic analyses on typical representatives of this “genus”.
Hormoscilla
Anagnostidis and Komárek, 1988 is very similar to
Borzia
and will not be considered here. A species isolated by E.G. Pringsheim and conforming to the description of
Borzia trilocularis
(Pringsheim, 1968) exists in culture strain SAG B 1407–1, but has been assigned to
Hormoscilla pringsheimii
(Schlösser, 1994).
Form‐ Crinalium
Authors: Castenholz Richard W. , Rippka Rosmarie , Herdman Michael
Published: August 2015

Cri.na' li.um
. L. adj.
crinalis
of hair; Gr. suff. ‐
ion
diminutive; M.L. neut. n.
Crinalium
small hairlike (filament).

Cyanobacteria / Subsection III / Incertae Sedis / Form‐ Crinalium

Members of this genus share structural similarities with
Oscillatoria
.
The trichome is flattened to elliptical in cross‐section
rather than cylindrical (or triradiate as in
Starria
). The only representative in axenic culture (strain PCC 9333), described as
Crinalium epipsammum
(SAG 22.89), has short cells (1–1.5 µm) that are 2–2.5 µm in narrow width and 5–7 µm in breadth (De Winder et al., 1990). The terminal cells are undifferentiated. Binary fission as in
Oscillatoria
. Trichomes are nonmotile. As seen in transmission electron microscopy, thylakoids are mainly parallel to the long axis and close to the cell periphery. The cell wall peptidoglycan layer is thick (80–100 nm). Reported to have a mean DNA base composition of 33.9 mol% G + C and to contain high levels of cellulose II, associated with the cell envelope (de Winder et al., 1990). A thin sheath may exist. No PE; β‐carotene and echinenone are the major carotenoids. There is no N
2
fixation under anoxic or oxic conditions. Apparently common in terrestrial sandy areas as surface crusts and is desiccation‐resistant. Two other species from field collections have been characterized poorly (see Desikachary, 1959).
Form‐ Geitlerinema stat. nov.
Authors: Castenholz Richard W. , Rippka Rosmarie , Herdman Michael
Published: August 2015

Geit' ler.i.nema. Geitler
Lothar Geitler, Austrian cyanobacterial taxonomist, 1899–1990; Gr. n.
nema
thread; M.L. fem. n.
Geitlerinema
Geitler's thread or filament.

Cyanobacteria / Subsection III / Incertae Sedis / Form‐ Geitlerinemia

Filamentous cyanobacteria which form straight to slightly sinuous cylindrical trichomes that divide by binary fission; trichome breakage transcellular.
Trichomes less than 5–6 μm in diameter; cells longer than broad or isodiametric, never disc‐ or coin‐like; constrictions between adjacent cells are absent or very shallow
; apical cells are rounded, conical or distinctly pointed, tapered, and often bent. Polar gas vesicles rarely present; large cyanophycin granules near crosswalls in some species. Ultrastructural studies of strain PCC 7105 demonstrated a single circular row of pores near the crosswalls (Guglielmi and Cohen‐Bazire, 1982a); whether this holds for the other strains assigned to this genus is unknown. Trichomes of freshly isolated cultures or observed in field material show active gliding motility accompanied by trichome rotation, sometimes leaving behind an extremely thin trail (or almost invisible sheath). Copious amounts of gel‐like matter may be produced by some strains, particularly in axenic liquid culture.

The mol
%
G
+
C of the DNA is
: 53–67 (Rippka and Herdman, 1992).
Form‐ Leptolyngbya
Authors: Castenholz Richard W. , Rippka Rosmarie , Herdman Michael , Wilmotte Annick
Published: August 2015

Lep.to.lyng' by.a
. Gr. adj.
leptos
delicate or thin;
lyngbya
named after H.C. Lyngbye, Danish botanist, 1782–1837;
Lyngbya
another genus of cyanobacteria; M.L. fem. n.
Leptolyngbya
delicate or thin Lyngbya.

Cyanobacteria / Subsection III / Incertae Sedis / Form‐ Leptolyngbya

Cylindrical trichomes less than 3 μm in diameter; cells isodiametric or longer than wide; constrictions between cells are generally absent or shallow
, seldom exceeding 1/8 of the trichome diameter; trichome breakage may be trans‐ or inter‐cellular; apical cells rounded (or exceptionally conical) (Figure 1);
persistent sheaths may be produced
but are not of firm consistency (and not laminated); in some members, several trichomes may be surrounded by a “mucous‐like” matrix.
Trichomes nonmotile (or inconspicuously motile as seen by light microscopy, <0.1 μm/s), except for transient motile hormogonia when free of any sheath or coalescent “mucous” material
. Some strains or natural specimens may undergo false branching, which may depend mainly on sheath strength.
Form‐ Lyngbya
Authors: Castenholz Richard W. , Rippka Rosmarie , Herdman Michael
Published: August 2015

Lyng' by.a
. M.L. fem. n.
Lyngbye
named after H.C. Lyngbye, Danish botanist, 1782–1837.

Cyanobacteria / Subsection III / Incertae Sedis / Form‐ Lyngbya

Filamentous organisms that share the entire range of cellular types with
Oscillatoria
(as here defined), but which produce a
distinct, persistent, and firm sheath
(Figure 1). The sheath may be thin but can be seen with phase contrast optics, particularly where it extends beyond the terminal cell of the trichome (Fig 1). The trichome diameters range from about 6 to ∼80 µm. Sheaths in some species may accrete to several µm in thickness and display laminations.
Cells composing the trichomes are disk shaped (shorter than broad)
, a feature also characteristic of
Oscillatoria
(as here defined).
Form‐ Microcoleus
Authors: Castenholz Richard W. , Rippka Rosmarie , Herdman Michael
Published: August 2015

Mi.cro.co' le.us
. Gr. adj.
mikros
small (or thin); Gr. n.
koleos
sheath; M.L. masc. n.
Microcoleus
small or thin sheath.

Cyanobacteria / Subsection III / Incertae Sedis / Form‐ Microcoleus

In members assigned to this form‐genus,
two to several trichomes oriented parallel
, often spirally and tightly interwoven, are
enclosed by a common homogeneous sheath
(Figure 1). Cells (diameter 3–6 µm) composing the trichomes are
longer than wide
(or isodiametric);
visible constrictions at the cross‐walls
(but usually much less than 1/4 of the cell diameter);
mature end cells are conical
; the bundles of filaments
generally exhibit slow gliding motility, not involving rotation
. Based on analysis of a limited number of isolates, a
radial arrangement of thylakoids
(in cross‐section, T.E.M.) seems to be
typical
.
Form‐ Oscillatoria
Authors: Castenholz Richard W. , Rippka Rosmarie , Herdman Michael
Published: August 2015

Os.cil.la.to' ri.a
. L. v.
oscillare
to swing; L. adj. suffix ‐
torius
belonging to; M.L. fem. n.
Oscillatoria
(filament) that swings.

Cyanobacteria / Subsection III / Incertae Sedis / Form‐ Oscillatoria

Filamentous organisms that divide exclusively by binary fission and in one plane. The cylindrical trichomes are straight (except for the terminal region in some cases); flexible or semirigid;
over ∼4 µm in diameter; disc‐like cells wider than long
. The trichome diameter of cultured representatives is 4–16 µm, but species with trichomes up to >100 µm in diameter have been described in the botanical literature. Invariably, in larger trichomes (>10 µm in diameter) the cells are much shorter than broad. Cross‐walls are generally visible by light microscopy (Figures 1 and 2). Constrictions at cross‐walls are lacking or slight, but the total indentation never exceeds 1/8 of the trichome diameter. Generally, the cross‐wall is thinner than the longitudinal wall.
The initiation of cross‐wall synthesis by centripetal growth precedes the completion of previously initiated cross‐walls
(Figure 3). During fission, the cytoplasmic membrane invaginates, with a thinner peptidoglycan layer following and separating the new membranes of the daughter cells. This characteristic also applies to the genera
Spirulina, Arthrospira
, and
Lyngbya
.
Reproduction
of trichomes is
by transcellular breakage
involving sacrificial cell death (i.e., “necridial” cells).
Form‐ Starria
Authors: Castenholz Richard W. , Rippka Rosmarie , Herdman Michael
Published: August 2015

Star' ri.a
. M.L. fem. n.
Starria
Starr, named after R.C. Starr, U.S. phycologist (1924–1998).

Cyanobacteria / Subsection III / Incertae Sedis / Form‐ Starria

This nonbranching filamentous cyanobacterium is unique in that the short
trichomes are triradiate in cross‐section
(Lang, 1977). The
immotile
trichomes are straight to helically twisted. The
cells are significantly shorter
(length 1–2 µm)
than wide
(diameter ∼15 µm). The triradiate form usually has broad, arm‐like projections 120 degrees apart, separated by U‐shaped depressions (Figure 1). The pigmentation is concentrated in the arms. A thin sheath (3 µm thick) covers the trichome. Cross‐walls are as found in the genus
Oscillatoria
, with an invagination of the peptidoglycan layer but not of the outer membrane. The relatively thick peptidoglycan layer of longitudinal walls is characterized by evenly distributed pits 70 nm in diameter, as in some species of
Oscillatoria
(e.g.,
O. princeps
) (Halfen and Castenholz, 1971; Guglielmi and Cohen‐Bazire, 1982b). Little is known about the physiology or biochemistry of this organism, but its very unusual structure has been documented by light and electron microscopy (Lang, 1977). This organism is known from a single strain isolated from a terrestrial sample in Zimbabwe. The scarce record of
Starria
may not imply that it is rare, since cyanobacteria of the soil have not been studied extensively.
Form‐ Trichodesmium
Authors: Castenholz Richard W. , Rippka Rosmarie , Herdman Michael
Published: August 2015

Trich' o.des' mium
. Gr. n.
trichos
hair; Gr. n.
desmos
bond; M.L. neut. n.
Trichodesmium
bonded filaments.

Cyanobacteria / Subsection III / Incertae Sedis / Form‐ Trichodesmium

Filamentous cyanobacteria that divide exclusively by binary fission and in one plane. Trichomes of different species or strains range from 6 to 22 µm in diameter. Cells are isodiametric or slightly longer than broad; constrictions at cross‐walls are shallow.
Trichomes are arranged in parallel fascicles or form radiate macroscopic clusters
;
Trichodesmium
species
often occur as major constituents of the plankton in tropical to semi‐tropical oceans
; they are
reddish to orange in color, containing PE with phycourobilin (PUB) chromophores
, exhibiting an absorption peak at ∼493–495 nm (Fujita and Shimura, 1 9 7 4; Glazer, 1 9 8 9). All known members contain
abundant gas vacuoles
(Figure 1),
generally dispersed throughout the cells, and particularly resistant to collapse
, even at hydrostatic pressures of 12–27 bars (Walsby, 1 9 9 4).
Form‐Anabaena
Authors: Rippka Rosmarie , Castenholz Richard W. , Iteman Isabelle , Herdman Michael
Published: August 2015

A.na.bae' na. Gr. adj.anaup again; Gr. v.bainoto walk, to step; M.L. fem. n.Anabaenato step up again, repeating line of units (cells).

Cyanobacteria / Subsection IV / Subsection IV.I / Form‐Anabaena

Trichomes straight or slightly sinuous, vegetative cells spherical, cylindrical, or barrel shaped, and separated by conspicuous constrictions at the crosswalls. Heterocysts predominantly intercalary, though terminal heterocysts may also occur. Akinetes located, singly or in groups (2–3), adjacent to heterocysts or occurring in chains, initiated distant from heterocysts. A firm sheath is absent, but mucilage production may be abundant. False branching generally not observed. Reproduction by random trichome fragmentation. Hormogonia, distinct in morphology from the parental trichomes, not produced.
Form‐Aphanizomenon
Authors: Rippka Rosmarie , Castenholz Richard W. , Iteman Isabelle , Herdman Michael
Published: August 2015

A.pha.ni.zo' me.non
. Gr. v.
aphanizo
to disappear; Gr. neut. pass. part.
aphanizomenon
; M.L. neut. n.
Aphanizomenon
obscure thing.

Cyanobacteria / Subsection IV / Subsection IV.I / Form‐ Aphanizomenon

Trichomes are straight and generally exhibit a slight attenuation in size toward their termini; a firm sheath is never produced. Intercalary vegetative cells are cylindrical, significantly longer than wide, and contain abundant gas vesicle clusters. The terminal cells are rounded to subconical and generally lack gas vesicles. Constrictions between individual cells are relatively shallow. Heterocysts differentiate exclusively in intercalary positions. Akinetes, singly or in pairs, are formed adjacent to, or distant from, heterocysts. Structurally distinct hormogonia are not produced.
Form‐Nostoc
Authors: Herdman Michael , Castenholz Richard W. , Rippka Rosmarie
Published: August 2015

Nos'toc. M.L. n.Nostocorigin uncertain, supposedly invented by Paracelsus from the old English wordNosthryl(nostril) and the corresponding German wordNasenloch=Nostoch.

Cyanobacteria / Subsection IV / Subsection IV.I / Form‐ Nostoc
Scytonema
Authors: Castenholz Richard W. , Herdman Michael , Rippka Rosmarie
Published: August 2015

Scy.to.ne' ma
. Gr. n.
skytos
leather; Gr. n.
nema
thread; M.L. neut. n.
Scytonema
leather thread.

Cyanobacteria / Subsection IV / Subsection IV.I / Form‐Scytonema

The mature trichomes are immotile, heavily ensheathed, and form numerous false branches that exhibit upright aerial mode of growth. Constrictions between the disk‐shaped to cylindrical cells are shallow. Heterocysts generally occupy intercalary positions, although some false branches may carry at their base a terminal heterocyst. Hormogonia are less ensheathed, exhibit no or only slow motility, and differ little in cell morphology from the mature filaments. Akinetes are not produced.
Form‐ Tolypothrix
Authors: Herdman Michael , Castenholz Richard W. , Rippka Rosmarie
Published: August 2015

To.ly.po' thrix
.Gr. n.
tolypa
bundle, tangle; Gr. fem. n.
thrix
hair; M.L. fem. n.
Tolypothrix
bundle/tangle of hairs.

Cyanobacteria / Subsection IV / Subsection IV.II / Form‐Tolypothrix

Mature trichomes exhibit a low degree of tapering, the ratio of the width of basal to apical cells not exceeding 1.5. False branches are frequent, often subtending a “basal” heterocyst. Hormogonia, generally motile and often containing gas vesicle clusters dispersed throughout the cells, give rise to young trichomes that differentiate a single terminal heterocyst. All are freshwater or soil inhabitants. Akinetes are lacking.
Subsection V
Authors: Hoffmann Lucien , Castenholz Richard W.
Published: August 2015

Cyanobacteria / Subsection V / Incertae Sedis / Subsection V

Genera of this subsection exhibit the highest degree of morphological complexity and differentiation within the cyanobacteria; the few available 16S rDNA sequence data analyses suggest that it is a monophyletic group, arising from within an assemblage of filamentous heterocystous cyanobacteria that divide in a single plane (Turner, 1997; “Phylogenetic relationships amongst the
Cyanobacteria
,” p. 487). Longitudinal and oblique cell divisions occur in addition to transverse cell divisions. This results in periodic true branching in all genera and in multiseriate trichomes (two or more rows of cells) in some genera. Three major types of true branchings, named “T”, “V”, and “Y”, can be distinguished (Golubic et al., 1996). T‐branching is a lateral, nearly perpendicular branching originating from the change of division plane from transverse to longitudinal (Figure 1), V‐branching is a dichotomous or pseudodichotomous bifurcation originating from a change in division plane at, or close to, the trichome tip (Figure 2), and Y‐branching arises from the displacement of an intercalary branch‐point cell by surrounding meristematic growth (Figure 3). False branching also occurs in some genera. Pit‐like synapses or pore channels occur between the cells of trichomes in some of these genera. Heterocysts are both intercalary and terminal. Although reproduction occurs by random breakage of trichomes, hormogonia are also formed in most strains. Akinetes or akinete‐ like cells are produced by some genera.
Form‐Fischerella
Authors: Hoffmann Lucien , Castenholz Richard W.
Published: August 2015

Fisch.er.el' la
. M.L. fem. n.
Fischerella
Fischer, probably named for B. Fischer, botanical bacteriologist, 1852–1915.

Cyanobacteria / Subsection V / Incertae Sedis / Form‐Fischerella

The true branches of these organisms are uniseriate and composed of cells, particularly those distal from the base, that are generally longer than broad. The axis (primary trichome) from which they arise is also mainly uniseriate, but may become multiseriate in part, with divisions in more than one plane. The axis in these regions, however, is seldom more than 2–3 cells in thickness. In addition, the cells of the axes become enlarged, often semispherical in shape. The older cells of a main axis may become separated from each other by sheath material and may act as akinetes (Martin and Wyatt, 1974). Most of the widened cells of the axial trichome, however, display a true filamentous nature, with only a peptidoglycan septum separating cells (Nierzwicki et al., 1982; Balkwill et al., 1984). The main axis forms when a hormogonium comes to rest, cells enlarge, and cell divisions that are parallel to the long axis or diagonal (oblique) begin; some of the resulting cells elongate to form branches (secondary trichomes) (Balkwill et al., 1984; Nierzwicki‐Bauer et al., 1984) (Figure 1). Extracellular sheaths are absent.
Form‐Iyengariella
Authors: Hoffmann Lucien
Published: August 2015

I.yen.gar.iel' la
. M.L. fem. n.
Iyengariella
Iyengar, named after M.O.P. Iyengar, Indian phycologist.

Cyanobacteria / Subsection V / Incertae Sedis / Form‐Iyengariella

Besides true and pseudodichotomous branchings, false branchings are also found; false branches occur after trichome breakage as a result of the formation of a necridium. True dichotomous branches originate from the longitudinal division of the apical cell and pseudodichotomous true branches originate from the oblique division of an intercalary cell. Filaments taper, the trichomes ending in long whips of the rivulariacean type. Heterocysts and akinetes are absent. Reproduction is through hormogonia‐ formation.
Form‐Nostochopsis
Authors: Hoffmann Lucien
Published: August 2015

Nost' och.op' sis
. Old English n.
Nost' hryl
nostril; German n.
Nasen'loch;
Gr. n. opsis appearance, hence resemblance; M.L. fem. n.
Nostochopsis
(cyanobacterium) resembling
Nostoc
Vaucher, “excrement from the nostrils of some rheumatick planet” (Paracelsus 1493–1541) referring to the rapid appearance of
Nostoc commune
colonies after thundershowers.

Cyanobacteria / Subsection V / Incertae Sedis / Form‐Nostochopsis

The uniseriate trichomes form lateral T‐branchings of two types, one long and many celled, the other one of limited growth (1–3 cells) with a heterocyst at the end; besides these pedicellate heterocysts, heterocysts are intercalary or lateral and sessile. A culture of this genus has been established (Weber et al., 1996), but has not been studied taxonomically.
Flexistipes
Authors: Stetter Karl O. , Huber Harald
Published: August 2015

Fle
.
xi
.
sti
'
pes
. M.L. masc. n.
flexus
winding; M L. masc. n.
stipes
stick; M L. masc. n.
Flexistipes
the flexible stick.

Deferribacteres / Deferribactere / Deferribacterales / Deferribacteraceae / Flexistipes

Flexible rods
, nonmotile. No spores formed. Gram negative.
Heterotrophic growth under anaerobic conditions. Halophilic, neutrophilic, and slightly thermophilic
. Muramic acid and mesodiaminopimelic acid present. Ester lipids in the cytoplasmic membrane. Based on 16S rRNA analyses,

Flexistipes
clusters with the genera
Deferribacter
and
Geovibrio

.

The mol
%
G
+
C of the DNA is
: ~39

Type species
:
Flexistipes sinusarabici
Fiala, Woese, Langworthy and Stetter 2000, 1415 (Effective publication: Fiala, Woese, Lang‐worthy and Stetter 1990, 125).