Zy.mo' mo.nas or Zy.mo.mo' nas
. Gr. n.
zyme
leaven, ferment; Gr. n.
monas
a unit, monad; M.L. fem. n.
Zymomonas
fermenting monad.
Proteobacteria / Alphaproteobacteria / Sphingomonadales / Sphingomonadaceae / Zymomonas
Rod‐shaped cells with rounded ends
, occasionally ellipsoidal, usually in pairs, 2–6 × 1.0–1.4 µm. Gram negative.
Usually non‐motile
;
if motile
,
they possess one to four polar flagella
. Motility may be lost spontaneously.
Facultatively anaerobic
;
some strains are obligately anaerobic
. Optimum temperature 25–30°C. Colonies on the standard medium
1
are glistening, regularly edged, white to cream colored, 1–2 mm in diameter after 2 d at 30°C. Oxidase negative. Chemoorganotrophic, growing on and
fermenting 1 mol of glucose or fructose to almost 2 mol of ethanol
,
2 mol of CO
2
,
and some organic acids such as lactic acid
. Some strains may also utilize sucrose, but other carbon sources are not used. Gluconate can be degraded but does not serve as sole carbon or energy source (Strohdeicher et al., 1 988). Sorbitol and gluconolactone are formed when grown on sucrose or mixtures of glucose and fructose by a so far unique enzyme, glucose‐fructose oxidoreductase.
Membranes contain pentacyclic triterpenoids of the hopane series
(Sahm et al., 1 993). Gelatinase negative. Nitrates are not reduced and indole is not produced.
Zymomonas
tolerates 5
%
ethanol and is acid tolerant
,
growing at pH 3
.
5–7
.
5
. Good growth is obtained only when a mixture of amino acids is present in the medium, but no one amino acid is essential. All strains require biotin and pantothenate.
Zymomonas
occurs as a spoiler in beers
,
ciders
,
and perries
;
as fermenting agents in
Agave
sap, palm sap, and sugarcane juice; and on honeybees and in ripening honey.
The mol
%
G
+
C of the DNA is
: 47.5–49.5.
Type species
:
Zymomonas mobilis
(Lindner 1 928a) Kluyver and van Niel 1 936, 399 (
Thermobacterium mobile
Lindner 1 928b, 253;
Zymomonas anaerobia
Kluyver 1 957, 199.)