Azomonas as Non symbiotic Nitrogen Fixer Bacteria

1. Azomonas
PRAKASH BAJAGAIN
Msc 2nd Semister
Agriculture Microbiology
Central Campus of Technology
Dharan,Nepal
+977-9815400201

2. Non-symbiotic nitrogen-fixing bacteria
• Some important non-symbiotic nitrogen-fixing bacteria
include :-
• Achromobacter, Acetobacter, Alcaligenes, Arthrobacter, Azosp
irillum, Azotobacter, Azomonas, Bacillus, Beijerinckia, Clostridi
um, Corynebacterium, Derxia, Enterobacter, Herbaspirillum, Kl
ebsiella, Pseudomonas, Rhodospirillum,
Rhodopseudomonas and Xanthobacter
• They colonize in rhizosphere and derived their energy by
oxidation of soil organic matter and fix atmospheric nitrogen
into the soil and subsequently increase the soil fertility.

3. Azotobacteriaceae
• Azotobacteriaceae comprises two genera:- Non-cyst
forming bacterial group:- Azomonas with three species
(A. agilis, A. insignis and A. macrocytogenes)
• and cyst-forming:-
Azotobacter comprising of 6 species namely, A.
chroococcum, A. vinelandii, A. beijerinckii, A. nigricans,
A. armeniacus and A. paspali
• Beijerinckia and Derxia are not closely related to the
genera Azotobacter and Azomonas, but that they
belong to other subdivisions or groups, i.e., the alpha
and the beta subclasses, respectively of the
Proteobacteria.

4. Classification
Scientific classification
Kingdom:Bacteria
Phylum:Proteobacteria
Class:Gammaproteobacteria
Order:Pseudomonadales
Family:Pseudomonadaceae/Azotobacteraceae
(unranked):Azotobacter group
Genus:Azomonas
Winogradsky, 1938
Species
Azomonas agilis
Azomonas insignis
Azomonas macrocytogenes

5. Azomonas
• Azomonas species are typically motile, oval to
spherical, and secrete large quantities of capsular slime.
They are distinguished from Azotobacter by their
inability to form cysts, but like Azotobacter, they can
biologically fix nitrogen under aerobic conditions
(diazotrophs).
• Bacteria of the genus Azomonas are known to form
intracellular inclusions of polyhydroxyalkanoates under
certain environmental conditions (e.g. lack of elements
such as phosphorus, nitrogen, or oxygen combined with
an excessive supply of carbon sources).

7. Species
• Azomonas agilis (Beijerinck 1901)
Winogradsky 1938
• Azomonas insignis (Derx 1951) Jensen
1955, species.
• Azomonas macrocytogenes (Jensen 1955)
New and Tchan 1982

8. Azomonas agilis
• Azomonas agilis, a nitrogen-fixing bacterium, was isolated from rhizospheric soil in central
Myanmar.
• Azomonas agilis is a species of motile, Gram-negative bacteria found in water and is
capable of fixing atmospheric nitrogen. It is the type strain for the genus Azomonas.
• A. agilis resembles protists with its ovoid, ellipsoidal, or coccoid cells. The cells are
relatively large, usually 2.5-6.4 μm long and 2.0-2.8 μm wide, though giant cells that are
10.0-13.5 μm have been described.
• The cells have peritrichous flagella which enable motility.The species also produces a
diffusible yellow-green or red-violet pigment which fluoresces bluish-white
under ultraviolet light.
• A. agilis was first isolated and described by Martinus Beijerinck in 1901, who obtained the
species from Dutch canal water in Delft. Beijernick's original strain has been lost, so the
strain isolated by Albert Kluyver and van den Bout is now the neotype. Despite the fact
that mannitol was used by Beijerinck in his enrichment medium for A. agilis, the bacteria in
pure culture cannot use it as a carbon source unless it is first degraded by other microbes.
• The species can tolerate salt concentrations up to 1.0% and is resistant to iodoacetate (1
μM) which suggests it may have ability to live in contaminated waters with relatively high
concentrations of organic matter and mineral salts.This bacterium has also been implicated
in the bioremediation of cadmium-polluted water.

9. Azomonas agilis

10. Azomonas macrocytogenes
• The name Azomonas macrocytogenes (Jensen 1955) Baillie, Hodgkiss, and
Norris 1962, 118 does not appear in the Approved Lists of Bacterial Names,
although it was accepted in the 8th edition of Bergey’s Manual and was
included in the first draft of the Approved Lists .
• This aerobic, nonsymbiotic, nitrogen-fixing organism was originally
included by Jensen in the microcyst-forming genus Azotobacter, although
the author was not certain whether cysts are actually formed.
• Baillie et al. assigned the organism to the genus Azomonas on the basis of
polar flagellation and lack of cyst formation. However, Thompson and
Skerman have reported cyst formation by four of seven strains.
• Azomonas rnacrocytogenes and Azomonas insignis are more similar to
each other than to the third member of the genus, Azomonas agilis, in
terms of flagellation and deoxyribonucleic acid base composition

11. Biofertilizer
• The commercial history of biofertilizers began by Nobbe and
Hiltner, a laboratory culture of Rhizobia in 1895, followed by
the discovery of Azotobacter and then the blue green algae
and a host of other microorganisms.

12. Thank You