ORDER I. PSEUDOMONADALES 



Genus VI. Azotonionas Stapp, 1940.* 



(Stapp, Zent. f. Bakt., II Abt., 102, 1940, 18; not Azotomonas Orla-Jensen, 

 Cent. f. Bakt., II Abt., U, 1909, 484.) 



A.zo.to.mo'nas. Gr. azous without life; Fr. noun azote nitrogen; Gr. fem.n. monas unit, 

 monad; M.L. fem.n. Azotomonas nitrogen (-fixing) monad. 



Rod- to coccus-shaped cells. Motile by means of 1 to 3 polar fiagella. No fat-like reserve 

 food granules in the cells. Chemo-heterotrophic. Produce acid and sometimes gas from glu- 

 cose and other sugars and alcohols. Many carbon compounds other than sugars are used as 

 sources of energj-. Indole is produced. Aerobic. Active in the fixation of atmospheric nitro- 

 gen. Found in soil. 



The type species is Azotomonas insolita Stapp. 



Key to the species of genus Azotonionas. 

 I. Acid and gas from glucose. 



II. Acid but no gas from glucose. 



1. Azotomonas insolita. 



2. Azotomonas fluorescens. 



1. Azotomonas insolita Stapp, 1940. 

 (Abstracts of Communications, Third In- 

 ternat. Congr. for Microbiol., Sect. VIII, 

 1939, 306; abst. in Proc. Soil Sci. Soc. of 

 America, 4, 1939, 244; Zent. f. Bakt., II 

 Abt., 102, 1940, 1.) 



in.so'li.ta. L. adj. insolitus unusual. 



Coccoid rods 0.6 to 1.2 by 0.6 to 1.8 mi- 

 crons. Motile by means of 1 to 3 polar 

 flagella. Gram-negative. 



Gelatin: No liquefaction. 



Agar colonies: Flat, whitish, entire, 

 weakly fluorescent. 



Agar slant: Glistening, white growth. 



Broth: Strongly turbid; sediment; pel- 

 licle. 



Milk: Unchanged. 



Potato: Growth somewhat dry, not slimy, 

 dirty gray, spreading. 



Hydrogen sulfide is produced. 



Acid and gas from adonitol, arabinose, 

 dextrin, glucose, galactose, glycerol, 

 inositol, lactose, fructose, maltose, man- 

 nose, mannitol, raffinose, rhamnose, salicin, 

 sorbitol, starch, sucrose and xylose. 



Starch is hydrolyzed. 



Nitrites produced from nitrates. 



Atmospheric nitrogen is fixed. 



Ammonium salts are utilized. 



Aerobic. 



Temperature relations: Optimum, be- 

 tween 25° and 30° C. Minimum, between 



7.0° and 9.5° C. Maximum, 48° C. Good 

 growth at 37° C. Thermal death point, 

 60° C. 



Limits of pH, 3.3 to 9.5. 



Source: Isolated from a mixture of chop- 

 ped cotton husks and rice hulls. 



Habitat: Soil. 



2. Azotonionas fluorescens Krassilni- 



kov, 1947. (Quoted from Krassilnikov, Guide 

 to the Bacteria and Actinomycetes, Izd. 

 Akad. Nauk, U.S.S.R., Moskau, 1949, 420.) 



flu.o.res'cens. L. noun fluor a flux; M.L. 

 v. fluoresco to fluoresce; fluor-spar, a flux- 

 ing mineral which is fluorescent; M.L. 

 part. adj. fluorescens fluorescing. 



Translated by Dr. A. Petraitis, New York 

 State Experiment Station, Geneva, New- 

 York. 



Rod-shaped cells, 0.5 to 0.8 by 2.0 to 5.0 

 microns, which become shorter in old cul- 

 tures. Motile by means of one to three 

 polar flagella. Gram-negative. 



Gelatin: Slow liquefaction. 



Inorganic media with or without nitro- 

 gen: Good growth. 



Colonies are wide, smooth and glistening. 



A slightly yellowish or violet fluorescent 

 pigment is produced which diffuses through 

 the medium. 



Milk: Peptonized. 



* Rearranged by Dr. A. W. Hofer, New York State Experiment Station, Cornell Univer- 

 sity, Geneva, New York, November, 1953. 



