PROSPECTS FOR A NATURAL SYSTEM OF CLASSIFICATION OF BACTERIA 



cephalotrichous flagella. No endospores formed. Chemo-heterotrophic. oxi- 

 dizing various organic compounds. Gram-negative. Adapted to life in neutral 

 to slightly alkaline media. 

 The type species is Pseudomonas fluorescens (Flugge) Migula. 



10. Rliizobium Frank, 1889. 



Ellipsoidal to rod-shaped bacteria, motile by means of cephalotrichous flagella. 

 Branched and swollen involution forms. No endospores formed. Chemo-hetero- 

 trophic, oxidizing various organic compounds. The association of the bacteria 

 and Legwninosae fixes atmospheric nitrogen (root-nodules!). 

 The type species is Rliizobium radicicola (Beijerinck). 



1 1 . Azotobacter Beijerinck, 1 90 1 . 



Ellipsoidal to rod-shaped bacteria, motile by means of cephalotrichous flagella. 

 No endospores formed. Chemo-heterotrophic, oxidizing various organic sub- 

 stances. Capable of fixing atmospheric nitrogen. 

 The type species is Azotobacter chroococcum Beijerinck. 



12. Listerella Pirie, 1927. 



Short rod-shaped bacteria, motile by means of cephalotrichous flagella. No 



endospores formed. Chemo-heterotrophic, oxidizing various organic compounds. 



Gram-positive. 



The type species is Listerella monocytogenes (Murray et al.) Pirie. 



13. Aeromonas nov. gen. 



Short rod-shaped bacteria, motile by means of cephalotrichous flagella. No 

 endospores formed. Chemo-heterotrophic, oxidizing various organic com- 

 pounds, and capable of fermenting carbohydrates with the production of 

 carbon dioxide and hydrogen, and 2,3-butylene glycol (?). Gram-negative. 

 The type species is Aeromonas liquefaciens (Beijerinck), Syn. : Aerobacter liquefaciens 

 Beijerinck. 



1 4. Zymomonas nov. gen. 



Ellipsoidal to rod-shaped bacteria, motile by means of cephalotrichous flagella. 

 No endospores formed. Chemo-heterotrophic, oxidizing various organic com- 

 pounds, and capable of fermenting carbohydrates with the production of carbon 

 dioxide, ethyl alcohol, and lactic acid. Gram-negative. 



The type species is ^ymomonas mobile (Li ndner), Syn. : Termobacterium mobile 

 Lindner. 



15. Methanol) acterium nov. gen. 



Straight or slightly bent rods, often united to bundles or long chains. Motility not 

 observed. No endospores formed. Chemo-heterotrophic, anaerobic, fermenting 

 various organic compounds with the formation of methane. Gram negative. 

 The type species to be described in the near future. 



IV. Tribe Micrococceae 



1 . Chlorobium Nadson, 1 906. 



Spherical cells with a tendency to the formation of chains, rods, and even 

 filamentous forms, the latter sometimes wound in tight spirals. Motility has not 



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