1016 COMPREHENSIVE KEY 



tract; will grow in selected synthetic media using pneumococcal capsular poly- 

 saccharide as the sole source of carbon Saccharobacterium 



Note: This genus is recorded in the sixth but not in the seventh edition of the 



Manual. 

 Not as above 10 



10. Colonies with a purple pigment Chromobacterium p. 292 



Note: Chromobacterium marismortui has a bluish-brown pigment; see also 



Pseiidomonas iodinum and Pseudomonas beijerinckii. 



Colonies red at 37° or 25°C., sometimes with a red, soluble pigment 11 



Other than above 17 



11. Red color due to prodigiosin; motile by means of peritrichous flagella or non-motile 



Serratia p. 359 

 Red color not due to prodigiosin 12 



12. Obligate halophiles requiring 20 to 30 per cent salt for growth; highly pleomorphic 



Halobacterium p. 207 

 Not obligately halophilic 13 



13. Organisms metabolize alkylamines; non-motile or motile by means of polar flagella 



Protaniinobacter p. 200 

 Not as above 14 



14. Motile by means of polar flagella; straight or curved rods 15 



Motile by means of peritrichous flagella 16 



15. Straight rods Pseudomonas p. 89 



(P. melophthora) 



Curved rods Vibrio p. 229 



(F. extorquens and V. hyphalus) 



16. Methyl-red positive; Voges-Proskauer negative Escherichia p. 335 



(E. aurescens) 

 Methyl-red negative; Voges-Proskauer positive; pathogenic on rhubarb 



Erwinia p. 349 

 {E. rhapontica) 



17. Organisms produce a water-soluble, blue, green or yellow pigment 18 



Not as above 19 



18. Agar hydrolyzed; alginic acid decomposed Alginomonas p. 202 



(A. fucicola) (See also Pseudomonas gelatica and Vibrio Juscus.) 

 Agar not hydrolyzed Pseudomonas p. 89 



19. Plant pathogens 20 



Not pathogenic or known to be pathogenic to plants 24 



20. Organisms produce hyperplastic diseases such as galls and hairy root 



Agrobacterium p. 288 

 Not as above 21 



21. Colonies yellow 22 



Colonies not yellow 23 



22. Flagella polar Xanthomonas p. 152 



(See also Bacterium tardicrescens, Bacterium albilineans, Pseudomonas trifolii, 

 Pseudomonas panicimiliacei , Pseudomonas radiciperda and Pseudomonas levistici.) 



Flagella peritrichous Erwinia p. 349 



Note: The following j'ellow-pigmented pathogenic organisms are either non- 

 motile or motility has not been recorded: Bacterium stewartii, Xanthomonas 

 clerodendri, Xanthomonas sesbaniae and Corijnebacterium agropyri. 



23. Flagella polar Pseudomonas p. 89 



(See also Xanthomonas panici, X. proteamaculans, X. manihotis, X. rubrisubalbi- 

 cans, X. cannae, X. zingiberi and X. translucens.) 

 Flagella peritrichous Erwinia p. 349 



