502 



Marine Microbiology 



TABLE 2 

 Determinative Groupings 



Motile Rods 



Non Motile Rods 



Kovacs Oxidase 



+ ve 

 (polar flagella) 



Kovacs Oxidase -ve 

 (peritrichous flagella) 



Pseudomonas 

 Xanthomonas 

 Aeromonas 

 Vibrio 



'Paracolons' 

 E. coli etc. 



Non Pigmented Colonies 



Short stout rods 

 often coccoid 



Achroniobacter 

 Alcaligenes 



Pigmented Colonies 

 (yellow, greenish 

 yellow, orange) 



Flavobacter 

 Cytophaga 



monas, Aeromonas, Vibrio, etc.) In our hands these are oxidase 

 -ve. Some Xanthomonas and Pseudomonas sp., associated with 

 plants which are also Gram -ve and polar flagellated, have also 

 been found to be oxidase -ve. 



DISCUSSION 



The polar-flagellate, oxidase positive groups:- These com- 

 prise members of the genera Pseudomonas, Aeromonas and Vi- 

 brio. From their reaction in Hugh and Leif son's media they can 

 be difi^erentiated into four groups giving 1 ) an oxidative reaction 

 {Pseudomonas sp.); 2) no reaction (Pseudomonas sp.); 3) an 

 alkaline reaction (Pseudomonas sp.) and 4) a fermentative reac- 

 tion (Aeromorms and Vibrio sp.). Group I can be further sub- 

 divided on the basis of the presence or absence of fluorescence 

 under U.V. light in the media of King et ah (35) or Paton (43). 



It is suggested, therefore, that the Pseudomonas sp. can be 

 divided into four groups (Table 3). 



Group I, includes those which are oxidative in Hugh and 

 Leifson's medium, and produce a diffusible fluorescent pigment. 

 Typical species are Pseudomonas fluorescens and Ps. aeruginosa. 



Group II strains attack glucose oxidatively but never pro- 

 duce a difi^usible pigment. 



Group HI strains, like Group IV, also produce no diffusible 



