618 Marine Microbiology 



floras of individual species within the vertebrates and inverte- 

 brates. 



The theory of commensahsm of bacteria assumes a selection 

 of certain predominant physiological and biochemical types as 

 a result of the physicochemical conditions of the environment. 

 Such selection is implicit in the previously noted generic differ- 

 ences associated with host and habitat since physiological and 

 biochemical characteristics constitute the main classification 

 criteria. However, a wide range of such characteristics is, in fact, 

 encompassed by species within any genus and this is particularly 

 evident in nutritionally non-exacting groups such as Pseudomonas. 

 The biochemical and physiological properties of all bacteria isola.- 

 ted from vertebrates and invertebrates in both areas of the Paci- 

 fic were therefore studied. 



The general biochemical capabilities of the two major groups 

 isolated from northern Pacific and southern Pacific marine ani- 

 mals ai-e listed in Table 3. Pseudomonas from the southern Pa- 

 cific animals seemed to be more active in attacking milk and, in 

 general, exhibited a more active nitrogen metabolism than those 



TABLE 3 



Physiological Profile of Pseudomonas and Achromobacter 

 FROM Marine Animals 



Pseudomonas Achromobacter 



North. Pacific South. Pacific North. Pacific South. Pacific 



Acid* 18** 32 31 46 



Peptonized* 46 55 8 



Negative* 40 13 51 35 



Gelatin liquefied 61 61 36 46 



Urease positive 35 35 36 15 



HiS produced 11 23 8 4 



Citrate positive 37 52 28 19 

 Free NHa produced 



in peptone water 71 96 51 23 



Nitrates reduced 26 61 31 31 



Acid in glucose (aerobic) 71 35 69 19 



Number in sample 174/338 31/108 39/338 26/108 



(51%) (29%) (12%) (24%) 

 * Litmus milk reactions. 

 ** Expressed as per cent of the sample testing positive. 



