Marine Microbiology 



0.17 M 



20 30 40 



OSMOTIC PRESSURE IN ATMOSPHERES 



'^0.48 M to.58M 10.95 M 



CONIC NaCI 



70 



1.38M 



)r 



74 



Fig. 2. Growth of Z. eistla at different temperatures on basic glucose-yeast- 

 extract medium containing NaCl in concentrations from 0.17 M to 1.74 M. 



No growth at 37 C. 



whose curves are similar to those from sea water cultures (Fig. 

 3). For simplicity, only the curves for 25 C and 30 C are given, 

 but in fact at each temperature except 37 C the peak of the 

 glucose curve was in about the same osmotic range as that of 

 the salinity curve. As with NaCl medium, the plant did not grow 

 on glucose at 37 C. 



With pentaerythritol, the concentrations which could be 

 made, supported growth in such a way as to suggest that this 

 compound acts like the other osmotically active materials. The 

 resulting curves are in fact like abbreviated copies of the glycerol 

 curves, with negative slope at low and positive slope at high 

 temperature (Fig. 4). 



Calcium chloride was used in metabolically active quantities, 

 but in the test concentrations it had no visible effect on the 

 growth pattern of Z. eistla at 25 C or 30 C. 



Increasing amounts of nitrogenous nutrients, supplied as 

 yeast extract, had no effect on growth at 25 C when present in 

 concentration above 0.05 per cent. From here to the maximum 



