358 



Marine Microbiology 



• — • 40°C . O O 45°C . ▲ A SO°C 



2 3 4 5 6 7 8 9 lO 



TIME OF EXPOSURE -MINUTES 



Fig. 1. The thermal inactivation of phage P/14 suspended in sea water 

 peptone water, at 40, 45 and 50 C. 



against the lactic streptococci. More detailed comparative in- 

 vestigations with marine phages and representative terrestrial 

 phages will certainly be required before it can be concluded that 

 a fundamental difference exists in sensitivity to thermal inactiva- 

 tion. 



Burnet and McKie (5) studied the influence of the cation 

 balance of the suspending medium on the thermal inactivation 

 of various phages and showed that wliile botli mono-and divalent 

 cations increased heat sensitivity when used separately, when 

 combined in a suitable proportion they exerted a "balanced 



