210 BACTERIA IN THE DEEP SEA 



gical reactions of bacteria are accelerated by high pressures comparable 

 to those prevailing on the deep-sea floor, whereas other reactions are 

 retarded or completely stopped by such pressures. Likewise we have 

 learned that reproduction, growth, and other vital activities of bacteria 

 are affected in different ways by changes in pressure. 



One of the important objectives of the Galathea Expedition was to 

 bring back living micro-organisms taken from the deep sea to their response 

 to high pressure and other physiological peculiarities could be studied 

 under controlled conditions. Several cultures of bacteria, taken from the 

 bottom of the Philippine Trench and other oceanic deeps, are now being 

 culti\'ated in the microbiology laboratories at the Scripps Institution of 

 Oceanography. These cultures are being kept alive and physiologically 

 active at pressures and temperatures approximating the conditions pre- 

 vailing on the floor. From them it is hoped to learn many secrets of life. 

 Learning how the protoplasm, physiology, and enzymes of these barophilic 

 bacteria differ from surface-dwelling organisms that are ordinarily damaged 

 by high pressure may contribute to our understanding of the equation 

 of state in the fundamental processes of life. 



Deep-sea bacteria cultivated at a pressure of i,ooo atmospheres. 

 Propagation by division is in progress. Magnification about 

 35,000 times. 



