204 



BACTERIA IN THE DEEP SEA 



Dr. B. Kullenberg with his corei, a steel 

 tube loaded on top with ^o kilograms of 

 lead, and having a plastic tube inside. 

 With the corer a sample of the bottom up 

 to a metre long can be obtained for biolog- 

 ical and geological study. 



In order to avoid contaminating the mud sample, clean sterile instru- 

 ments were employed to remove small portions for bacteriological analysis. 

 Extremely thin films of the freshly collected material were spread on 

 glass slides for examination with a microscope. A magnification of nearly 

 a thousand diameters made it possible to see many small bodies in the 

 mud. Under the microscope, some of these bodies appeared to be about 

 the size and shape of the periods on this page. Others were curved, comma- 

 like bodies ; more were straight rods resembling the printed dash or hyphen 

 of various lengths and widths. Unquestionably they were bacteria — • 

 cocci, vibrio, spirilla, and bacilli. Unfortunately, however, microscopic 

 examination failed to prove whether the bacteria were living or dead or 

 even fossil forms. 



In order to determine if the bacteria were alive, small quantities of 

 the mud were planted in glass tubes containing nutrient medium prepared 

 with sea water, peptone, and yeast extract. In fact, several other different 

 kinds of nutrient substances were used in different tubes, since nothing 

 was known in July 1951 about the nutrient or food requirements of deep- 

 sea bacteria. 



