534 Marine Microbiology 



40 ml aliquots of Antarctic sea water heterotrophic bacteria were 

 usually absent. 



The purpose of this paper is to show that in certain Antarctic 

 habitats an inability to cultivate bacteria may be due to a lack 

 of knowledge of natural nutrient-temperature interrelationships 

 and regulating mechanisms rather than to the actual sparsity of 

 bacteria. In an attempt to explain this opinion, data are presented 

 in order to 1) verify the apparent sparsity of bacteria in the air 

 and sea; 2) illustrate the role of an algal acid in the gastrointes- 

 tinal antibiosis of penguins; 3) suggest the role of algal acrylic 

 acid in nurtining and inhibiting marine bacteria associated with 

 Phaeocystis blooms; and 4) illustrate the active decomposition 

 of organic matter at ambient temperatures as indicated by bac- 

 teriological changes in the guano at penguin rookeries. 



THE BACTERIAL CONTENT OF AIR 

 AND SURFACE SEA WATER 



An aerosol sampler for membrane filters (AA type, Milli- 

 pore Filter Corp. ) was used to sample the air from the foredeck 

 of the ship. Samples ranging from 25 to 100 liters of air obtained 

 in the Drake Passage in December 1957 failed to demonstrate the 

 presence of bacteria when the membranes were cultivated on 

 Eugonagar (-B.B.L.). While fecal and soil samples were being ob- 

 tained from penguin rookeries at three islands in the South Shet- 

 land Group, air exposure plates were also made. Heart infusion 

 agar plates (Difco) exposed on the ground between nests for 

 periods up to eight hours failed to yield detectable organisms. 



During the 1957 crossing of the Drake Passage, HA type 

 Millipore filters were inoculated with aseptically collected surface 

 water samples and cultivated on media made with varying 

 amounts of Eugonbroth (-B.B.L.) and sea water. A few samples 

 below the Antarctic convergence contained as many as a hundred 

 orange pigmented mesophilic heterotrophs per ml, however, most 

 of the samples contained fewer than ten organisms per ml. Sea 

 water agar pour plates (heart infusion agar base) prepared by 

 Paul R. Burkholder during the 1958-1959 phytoplankton studies in 

 the Bransfield and Gerlache Straits (5) also detected only several 

 organisms per ml in surface water samples. Burkholder (4) foiuid 



