ZoBell 



— 178 



Marine Microbiology 



Table XXXVI. — Average number of bacteria which developed on sea-water and fresh-water 

 nutrient agar exposed to air under comparable conditions during a sustained otishore breeze {from 

 ZoBell, 1942c) : — 



positive, sporogenous rods generally characterize continental air. Only 

 15 of the 100 different cultures of bacteria isolated at random by Ritten- 

 BERG (1939) from plates exposed to air over the ocean proved t:o be ter- 

 restrial species. 



Reitano and Morselli (1938) found bacteria in the air at all stations 

 where observations were made 2 to 9 kilometers from the coast over the 

 Mediterranean Sea. Their analytical procedures precluded the possibility 

 of differentiating marine from terrestrial bacteria. They failed to take 

 into account meteorological conditions. This also applies to the observa- 

 tions of GiUDiCE (1939) who found from 12 to 280 bacteria per cubic meter 

 of air in samples collected from 30 stations on the Red Sea and Mediter- 

 ranean Sea. 



The California State Bureau of Sanitary Engineering (1943) presents 

 evidence that Escherichia coli and other enteric organisms may be carried 

 by the wind several miles from sewage outfalls. This observation further 

 emphasizes the ecological and possible sanitary significance of the aerial 

 transport of microorganisms. Proctor and Parker (1942) reported the 

 presence of a great variety of living microorganisms in the air at elevations 

 exceeding 35,000 feet above the earth, which indicates the possibilities of a 

 world-wide distribution by air currents. 



Yeasts and mold spores in air : — Pink yeasts, probably Torula spe- 

 cies, have been observed on plates exposed to marine air by many investi- 

 gators, including Fischer (1894c). McLean (1918) recovered two pink 

 yeasts from marine air over Antarctica. 



The number of mold spores in air over the ocean generally decreases 

 with distance from land. This is illustrated by the following data from 

 Rittenberg (1939): 



All of the mold fungi isolated from marine air by Rittenberg proved to 

 be common terrestrial species. The mold spores recovered from air over 

 the ocean by Fischer (1886) were chiefly common varieties of Penicillium, 

 Aspergillus, and Mucor. 



The fungus content of air is believed to be an indicator of its origin and 

 history, since few if any mold spores enter the atmosphere from the ocean. 



