Nutrition and Metabolism of Marine Bacteria

Marine bacteria have been arbitrarily defined as bacteria from the sea which on initial isolation require for growth a medium containing sea water as the diluent (ZoBell and Upham, 1944). The function of sea water in media for the growth of these organisms has never been clearly established. It has been stated, however, that neither isotonic salt solution nor artificial sea water is as good as natural sea water for the cultivation of recently isolated marine bacteria (ZoBell, 1946). The nutritional requirements of a number of marine bacteria have been determined recently (MacLeod et al., 1954). In the course of this study it was found that a mixture of inorganic salts approximating the composition of sea water could be used in place of natural sea water in a chemically defined medium suitable for the growth of these organisms. A limited amount of information regarding a requirement of the bacteria for specific inorganic ions was also obtained. The present report presents the results of a more detailed study of the relation of the constituents of sea water to the growth of marine bacteria.