ROLE OF OXYGEN IN THE HIGH CELL YIELDS OF PSYCHROPHILES AND MESOPHILES AT LOW TEMPERATURES

Sinclair, N. A. (Washington State University, Pullman) and J. L. Stokes. Role of oxygen in the high cell yields of psychrophiles and mesophiles at low temperatures. J. Bacteriol. 85:164-167. 1963.-Psychrophilic and mesophilic bacteria produce maximal cell crops in stationary cultures at temperatures 10 to 20 C below those at which growth is most rapid. Our data indicate that O(2) is rapidly depleted to growth-limiting levels in stationary cultures, and that the higher cell yields at the lower temperatures are due simply to the increased solubility and, therefore, availability of O(2). This conclusion is supported by the observation that equal cell crops are produced at high and low temperatures when cultures are vigorously aerated so that O(2) is not limiting, and also when facultative bacteria are grown anaerobically so that there is no O(2) to exert an effect.