Studies on the Relationship between Growth and Substrate Oxidation Activity in Pseudomonas fragi and Pseudomonas aervginosa

Abstract

The effect of temperature on the growth and substrate oxidation activity in Pseudomonas fragi (as a psychrophile) and P. aeruginosa (as a mesophile) was investigated. The results obtained are summarized as follows.
1. Both organisms showed essentially the same temperature-characteristic patterns of growth rate, except that the temperature-optima for growth of P. fragi and P. aeruginosa were 25 and 35C, respectively.
2. Both organisms resembled each other with regard to the temperature-characteristic patterns of malate or succinate oxidation and those of several dehyrogenase activities within a range from 5 to 35C.
3. In a higher temperature range, for instance, at 45 C, P. aeruginosa oxidized pyruvate, ethanol, acetate, and malate more effectively than P. fragi did, and vice versa in a lower tempetaure range, except for malate oxidation.
44. The temperature-characteristic patterns of malate oxidation activity in intact cells were similar to those in dried cells of each Pseudomonas species.