1979 Volume 25 Issue 5 Pages 299-306
In sonic extracts, the electron transport system of a psychrotrophic Pseudomonas sp. strain 351 (P. 351) was operating more actively than that of P. aeruginosa at 25° and below. The coupled phosphorylation in P. 351 was also brought about by as much as about three times that in P. aeruginosa at 7°. The activities of the NADH oxidation and the coupled phosphorylation were influenced by the growth temperatures in P. 351, but not in P. aeruginosa. The P/O ratios in the sonic extracts of P. 351, P. aeruginosa, and Vibrio sp. strain ABE-1, a psychrophile, were higher at 7° than at 25°, even when the growth temperatures were varied. The efficiency of the coupled phosphorylation does not seem to be depressed under lower temperatures in these bacteria.