Effect of Temperature Stress on Adenylate Pools and Energy Charge in a Psychrophilic Bacterium, Vibrio sp. ABE-1

The adenylate energy charge in the psychrophilic bacterium Vibriosp. ABE-1 remained unchanged while the cells grew, althoughthe ATP pool varied in parallel with the growth rates underdifferent temperature conditions (0–20°C). However,at a nonpermissive temperature (25°C), the bacteria couldnot grow, the energy charge decreased due to temporary disappearanceof ATP, and before long, both the number of viable cells andthe energy charge decreased. Phosphoribosyl pyrophosphate synthetase, an ATP-utilizing enzyme,could be efficiently controlled by the energy charge at permissivetemperatures, but was regulated little or not at all at a nonpermissivetemperature (25°C). The regulation possibly arose from inhibitionof the enzyme activity by ADP or AMP, and especially by thereaction product AMP. (Received December 18, 1982; Accepted April 16, 1983)