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Abstract
The marine bacterium Beneckea natriegens was grown in batch culture on a glucose/NH4 +/salts medium; growth terminated due to either carbon or nitrogen depletion from the medium. Nitrogen-limited cultures converted part of the excess glucose into glycogen whereas the carbon-limited cultures formed little glycogen. Glycogen-rich cultures survived longer than glycogen-poor cultures during starvation. Little protein was utilized during starvation and RNA was degraded as the primary endogenous source of energy. Glycogen was consumed only when the RNA content had decreased to about a third of the growth value.
The adenine nucleotide content of nitrogen-limited cultures increased at the start of the stationary phase but the energy charge remained at the growth value of 0·9 to 0·95. The maximum size of the adenine nucleotide pool depended on the concentration of glucose remaining in the medium at the start of the stationary phase but a limiting value of about 60 mol ATP (g protein)−1 was attained, compared with 12 to 14 μmol ATP (g protein)−1 in exponentially growing cultures. During extended starvation of both glycogen-rich and glycogen-poor clutures, there was a large decrease in adenine nucleotide content, but the energy charge remained above 0·6 even when viability was very low.
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