Abstract
Synechocystis sp. PCC6803 grow photoautotrophically and photoheterotrophically, and requires light for photoheterotrophic growth. We investigated the cause of this light requirement. The pool size of glutamic acid in the cell falls when cells are put on the dark places and increases when cells are irradiated by light. It was suggested that the glycolytic pathway or TCA cycle are inactivated in the dark and are activated in the light. The expressions of the genes encoding glycolytic enzymes was stimulated by light. Therefore, transcription of genes in glycolysis was suppressed under the dark condition and increased by the light irradiation. Moreover, the activity of glycolytic enzyme of the cells put on the dark condition was lower than the cells carried out light irradiation. These results suggest that the gene expression and enzyme activity of the glycolytic pathway are controlled by light irradiation, which maintain the photoheterotorophic growth.
