Abstract
A glucose-tolerant strain of Synechocystis sp. PCC6803 grows both photoautotrophically and photoheterotrophically consuming glucose as the source of reduced organic carbon. Additionally, light is necessary for the maintenance of photoheterotrophic growth. However, there is little knowledge about the role of the light irradiation to be activating photoheterotrophic growth. The objective of this study is to elucidate the effect of the light on the glucose utilization during the photoheterotrophic growth. Extensive analysis of the activities of the glycolytic enzymes revealed that glycolytic enzymes require light irradiation to maintain the activity. The changes in expression profiles at the protein level in cells incubated in heterotrophic growth conditions in the presence of intermittent light were investigated. Synthesis of at least 30 proteins was induced by light irradiation in the presence of glucose. These results suggest that enzyme activity and protein expression are controlled by light irradiation that enables to maintain the photoheterotorophic growth.
