Chlorophyll Synthesis in Chlorella II. Effect of Glucose and Light Intensity on the Lag Phase

Dense cultures of Chlorella grown under our conditions contain large amounts of chlorophyll on a packed cell basis. Upon dilution the cells are, in effect, put into an environment in which light is not limiting and chlorophyll seemingly in excess (at least temporarily). Thus it is not economical for the cell to produce more chlorophyll until it is the limiting factor. It is our contention that the cell may sense this situation by the piling up of products such as glucose or starch. The observed light intensity effect which causes a stimulation of chlorophyll production at lowered intensities is analogous to that previously reported by others and is felt to be related to the rate of photosynthate production.