Figure 1. Variation of P. donghaiense cell density over time.

The cell cycle experiment started at 1600 of the second day and ended at 1200 of the third day. Cell division was phased with the diurnal cycle, and cell density was maintained relatively stable until 0600 h and increased sharply between 0600 and 1000 h, mainly from 0600 to 0800 h.