Fig. 1

Images of H. pluvialis cells at different time points. H. pluvialis images of control group (a 1235 SHDP route) and treatment group (b 1246 SHDP route) were conducted using scanning electron microscope (SEM, scale bar = 10 μm) and transmission electron microscope (TEM, scale bar = 5 μm), respectively. In both routes, samples 1 and 2 were the same heterotrophic sample at 100 h and 250 h, respectively. H 100 h, H 250 h and H 550 h represent heterotrophic culture for 100 h, 250 h and 550 h, respectively. P 0.5 days and P 6 days represent photoinduction for 0.5 days and 6 days, respectively. Blue arrow and red arrow represent heterotrophic culture and photoinduction, respectively