When C. vulgaris had grown to stationary phase, air aeration to
the culture medium was stopped. The microalgae were let to settle
naturally to the bottom of photobioreactor for two days. Two distinguished
layers were observed, in which the upper layer consist
of water with suspended microalgae cells and the bottom layer
was microalgae biomass. The upper layer water was slowly decanted,
leaving behind the microalgae biomass which was further
dried in an oven at 80 C for 24 h. The dried microalgae biomass
were collected and sealed in an empty container for lipid
extraction.