The total phenolic content of the extracts was estimated by the Folin-Ciocalteu method. Two hundred microlitres of diluted sample were added to 1 mL of 1:10 diluted Folin-Ciocalteu reagent. After 4 min, 800 毺L of saturated sodium carbonate (75 g/L) was added. After 2 h of incubation at room temperature, the absorbance at 765 nm was measured using the Perkin Elmer Lamba 25 UV-vis Spectrophotometer. The results were expressed as Gallic acid equivalent (GAE)/g dry weight of microalgae, and calculated as mean value 暲 SD (n = 3).