Fig. 2From: Two-stage mixotrophic cultivation for enhancing the biomass and lipid productivity of Chlorella vulgaris Plots showing the time-dependent changes observed in: a the growth of C. vulgaris, and b pH of the culture during the cultivation period for the four treatment groups. Experiments were conducted in triplicate, and the results shown are the means (with standard deviations, n = 3)Back to article page