Effects of inoculum physiological stage on the growth characteristics of Chlorella sorokiniana cultivated under different CO(2) concentrations.

In order to maximize microalgae biomass production and reduce its overall costs, it is important to optimize inoculum conditions based on its physical and physiological characteristics. Chlorella sorokiniana cultures inoculated with inoculum at three different physiological stages (lag, exponential, and stationary) diluted to the same optical density were cultivated for 12 days under three different CO(2) concentrations (0.038, 5, or 10 % CO(2) v/v) and growth pattern and biomass production was observed. Samples inoculated with lag phase inoculum supplied with 5 % CO(2) achieved the maximum biomass production, whereas samples supplied with 0.038 % CO(2) never reached exponential growth. The better growth of samples inoculated with lag phase inoculum was attributed to its increased number of cells compared to the other two inocula.