The effects of CO2-induced acidification on Tetraselmis biomass production, photophysiology and antioxidant activity: A comparison using batch and continuous culture

•Tetraselmis has a higher antioxidant activity in balanced culture in acidic condition.•CO2-acidification enhances Tetraselmis growth in batch and continuous culture.•Culture mode and CO2-acidification have interactive effects on Tetraselmis physiology.•CO2-acidification with N-limitation induce a decrease of photosynthetic parameters.•CO2-acidification and culture mode are effective tools to optimize antioxidant activity.