Enhancing growth and lipid productivity in Dunaliella salina under high light intensity and nitrogen limited conditions

Abstract

Microalgae are potential feedstocks for renewable energy production and solving some environmental problems. The effects of nitrogen, sulfur and phosphorus limitations, light intensity (100 or 800 μmol·m−2·s−1) and CO2 concentration (1% or 10%) on growth and lipid accumulation were investigated for Dunaliella salina. The effects of nutrient limitation and light intensity were also characterized by flow cytometry and photosynthetic activity. High light intensity promoted the carbohydrate accumulation and low light intensity was beneficial to lipid accumulation under N-limited conditions. The highest biomass productivity was 1.03 g L−1 d−1 at day 2 under 1% CO2, high light intensity and 1/4 N conditions. The highest lipid productivity was 0.24 g L−1 d−1 at day 2 under 10% CO2, high light intensity and N-limited conditions. A novel approach was proposed and it is helpful for the microalgae biofuel development in future.