Biochemical composition of green microalgae Pseudoneochloris marina grown under different temperature and light conditions

Abstract

Abstract Environmental factors such as temperature, light intensity, and nutrient availability, are central in microalgae metabolism, affecting their growth and composition. This study evaluated the effects of nitrogen concentration (37.1–78.8 mg L−1 N-NO3), temperature (20–36 °C) and light intensity (140–364 μmol m−2 s−1) on biomass productivity and biochemical composition of Pseudoneochloris marina. The highest biomass productivity (0.26 g L−1 d−1) was achieved with 74.1 mg L−1 N-NO3 at 28 °C and 252–364 μmol m−2 s−1. Protein content decreased with the increment of factors levels and the highest content was 236 ± 18 mg g−1 at 20 °C and 140 μmol m−2 s−1. The carotenoids and lipids were affected negatively by light intensity. The highest xanthophylls and carotenes contents were, respectively, 2.55 ± 0.39 mg g−1 and 1.25 ± 0.01 mg g−1 at 20 °C/28 °C and 140 μmol m−2 s−1. The major carotenoids were all-trans-lutein (36.0 ± 2.9%) and all-trans-β-carotene (13.2 ± 1.2% of total carotenoids). The saturated, monounsaturated and polyunsaturated fatty acids represented 46.1 ± 1.5%, 10.6 ± 1.7% and 43.3 ± 1.0% of total fatty acids. The main fatty acids were C16:0, C18:2n-6, C18:3n-3 and C18:1. The lowest ω6:ω3 ratio was 1.6 ± 0.1, at the lowest temperature.