Effects of the Light Irradiance on the Growth and Lipid Content of Amphidinium carterae (Dinophyceae) for Biofuel Production

Abstract

The irradiance level used in the microalgae cultures can modify the growth and proximate composition; however, this response is specie specific. The dinoflagellate group has the potential to be used as a source of biofuel production. This study evaluated the effect of five irradiance levels (50, 100, 150, 200, and 250 µmol photon m−2 s−1) on the growth rate, proximal composition, pigment content, and photosynthesis of Amphidinium carterae. The highest cell concentration was for the cultures at 150 µmol photon m−2 s−1 (130 × 103 cells mL−1) and the lowest value for 50 µmol photon m−2 s−1 (49 × 103 cells mL−1). The cultures maintained under the lowest irradiance had the highest values of organic dry weight (ODW) and inorganic dry weight (IDW). The protein and carbohydrate content changes significantly concerning the irradiance level, with the higher values (1599.46 pg cell−1 and 557.24 pg cell−1, respectively) at an irradiance of 200 µmol photon m−2 s−1. Lipid content was modified by the effect of irradiance, with the highest values (6920.89 pg cell−1) at the lowest irradiance used. As a general trend, the high irradiances increased the photosynthesis rates. These findings demonstrate that the strain of A. carterae used in this work can grow in high irradiances (100 to 250 µmol photon m−2 s−1) and significantly increase the lipid content at low irradiance used.