Evaluation of effective environmental parameters on lipid, protein and beta-carotene production in Spirulina platensis microalga

Abstract

Microalgae are able to produce various products, including biofuel, proteins, and beta-carotene. Hence, the determination of optimal conditions for the production of these compounds is of utmost importance. This study aims to evaluate the impact of environmental parameters on the production of lipid, protein, and beta-carotene in Spirulina platensis microalgae. The studied parameters included salinity levels of 1, 2, and 3 M, pH values above and below seven, nitrate concentrations of 0.25 and 0.5 g L−1, light intensities of 2500 and 5000 lux, and temperatures of 25 and 30 °C. The results suggest that the highest protein level is synthesized at 2 M salinity, acidity above seven, 0.25 g L−1 nitrate concentration, 5000 lux of light intensity, and 30 °C temperature. However, the optimal conditions for lipid accumulation are found as the salinity of 2 M, pH greater than 7, nitrate concentration of 0.25 g L−1, the light intensity of 5000 lux, and temperature of 30 °C. The optimal beta-carotene production occurs at 3 M salinity, pH ≥ 7, nitrate concentration of 0.5 g L−1, the light intensity of 5000 lux, and temperature of 30 °C. A better understanding of the optimal conditions can ensure the maximum production of bioproducts, including biofuel, protein, and beta-carotene in Spirulina platensis microalga, at minimum costs.