Effect of physicochemical parameters on the growth of two microalgae strains, the Chlorella vulgaris and Skeletonema costatum isolated from different sites in the nador lagoon

Abstract

Microalgae have become a major focus of scientific research in recent years, due to their use in food human and animal, pharmaceuticals and renewable energy production.The main objective of our study was to identify the phytoplankton of the Nador lagoon and to study the effect of physico-chemical parameters such as nitrogen, phosphorus and pH on the growth of two strains isolated from different sites in the Nador lagoon: Chlorella vulgaris and Skeletonema costatum, in order to optimize culture medium compositions and achieve good phytoplankton growth.Morphological studies using inverted optical microscopy revealed the important morphological distinguishing features of the two phytoplankton species studied, originated from the six different sampling stations.The results of the optimization protocols for medium composition and culture conditions (the effect of nitrogen, phosphorus, pH and vitamins) allow us to conclude that the two strains tested are growing well.In fact, the results of the physico-chemical parameters in our study show pH values of 7.5, 7 and 6.5 and nitrate and orthophosphate concentrations during the bloom period of 1.5 g/l and 0.31 g/l respectively. And for the quantitative study, we can conclude that Chlorella vulgaris was dominant with a density of 2840 cells/l, and that Skeletonema costatum was dominant with a density of 2160 cells/l.The study provides crucial insights into the growth patterns of these microalgae under different physico-chemical conditions, contributing to the optimization of culture practices for potential applications in various industries.