Etude comparative des paramètres biochimiques chez les microalgues (Nannochloropsis gaditana) et les macroalgues (Ulva lactuca, Coralina elongata et Cystoseira sp ).

Abstract

Marine algae are a potential source of a compound with applications in different fields. Lipids and proteins represent the two main groups of molecules of interest both in macroalgae and in the microalgae that make up phytoplankton. As part of the valuation of marine algae biomass, as well as the Algerian dimensions, we are interested in the study of the biochemical composition of some algae of the Algerian west coast (Green algae: Ulva lactuca, Brown algae: Cystoseira sp, Red algae: Coralina elongata, and Micro algae: Nannochloropsis gaditana). The objective of this work is to study the biochemical composition of algal biomass and more specifically the following species: Ulva lactuca, Cystoseira sp, Coralina elongata and Nannochloropsis gaditana. This study is based on a quantification of the lipid content by the Soxhlet method, an assay of the protein concentration by the Bradford method and an extraction of photosynthetic pigments (Chlorophyll a and b). The results obtained show that the lipid content in Ulva lactuca, Cystoseira sp, Coralina elongata and Nannochloropsis gaditana is 18.8%, 34.7% 34.9% and 57.1% respectively. The protein yield quantified by the Bradford reaction is greater in microalgae than in macroalgae and. The pigment level in Cystoseira sp and Ulva lactuca is 1.59% and 1.04%, respectively. Determination of the biochemical composition revealed that these species are an excellent source of lipid, pigments and proteins.