Morphological and chemical aspects of Chlorella pyrenoidosa, Dunaliella tertiolecta, Isochrysis galbana and Tetraselmis gracilis microalgae

Abstract

This study evaluates the growth and chemical composition of the following marine microalgae: Dunaliella tertiolecta, Isochrysis galbana, and Tetraselmis gracilis and the chemical composition of Chlorella pyrenoidosa. Microalgae can produce a number of compounds of high commercial value for the industry, mainly for the food industry. The growth kinetics, cell volume, pigments, carbohydrates, proteins, lipids, and fatty acid and amino acid composition were evaluated. I. galbana had the largest number of cells per mL-1 (107), concentration of carotenoids (6.33 μg·mL-1), and carbohydrates (34.32%). D. tertiolecta and T. gracilis had the highest cell volume (560.6 and 592.7 μm3, respectively), the highest amount of total dry biomass. D. tertiolecta had the highest chlorophyll concentration (9.05 μg·mL-1), and C. pyrenoidosa had the highest protein (48.16%) and lipid (14.30%) content. The marine species D. Tertiolecta, I. galbana, and T. gracilis had high levels of monounsaturated fatty acids (C18:1 n9), and C. pyrenoidosa was high in polyunsaturated fatty acids (C18:2 n6 and C18:3 n3), indicating the present high nutritional value fatty acids. The microalgae studies showed a composition of amino acids that meet the nutritional requirements recommended by the FAO g·100 g-1 (FAO/WHO/UN, 1985) for adults and children (2 - 5 years), indicating that these proteins can be used in foods.