Chemical composition of five marine microalgae that occur on the Brazilian coast

Abstract

Giselle S Costard, Rodrigo R. Machado, Elisabete Barbarino, Ricardo C. Martino, Sergio O Lourenço

Five native species of marine microalgae were batch cultured and their chemical composition was measured in different growth phases. The highest cell yield was recorded in CHLORELLA sp. CHLORELLA sp. and BELLEROCHEA sp. showed a reduction of the mean cell volume throughout growth. All microalgae showed protein as the main chemical component, with peaks in the exponential growth phase. The same was found for chlorophyll. Carbohydrates (CHLORELLA sp.), ash (BELLEROCHEA sp. and CHLORELLA sp.), and lipids (RHODOMONAS sp. and THALASSIOSIRA sp.) were relatively high in some of the species, at least in one of the growth phases. The carbohydrate content increased throughout growth, but no clear relationship among growth, total lipid and ash content was identified. Total saturated fatty acids were higher in the exponential growth phase of all species, decreasing throughout growth. RHODOMONAS sp. showed high levels of polyunsaturated fatty acid (PUFA), but low percentages of some essential fatty acids. BELLEROCHEA sp., CHAETOCEROS sp. and CHLORELLA sp. showed low percentages of total PUFA, but all essential fatty acids were present, except for the green alga. Current results may contribute to selecting strains that possess suitable chemical composition and fast growth, useful characteristics for the sustainable use of native species in aquaculture.