Biomass nutrient profiles of the microalga Porphyridium cruentum

Nutritional composition is analysed for the red microalga Porphyridium crue ntum cultured under various conditions in an external tubular photobioreact or. The data include the proximate composition (moisture, ash, crude protei n, available carbohydrates, fiber, lipids and energy), nitrate, RNA, minera l elements (Na, K, Ca, Mg, Fe, Cu, Zn, Mn, Cr, Mn, Co, S, As, Pb, Cd), C/N ratio, fatty acids and pigments (carotenoids, phycobiliproteins, chlorophyl ls and degradation products). On average, the biomass contains 32.1% (w/w) available carbohydrates and 34.1% crude protein. The mineral contents in 10 0 g dry biomass were: Ca (4960 mg), K (1190 mg), Na (1130 mg), Mg (629 mg) and Zn (373 mg). Toxic heavy metal contents were negligible. The fatty acid contents were (in percent dry wt): 1.6% of 16:0; 0.4% of 18:2 omega 6; 1.3 % of 20:4 omega 6 and 1.3% of 20:5 omega 3. Nutrient composition of biomass was highly influenced by residence time in the bioreactor and the external irradiance. The biomass collected for short residence times was richer in protein and eicosapentaenoic acid. (C) 2000 Elsevier Science Ltd. All right s reserved.