Quality of algal material produced on a fertilizer-tap water medium in outdoor plastic-enclosed systems

A naturally developed Chlorella species was cultured on a fertilizer-tap water medium in outdoor plastic-enclosed units. Algal material, harvested from an actively growing culture, was analysed for crude protein, lipids, carbohydrates, ash and amino acid composition. The composition compared favourably with figures previously reported in the literature, with the crude-protein content of 59% being the main feature. The amino acids cystine and methionine were, however, present in low amounts. An ultrastructural comparison of a naturally developed outdoor Scenedesmus culture, grown with varying fertilizer additions, confirmed that optimum addition of superphosphate (40 mg/l=4.5 mg P/l) and urea (65 mg/l=29.9 mg N/l) yielded a material which compared favourably with that grown in well-balanced nutrient media.