AbstractThe potential of microalgal biomasses for the production of biochemicals such as pigments, vitamins, antibiotics, polysaccharides, proteins, essential fatty acids, bio-flocculants, enzymes, etc. is well known. The purpose of this study was to cultivate two cyanobacterial species namely Chroococcus turgidus and Oscillatoria sp., isolated from industrial effluents, using a suitable growth medium in a large-scale High Rate Algal (HRA) pond. The biomolecules such as total protein, total carbohydrate and total lipid, and the pigments chlorophyll, phycobilins, β-carotene, were analysed at regular intervals during cultivation. In addition, the total bacterial cell numbers were enumerated during the study and their influence on algal growth was studied. The algal biomass was harvested by low-cost methods such as auto-flocculation and auto-floatation.