Resumo

Introduction: Photosynthetic microorganisms convert abundant solar energy into chemical energy and its conversion efficiency is higher than terrestrial plants. The cultivation of photosynthetic microorganisms is an attractive process for obtaining biochemical components with value-added. They can be used as important food source since their composition include proteins, carbohydrates, pigments, vitamins and value trace elements. Among these microorganisms, Arthrospira has high protein content (50–70 % of dry weight) and its proteins include all the essential amino acids (~4.5 % of the total protein weight). It also can be used for environmental bioremediation and as energy source. Iron salts are important in photosynthetic microorganism growth. Material and Methods: This research evaluates A. platensis growth and its biomass’ composition in batch cultivation using Schlösser medium with ferric sulfate. A. platensis was cultivated in Erlenmeyer 0.5 L flasks with initial cell concentration of 50 mg L^-1) in rotatory shaker at 100 rpm, 30 °C and light intensity of 72 μmol photons m^-2 s^-1, considering ferric sulfate quantities and EDTA presence as independent variables. Cellular concentration was determinate by measuring the optical density at 560 nm. Two way ANOVA was used in order to explain the experimental results considering a P-value of 0.05. Discussion: The maximum cell concentrations, total lipids and total proteins were influenced by ferric sulfate increment and EDTA presence. The highest maximum cell concentration (2049 ± 8 mg L^-1) was reached with 60 mg L^-1 without EDTA, leading to biomass with 54 ± 1 % of total proteins and 15.9 ± 0.2 % of lipids. The maximum cell concentration, total proteins and total lipids are 31, 25 and 29 % higher than the values reached in standard medium probably due to the influence of ferric ions in culture medium. However, the chlorophyll productivities reached were not influenced by ferric sulfate addition and EDTA presence. Conclusion: It was demonstrated that ferric sulfate addition and EDTA presence could influence on A. platensis cultivation. Therefore, they could enhance cellular growth and total protein values leading to produce biomass with higher quality than that one produced with only standard medium.