Global population growth combined with progressively inadequate resources of arable land and fresh water has resulted in a need for alternative protein sources. Microalgae are examples of viable source of protein that do not compete with traditional high-protein crops such as soybean and legumes for space and resources. Arthrospira platensis (Spirulina platensis) is a filamentous Cyanobacterium that has among the highest documented protein content of any foods. In current investigation, effect of alginate (0, 0.5, 1 and 2 g/L) and chitosan (0, 0.5, 1 and 1.5 g/L) on protein and phycocyanin production of Spirulina platensis was investigated. Furthermore, cytotoxic effect of algal methanolic extracts on two breast cancer cell lines MCF-7 and MDA-MB-231 were investigated. According to the results, the highest amount of growth (1.95g/l), protein (0.932g/l), and phycocyanin (0.651g/l) on 2 g/L alginate-treated samples were observed. Based on the results, the highest anticancer effect was related to methanolic extract of alginate-treated samples (300 μg/ml) on both cell lines and they showed dose- and time- dependent manner.
