In this research, a new cost-effective carbon source of medium was provided in terms of high-efficiency growth from Arthrospira maxima. Sugarcane molasses was used in two different modes (alternative and additive) at four different concentrations (0, 0.5, 1.0 and 1.5 gL-1 ) to determine the effect of new carbon source versus its standard carbon source of Zarrouk’s medium (NaHCO3). The experimental results were analyzed by Taguchi L8 method as a statistical technique. The highest biomass production obtained when sugarcane molasses was added as an alternative source, which was 5.31 times higher than the usual Zarrouk's media. Furthermore, final biomass concentration increased with increasing molasses concentration from 0 to 1.5 gL-1 in this group. At highest concentration, phycocyanin (at 0.11 and 0.12 gL-1 ), allophycocyanin (at 0.13 and 0.12 gL-1 ), carotenoids (at 2340 and 2535 mgL-1 ), chlorophyll a (at 23.83 and 24.83 mgL-1 ), and chlorophyll b (at 0.343 and 2.99 mgL-1 ) obtained when molasses were added as an additive and alternative sources, respectively. Finally, the replacement of standard carbon sources of medium with sugarcane molasses had the potential possibility in order to reduce the production costs of Arthrospira maxima growth
