Experimental Evaluation of Seaweeds Liquid Extracts as an Alternative Culture Medium on the Growth and Proximate Composition of Picochlorum maculatum

The present study reveals that the extracts of Sargassum wightii, Sargassum muticum and Turbinaria ornata are possible replacements for commercial and artificial culture mediums. These macro-algae were collected from nature in the Palk Bay region of India. The proximate (carbohydrate, lipid and protein) and mineral (Fe, Ca, PO43−, Na, K, Cl, Zn, Cu, Cd, Mn, NI, Pb, Hg) contents of the algae were analysed before being used as seaweed liquid extract (SWE). This SWE was used for culturing Picochlorum maculatum in combination with additional supplements, artificial culture medium chemicals and commercial fertilizers (instead of using whole medium) to test its efficiency. The results show that P. maculatum can be successfully cultured using SWE as additive or substitute energy source resulting in higher algal cell concentration (0.496 abs) and total biomass (0.57 g L−1). The SWE employed along with commercial fertilizer resulted in 36.4%, 9.98%, 26.8% protein, carbohydrate and lipid levels, respectively, which are higher than the levels obtained using artificial culture medium. In addition, higher amounts of total amino acids (78.2%) and fatty acids (92.52%) were obtained using SWE + SM compared to ACM cultured microalgae (fatty acids—72.27%) and amino acids − 85.85%). This study demonstrates the possibility of using SWE as a commercially viable solution for improving growth and proximate compositions of microalgae in algal feed sector.