Development of Cost-Effective Fertilizer-Based Media for the Microalgae Cultivation Aimed at Effective Biomass Production

Abstract

In the diversification of the world's energy portfolio, microalgae biofuels have gained particular attention as a means of providing carbon-neutral hydrocarbon-based fuels. The progress on this front has been hindered because of expensive and unreliable microalgae cultivation systems, where the preparation of synthetic culture media poses a monetary strain. This study aims to investigate a new microalgae growth media that is readily available and cost-effective. The new microalgae fertilizerbased media (FBM) were designed and compared with Bold Basal media (BBM) in terms of growth parameters, production of lipid and value-added algal by-products (carotenoid and phycobiliprotein). The growth parameters such as cell count and specific growth rate were investigated for FBM and BBM. FBM showed a significant growth rate of 7 million/mL-per day as compared to 2 million/ml per day. A similar growth trend was observed for chlorophyll (a), (b) and carotenes which increased to the values of 5microgram/gram formula weight (µg/gfw), 3 µg/gfw and 2 µg/gfw for FBM. On the other hand, lipid and phycobiliprotein showed a decrease of 18.75 % and 16.66 %, respectively, compared to BBM. Even though some growth parameters are negatively affected by fertilizer-based media, the cost reduction is substantial to allow this drawback to be overlooked. The medium's cost is reduced by a factor of 7 and provides ground for the use of the FBM in the large-scale cultivation of algae for biomass production.