Cultivation of freshwater microalga Scenedesmus sp using a low-cost inorganic fertilizer for enhanced biomass and lipid yield

The potential of an inorganic fertilizer as an alternative nutrient source for the cultivation of Scenedesmus sp. IMMTCC-6 was investigated. With a preliminary study at a shake-flask scale, the microalgae cultivation was scaled up in a photobioreactor containing an inorganic fertilizer medium. Microalgae cultured in a shake flask containing 0.1 g L-1 of urea and 1.0 g L-1 of NPK (Nitrogen: Phosphorus: Potassium) fertilizers showed a promising result in biomass productivity. During the scale-up study in a photobioreactor the specific growth rate (mu d(-1)), biomass yield (g L-1), and total biomass productivity (mg L-1 d(-1)), was found to be 0.265, 1.19 and 66.1, respectively. The lipid yield (%) as per dry cell weight (DCW) and lipid productivity (mg L-1 d(-1)) was found to be a maximum of 28.55 and 18.87, respectively, in a stationary phase of the microalgae growth. The fatty acids methyl ester profile was proven to be desirable for biodiesel production.