Influence of salinity as a stress factor to harness biodiesel was assessed during dual mode cultivation of
microalgae by integrating biomass growth phase (BGP) and salinity induced lipid induction phase (LIP).
BGP was evaluated in mixotrophic mode employing nutrients (NPK) and carbon (glucose) source while
LIP was operated under stress environment with varying salt concentrations (0, 0.5, 1 and 2 g NaCl/l).
Salinity stress triggered both biomass growth and lipid synthesis in microalgae significantly. BGP showed
higher increments in biomass growth (2.55 g/l) while LIP showed higher lipid productivity (1 g NaCl/l;
total/neutral lipid, 23.4/9.2%) than BGP (total/neutral lipid, 15.2/6%). Lower concentrations of salinity
showed positive influence on the process while higher concentrations showed marked inhibition. Salinity
stress also facilitated in maintaining saturated fatty acid methyl esters in higher amounts which associates
with the improved fuel properties. Efficient wastewater treatment was observed during BGP operation
indicating the assimilation of carbon/nutrients by microalgae.