Influence of nutrient supplementation and stress conditions on the biomass and lipid production of Microchloropsis salina for biodiesel production.

This work aimed to introduce a new technique for improving sustainable biodiesel from Microchloropsis salina by examining the impact of various nitrogen sources, salt stress, and carbon enrichment, individually or in combination, to determine the best treatment conditions for biomass and lipid productivity as well as biodiesel quality. M. salina effectively utilizes nitrate (NaNO₃ and KNO₃) and organic nitrogen (especially yeast extract and glycine) but not ammonium for growth. The highest biomass and lipid productivity were observed on yeast extract (0.11 g L⁻¹ day⁻¹ and 52.11 μgmL⁻¹ day⁻¹, respectively). Lipid production enhanced by 80% under 300 mM of NaCl, while growth increased only by 30%. Acetate could not be used to cultivate the alga mixotrophically; only glucose and glycerol were effective. The ideal organic carbon supply values for glucose and glycerol were 3 g L⁻¹ and 2 g L⁻¹, respectively. Nutrition by 2 g L⁻¹ glycerol promoted biomass and lipid productivities by 62% and 95%, respectively, while biomass productivity was reduced by 16% under combined and lipid productivity increased by 80%. All treatments significantly improved the biomass and biodiesel quality-related fatty acid profile. [ABSTRACT FROM AUTHOR]