UNLOCKING BIODIESEL POTENTIAL: PROFILING FATTY ACIDS FROM MICROALGAE ISOLATED FROM AGRICULTURAL SOIL

This study investigates the potential of using three microalgae as biodiesel substitutes.These microalgae were previously isolated from agricultural soil from Saudi Arabia.The isolates exhibited varying fatty acid profiles, with saturated fatty acids constituting nearly 50% of the total fatty acid composition and the polyunsaturated fatty acids constituting 37%-49%.Highly unsaturated fatty acids with more than four double bonds are absent in the investigated microalgae.In terms of biodiesel properties, all isolates demonstrated similar cetane numbers within the recommended standards.Coelastrella sp.UJ and Chlorella sorokiniana UJ had slightly elevated iodine values, but close to the recommended values.Chlamydomonas zebra UJ showed the lowest degree of saturation (DU=93), while Chlorella sorokiniana UJ had the highest (DU=108).The long-chain saturated fatty acids were highest in Chlorella sorokiniana UJ and lowest in Coelastrella sp UJ.Cold filter plugging point was around -16C, slightly lower than the recommended values.Viscosity levels for all strains fell between 0.69 and 1.96, aligning with US minimum requirements but below EN standards.This research evaluated the viability of these microalgae as sustainable biodiesel sources.Based on these findings, future studies are necessary to optimize growth conditions, enhance fatty acid profiles, and maximize biodiesel yield.