Among the various potential sources of renewable energy, biofuels are of most interest. Marine microalgae are the most promising oil sources for making biofuels, which can grow very rapidly and convert solar energy to chemical energy via CO2fixation. The fatty acid profile of almost all the microalgal oil is suitable for the synthesis of biofuel. In this research, fatty acid and lipid contents of Bangladeshi strains of marine microalgaeSkeletonema costatumwere performed. For this, the crude oil was extracted by Soxhlet extraction method, using three most common solvent systems, pure hexane and mixture of CHCl3 : MeOH (2 : 1) and hexane : EtOH (3 : 1) one by one. Highest oil recovery (15.37%) came from CHCl3 : MeOH (2 : 1) solvent system from dry biomass whereas the lowest (2.49%) came from n-hexane from wet biomass. The qualitative analysis of the extracted oil by GC/MS analysis revealed that it contained significant amount of myristic acid (C14:0), palmitic acid (C16:0), stearic acid (C18:0), and palmitoleic acid (C16:1). It also indicated presence of hexadecatrienoic acid, benzenedicarboxylic acid, oleic acid, arachidonic acid, eicosapentaenoic acid (EPA), 9-Octadecenoic acid methyl ester (C19H36O2), and so forth. The obtained fatty acid profile indicates high potentiality ofS. costatumspecies to be used as promising biofuel feedstock a little improvisation and substantially it can replace diesel in near future.

Chlorococcum sp. has been studied as its possibility for biofuel feedstock. This alga was grown in Zarrouk media. After harvesting, lipid extraction was done by pure n-hexane and mixture of chloroform: methanol (2 : 1)) and hexane: ethanol (3 : 1). Highest oil recovery (21.20%) derived from chloroform: methanol (2 : 1) solvent system from dry biomass whereas the lowest (2.83%) came from n-hexane: ethanol solvent system from wet biomass. GC/MS used for the analysis of extracted lipid revealed that, palmitic acid methyl ester (C 17 H 34 O 2 ), 9-octadecenoic acid methyl ester (C 19 H 36 O 2 ) were major contents of this biofuel. The acquired fatty acid profile indicates that Chlorococcum sp. could be used as promising biofuel feedstock in near future.