Content and component analysis of lipid in three freshwater diatoms.
Three strains of freshwater diatoms(Nitzschia capitellata,Synedra acus,Synedra ulna var.danica) were cultured and their lipid content and composition were examined and analyzed to assess the potential of these microalgae as biodiesel feedstocks.Growth period of Nitzschia capitellata was shorter and its biomass higher than that of Synedra acus and Synedra ulna var.danica.Total lipid represented 2.92%~9.25% of dry weight with the highest percentage in Nitzschia capitellata(9.25%).The fatty acid component was similar and indicated that the main components were myristic(C14:0),palmitic(C16:0),palmitoleic(C16:1),oleic(C18:1),linoleic(C18:2)and parinaric acids(C18:4);The percentage of unsaturated fatty acids(UFAs) in each lipid fraction was more than 60% of the total fatty acids with Nitzschia capitellata reaching up to 63.54%.The results indicated that Nitzschia capitellata could be used as a biodiesel feedstock after further improvement of the culture conditions.