Effects of nitrogen source and concentration on total fatty acids production in heterotrophic culture of Chlorella protothecoides CS-41

摘要

Four nitrogen sources (urea, tryptone, Bacto peptone and yeast extract) at various concentrations (0.01-0.09 mol N/L) were investigated to evaluate the effects on biomass and total fatty acids (TFA) production as biodiesel feedstock in batch culture of heterotrophic Chlorella protothecoides CS-41. With 40 g/L of glucose, urea at 0.05 mol N/L gave the highest biomass production (26.9 g/L). Over 99% of TFA was C18 (~72.5%) and C16 (~26.5%) fatty acids in biomass. The highest TFA yield of 5.2 g/L was obtained at 0.07 mol urea-N/L, which produced a high biomass concentration (25.9 g/L) with a high TFA content (20.1% DW) and a desirable fatty acids composition (C18 fatty acids >72% TFA). The results indicated that the simple nitrogen source, urea, at a suitable concentration can significantly improve the TFA yield in the batch culture of heterotrophic C. protothecoides CS-41, which can provide a cost-effective algal oil source for biodiesel production.