Lipid quality of Skeletonema costatum and Navicula gregaria from South Atlantic Coast (Argentina): evaluation of its suitability as biodiesel feedstock

POPOVICH C. A.; DAMIANI, M. C; CONSTENLA, D.; LEONARDI, P. I.

JOURNAL OF APPLIED PHYCOLOGY

SPRINGER

Año: 2010

0921-8971

Since the fatty-acid ester profile of a given biofuel is relatively consistent with the source’s fatty-acid profile, the properties of the biodiesel produced from a particular feedstock exhibit predictable quality. Thus, lipid fractions and the fatty-acid composition of stationary growth-phase cultures of the native strains Skeletonema costatum and Navicula gregaria were analysed to evaluate their suitability as biodiesel feedstock. Total lipid amount per cell was 20.83 pg cell-1 in S. costatum and 19.17 pg cell-1in N. gregaria. Neutral lipids were the main fraction of total lipids in both species, accounting for ca. 65 % and 76%, respectively. Skeletonema costatum was predominant in saturated fatty acids (SFAs) (43.48 %) and monounsaturated fatty acids (MUFAs) (40.11%), while N. gregaria was predominant in MUFAs (54.85%), followed by SFAs (33.42%). The oils extracted from these species presented linolenic-acid contents within biodiesel’s quality specifications. However, in neutral-lipid fraction both species showed eicosapentaenoic acid levels higher than the required limit. The lipid quality analysed in both species suggests that a biodiesel derived from these oils may present an acceptable cetane number, but likely poor cold flow properties. This baseline information is useful for future research tending to find more suitable conditions in order to improve oil yield. In addition, both estuarine species neither compete with agriculture for food nor require farmland nor fresh water.