Productivity and fuel quality parameters of lipids obtained from 12 species of microalgae from the northeastern region of Brazil

Abstract

The present work evaluated the growth potential, lipid productivities and the fatty acids methyl esters profiles of 6 chlorophytes and 6 cyanobacteria isolated from the northeast of Brazil, aiming to predict the quality of the biodiesel that could be produced from these microalgae. Among the chlorophytes, Chlorella sp. (D101Z) stood out as having the greatest daily cell division rate (2.42 d−1). Among the cyanobacteria examined, the species Synechocystis sp. (M3C) and Synechococcus nidulans (D109WC) showed elevated lipid (54.2 and 93.8 mg L−1 d−1 respectively) and biomass productivities (0.39 and 0.69 g L−1 d−1 respectively). The lipids produced by the chlorophytes were mainly saturated, monounsaturated, and tri-unsaturated esters, while the cyanobacteria produced high levels of saturated esters and fatty acids with different degrees of unsaturation. Statistical analyses indicated D101Z and D109WC as promising species, as they showed high lipid productivity and the biodiesel produced from their lipids demonstrated low cold filter clogging point values, with a low iodine index for D101Z; the rather high iodine index of D109WC, however, disqualified it for biodiesel production purposes. Among the species studied, only the chlorophyte Monoraphidium contortum (D173WC) and the cyanobacteria D109WC did not meet all of the quality specifications.