Relative abundance of lipid types among Chlorella sp. and Scenedesmus sp. and ameliorating homogeneous acid catalytic conditions using central composite design (CCD) for maximizing fatty acid methyl ester yield

Abstract

The present study has tested the biodiesel potential of two hyper lipid producing strains Chlorella sp. and Scenedesmus sp. in terms of biomass yield, quantity and quality of lipid and fatty acid composition. Biomass yield of Chlorella sp. and Scenedesmus sp. was 1.26 and 1.33 g/L, respectively on day 18 and 20. The lipid content and lipid productivity of Chlorella sp. and Scenedesmus sp. was estimated to be 21.3, 26.5% and 12.33, 14.74 mg/L/d, respectively. Notably, relative abundance of lipid types in both the strains revealed >60% neutral lipids followed by glycolipids and phospholipids in minimal level. Central composite design based optimization revealed 69 and 65.4% FAME yield from Chlorella sp. and Scenedesmus sp. at 3% sulphuric acid and 65 °C reaction temperature. Eventually, higher levels of saturated fatty acids (~45%) and monounsaturated fatty acids (~34%) and make Scenedesmus sp. a promising parent material for workable biodiesel production.

Keywords: Acid catalysis; Biodiesel; CCD; Fatty acid; Lipidomic analysis; Microalgae.