CONTENT AND COMPOSITION OF LIPID PRODUCED BY CHLORELLA VULGARIS FOR BIODIESEL PRODUCTION

Abstract

This study aims at investigating the lipid profile of Chlorella vulgaris to determine its suitability as an alternative bio-fuel source. Chlorella vulgaris (stock culture UTEX 259) was sub-cultured at laboratory scale. The cells were kept in 250ml, 500ml, and 1000ml Erlenmeyer flasks with 200ml, 300ml, and 600ml of medium respectively and shaken occasionally in Bold Basal Medium with initial pH value 7 at the temperature of 22+ 3⁰c with constant light intensity for the culture medium which was not more than 2500 lux on a 16:8 light to dark cycle for 7 weeks. The Chlorella vulgaris cells were harvested and the oil extracted. The percentage lipid content was determined by soxhlet extraction and was shown to be 25%. The GC-MS analysis of the transesterified oil showed this lipid profile; nonanoic acid, decanoic acid, palmiltic acid, stearic acid ,oleic acid, linoleic acid with this  chain length C9:0,10:0,16:0,18:0,18:1,18:2 respectively. The percentage unsaturated fatty acid for nitrogen rich media and nitrogen deprived media were 79.22% and 74.2% respectively while the percentage saturated fatty acids were 20.2% and 25.8% respectively. This study shows that Chlorella vulgaris is a suitable candidate for biodiesel production because the lipid profile, lipid composition and level of unsaturation meets requirement of oil suitable for biodiesel production.

Key words: Chlorella vulgaris , lipids, oleic acid ,bio-fuel.