High quality oil for biodiesel production and biomass yields from a microalga Coccomyxa sp. by autotrophic growth

The aim of this study was to obtain high quality oil for biodiesel production and biomass yields from an isolated oligotrophic strain of genus Coccomyxa. Common media for microalgae, as BG11 and Zarrouk's, have been used to investigate on Coccomyxa nutritional requirements. To optimise biomass yields and growth rate, a new growth medium has been formulated. The results showed that cell density significantly increased under several nutritional conditions, especially with increased amounts of phosphate and magnesium sources; moreover, urea has been used as nitrogen source, because biomass yields were higher than those obtained using either nitrate or ammonium chloride. Fatty acid composition, evaluated in stationary phase, revealed that 72.29% was represented by saturated and mono-unsaturated fatty acids, mostly oleic (42.43%) and palmitic (18.86) acids. Polyunsaturated acids were mostly represented by linoleic acid (21.87%). Data strongly indicate that, due to absence of fatty acids with more than four double bonds, Coccomyxa oil is a very good substrate for transesterification and consequent biodiesel production