Background: The aim of this study was to investigate the possibility of growing of algae
Ulva lactuca L under different salinity levels coupled with varied KNO3 concentrations (source of
N) as a potential source of oil for biodiesel production.
Methods: U. lactuta was cultured in 10.0% NaCl coupled with either 2.5 g/L (S1+ 1N) or 1.0 g/L
KNO3 (S1+ 2N) and in 30.0% NaCl coupled with 2.5 g/L (S2+ 1N) or 1.0 g/L KNO3 (S2+ 2N) nutrient
medium. Among all algae cultures, biomass (dry weight) and lipid accumulation (total lipid
content, TL) were significantly different (P>0.5%), with various degrees. The TL was increased
(8.21% to 15.95%, g/100g) by increasing the NaCl % (from 10% to 30%) coupled with the depletion
of KNO3 level (from 2.5% to 1%) in culture medium. High lipid content (15.95%) was obtained
in S2+ 2N culture, this lipid showed physical (density, viscosity and average molecular weight) and
chemical (iodine, acid, saponification and peroxide values) properties suitable for biodiesel production.
Results: The fatty acid methyl esters (FAME, biodiesel) prepared by trans-esterifiction reaction under
acidic condition were mainly composed of saturated (50.33%), monounsaturated (MUFA,
36.12%) and polyunsaturated (13.55%) esters. C-18:1 was found to be the main MUFA, representing
25.76% of total FAME. On the other hand, the values of some critical of physiochemical parameter
(density, kinematic viscosity, iodine value, acid value and oxidation stability) of biodiesel
were found to meet the standards for a high quality biodiesel.
Conclusion: Hence, U. lactuta could be serving as a valuable renewable biomass of oil for biodiesel
production. There are recent patents also suggesting use of oil of U. lactuta marine biomass for biodiesel