Strain selection of microalgae isolated from Tunisian coast: characterization of the lipid profile for potential biodiesel production

Abstract

Microalgae could be of importance for future biodiesel production as an alternative for a third generation of biofuels. To select the most appropriate strain for biodiesel production, three microalgae species, namely Isochrysis sp., Nannochloropsis maritima and Tetraselmis sp., isolated from Tunisian coast, were biochemically characterized. Initially, gas chromatography analysis showed that Isochrysis sp. and N. maritima contained 5- and 10-fold total fatty acids, respectively, more than Tetraselmis sp. Then, the two microalgae Isochrysis sp. and N. maritima were subject to random mutagenesis using ultraviolet-C radiation. Subsequently, a total of 18 mutants were obtained from both species. The neutral lipid evaluation on said 18 mutants allowed the retention of only 7 to further fatty acid characterization. Finally, gas chromatography revealed that the mutant 5c Isochrysis sp. was characterized by a high level of saturated fatty acids (52.3%), higher amount of monounsaturated fatty acids (29.3%), lower level of polyunsaturated fatty acids (18.4%) and a significant 1.3-fold increase in its C16-C18 content compared to the wild-type strain, which would make it an interesting candidate for biofuel production.

Integration of Microalgae‐Based Wastewater Bioremediation–Biorefinery Process to Promote Circular Bioeconomy and Sustainability: A Review

“…Screening of microalgae for robust strain selection is a crucial step and several factors are to be considered as screening parameters such as characteristics of wastewater, desired level of treatment efficiency, tolerance of algae to adverse environment, growth, biomass production, nutrient removal, lipid production, self‐flocculation, biosynthesis of secondary products, ease of downstream processing, cost and energy requirements at various stages. [ 21–23 ]…”

“…Screening of microalgae for robust strain selection is a crucial step and several factors are to be considered as screening parameters such as characteristics of wastewater, desired level of treatment efficiency, tolerance of algae to adverse environment, growth, biomass production, nutrient removal, lipid production, self-flocculation, biosynthesis of secondary products, ease of downstream processing, cost and energy requirements at various stages. [21][22][23] Although traditional culture techniques are the most commonly used techniques for screening and selection of microalgae with defined characteristics, recently there has been focus upon high-throughput techniques that enable the screening of several thousands of cells in a short period of time. This part of review summarizes different techniques that could be used for screening and selection of productive microalgal strains for combined bioremediation-biorefinery applications.…”