Analysis of fatty acid content and composition in microalgae

Area of Science:

• Biotechnology
• Analytical Chemistry
• Marine Biology

Background:

• Fatty acids are key components of microalgal biomass, found in various acyl-lipid classes.
• Triacylglycerol (TAG) fatty acids are commercially valuable for biofuels, chemicals, nutraceuticals (e.g., omega-3), and food.
• Accurate analytical methods are crucial for quantifying microalgal fatty acid content and composition to enable commercial applications.

Purpose of the Study:

• To develop and present a robust method for the accurate and reproducible determination of total fatty acid content and composition in microalgae.
• To ensure the method effectively disrupts rigid microalgal cell walls and extracts all acyl lipid classes.
• To provide a quantitative analysis independent of fatty acid chain length, unsaturation, or lipid class.

Main Methods:

• Mechanical cell disruption to liberate acyl lipids.
• Solvent-based lipid extraction to recover all acyl lipid classes.
• Transesterification of fatty acids into fatty acid methyl esters (FAMEs).
• Gas chromatography with Flame Ionization Detection (GC-FID) for FAME identification and quantification.
• Inclusion of a triacylglycerol (TAG) internal standard (tripentadecanoin) to correct for procedural losses.

Main Results:

• The method accurately and reproducibly quantifies all fatty acids in microalgae using small sample amounts (5 mg).
• Quantification is independent of fatty acid chain length, degree of unsaturation, or the specific lipid class.
• The method provides total fatty acid profiles but can be extended for lipid class separation.

Conclusions:

• The presented method offers a reliable approach for total fatty acid analysis in microalgae.
• This technique supports the commercial development of microalgal biomass by providing essential compositional data.
• The method ensures comprehensive fatty acid recovery and accurate quantification for diverse applications.