Production of structured triacylglycerols from microalgae

Area of Science:

• Biochemistry
• Marine Biology
• Microalgal Biotechnology

Background:

• Triacylglycerols (TAGs) are key energy storage molecules in microalgae.
• TAG structure, including fatty acid composition and positional arrangement, influences their properties.
• Understanding TAG biosynthesis in diverse microalgal strains is crucial for biotechnological applications.

Purpose of the Study:

• To isolate and characterize structured TAGs from nine cultivated microalgal strains.
• To identify positional isomers and enantiomers of TAGs containing palmitic acid (P), arachidonic acid (A), and eicosapentaenoic acid (E).
• To investigate the influence of algal taxonomy and nutrient availability on TAG structure.

Main Methods:

• Isolation of structured TAGs using NARP-LC/MS-APCI.
• Separation and identification of positional isomers and enantiomers via chiral LC.
• Analysis of TAG composition in response to nutrient starvation (nitrogen and phosphorus).

Main Results:

• Microalgae producing eicosapentaenoic acid (E) predominantly synthesized asymmetrical TAGs (PPE, PEE).
• Microalgae producing arachidonic acid (A) predominantly synthesized symmetrical TAGs (PAP, APA), regardless of taxonomic group.
• Nitrogen and phosphorus starvation consistently reversed the ratio of asymmetrical to symmetrical TAGs.

Conclusions:

• Algal fatty acid profile dictates TAG symmetry, with implications for biosynthesis pathways.
• Nutrient availability acts as a significant regulator of TAG structural organization in microalgae.
• These findings provide insights into microalgal lipid metabolism and potential for targeted lipid production.