Lipids rich in ω-3 polyunsaturated fatty acids from microalgae.

Area of Science:

• Biotechnology
• Marine Biology
• Biochemistry

Background:

• Microalgae are explored for biodiesel, but their high added value lies in bioactive compounds like polyunsaturated fatty acids (PUFA).
• Marine microalgae species show promise for higher PUFA concentrations compared to freshwater counterparts.
• Optimizing PUFA production requires careful consideration of cultivation and extraction methods.

Purpose of the Study:

• To review critical factors for optimizing polyunsaturated fatty acid (PUFA) production from microalgae.
• To assess suitable microalgae species, cultivation systems, and environmental conditions for enhanced PUFA yields.
• To discuss efficient harvesting and extraction techniques for commercial-scale PUFA recovery.

Main Methods:

• Selection of high-PUFA-producing microalgae species (e.g., Nannochloropsis gaditana, Crypthecodinium cohnii).
• Utilization of closed cultivation systems like photobioreactors with controlled temperature (15-28°C), pH (7-8), and nutrient levels.
• Application of medium light irradiances (50-300 μmol photons m⁻² s⁻¹), enriched CO2, and nutrient limitations (N, P).
• Employing methods for cell harvesting (tangential flow filtration, disk stack centrifugation) and PUFA extraction (solvent-assisted, supercritical fluids, physical methods).

Main Results:

• Marine species like Nannochloropsis gaditana and Crypthecodinium cohnii are favored for high PUFA content.
• Controlled photobioreactor conditions, including specific light, CO2, and nutrient limitations, significantly enhance PUFA production.
• Mixotrophic cultivation and optimized extraction methods are crucial for industrial viability.

Conclusions:

• Successful commercial PUFA production from microalgae hinges on strategic selection of species and cultivation parameters.
• Advanced harvesting and extraction technologies are vital for cost-effective recovery of high-value PUFAs.
• This review synthesizes key considerations for developing efficient microalgal PUFA production systems.