Microalgal cell disruption in a high-power ultrasonic flow system

Area of Science:

• Biotechnology
• Microalgal processing
• Sustainable energy

Background:

• Microalgae are a promising source for biofuels and biochemicals.
• Efficient cell disruption is crucial for extracting intracellular products.
• Conventional methods can be energy-intensive or inefficient.

Purpose of the Study:

• To evaluate the effectiveness of a continuous ultrasonic flow system (UFS) for disrupting microalgal cells.
• To determine the impact of UFS parameters on cell disruption and lipid recovery.
• To compare UFS performance with control treatments.

Main Methods:

• Utilized a 2-kW continuous ultrasonic flow system (UFS).
• Treated two microalgal strains: Scenedesmus dimorphus and Nannochloropsis oculata.
• Measured cell debris concentration and Nile red stained lipid fluorescence density (NRSLD).
• Varied ultrasound intensity, sonication time, and initial cell concentration.

Main Results:

• UFS significantly increased cell debris concentration (up to 202% for S. dimorphus, 112% for N. oculata).
• NRSLD increased significantly (up to 59.5% for S. dimorphus, 56.3% for N. oculata).
• Increased ultrasound intensity and sonication time (3 min) improved NRSLD.
• Higher initial cell concentrations reduced NRSLD per cell by up to 98.2%.

Conclusions:

• The 2-kW UFS is effective for disrupting S. dimorphus and N. oculata.
• Optimizing UFS parameters like intensity and time enhances lipid accessibility.
• Managing initial cell concentration is critical for efficient UFS-based microalgal processing.